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A Study of Palbociclib in Combination With Bazedoxifene in Hormone Receptor Positive Breast Cancer

A Phase Ib/II Study of Palbociclib in Combination With Bazedoxifene in Hormone Receptor Positive Breast Cancer

Status
Completed
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02448771
Enrollment
36
Registered
2015-05-19
Start date
2015-07-09
Completion date
2021-03-03
Last updated
2022-10-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast Cancer Stage IV, Unresectable Locally Advanced Invasive Breast Cancer, Metastatic Invasive Breast Cancer

Keywords

Unresectable locally advanced invasive breast cancer, Metastatic invasive breast cancer

Brief summary

This research study is studying a drug called Palbociclib in combination with Bazedoxifene (a type of endocrine therapy, which prevents breast cancer cell growth by blocking estrogen stimulation) as a possible treatment for this diagnosis. The names of the study interventions involved in this study are: * Palbociclib * Bazedoxifene

Detailed description

This research study is a Phase I/II clinical trial. Phase II clinical trial tests the safety and effectiveness of an investigational intervention to learn whether the intervention works in treating a specific disease. Investigational means that the intervention is being studied. It also means that the FDA (the U.S. Food and Drug Administration) has not yet approved Palbociclib in combination with Bazedoxifene for use in participants with your type of cancer, but it has been approved for other uses (metastatic breast cancer). Palbociclib is a drug that may stop cancer cells from growing. Palbociclib blocks activity of two closely related enzymes (proteins that help chemical reactions in the body occur), called Cyclin D Kinases 4 and 6 (CDK 4/6). These proteins are part of a pathway, or a sequence of steps which is known to control cell growth. Laboratory testing has shown that palbociclib may stop the growth of hormone receptor positive breast cancer. Endocrine therapy prevents breast cancer cell growth by blocking the activity of the estrogen receptor. During this study the endocrine therapy will be bazedoxifene. In this research study, the investigators are evaluating how safe palbociclib is and how well palbociclib in combination with bazedoxifene, a form of endocrine treatment, works in participants with a history of stage four breast cancer.

