Breast Neoplasms
Conditions
Keywords
Neratinib, fulvestrant, HER2 mutation, metastatic breast cancer, trastuzumab
Brief summary
This phase II study will test cancer to see if it has a HER2 mutation and, if so, see how HER2 mutated cancer responds to treatment with neratinib.
Detailed description
Overexpression of HER2 due to gene amplification is an established therapeutic target in breast cancer for which multiple HER2 targeted drugs are now available. However, the majority of breast cancers are without HER2 overexpression/non-amplified and not currently eligible to receive HER2 targeted drugs. Advances in tumor genome sequencing technology led to the identification of recurrent HER2 mutations (HER2mut) in approximately 2% of HER2 non-amplified primary breast cancers, and 3-5% of metastatic tumors. Importantly, tumor cells harboring HER2mut are sensitive to the anti-tumor effects of HER2-targeted agents in preclinical models, especially neratinib, a potent irreversible pan-HER inhibitor. However, neratinib monotherapy has demonstrated only modest single agent activity in HER2mut,, non-amplified metastatic breast cancer (MBC). Based on the hypothesis that the combination of neratinib and fulvestrant will be more effective than neratinib alone in ER+/HER2mut, non-amplified MBC the investigators conducted a single arm phase II study of neratinib plus fulvestrant with 2 cohorts, fulvestrant (FUL)-treated and FUL-naïve, for patients with ER+/HER2mut, non-amplified MBC to assess the anti-tumor effects of this combination. An exploratory ER-negative (ER-) HER2mut cohort was also included for the efficacy of neratinib monotherapy.
Interventions
DRUGNeratinib
DRUGFulvestrant
DRUGTrastuzumab
PROCEDURETumor biopsy
-Optional at baseline and disease progression
PROCEDUREResearch blood sample
-Baseline, cycle 1 day 15, cycle 2 day 1, cycle 3 day 1, day 1 of each odd cycle, end of treatment (progression)
Sponsors
Puma Biotechnology, Inc.
United States Department of Defense
Washington University School of Medicine
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
for Pre-registration (for patients with unknown HER2 mutation status to have tumor tissue screened centrally by Washington University GPS laboratory): * Histologically or cytologically confirmed HER2-negative (0 or 1+ by IHC or non-amplified by FISH) breast cancer that is stage IV. * Agree to provide archival tumor material for research * There is no limitation on the number of prior lines of systemic therapy. * Presence of measurable or non-measurable disease by RECIST 1.1 is acceptable, except to be eligible for the Part II fulvestrant-naive ER+ cohort, at least one measurable disease by RECIST 1.1 is required. * At least 18 years of age. * ECOG performance status ≤ 2 * Adequate organ function as defined below within 8 weeks of pre-registration: * Serum creatinine ≤1.5 x ULN * Chil-Pugh class A if with liver disease * Able to understand and willing to sign an IRB approved written informed consent document. Note: HER2 mutation testing may be performed while the patient is receiving active systemic therapy for metastatic breast cancer so that the result can be used to determine eligibility for study drug therapy in the future.
Exclusion criteria
for Pre-registration: * Testing for LVEF is not required for pre-registration, but patient must not have a recent LVEF \< LLN or have symptoms of congestive heart failure. * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Acute or currently active hepatic or biliary disease requiring antiviral therapy (with the exception of Gilbert's syndrome, asymptomatic gallstones, liver metastases, or stable chronic liver disease per investigator assessment). * History of significant cardiac disease, cardiac risk factors, or uncontrolled arrhythmias. * Symptomatic intrinsic lung disease or extensive tumor involvement of the lungs resulting in dyspnea at rest. Inclusion Criteria for Registration (for patients initially pre-registered and with HER2 mutation identified by Washington University GPS laboratory) * Tumor tissue tested positive for HER2 mutation. HER2 mutations detected by Guardant360 are also eligible. * Agree to provide archival tumor material for research * ECOG performance status ≤2 * Adequate organ function as defined below within 2 weeks of registration: * ANC ≥1.5 x 10\^9/L * Platelet count ≥100 x 10\^9/L * Serum creatinine ≤1.5 x ULN * Child-Pugh class A if with liver disease * The patient must have completed radiation therapy and be at least 1 week from the last systemic chemotherapy administration, with adequate recovery of bone marrow and organ functions, before starting neratinib. * Presence of disease progression on the most recent disease evaluation. * Patients with known brain metastasis are eligible, but must have received radiation and be off steroids and stable (without evidence of disease progression by imaging or exam) for 3 months. * QTc interval ≤450 msec for men or \< or ≤ 470 msec for women within 2 weeks of registration. * LVEF \> or = institutional ILLN within 4 weeks of