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A Study of Multiple Immunotherapy-Based Treatment Combinations in Hormone Receptor (HR)-Positive Human Epidermal Growth Factor Receptor 2 (HER2)-Negative Breast Cancer

Trial Status: Active

This study is designed to evaluate the efficacy, safety, and pharmacokinetics of several immunotherapy-based combination treatments in participants with inoperable locally advanced or metastatic HR-positive, HER2-negative breast cancer who have progressed during or following treatment with a cyclin-dependent kinase (CDK) 4 / 6 inhibitor in the first- or second-line setting, such as palbociclib, ribociclib, or abemaciclib. The study will be performed in two stages. During Stage 1, participants will be randomized to fulvestrant (control) or an atezolizumab-containing doublet or triplet combination. Those who experience disease progression, loss of clinical benefit, or unacceptable toxicity may be eligible to receive a new triplet combination treatment in Stage 2 until loss of clinical benefit or unacceptable toxicity. New treatment arms may be added and / or existing treatment arms may be closed during the course of the study on the basis of ongoing clinical efficacy and safety as well as the current treatments available.

Inclusion Criteria

  • Inclusion Criteria for Both Stages: - Measurable disease per RECIST v1.1 - Adequate hematologic and end organ function - Disease progression during or after first- or second-line hormonal therapy with CDK4/6 inhibitor Inclusion Criteria for Stage 1: - Eastern Cooperative Oncology Group (ECOG) performance status 0-1 - Metastatic or inoperable, locally advanced, histologically or cytologically confirmed invasive HR-positive HER2-negative breast cancer - Recommended for endocrine therapy, and cytotoxic chemotherapy not indicated at study entry - Recurrence or progression following most recent systemic breast cancer therapy - Disease progression during or after first- or second-line hormonal therapy for locally advanced or metastatic disease - Postmenopausal according to protocol-defined criteria - Life expectancy >3 months - Available tumor specimen for determination of PD-L1 status Inclusion Criteria for Stage 2: - ECOG performance status of 0-2 - Ability to initiate treatment within 3 months after disease progression or unacceptable toxicity on a Stage 1 regimen Exclusion Criteria for Both Stages: - Significant or uncontrolled comorbid disease as specified in the protocol - Uncontrolled tumor-related pain - Autoimmune disease except for stable/controlled hypothyroidism, Type 1 diabetes mellitus, or certain dermatologic conditions - Positive human immunodeficiency virus test - Active hepatitis B or C - Active tuberculosis - Severe infection within 4 weeks and/or antibiotics within 2 weeks prior to study treatment - Prior allogeneic stem cell or solid organ transplantation - History of malignancy other than breast cancer within 2 years prior to screening except those with negligible risk of metastasis/death - History of or known hypersensitivity to study drug or excipients - For patients entering Stage 2, recovery from all immunotherapy-related adverse events to Grade 1 or better or to baseline at the time of consent Exclusion Criteria for Stage 1: - Prior fulvestrant or cytotoxic chemotherapy for metastatic breast cancer, or certain other agents as specified in the protocol - Unresolved AEs from prior anti-cancer therapy - Eligibility only for the control arm - Prior treatment with inhibitors as specified in the protocol Exclusion Criteria for Stage 2: - Unacceptable toxicity with atezolizumab during Stage 1 - Uncontrolled cardiovascular disease or coagulation disorder, including use of anticoagulants as specified in the protocol - Significant abdominal or intestinal manifestations within 6 months prior to treatment - Grade 2 or higher proteinuria


University of Alabama at Birmingham Cancer Center
Contact: Andres Forero-Torres
Phone: 205-975-2837


Los Angeles
UCLA / Jonsson Comprehensive Cancer Center
Status: ACTIVE
Contact: Dorreth King-Rucker
Phone: 310-794-5782
Palo Alto
Stanford Cancer Institute Palo Alto
Status: ACTIVE
San Francisco
UCSF Medical Center-Mount Zion


Johns Hopkins University / Sidney Kimmel Cancer Center
Status: ACTIVE

New York

New York
Memorial Sloan Kettering Cancer Center
Status: ACTIVE
Contact: Elizabeth Anne Comen
Phone: 646-888-5104


Ohio State University Comprehensive Cancer Center


Thomas Jefferson University Hospital
Status: ACTIVE
University of Pittsburgh Cancer Institute (UPCI)
Status: ACTIVE

Trial Phase Phase I/II

Trial Type Treatment

Lead Organization
Hoffmann-La Roche

  • Primary ID CO39611
  • Secondary IDs NCI-2018-00013, 2017-000335-14
  • ID NCT03280563