Interventions

DRUGPalbociclib

Sponsors

Pfizer
CollaboratorINDUSTRY
Dana-Farber Cancer Institute
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* Participants must have histologically confirmed invasive breast cancer that is metastatic or unresectable locally advanced. Histological documentation of metastatic/recurrent breast cancer is not required if there is unequivocal evidence for recurrence of the breast cancer. * Estrogen and/or progesterone receptor positive breast cancer (\>10% staining), as determined by pathology from either primary or metastatic site(s). Central confirmation is not required. * HER2 negative, defined as 0-1+ by immunohistochemistry or FISH-negative (HER2 copy number \<6 and HER2/CEP17 ratio \< 2.0). Central confirmation is not required. * Postmenopausal women are eligible. Postmenopausal is defined as any of the following: * Age ≥60 years * Age \<60 and amenorrhea for 12 or more months (in the absence of chemotherapy, tamoxifen, toremifen, or ovarian suppression) and FSH and estradiol in the postmenopausal range per local normal range. * Premenopausal women who have been on a GnRH agonist for at least 3 consecutive months prior to study entry are eligible. Women in this group MUST remain on the GnRH agonist for the duration of protocol treatment. * Status-post bilateral oophorectomy-After adequate healing post surgery. * Women, age ≥18 years of age. Men are excluded. * Because no dosing or adverse event data are currently available on the use of palbociclib and bazedoxifene in participants \<18 years of age, children are excluded from this study. In addition, breast cancer is exceedingly rare in individuals under 18 years of age. * Participants must have measurable disease by RECIST 1.1. See section 11 for the definition of measurable disease. * Bone only disease if there are lytic lesions is also allowed and treatment response will be evaluated based on the MD Anderson criteria. See section 11. * Endocrine resistant breast cancer, defined as either: * Relapsed while on adjuvant endocrine therapy or within 1 year of completion of adjuvant endocrine therapy \--- -or- * Progression through at least one line of endocrine therapy for metastatic or locally advanced breast cancer. There is no limit on the number of prior endocrine therapies received. * Patients may have received up to one prior line of chemotherapy for metastatic or unresectable locally advanced breast cancer. * Patients may have initiated bisphosphonate therapy prior to start of protocol therapy. Bisphosphonate therapy may continue during protocol treatment. Such patients will have bone lesions considered evaluable for progression * Patients must be at least 2 weeks from prior chemotherapy or radiotherapy, or any investigational drug product, with adequate recovery of toxicity to baseline, or grade \<1, with the exception of alopecia and hot flashes. There is no washout period for prior endocrine therapy. * ECOG Performance Status 0-1 (Appendix A) * Life expectancy of greater than 3 months * Willingness to undergo research biopsy under the following circumstances: * Patients with easily accessible disease * Patients with skin or chest wall disease amenable to a punch biopsy under local anesthesia are required to undergo a baseline biopsy and a biopsy at the time of disease progression as part of this protocol. * Patients with a breast mass or axillary lymph node amenable to an image-guided core biopsy are also required to undergo a baseline biopsy and a biopsy at the time of disease progression as part of this protocol. * Patients with malignant ascites fluid or a malignant pleural effusion of sufficient volume to be amenable to tap (either in-office or image-guided) are also required to undergo a baseline tap and a tap at the time of disease progression as part of this protocol. * Patients who undergo a research biopsy procedure for the purpose of this protocol, and in whom inadequate tissue is obtained, are still eligible and are not required to undergo a repeat biopsy in order to enter the study. * Patients will be approached during cycle 1 about providing an optional tissue sample at that time; however, this biopsy will be optional. * Patients with accessible disease * Patients with sites felt to be accessible to an image-guided or incisional biopsy in the opinion of the patient's treating oncologist and physician performing the procedure, and not meeting the criteria for easily accessible disease as described in Section 3.1.14.1, are required to undergo a baseline biopsy as part of this protocol. Such sites may include, but are not limited to: liver, lymph nodes, soft tissue, lung, chest wall, and bone. Cycle 1 biopsy and biopsy at time of disease progression are optional. * Biopsies may be done with local anesthesia or intravenous conscious sedation, according to standard institutional guidelines. * If a biopsy requires general anesthesia, then it is only allowed if acquisition of tissue is necessary for clinical reasons (i.e. is clinically indicated), and excess tissue that would otherwise have been discarded is then used for research purposes. If a biopsy requires general anesthesia, then a biopsy of that site for research purposes only, without a coexisting clinical indication is not allowed on this