registration. * Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately. Men must agree and commit to use a barrier method of contraception while on treatment and for 3 months after the last dose of the investigational product. * Able to understand and willing to sign an IRB approved written informed consent document. * There is no limitation on the number of prior lines of systemic therapy. * To be eligible for the Part II fulvestrant-naive ER+ cohort, prior treatment with fulvestrant is not allowed. In addition, ER and/or PR positivity by institutional standard is required on pathology from the most recent tumor specimen if biopsy was done unless the tissue source (for example, pleural effusion or ascites or bone biopsy) may yield false negative ER and/or PR result, in which case the pathology from an earlier time point could be used and a discussion with the study chair is required. * To be eligible for the Part II fulvestrant-treated ER+ cohort, prior disease progression on fulvestrant is required. In addition, ER and/or PR positivity by institutional standard is required on pathology from the most recent tumor specimen unless the tissue source (for example, pleural effusion or ascites or bone biopsy) may yield false negative ER and/or PR result, in which case the pathology form an earlier time point could be used and a discussion with the study chair is required. Inclusion Criteria for Registration (for patients with HER2 mutation identified at an outside CLIA certified location): * Histologically or cytologically confirmed HER2-negative (0 or 1+ by IHC or non-amplified by FISH) breast cancer that is stage IV. * Tumor tissue or circulating tumor DNA tested positive for HER2 mutation. Mutations outside the list will be assessed on a case-by-case basis by the study team to determine eligibility. * Presence of measurable or non-measurable disease by RECIST 1.1 is acceptable, except to be eligible for the Part II fulvestrant-naïve ER+ cohort, at least one measurable disease by RECIST 1.1 is required. * At least 18 years of age. * ECOG performance status \< 2 (see Appendix A). * Adequate organ function as defined below within 2 weeks of registration: * Absolute neutrophil count: ≥1.5 × 109/L (1500/mm3) * Platelet count: ≥100 × 109/L (100,000/mm3) * Serum creatinine: ≤1.5 x ULN * Child-Pugh class A if with liver disease * The patient must have completed radiation therapy and be at least 1 week from the last systemic therapy administration, with adequate recovery of bone marrow and organ functions, before starting neratinib. * Presence of disease progression on the most recent disease evaluation. * Patients with known treated brain metastasis are eligible, but must have received radiation and be off steroids and stable (without evidence of disease progression by imaging or exam) for 3 months. * QTc interval ≤ 450 msec for men or ≤ 470 msec for women within 2 weeks of registration. * LVEF \> institutional LLN within 4 weeks of registration. * Women of childbearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control, abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she must inform her treating physician immediately. Men must agree and commit to use a barrier method of contraception while on treatment and for 3 months after the last dose of the investigational product * Able to understand and willing to sign an IRB approved written informed consent document. * There is no limitation on the number of prior lines of systemic therapy. * To be eligible for the Part II fulvestrant-naïve ER+ cohort, prior treatment with fulvestrant is not allowed. In addition, ER and/or PR positivity by institutional standard is required on pathology from the most recent tumor specimen if biopsy was done unless the tissue source (for example, pleural effusion or ascites or bone biopsy) may yield false negative ER and/or PR result, in which case the pathology from an earlier time point could be used and a discussion with the study chair is required. * To be eligible for the Part II fulvestrant-treated ER+ cohort, prior disease progression on fulvestrant is required. In addition, ER and/or PR positivity by institutional standard is required on pathology from the most recent tumor specimen unless the tissue source (for example, pleural effusion or ascites or bone biopsy) may yield false negative ER and/or PR result, in which case the pathology from an earlier time point could be used and a discussion with the study chair is required.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Part I Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Patients Who Received Neratinib Alone | Through completion of treatment (median treatment time of 90 days, full range 54-716 days) | * Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months. |
| Part II ER-cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib in Patients With Metastatic HER2-, ER- Breast Cancer That Carry HER2 Mutation | Through completion of treatment (median treatment time of 62 days, full range 56-413 days) | * Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months. |
