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Atezolizumab and Cobimetinib or Idasanutlin in Participants With Stage IV or Unresectable Recurrent Estrogen Receptor Positive Breast Cancer

BRE 17107: A Phase Ib/II Trial of Atezolizumab (an Anti-PD-L1 Monoclonal Antibody) With Cobimetinib (a MEK1/2 Inhibitor) or Idasanutlin (an MDM2 Antagonist) in Metastatic ER+ Breast Cancer

Status
Terminated
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03566485
Enrollment
12
Registered
2018-06-25
Start date
2018-07-10
Completion date
2020-12-10
Last updated
2021-08-11

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

Conditions

Stage III Breast Cancer, Stage IIIA Breast Cancer, Stage IIIB Breast Cancer, Stage IIIC Breast Cancer, Stage IV Breast Cancer, Estrogen Receptor-positive, HER2/Neu Negative

Brief summary

This phase I/II trial studies the side effects and best dose of idasanutlin when given together with atezolizumab, and to see how well atezolizumab and cobimetinib or idasanutlin work in treating participants with stage IV estrogen-receptor positive (ER+) breast cancer, or ER+ breast cancer that has come back (recurrent) and cannot be removed by surgery (unresectable). Monoclonal antibodies, such as atezolizumab, may interfere with the ability of tumor cells to grow and spread. Cobimetinib and idasanutlin may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving atezolizumab with cobimetinib or atezolizumab with idasanutlin may work better in treating participants with estrogen-receptor positive breast cancer.

Detailed description

PRIMARY OBJECTIVES: I. To determine the safety and tolerability of atezolizumab and idasanutlin in patients with estrogen receptor positive (ER+) metastatic breast cancer (mBC) (Phase I). II. To determine the anti-tumor effect of atezolizumab and cobimetinib or idasanutlin in patients with ER+ mBC (Phase II). SECONDARY OBJECTIVES: I. To determine the anti-tumor duration of effect of atezolizumab and cobimetinib or idasanutlin in patients with ER+ mBC (Phase II). II. To determine the safety and tolerability of atezolizumab and cobimetinib or idasanutlin in patients with ER+ mBC (Phase II). EXPLORATORY OBJECTIVES: I. To evaluate if CD8+ T cells are enhanced in the tumor with either MEK or MDM2 inhibition (Phase II). II. To evaluate if MHC-I/II and/or PD-L1 expression is enhanced with MEK inhibition (Phase II). III. To evaluate if T cell chemotractants (CCL5, CXCL9,10,11,13) are upregulated upon MDM2 antagonism (Phase II). IV. To determine if baseline or changes in PDL1 expression, MHC expression, presence of tumor infiltrating lymphocytes, neoantigen expression/ mutation burden (using ribonucleic acid \[RNA\]-and whole exome sequencing), CCL5, CXCL9, CXCL10, CXCL11, and CXCL13 correlate with clinical outcome (Phase II). V. To determine if immunological activity of MEK inhibition can be tracked noninvasively using Zr\^89-atezolizumab (Phase II). OUTLINE: This is a phase 1, dose-escalation study of idasanutlin followed by a phase II study. Participants are assigned to 1 of 2 arms. ARM I: Participants with TP53 gene mutation receive atezolizumab intravenously (IV) over 60 minutes starting with day 15 of course 1 and then on days 1 and 15 of subsequent courses, and cobimetinib orally (PO) daily on days 1-21. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. ARM II: Participants without TP53 gene mutation receive atezolizumab IV over 60 minutes starting with day 15 of course 1 and then on days 1 and 15 of subsequent courses, and idasanutlin PO daily on days 1-5. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, participants are followed for 28 days.