protocol. * Patients who undergo a research biopsy procedure for the purpose of this protocol, and in whom inadequate tissue is obtained, are still eligible and are not required to undergo a repeat biopsy in order to enter the study. * Some patients may have had a clinically indicated biopsy upon recent disease progression. No additional pre-treatment biopsy is required if that specimen can be used for the correlative studies described in this protocol. * Patients will be approached at the time of progression about providing an optional tissue sample at that time; however, the time of progression biopsy will be optional. * Other patients * Patients who do not have biopsy-accessible disease are not required to undergo a biopsy as part of study participation. * In addition, patients who are being treated with therapeutic doses of anticoagulant(s), are not required to undergo a biopsy as part of study participation. If it is felt clinically appropriate despite anticoagulation (i.e. a skin punch biopsy, etc) by the treating physician, a biopsy is allowed, it is simply not required. * The sites of metastatic disease and reason that the disease is not biopsy-accessible should be documented in the medical record and case report form(s). * Patients who do not undergo baseline biopsy must have their study participation approved by the overall PI before start of protocol therapy. Only patients who have biopsy inaccessible disease may enter the study without the requirement for baseline biopsy. * Participants must have normal organ and marrow function as defined below: * Absolute neutrophil count ≥1,500/mcL * Platelets ≥100,000/mcL * Hgb ≥9 mg/dL (which may be post transfusion) * Total bilirubin ≤1.5 X institutional upper limit of normal (patients with \---- documented Gilbert's disease are allowed total bilirubin up to 3X ULN) * AST (SGOT)/ALT (SGPT) ≤ 2.5 X institutional upper limit if no liver metastases; and ≤ 5 X institutional upper limit if liver metastases are present. * Creatinine ≤ 2X institutional upper limit of normal * Baseline QTc ≤ 480 ms * Ability to take oral medications. * The effects of palbociclib and bazedoxifene on the developing human fetus are unknown. If, for any reason, a woman should become pregnant or suspect that she is pregnant while participating in this study, she should inform her treating physician immediately. * Women who are made postmenopausal through use of GNRH agonists, and men are required to use adequate contraception for the duration of protocol treatment and for 6 months after the last dose of palbociclib and bazedoxifene. Adequate contraception is defined as one highly effective non-hormonal form of contraception or two effective forms of non-hormonal contraception by the patient and/or partner. * Highly Effective Non-Hormonal Contraception Methods of birth control which result in a low failure rate (i.e., less than 1% per year) when used consistently and correctly are considered highly-effective forms of contraception. The following non-hormonal methods of contraception are acceptable: * True abstinence when this is in line with the preferred and usual lifestyle of the patient. \[Periodic abstinence (e.g., calendar, ovulation, symptothermal post-ovulation methods) and withdrawal are not acceptable methods of contraception\]. * Male sterilization (with appropriate post-vasectomy documentation of the absence of sperm in the ejaculate). For female patients, the vasectomized male partner should be the sole partner. \--- OR * Effective Non-Hormonal Contraception Alternatively two of the following effective forms of contraception may be used instead: * Placement of non-hormonal intrauterine device (IUD) or intrauterine system (IUS). Consideration should be given to the type of device being used, as there is higher failure rates quoted for certain types, e.g., steel or copper wire. * Condom with spermicidal foam/gel/film/cream/suppository. * Occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream/suppository. The use of barrier contraceptives should always be supplemented with the use of spermicide. \- The following should be noted: * Failure rates indicate that, when used alone, the diaphragm and ondom are not highly effective forms of contraception. Therefore, the use of additional spermicides does confer additional theoretical contraceptive protection. * However, spermicides alone are ineffective at preventing pregnancy when the whole ejaculate is spilled. Therefore, spermicides are not a barrier method of contraception and should not be used alone. * It should be noted that two forms of effective contraception are required. A double barrier method is acceptable, which is defined as condom and occlusive cap (diaphragm or cervical/ vault caps) with spermicidal foam/gel/film/cream /suppository. Premenopausal women who have been on a GnRH agonist for at least 3 consecutive months prior to study entry are eligible. Women in this group MUST remain on the GnRH agonist for the duration of protocol treatment. Such patients should be counseled that GnRH agonists alone may not be adequate contraception and that adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation should be employed. * Ability to understand and the willingness to sign a written informed consent document.