| Part II Fulvestrant-naive ER+ Cohort Only: Clinical Benefit (CR+PR+SD≥6 Months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-naive Breast Cancer That Carry HER2 Mutation | Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days) | * Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months. |
| Part II Fulvestrant-treated ER+ Cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-treated Breast Cancer That Carry HER2 Mutation | Through completion of treatment (median treatment time of 168 days, full range 28-671 days) | * Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | Through completion of follow-up; follow-up was through 30 days following completion of treatment (median follow-up of 142 days, full range 54-800 days) | * Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase. |
| Part II ER-cohort Only: Progression-free Survival (PFS) | Through completion of treatment (median treatment time of 62 days, full range 56-413 days) | * Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase. |
| Part II Fulvestrant-naive ER+ Cohort Only: Progression-free Survival (PFS) | Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days) | * Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase. |
| Progression-free Survival (PFS) of Patients Treated With Neratinib Alone in Patients With Metastatic HER2- But HER2 Mutated Breast Cancer by ER Status and by HER2 Mutations (Activating Versus Unknown Significance) | Through completion of follow-up; follow-up was through 30 days following completion of treatment (median follow-up of 92 days, full range 86 days-443 days) | * Participants were followed for progressive disease from start of treatment until completion of follow-up. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase. |
| Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Through completion of follow-up; follow-up was through 28 days following completion of treatment (median follow-up of 140 days, full range 52-798 days) | -CTCAE v 4.0 will be used to record adverse events. Related includes those possibly, probably, or definitely related to the treatment regimen. |
| Part II Fulvestrant-naive ER+ Cohort Only: Response Rate (RR) | Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days) | * RR is defined as number of participants with complete response or partial response as best response. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. |
| Part II Fulvestrant-treated ER+ Cohort Only: Response Rate (RR) | Through completion of treatment (median treatment time of 168 days, full range 28-671 days) | * RR is defined as number of participants with complete response or partial response as best response. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. |
| Part II Fulvestrant-treated ER+ Cohort Only: Progression-free Survival (PFS) | Through completion of treatment (median treatment time of 168 days, full range 28-671 days) | * Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase. |
| Number of Participants With HER2 Mutation Subtype and Histology Subtype | At the time of enrollment | — |
| Number of Participants With HER2 Mutation Subtype and Tumor Grade | A time of enrollment | -Cancer cells are graded when they are removed from the breast. The grade is based on how much the cancer cells look like normal cells. * A low grade number (grade 1) usually means the cancer is slower-growing and less likely to spread. * An intermediate grade number (grade 2) means the cancer is growing faster than a grade 1 cancer but slower than a grade 3 cancer. * A high grade number (grade 3) means a faster-growing cancer that's more likely to spread. |
| Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | At time of enrollment | * Staging occurred at initial diagnosis after physical exam, mammogram, and other diagnostic imaging tests. The staging also takes into account pathology reports from the breast biopsy or surgery. * Stage I has a better outcome than Stage IV. |
Countries
Canada, United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Part I: Neratinib Only -Patients will receive neratinib PO daily on Days 1-28. Each cycle is 4 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. | 16 |
| Part II: Neratinib Only (ER-) -Patients will receive neratinib PO daily on Days 1-28. Each cycle is 4 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. | 5 |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) -Patients will receive neratinib PO daily on Days 1-28 and fulvestrant on Day 1 of each cycle (and C1D15). Each cycle is 4 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. | 11 |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) -Patients will receive neratinib PO daily on Days 1-28 and fulvestrant on Day 1 of each cycle (and C1D15). Each cycle is 4 weeks. Treatment continues in the absence of disease progression or unacceptable toxicity. | 24 |
| Total | 56 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 | FG002 | FG003 | FG004 | FG005 |
|---|---|---|---|---|---|---|---|
| Part I and Part 2 | Grade 2 vomiting | 0 | 0 | 0 | 1 | 0 | 0 |
| Part I and Part 2 | Grade 2 vomiting and progressive disease | 0 | 1 | 0 | 0 | 0 | 0 |