Interventions

DRUGAtezolizumab

Given by IV

DRUGCobimetinib

Given by mouth

Given by mouth

Sponsors

Genentech, Inc.
CollaboratorINDUSTRY
Stand Up To Cancer
CollaboratorOTHER
Vanderbilt-Ingram Cancer Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

* Signed and dated written informed consent. * Subjects ≥ 18 years of age. * Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1. * Clinical stage IV invasive mammary carcinoma or unresectable locoregional recurrence of invasive mammary carcinoma that is: * ER/PR-positive (\> 1% cells) by IHC and HER2 negative per ASCO guidelines (by IHC or FISH) * Previously exposed to an aromatase inhibitor (AI) or a selective estrogen-receptor modulator/ downregulator (SERM; SERD) + a CDK4/6 inhibitor * Appropriate candidates for chemotherapy * Amenable to biopsy at the time of study entry * Adequate organ function including: * Absolute neutrophil count (ANC) ≥ 1.5 × 109/L * Platelets ≥ 100 × 109/L * Hemoglobin ≥ 9/g/dL (may have been transfused) * Total serum bilirubin ≤ 1.5 times upper limit of normal (ULN) * Aspartate aminotransferase (AST/SGOT) and alanine aminotransferase (ALT/SGPT) ≤ 2.5 × ULN (or ≤ 5 × ULN if liver metastases are present) * Serum creatinine ≤ 1.5 x ULN or estimated creatinine clearance ≥ 50 mL/min as calculated using the Cockcroft-Gault (CG) equation * Thyroid Stimulating Hormone (TSH) ≤ 1 x ULN * Amylase ≤ 1 x ULN * Lipase ≤ 1 x ULN * CPK ≤ 1.5 x ULN * LVEF (echo) ≥ LLN (Cobi arm only) * Female patients of childbearing potential must agree to use at least two methods of acceptable contraception with a failure rate of \< 1% per year from 15 days prior to first trial treatment administration until at least 5 months after study participant's final dose of study drugs. See appendix C for details. Note: Females of childbearing potential are defined as those who are not surgically sterile or post-menopausal (i.e. patient has not had a bilateral tubal ligation, a bilateral oophorectomy, or a complete hysterectomy; or has not been amenorrheic for 12 months without an alternative medical cause). Post-menopausal status in females under 55 years of age should be confirmed with a serum follicle-stimulating hormone (FSH) level within laboratory reference range for postmenopausal women. * Patients unable to read/write in English are eligible to participate in the overall study but will not participate in the Patient-Reported Outcome questionnaires throughout the trial * Re-enrollment of a subject that has discontinued the study as a pre-treatment screen failure (i.e. a consented patient who did not receive study drugs) is permitted. If re-enrolled, the subject must be re-consented. Only the screening procedures performed outside of protocol-specified timing must be repeated.

