This is a Phase Ib/II, open-label, multicenter, randomized umbrella study in participants with breast cancer. The study is designed with the flexibility to open new treatment arms as new treatments become available, close existing treatment arms that demonstrate minimal clinical activity or unacceptable toxicity, or modify the patient population. Cohort 1 will focus on participants with inoperable, locally advanced or metastatic, estrogen receptor-positive (ER+), HER2-negative breast cancer who had disease progression during or following treatment with a cyclin-dependent kinase 4/6 inhibitor (CDK4/6i; e.g., palbociclib, ribociclib, abemaciclib) in the first- or second-line setting. Cohort 2 will focus on inoperable, locally advanced or metastatic, ER+, HER2-positive breast cancer with previous progression to standard-of-care anti-HER2 therapies, of which one was a trastuzumab-and-taxane-based systemic therapy (including in the early setting if recurrence occurred within 6 months of finishing adjuvant therapy) and one was a HER2-targeting antibody-drug conjugate (ADC; e.g., ado-trastuzumab emtansine or trastuzumab-deruxtecan) or a HER2-targeting tyrosine kinase inhibitor (TKI; e.g., tucatinib, lapatinib, pyrotinib, or neratinib). Cohort 3 will focus on inoperable, locally advanced or metastatic, ER+, HER2-negative, PIK3CA-mutated breast cancer with resistance to adjuvant endocrine therapy.
Age range
18 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Percentage of Participants with Objective Response, Defined as a Complete or Partial Response, as Determined by the Investigator According to Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1)
Timeframe: From Baseline until disease progression (up to 6 years)
Number of Participants with Adverse Events, Severity Determined According to National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0 (NCI CTCAE v5.0)
Timeframe: From Baseline until 30 days after the last dose of study drug (up to 6 years)
Reference Study ID Number: CO42867 https://forpatients.roche.com/