| Part I and Part 2 | Grade 3 diarrhea and duodenal ulcer | 0 | 0 | 0 | 1 | 0 | 0 |
| Part I and Part 2 | Grade 3 diarrhea and withdrawal | 0 | 0 | 1 | 0 | 0 | 0 |
| Part I and Part 2 | Grade 3 dizziness and progressive disease | 0 | 0 | 0 | 1 | 0 | 0 |
Baseline characteristics
| Characteristic | Part I: Neratinib Only | Part II: Neratinib Only (ER-) | Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Total |
|---|---|---|---|---|---|
| Age, Continuous | 58 years | 63 years | 58 years | 64 years | 61 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants | 2 Participants | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 16 Participants | 5 Participants | 9 Participants | 17 Participants | 47 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 2 Participants | 5 Participants | 7 Participants |
| HER2 Status Activating | 15 Participants | 5 Participants | 11 Participants | 24 Participants | 55 Participants |
| HER2 Status Novel | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants |
| Histology Subtype Ductal | 10 Participants | 3 Participants | 7 Participants | 10 Participants | 30 Participants |
| Histology Subtype Lobular | 5 Participants | 2 Participants | 2 Participants | 12 Participants | 21 Participants |
| Histology Subtype Other | 1 Participants | 0 Participants | 1 Participants | 2 Participants | 4 Participants |
| Histology Subtype Unknown | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 0 Participants | 1 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 1 Participants | 2 Participants | 1 Participants | 5 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 0 Participants | 0 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) White | 13 Participants | 4 Participants | 8 Participants | 23 Participants | 48 Participants |
| Region of Enrollment Canada | 2 participants | 0 participants | 0 participants | 0 participants | 0 participants |
| Region of Enrollment United States | 14 participants | 5 participants | 11 participants | 24 participants | 56 participants |
| Sex: Female, Male Female | 16 Participants | 5 Participants | 10 Participants | 24 Participants | 55 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Tumor Grade II | 1 Participants | 1 Participants | 0 Participants | 3 Participants | 5 Participants |
| Tumor Grade III | 7 Participants | 4 Participants | 2 Participants | 3 Participants | 16 Participants |
| Tumor Grade I/II | 8 Participants | 0 Participants | 5 Participants | 12 Participants | 25 Participants |
| Tumor Grade Unknown | 0 Participants | 0 Participants | 4 Participants | 6 Participants | 10 Participants |
| Tumor Stage at Initial Diagnosis I | 2 Participants | 1 Participants | 2 Participants | 4 Participants | 9 Participants |
| Tumor Stage at Initial Diagnosis II | 6 Participants | 2 Participants | 3 Participants | 9 Participants | 20 Participants |
| Tumor Stage at Initial Diagnosis IIA | 0 Participants | 0 Participants | 1 Participants | 0 Participants | 1 Participants |
| Tumor Stage at Initial Diagnosis IIB | 2 Participants | 0 Participants | 0 Participants | 0 Participants | 2 Participants |
| Tumor Stage at Initial Diagnosis III | 4 Participants | 1 Participants | 0 Participants | 4 Participants | 9 Participants |
| Tumor Stage at Initial Diagnosis IIIA | 0 Participants | 0 Participants | 0 Participants | 3 Participants | 3 Participants |
| Tumor Stage at Initial Diagnosis IIIC | 0 Participants | 0 Participants | 0 Participants | 1 Participants | 1 Participants |
| Tumor Stage at Initial Diagnosis IV | 1 Participants | 1 Participants | 2 Participants | 1 Participants | 5 Participants |
| Tumor Stage at Initial Diagnosis Unknown | 1 Participants | 0 Participants | 3 Participants | 2 Participants | 6 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk | EG004 affected / at risk | EG005 affected / at risk |
|---|---|---|---|---|---|---|
| deaths Total, all-cause mortality | 10 / 16 | 1 / 5 | 5 / 11 | 9 / 24 | 3 / 3 | 4 / 5 |
| other Total, other adverse events | 16 / 16 | 5 / 5 | 11 / 11 | 24 / 24 | 3 / 3 | 4 / 5 |
| serious Total, serious adverse events | 5 / 16 | 1 / 5 | 2 / 11 | 9 / 24 | 2 / 3 | 0 / 5 |
Outcome results
Primary
Part II ER-cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib in Patients With Metastatic HER2-, ER- Breast Cancer That Carry HER2 Mutation
* Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months.
Time frame: Through completion of treatment (median treatment time of 62 days, full range 56-413 days)
Population: Only participants enrolled in the Part II ER-cohort are evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part II: Neratinib Only (ER-) | Part II ER-cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib in Patients With Metastatic HER2-, ER- Breast Cancer That Carry HER2 Mutation | 1 Participants |
Primary
Part II Fulvestrant-naive ER+ Cohort Only: Clinical Benefit (CR+PR+SD≥6 Months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-naive Breast Cancer That Carry HER2 Mutation
* Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months.