Exclusion criteria

* Prior therapy with anti-PD-L1 and anti-PD1 antibodies, MEK inhibitors or MDM2 antagonists. * No more than 3 lines of chemotherapy in the metastatic setting * No concurrent anticancer therapy. Required washout from prior therapy: * Endocrine therapy: no required wash-out * Chemotherapy: 14 days * Major surgery: 14 days (provided wound healing is adequate) * Radiation: 7 days * Investigational/Biologic Therapy (half -life ≤ 40 hours): 14 days * Investigational/Biologic Therapy (half -life \> 40 hours): 28 days * Use of corticosteroids or immunosuppressive medication is exclusionary, except the following in the absence of active autoimmune disease: * Subjects are permitted the use of corticosteroids with minimal systemic absorption (e.g. topical, ocular, intra-articular, intranasal, and inhaled); * Systemic corticosteroids at physiologic doses ≤10 mg/day of prednisone or equivalent are permitted; * Adrenal replacement steroid doses including doses \> 10 mg daily prednisone are permitted; * A brief (less than 3 weeks) course of corticosteroids for prophylaxis (e.g. CT scan premedication against contrast dye allergy) or for treatment of non-autoimmune conditions (e.g. delayed-type hypersensitivity reaction caused by a contact allergen) is permitted. * Previous malignant disease other than breast cancer within the last 5 years, with the exception of basal or squamous cell carcinoma of the skin, cervical carcinoma in situ, or low-risk cancers considered curatively treated (i.e. complete remission achieved at least 2 years prior to first dose of study drugs AND additional therapy not required while receiving study treatment). * All subjects with brain metastases, except those meeting the following criteria: * Brain metastases that have been treated locally and are clinically stable for at least 2 weeks prior to enrollment * No history of intracranial or spinal cord hemorrhage * No evidence of interim CNS disease progression * Metastasis to the midbrain, pons, and medulla * No ongoing neurological symptoms that are related to the brain localization of the disease (sequelae that are a consequence of the treatment of the brain metastases are acceptable. * Subjects must be either off steroids or on a stable or decreasing dose of ≤ 10 mg daily prednisone (or equivalent) * Receipt of any organ transplantation including allogeneic stem-cell transplantation. * Significant acute or chronic infections including, among others: * Known history of testing positive for human immunodeficiency virus (HIV), or acquired immunodeficiency syndrome (AIDS). * Active tuberculosis * Positive test for hepatitis B virus (HBV) surface antigen (and/or core antibody) and/or confirmatory hepatitis C virus (HCV) RNA (if anti-HCV antibody tested positive). * Active autoimmune disease with reasonable possibility of clinically significant deterioration when receiving an immunostimulatory agent: * Subjects with Type 1 diabetes mellitus, vitiligo, psoriasis, hypo- or hyperthyroid disease not requiring immunosuppressive treatment are eligible. * Subjects requiring hormone replacement with corticosteroids are eligible if the steroids are administered only for the purpose of hormonal replacement and at doses ≤ 10 mg or 10 mg equivalent prednisone per day. * Administration of steroids through a route known to result in a minimal systemic exposure (topical, intranasal, intro-ocular, or inhalation) are acceptable. * Interstitial lung disease that is symptomatic or which may interfere with the detection or management of suspected drug-related pulmonary toxicity. * Uncontrolled asthma \[defined as having 3 or more of the following features of partially controlled asthma within 28 days prior to starting study treatment: Daytime symptoms more than twice per week, any limitation of activities, any nocturnal symptoms/awaking, need for reliever/rescue inhaler more than twice per week, or known lung function (PEF or FEV1) without administration of a bronchodilator that is \< 80% predicted or personal best (if known)\]. * Current symptomatic congestive heart failure (New York Heart Association \> class II), unstable cardiac arrhythmia requiring therapy (e.g. medication or pacemaker), unstable angina (e.g. new, worsening or persistent chest discomfort), or uncontrolled hypertension (systolic \> 160 mmHg or diastolic \> 100mmHg). Or any of the following occurring within 6 months (180 days) prior to first dose of study drugs: Myocardial infarction, coronary/peripheral artery bypass graft, cerebrovascular accident or transient ischemic attack. (Use of antihypertensive medication to control blood pressure is allowed.) * Concurrent treatment with a non-permitted drug (refer to prohibited medication list) as well as foods or supplements that are strong or moderate CYP3A4 enzyme inducers or inhibitors. Any of the above has to be discontinued at least 7 days prior to Cycle 1/ Day 1 of study treatment. * Requirement of anticoagulant therapy with oral vitamin K antagonists such as Coumadin (warfarin). Low-dose anticoagulants for the maintenance of patency in a central venous access device or the prevention of deep vein thrombosis or pulmonary embolism is allowed. Therapeutic use of low molecular weight heparin is allowed provided patients are safely able to interrupt it prior to biopsy procedures. * Persisting toxicity related to prior therapy that has not reduced to Grade 1 \[National Cancer Institute Common Toxicity Criteria for Adverse Events (NCI CTCAE) version 5.0\]; however, alopecia and sensory neuropathy Grade ≤ 2 are acceptable and Grade ≤ 2 non-hematological toxicities well controlled with medical management are allowed (for example: hypomagnesemia well controlled on magnesium replacement). * Known severe (Grade ≥ 3 NCI-CTCAE) hypersensitivity reactions to monoclonal antibodies, or history of anaphylaxis. * Vaccination within 28 days of the first dose of study drugs and while on trial is prohibited, except for administration of inactivated vaccines (for example, inactivated influenza vaccine). * Pregnant or breastfeeding females. * Known current alcohol or drug abuse * Prisoners or subjects who are involuntarily incarcerated. * Known psychiatric condition, social circumstance, or other medical condition reasonably judged by the patient's study physician to unacceptably increase the risk of study participation; or to prohibit the understanding or rendering of informed consent or anticipated compliance with scheduled visits, treatment schedule, laboratory tests and other study requirements. * Known risk factors for ocular toxicity, consisting of any of the following (Cobi arm only): * presence of serous retinopathy within 6 months of protocol enrollment * presence of retinal vein occlusion (RVO) within 6 months of protocol enrollment