Exclusion criteria

* Prior treatment with a CDK4/6 inhibitor and/or bazedoxifene. * Participants may not be receiving any other investigational agents. * Concurrent treatment with commercial agents or other agents with the intent to treat the participant's malignancy, including endocrine therapy, chemotherapy, and/or targeted therapy, with the exception of bisphosphonates and GnRH agonists, as detailed in sections 3.1.4 and 3.1.9. * Untreated or progressive brain metastases. Patients with treated brain metastases not requiring chronic corticosteroids for symptom control are eligible. * Pending visceral crisis, in the opinion of the treating investigator. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to palbociclib and /or bazedoxifene. * Participants receiving any medications or substances that are strong inhibitors or inducers of CYP3A isoenzymes are ineligible. Lists including medications and substances known or with the potential to interact with the CYP3A isoenzymes are provided in Appendix D. Because the lists of these agents are constantly changing, it is important to regularly consult a frequently-updated list such as http://medicine.iupui.edu/clinpharm/ddis/table.aspx; medical reference texts such as the Physicians' Desk Reference may also provide this information. As part of the enrollment/informed consent procedures, the patient will be counseled on the risk of interactions with other agents, and what to do if new medications need to be prescribed or if the patient is considering a new over-the-counter medicine or herbal product. * Current use of drugs that are known to prolong the QT interval (See Appendix C) * Subjects with organ allograft requiring immunosuppression. * Uncontrolled intercurrent illness including, but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. Ability to comply with study requirements is to be assessed by each investigator at the time of screening for study participation. * Pregnant women are excluded from this study because effects of palbociclib and bazedoxifene on a developing fetus is unknown. Breastfeeding should be discontinued prior to entry onto the study. * Individuals with a history of a different malignancy are ineligible except for the following circumstances. Individuals with a history of other malignancies are eligible if they have been disease-free for at least 5 years and are deemed by the investigator to be at low risk for recurrence of that malignancy. Individuals with the following cancers are eligible if diagnosed and treated within the past 5 years: ductal carcinoma in situ of the breast, cervical cancer in situ, and basal cell or squamous cell carcinoma of the skin. * Patients on combination antiretroviral therapy, i.e. those who are HIV-positive, are ineligible because of the potential for pharmacokinetic interactions or significant immunosuppression with Palbociclib.

Design outcomes

Primary

MeasureTime frameDescription
Clinical Benefit RateAssessed for response for up to 34 monthsClinical Benefit Rate is the percentage of participants who achieve clinical benefit from the study treatment. Clinical benefit is defined as at least 24 weeks of confirmed Complete Response (CR), Partial Response (PR), or Stable Disease (SD). SD or better is achieved if the following are true: Target Lesions: -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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: * \< 25% increase in lesions. * No new lesions.
Clinical Benefit Rate by ESR1 GenotypeAssessed for response for up to 34 monthsClinical Benefit Rate is the percentage of participants who achieve clinical benefit from the study treatment. Clinical benefit is defined as at least 24 weeks of confirmed CR, PR, SD. SD or better is achieved if the following are true: Target Lesions: -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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: * \< 25% increase in lesions. * No new lesions. ESR1 genotype determined using established methods
Percent of Participants With All Grade Neutrophil Count DecreaseBaseline, until resolution or for 30 days after the subject's last study visit, up to 43 months.Assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 regardless of whether the event is related or unrelated to treatment. Neutrophil counts are evaluated using established methods.

Secondary

MeasureTime frameDescription
Median Overall SurvivalUp to 42 monthsOverall Survival (OS) is defined as the time from randomization (or registration) to death due to any cause, or censored at date last known alive.
Median Progression-Free Survival for Patients by ESR1 GenotypeUp to 24 monthsProgression free survival (PFS) is defined as the time from start of treatment to disease progression or death from any cause as estimated by Kaplan Meier methods. Patients who have not progressed and are alive are censored at the date the patient is known to be progression-free. ESR1 genotype is determined using established methods. Progression is measured using RECIST 1.1 criteria, defined as at least a 20% increase in size in target lesion and/or unequivocal progression of non-target lesions and/or appearance of new lesions
Number of Participants With All Grade Neutrophil Count DecreaseBaseline, until resolution or for 30 days after the subject's last study visit, up to 43 months.Assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 regardless of whether the event is related or unrelated to treatment. Neutrophil counts are evaluated using established methods.
Objective Response Rate by ESR1 GenotypeUp to 34 monthsThe objective response rate is the proportion of participants achieving complete response (CR) or partial response (PR) on treatment based on Response Evaluation Criteria In Solid Tumors Criteria (RECIST 1.1) criteria. PR or better is achieved if the following are true: Target Lesions: -At least a 30% 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. Non-target Lesions: No progression. No appearance new lesions 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. Bone Lesions: -\>50% increase in lesions. -No new lesions. ESR1 genotype determined by established methods.
Overall Survival by ESR1 GenotypeUp to 42 monthsOverall Survival (OS) is defined as the time from randomization (or registration) to death due to any cause, or censored at date last known alive. ESR1 genotype determined by established methods.
Objective Response RateAssessed for response for up to 34 monthsThe objective response rate is the proportion of participants achieving complete response (CR) or partial response (PR) on treatment based on Response Evaluation Criteria In Solid Tumors Criteria (RECIST 1.1) criteria. PR or better is achieved if the following are true: Target Lesions: -At least a 30% 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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: -\>50% increase in lesions. -No new lesions.
Median Progression-Free SurvivalUp to 42 monthsProgression free survival (PFS) is defined as the time from start of treatment to disease progression or death from any cause as estimated by Kaplan Meier methods. Progression is measured using RECIST 1.1 criteria, defined as at least a 20% increase in size in target lesion and/or unequivocal progression of non-target lesions and/or appearance of new lesions. Patients who have not progressed and are alive are censored at the date the patient is known to be progression-free.