Time frame: Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days)
Population: Only participants enrolled in the Part II fulvestrant-naive ER+ cohort is evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Part II Fulvestrant-naive ER+ Cohort Only: Clinical Benefit (CR+PR+SD≥6 Months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-naive Breast Cancer That Carry HER2 Mutation | 3 Participants |
Primary
Part II Fulvestrant-treated ER+ Cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-treated Breast Cancer That Carry HER2 Mutation
* Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months.
Time frame: Through completion of treatment (median treatment time of 168 days, full range 28-671 days)
Population: Only participants enrolled in the fulvestrant-treated ER+ cohort are evaluable for this outcome measure. Three participants were not evaluable in this cohort as the participants stopped treatment in cycle 1.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Part II Fulvestrant-treated ER+ Cohort Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Neratinib + Fulvestrant in Patients With Metastatic HER2- ER+ Fulvestrant-treated Breast Cancer That Carry HER2 Mutation | 8 Participants |
Primary
Part I Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Patients Who Received Neratinib Alone
* Imaging for clinical benefit rate occurred at baseline (for an initial comparison scan) and every 2 cycles (28 day length) thereafter. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. * Stable disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum diameters while on study. Persistence of one or more non-target lesion(s) and/or maintenance of tumor marker level above the normal limits. Must have had stable disease for at least 6 months.
Time frame: Through completion of treatment (median treatment time of 90 days, full range 54-716 days)
Population: Only Part I participants were evaluable for this outcome measure.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part I: Neratinib Only | Part I Only: Clinical Benefit Rate (CR+PR+SD≥6months) of Patients Who Received Neratinib Alone | 5 Participants |
Secondary
Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival
* Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase.
Time frame: Through completion of follow-up; follow-up was through 30 days following completion of treatment (median follow-up of 142 days, full range 54-800 days)
Population: The number analyzed for each row adds up to overall total number analyzed.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | ECD mutation | 11.0000 weeks |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | KD mutation | 9.0000 weeks |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | Exon 20 ins mutation | 26.0000 weeks |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | ECD mutation | 8.0000 weeks |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | KD mutation | 6.5000 weeks |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | Exon 20 ins mutation | 17.0000 weeks |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | Exon 20 ins mutation | 26.000 weeks |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | ECD mutation | 48.5000 weeks |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | KD mutation | 8.0000 weeks |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | ECD mutation | 3.0000 weeks |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | KD mutation | 16.0000 weeks |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Progression-free Survival | Exon 20 ins mutation | 36.5000 weeks |
Secondary
Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis
* Staging occurred at initial diagnosis after physical exam, mammogram, and other diagnostic imaging tests. The staging also takes into account pathology reports from the breast biopsy or surgery. * Stage I has a better outcome than Stage IV.
Time frame: At time of enrollment
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage II | 2 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Unknown | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage III | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage II | 3 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage IV | 1 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage I | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage I | 2 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Unknown | 1 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage I | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage II | 3 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage IV | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage IV | 0 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage III | 3 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage III | 1 Participants |
| Part I: Neratinib Only | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage III | 1 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage IV | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage I | 1 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage III | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage IV | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage IV | 1 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage I | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage II | 1 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage III | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage II | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage I | 0 Participants |
| Part II: Neratinib Only (ER-) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage II | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage I | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage II | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage IV | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Unknown | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage I | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage II | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage IV | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Unknown | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage I | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage II | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage IV | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Unknown | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage IV | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage II | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage II | 6 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage II | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage I | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage I | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage III | 6 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Unknown | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | ECD mutation : Stage III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Unknown | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Unknown | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage IV | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage IV | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | KD mutation : Stage I | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Correlate the Presence of HER2 Mutation Subtype With Tumor Staging at Initial Diagnosis | Exon 20 ins mutation : Stage III | 2 Participants |
Secondary
Number of Participants With HER2 Mutation Subtype and Histology Subtype
Time frame: At the time of enrollment
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Other histology | 0 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Ductal histology | 5 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Other histology | 2 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Other histology | 4 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Ductal histology | 3 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Ductal histology | 2 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Ductal histology | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Other histology | 1 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Ductal histology | 1 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Other histology | 1 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Other histology | 1 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Ductal histology | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Other histology | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Ductal histology | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Other histology | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Ductal histology | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Other histology | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Ductal histology | 5 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Other histology | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | ECD mutation : Ductal histology | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Ductal histology | 7 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Other histology | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | KD mutation : Other histology | 10 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Histology Subtype | Exon 20 ins mutation : Ductal histology | 2 Participants |
Secondary
Number of Participants With HER2 Mutation Subtype and Tumor Grade
-Cancer cells are graded when they are removed from the breast. The grade is based on how much the cancer cells look like normal cells. * A low grade number (grade 1) usually means the cancer is slower-growing and less likely to spread. * An intermediate grade number (grade 2) means the cancer is growing faster than a grade 1 cancer but slower than a grade 3 cancer. * A high grade number (grade 3) means a faster-growing cancer that's more likely to spread.