Design outcomes

Primary

MeasureTime frameDescription
Number of Participants With a Dose Limiting Toxicity (DLT) (Phase I)At 28 daysAssessment of DLT for the patients in the atezolizumab and idasanutiln arm of the study
Maximum Tolerated Dose (Phase I)At 28 daysAssessment of MTD for the atezolizumab and idasanutiln combination arm of the study
Recommended Phase II Dose (Phase I)At 28 daysAssessment of recommended phase II dose for the atezolizumab and idasanutiln combination arm of the study
Overall Response Rate (ORR; by Response Evaluation Criteria in Solid Tumors [RECIST]1.1) (Phase II)Up to 28 days after completion of study treatment, for a total of 2 yearsAssessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of complete and partial responses seen in patients with measurable disease. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.

Secondary

MeasureTime frameDescription
Clinical Benefit Rate (CBR) (Phase II)At 6 monthsAssessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of complete and partial responses + stability of disease at 6 months seen in patients with measurable disease. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.
Number of Adverse Events (Phase II)Up to 28 days after completion of study treatment, for a total of 2 yearsAssessment of adverse events throughout the phase II study
Immune Related Response Criteria (irRC) (Phase II)Up to 28 days after completion of study treatment, for a total of 2 yearsAssessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of immune-related complete and partial responses seen in patients with measurable disease
Progression-free Survival (PFS) (Phase II) in DaysAt 12 monthsAssessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measuring the interval (in months) between treatment initiation and disease progression. Progression is defined using Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1).
Overall Survival (OS) (Phase II) in DaysAt 12 monthsAssessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measuring the interval (in months) between treatment initiation and death from any cause

Countries

United States

Participant flow

Recruitment details

Participants were recruited to this study from July 2018 to November 2019 at Vanderbilt-Ingram Cancer Center in Nashville, TN. This study stopped early due to low accrual.

Pre-assignment details

Twelve participants were enrolled onto this study.

Participants by arm

ArmCount
Phase 2 (Atezolizumab, Cobimetinib)
Participants with TP53 gene mutation receive atezolizumab IV over 60 minutes starting with day 15 of course 1 and then on days 1 and 15 of subsequent courses, and cobimetinib PO daily on days 1-21. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Atezolizumab: Given by IV Cobimetinib: Given by mouth
5
Phase 1b - (Atezolizumab, Idasanutlin)
Atezolizumab: Given by IV Idasanutlin: Given by mouth
7
Total12

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyClinical progression01
Overall StudyDisease progression54
Overall StudyToxicity02

Baseline characteristics

CharacteristicPhase 2 (Atezolizumab, Cobimetinib)Phase 1b - (Atezolizumab, Idasanutlin)Total
Age, Categorical
<=18 years
0 Participants0 Participants0 Participants
Age, Categorical
>=65 years
1 Participants2 Participants3 Participants
Age, Categorical
Between 18 and 65 years
4 Participants5 Participants9 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants0 Participants0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
4 Participants5 Participants9 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
1 Participants2 Participants3 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Black or African American
0 Participants0 Participants0 Participants
Race (NIH/OMB)
More than one race
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
1 Participants2 Participants3 Participants
Race (NIH/OMB)
White
4 Participants5 Participants9 Participants
Region of Enrollment
United States
5 participants7 participants12 participants
Sex: Female, Male
Female
5 Participants7 Participants12 Participants
Sex: Female, Male
Male
0 Participants0 Participants0 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
3 / 53 / 7
other
Total, other adverse events
5 / 57 / 7
serious
Total, serious adverse events
2 / 54 / 7

Outcome results

Primary

Maximum Tolerated Dose (Phase I)

Assessment of MTD for the atezolizumab and idasanutiln combination arm of the study

Time frame: At 28 days

Population: Patients in the atezolizumab and idasanutiln combination arm of the study. Dosage used: Atezolizumab 840mg IV + Idasanutlin 100mg PO

ArmMeasureValue (NUMBER)
Phase 1b - (Atezolizumab, Idasanutlin)Maximum Tolerated Dose (Phase I)NA mg
Primary

Number of Participants With a Dose Limiting Toxicity (DLT) (Phase I)

Assessment of DLT for the patients in the atezolizumab and idasanutiln arm of the study

Time frame: At 28 days

Population: patients in the atezolizumab and idasanutiln arm of the study

ArmMeasureValue (COUNT_OF_PARTICIPANTS)
Phase 1b - (Atezolizumab, Idasanutlin)Number of Participants With a Dose Limiting Toxicity (DLT) (Phase I)1 Participants
Primary

Overall Response Rate (ORR; by Response Evaluation Criteria in Solid Tumors [RECIST]1.1) (Phase II)

Assessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of complete and partial responses seen in patients with measurable disease. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.