Countries

United States

Participant flow

Recruitment details

Patients were enrolled between 7/9/2015 and 7/19/2017

Participants by arm

ArmCount
Palbociclib in Combination With Bazedoxifene
Palbociclib 125 mg Oral on days 1-21 per cycle Bazedoxifene 40 mg Oral on days 1-28 per cycle One cycle is 28 days.
36
Total36

Withdrawals & dropouts

PeriodReasonFG000
Overall StudyDisease Progression30
Overall StudyPhysician Decision3
Overall StudyStarted new therapy2
Overall StudyUnacceptable Toxicity1

Baseline characteristics

CharacteristicPalbociclib in Combination With Bazedoxifene
Age, Continuous59.5 years
ECOG Performance Status
00 - Fully Active
33 Participants
ECOG Performance Status
01 - Restricted
3 Participants
Estrogen Receptor Status
Low Positive
1 Participants
Estrogen Receptor Status
Positive (>10% cell staining)
34 Participants
Estrogen Receptor Status
Unknown
1 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
31 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
4 Participants
Everolimus for Metastatic Breast Cancer
No
32 Participants
Everolimus for Metastatic Breast Cancer
Yes
4 Participants
Human Epidermal Growth Factor Receptor 2 Amplification
Negative
36 Participants
Human Epidermal Growth Factor Receptor 2 Amplification
Positive
0 Participants
Prior Chemotherapy for Metastatic Breast Cancer
One
16 Participants
Prior Chemotherapy for Metastatic Breast Cancer
Two
3 Participants
Prior Chemotherapy for Metastatic Breast Cancer
Zero
17 Participants
Prior Hormonal Therapy for Metastatic Breast Cancer
Four
2 Participants
Prior Hormonal Therapy for Metastatic Breast Cancer
One
14 Participants
Prior Hormonal Therapy for Metastatic Breast Cancer
Three
6 Participants
Prior Hormonal Therapy for Metastatic Breast Cancer
Two
8 Participants
Prior Hormonal Therapy for Metastatic Breast Cancer
Zero
6 Participants
Prior Hormonal Therapy for Primary Cancer
No
11 Participants
Prior Hormonal Therapy for Primary Cancer
Yes
25 Participants
Prior Tamoxifen for Primary or Metastatic Breast Cancer
No
10 Participants
Prior Tamoxifen for Primary or Metastatic Breast Cancer
Yes
26 Participants
Progesterone Receptor Status
Low Positive
1 Participants
Progesterone Receptor Status
Negative (<=10% cell staining)
12 Participants
Progesterone Receptor Status
Positive (>10% cell staining)
22 Participants
Progesterone Receptor Status
Unknown
1 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
Race (NIH/OMB)
Asian
0 Participants
Race (NIH/OMB)
Black or African American
0 Participants
Race (NIH/OMB)
More than one race
1 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
Race (NIH/OMB)
Unknown or Not Reported
3 Participants
Race (NIH/OMB)
White
32 Participants
Sex: Female, Male
Female
34 Participants
Sex: Female, Male
Male
2 Participants
Site of Metastatic Disease
Bone
26 Participants
Site of Metastatic Disease
Breast and Chest
14 Participants
Site of Metastatic Disease
Liver
23 Participants
Site of Metastatic Disease
Lung and Pleural
12 Participants
Site of Metastatic Disease
Lymph Node
13 Participants
Site of Metastatic Disease
Others
7 Participants
Site of Metastatic Disease: Bone Only
No
34 Participants
Site of Metastatic Disease: Bone Only
Yes
2 Participants
Site of Metastatic Disease: Visceral Disease
No
7 Participants
Site of Metastatic Disease: Visceral Disease
Yes
29 Participants