Time frame: A time of enrollment
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade I/II | 6 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade I/II | 2 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade III | 1 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Unknown | 0 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade I/II | 1 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade III | 3 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Unknown | 0 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade III | 3 Participants |
| Part I: Neratinib Only | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade I/II | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade III | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade III | 3 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade III | 2 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade I/II | 1 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Unknown | 0 Participants |
| Part II: Neratinib Only (ER-) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade I/II | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade III | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Unknown | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade I/II | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade III | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Unknown | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade I/II | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Unknown | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade I/II | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade I/II | 11 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Unknown | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Unknown | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade I/II | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Tumor grade III | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | ECD mutation : Tumor grade I/II | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | Exon 20 ins mutation : Unknown | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Number of Participants With HER2 Mutation Subtype and Tumor Grade | KD mutation : Tumor grade III | 3 Participants |
Secondary
Part II ER-cohort Only: Progression-free Survival (PFS)
* Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase.
Time frame: Through completion of treatment (median treatment time of 62 days, full range 56-413 days)
Population: Only participants enrolled in the Part II ER-cohort are evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Part II: Neratinib Only (ER-) | Part II ER-cohort Only: Progression-free Survival (PFS) | 8.5 weeks |
Secondary
Part II Fulvestrant-naive ER+ Cohort Only: Progression-free Survival (PFS)
* Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase.
Time frame: Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days)
Population: Only participants enrolled in the Part II fulvestrant-naive ER+ cohort is evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Part II Fulvestrant-naive ER+ Cohort Only: Progression-free Survival (PFS) | 20 weeks |
Secondary
Part II Fulvestrant-naive ER+ Cohort Only: Response Rate (RR)
* RR is defined as number of participants with complete response or partial response as best response. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Through completion of treatment (median treatment time of 140.5 days, full range 48-770 days)
Population: Only participants enrolled in the Part II fulvestrant-naive ER+ cohort is evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Part II Fulvestrant-naive ER+ Cohort Only: Response Rate (RR) | 3 Participants |
Secondary
Part II Fulvestrant-treated ER+ Cohort Only: Progression-free Survival (PFS)
* Progression-free survival is defined as the number of weeks from start of treatment until disease progression or death. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase.
Time frame: Through completion of treatment (median treatment time of 168 days, full range 28-671 days)
Population: Only participants enrolled in the fulvestrant-treated ER+ cohort are evaluable for this outcome measure. Three participants were not evaluable in this cohort as the participants stopped treatment in cycle 1.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Part II Fulvestrant-treated ER+ Cohort Only: Progression-free Survival (PFS) | 24 weeks |
Secondary
Part II Fulvestrant-treated ER+ Cohort Only: Response Rate (RR)
* RR is defined as number of participants with complete response or partial response as best response. * Complete response (CR): Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. Disappearance of all non-target lesions and normalization of tumor marker level. * Partial response (PR): At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters.
Time frame: Through completion of treatment (median treatment time of 168 days, full range 28-671 days)
Population: Only participants enrolled in the fulvestrant-treated ER+ cohort are evaluable for this outcome measure. Three participants were not evaluable in this cohort as the participants stopped treatment in cycle 1.
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Part II Fulvestrant-treated ER+ Cohort Only: Response Rate (RR) | 5 Participants |
Secondary
Progression-free Survival (PFS) of Patients Treated With Neratinib Alone in Patients With Metastatic HER2- But HER2 Mutated Breast Cancer by ER Status and by HER2 Mutations (Activating Versus Unknown Significance)
* Participants were followed for progressive disease from start of treatment until completion of follow-up. * Progressive Disease (PD): At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must also demonstrate an absolute increase of at least 5 mm. Appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions. Unequivocal progression should not normally trump target lesion status. It must be representative of overall disease status change, not a single lesion increase.