Time frame: Up to 28 days after completion of study treatment, for a total of 2 years

Population: Patients on Phase 2 Arm 1 (TP53-mut) - Atezolizumab 840mg IV + Cobimetinib 60mg PO

ArmMeasureValue (NUMBER)
Phase 1b - (Atezolizumab, Idasanutlin)Overall Response Rate (ORR; by Response Evaluation Criteria in Solid Tumors [RECIST]1.1) (Phase II)NA percentage of participants
Primary

Recommended Phase II Dose (Phase I)

Assessment of recommended phase II dose for the atezolizumab and idasanutiln combination arm of the study

Time frame: At 28 days

Population: Patients on the atezolizumab and idasanutiln combination arm of the study. Dosage used: Atezolizumab 840mg IV + Idasanutlin 100mg PO.

ArmMeasureValue (NUMBER)
Phase 1b - (Atezolizumab, Idasanutlin)Recommended Phase II Dose (Phase I)NA mg
Secondary

Clinical Benefit Rate (CBR) (Phase II)

Assessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of complete and partial responses + stability of disease at 6 months seen in patients with measurable disease. Per Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1) for target lesions and assessed by MRI: Complete Response (CR), Disappearance of all target lesions; Partial Response (PR), \>=30% decrease in the sum of the longest diameter of target lesions; Overall Response (OR) = CR + PR.

Time frame: At 6 months

Population: patients on Phase 2 Arm 1 (TP53-mut) - Atezolizumab 840mg IV + Cobimetinib 60mg PO

ArmMeasureValue (NUMBER)
Phase 1b - (Atezolizumab, Idasanutlin)Clinical Benefit Rate (CBR) (Phase II)NA percentage of participants
Secondary

Immune Related Response Criteria (irRC) (Phase II)

Assessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measure the rate (%) of immune-related complete and partial responses seen in patients with measurable disease

Time frame: Up to 28 days after completion of study treatment, for a total of 2 years

Population: An insufficient number of participants exhibited response for analysis.

Secondary

Number of Adverse Events (Phase II)

Assessment of adverse events throughout the phase II study

Time frame: Up to 28 days after completion of study treatment, for a total of 2 years

Population: patients on atezolizumab and cobimetinib.

ArmMeasureValue (NUMBER)
Phase 1b - (Atezolizumab, Idasanutlin)Number of Adverse Events (Phase II)99 events
Secondary

Overall Survival (OS) (Phase II) in Days

Assessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measuring the interval (in months) between treatment initiation and death from any cause

Time frame: At 12 months

Population: Patients on Phase 2 Arm 1 (TP53-mut) - Atezolizumab 840mg IV + Cobimetinib 60mg PO

ArmMeasureValue (MEDIAN)
Phase 1b - (Atezolizumab, Idasanutlin)Overall Survival (OS) (Phase II) in Days161 days
Secondary

Progression-free Survival (PFS) (Phase II) in Days

Assessment of clinical impact (anti-tumor effect) of the combination of atezolizumab and cobimetinib or idasanutiln in patients with metastatic ER \+ breast cancer by measuring the interval (in months) between treatment initiation and disease progression. Progression is defined using Response Evaluation Criteria In Solid Tumors Criteria (RECIST v1.1).

Time frame: At 12 months

Population: Patients on Phase 2 Arm 1 (TP53-mut) - Atezolizumab 840mg IV + Cobimetinib 60mg PO

ArmMeasureValue (MEDIAN)
Phase 1b - (Atezolizumab, Idasanutlin)Progression-free Survival (PFS) (Phase II) in Days56 days

Source: ClinicalTrials.gov · Data processed: Feb 20, 2026