Adverse events

Event typeEG000
affected / at risk
deaths
Total, all-cause mortality
17 / 36
other
Total, other adverse events
34 / 36
serious
Total, serious adverse events
17 / 36

Outcome results

Primary

Clinical Benefit Rate

Clinical Benefit Rate is the percentage of participants who achieve clinical benefit from the study treatment. Clinical benefit is defined as at least 24 weeks of confirmed Complete Response (CR), Partial Response (PR), or Stable Disease (SD). SD or better is achieved if the following are true: Target Lesions: -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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: * \< 25% increase in lesions. * No new lesions.

Time frame: Assessed for response for up to 34 months

ArmMeasureValue (NUMBER)
Palbociclib in Combination With BazedoxifeneClinical Benefit Rate33 percentage of participants
Primary

Clinical Benefit Rate by ESR1 Genotype

Clinical Benefit Rate is the percentage of participants who achieve clinical benefit from the study treatment. Clinical benefit is defined as at least 24 weeks of confirmed CR, PR, SD. SD or better is achieved if the following are true: Target Lesions: -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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: * \< 25% increase in lesions. * No new lesions. ESR1 genotype determined using established methods

Time frame: Assessed for response for up to 34 months

Population: Total number analyzed is the sum of both categories (mutant and wild type).

ArmMeasureGroupValue (NUMBER)
Palbociclib in Combination With BazedoxifeneClinical Benefit Rate by ESR1 GenotypeWild Type31 percentage of participants
Palbociclib in Combination With BazedoxifeneClinical Benefit Rate by ESR1 GenotypeMutant43 percentage of participants
Primary

Percent of Participants With All Grade Neutrophil Count Decrease

Assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 regardless of whether the event is related or unrelated to treatment. Neutrophil counts are evaluated using established methods.

Time frame: Baseline, until resolution or for 30 days after the subject's last study visit, up to 43 months.

ArmMeasureValue (NUMBER)
Palbociclib in Combination With BazedoxifenePercent of Participants With All Grade Neutrophil Count Decrease61.1 percentage of participants
Secondary

Median Overall Survival

Overall Survival (OS) is defined as the time from randomization (or registration) to death due to any cause, or censored at date last known alive.

Time frame: Up to 42 months

ArmMeasureValue (MEDIAN)
Palbociclib in Combination With BazedoxifeneMedian Overall Survival26.5 months
Secondary

Median Progression-Free Survival

Progression free survival (PFS) is defined as the time from start of treatment to disease progression or death from any cause as estimated by Kaplan Meier methods. Progression is measured using RECIST 1.1 criteria, defined as at least a 20% increase in size in target lesion and/or unequivocal progression of non-target lesions and/or appearance of new lesions. Patients who have not progressed and are alive are censored at the date the patient is known to be progression-free.

Time frame: Up to 42 months

Population: Rows are representative of subgroups of study population.