Time frame: Through completion of follow-up; follow-up was through 30 days following completion of treatment (median follow-up of 92 days, full range 86 days-443 days)
Population: Only participants enrolled in the Part II ER-cohort are evaluable for this outcome measure. One participant was not evaluable in this cohort as the participant stopped treatment in cycle 1. The data represents exact number of weeks that each participant had progression-free survival. 2 participants with Activating mutation - S310F both had 8 weeks of PFS.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Part II: Neratinib Only (ER-) | Progression-free Survival (PFS) of Patients Treated With Neratinib Alone in Patients With Metastatic HER2- But HER2 Mutated Breast Cancer by ER Status and by HER2 Mutations (Activating Versus Unknown Significance) | Activating mutation - L7L755S | 9 weeks |
| Part II: Neratinib Only (ER-) | Progression-free Survival (PFS) of Patients Treated With Neratinib Alone in Patients With Metastatic HER2- But HER2 Mutated Breast Cancer by ER Status and by HER2 Mutations (Activating Versus Unknown Significance) | Activating mutation - S310F | 8 weeks |
| Part II: Neratinib Only (ER-) | Progression-free Survival (PFS) of Patients Treated With Neratinib Alone in Patients With Metastatic HER2- But HER2 Mutated Breast Cancer by ER Status and by HER2 Mutations (Activating Versus Unknown Significance) | Activating mutation - A775_G776insYVMA | 17 weeks |
Secondary
Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events
-CTCAE v 4.0 will be used to record adverse events. Related includes those possibly, probably, or definitely related to the treatment regimen.
Time frame: Through completion of follow-up; follow-up was through 28 days following completion of treatment (median follow-up of 140 days, full range 52-798 days)
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 3 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 3 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 9 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 15 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 3 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 6 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 6 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 7 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 3 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 2 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 3 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 5 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 1 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 0 Participants |
| Part I: Neratinib Only | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 3 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 5 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 1 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 0 Participants |
| Part II: Neratinib Only (ER-) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 8 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 5 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 7 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+, Fulvestrant-naive) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 6 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 20 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 6 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 11 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 6 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 12 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 7 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 9 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 3 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 2 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 4 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 0 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 1 Participants |
| Part II: Neratinib + Fulvestrant (ER+. Prior Fulvestrant-tx) | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 1 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 1 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 1 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 1 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 0 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 1 Participants |
| Crossover: Neratinib + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspnea | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Joint range of motion decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomatitis | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Myalgia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypercalcemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Stomach pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anorexia | 2 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash acneiform | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperkalemia | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain at injection site | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyponatremia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | White blood cell decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Epistaxis | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | LVEF Decrease | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nail changes | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain in extremity | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Weight loss | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Nausea | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Platelet count decreased | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dizziness | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry eye | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Neutrophil count decreased | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness left sided | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Tinnitus | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hoarseness | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dysgeusia | 2 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Lymphocyte count decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Mucositis oral | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | INR increased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Anemia | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hot flashes | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Headache | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flatulence | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Ejection fraction decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Sterile abscess at subcutaneous injection site | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinitis infective | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Heart failure with preserved ejection fraction | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Peripheral sensory neuropathy | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Creatinine increased | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Postnasal drip | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | CD4 lymphocytes decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bone pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dyspepsia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Syncope | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pruritus | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Aspartate aminotransferase increased | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hyperglycemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rash maculopapular | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Flank pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Depression | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase decreased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Rhinorrhea | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alkaline phosphatase increased | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry mouth | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Leg cramp | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Insomnia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Diarrhea | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alaline aminotransferase increased | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Back pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypokalemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Alopecia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Acute kidney injury | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract infection | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized muscle weakness | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Upper respiratory infection | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Constipation | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Arthralgia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dehydration | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Skin hyperpigmentation | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypoalbuminemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine discoloration | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry hair | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Generalized weakness | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urinary tract obstruction | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Bloating | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Urine odor | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypophosphatemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fever | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal pain | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypotension | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Hypocalcemia | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Cough | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Fatigue | 1 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Dry skin | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Vomiting | 2 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Muscle weakness lower limb | 0 Participants |
| Crossover: Neratinib + Fulvestrant + Trastuzumab | Safety and Tolerability of Neratinib in Combination With Fulvestrant in Patients With HER2- ER+ HER2 Mutated Breast Cancer as Measured by Number of Participants With Related Adverse Events | Abdominal cramping | 0 Participants |