ArmMeasureValue (MEDIAN)
Palbociclib in Combination With BazedoxifeneMedian Progression-Free Survival3.58 months
Secondary

Median Progression-Free Survival for Patients by ESR1 Genotype

Progression free survival (PFS) is defined as the time from start of treatment to disease progression or death from any cause as estimated by Kaplan Meier methods. Patients who have not progressed and are alive are censored at the date the patient is known to be progression-free. ESR1 genotype is determined using established methods. Progression is measured using RECIST 1.1 criteria, defined as at least a 20% increase in size in target lesion and/or unequivocal progression of non-target lesions and/or appearance of new lesions

Time frame: Up to 24 months

Population: Total number analyzed is the sum of both categories (mutant and wild type).

ArmMeasureGroupValue (MEDIAN)
Palbociclib in Combination With BazedoxifeneMedian Progression-Free Survival for Patients by ESR1 GenotypeWild Type3.6 months
Palbociclib in Combination With BazedoxifeneMedian Progression-Free Survival for Patients by ESR1 GenotypeMutant2.0 months
Secondary

Number of Participants With All Grade Neutrophil Count Decrease

Assessed by Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 regardless of whether the event is related or unrelated to treatment. Neutrophil counts are evaluated using established methods.

Time frame: Baseline, until resolution or for 30 days after the subject's last study visit, up to 43 months.

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Palbociclib in Combination With BazedoxifeneNumber of Participants With All Grade Neutrophil Count Decrease22 Participants
Secondary

Objective Response Rate

The objective response rate is the proportion of participants achieving complete response (CR) or partial response (PR) on treatment based on Response Evaluation Criteria In Solid Tumors Criteria (RECIST 1.1) criteria. PR or better is achieved if the following are true: Target Lesions: -At least a 30% 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. Non-target Lesions: * No progression. * No appearance new lesions 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. Bone Lesions: -\>50% increase in lesions. -No new lesions.

Time frame: Assessed for response for up to 34 months

ArmMeasureValue (NUMBER)
Palbociclib in Combination With BazedoxifeneObjective Response Rate11.1 percentage of participants
Secondary

Objective Response Rate by ESR1 Genotype

The objective response rate is the proportion of participants achieving complete response (CR) or partial response (PR) on treatment based on Response Evaluation Criteria In Solid Tumors Criteria (RECIST 1.1) criteria. PR or better is achieved if the following are true: Target Lesions: -At least a 30% 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. Non-target Lesions: No progression. No appearance new lesions 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. Bone Lesions: -\>50% increase in lesions. -No new lesions. ESR1 genotype determined by established methods.

Time frame: Up to 34 months

Population: Total number analyzed is the sum of both categories (mutant and wild type).

ArmMeasureGroupCategoryValue (COUNT_OF_PARTICIPANTS)
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeWild TypeComplete Response0 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeWild TypeProgressive Disease5 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeMutantComplete Response0 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeMutantProgressive Disease5 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeWild TypePartial Response0 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeWild TypeStable Disease13 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeWild TypeNot Evaluable1 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeMutantPartial Response0 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeMutantStable Disease3 Participants
Palbociclib in Combination With BazedoxifeneObjective Response Rate by ESR1 GenotypeMutantNot Evaluable1 Participants
Secondary

Overall Survival by ESR1 Genotype

Overall Survival (OS) is defined as the time from randomization (or registration) to death due to any cause, or censored at date last known alive. ESR1 genotype determined by established methods.

Time frame: Up to 42 months

Population: Total number analyzed is the sum of both categories (mutant and wild type).

ArmMeasureGroupValue (MEDIAN)
Palbociclib in Combination With BazedoxifeneOverall Survival by ESR1 GenotypeWild Type21.1 probability of survival
Palbociclib in Combination With BazedoxifeneOverall Survival by ESR1 GenotypeMutant26.5 probability of survival

Source: ClinicalTrials.gov · Data processed: Feb 12, 2026