Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy for HR+/HER2-… (NCT04895358) | Clinical Trial Compass
Active — Not RecruitingPhase 3
Study of Pembrolizumab (MK-3475) Plus Chemotherapy Versus Placebo Plus Chemotherapy for HR+/HER2- Locally Recurrent Inoperable or Metastatic Breast Cancer (MK-3475-B49/KEYNOTE-B49)
United States, Argentina, Australia340 participantsStarted 2021-06-18
Plain-language summary
The safety and efficacy of pembrolizumab plus the investigator's choice of chemotherapy will be assessed compared to placebo plus the investigator's choice of chemotherapy in the treatment of chemotherapy-candidate hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) locally recurrent inoperable or metastatic breast cancer.
The primary hypotheses are that the combination of pembrolizumab and chemotherapy is superior to placebo and chemotherapy in regards to Progression-Free Survival (PFS) in participants with programmed cell death-ligand 1 (PD-L1) combined positive score (CPS) ≥1.
Prior to protocol amendment 7, participants who discontinued pembrolizumab/placebo with SD or better and subsequently experienced disease progression may have been eligible for up to 17 additional administrations of pembrolizumab if, upon unblinding, they were found to have received pembrolizumab, at the same dose and schedule used for the initial treatment period.
Who can participate
Age range
18 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
The key inclusion and exclusion criteria include but are not limited to the following:
Inclusion Criteria:
* Has locally recurrent inoperable or metastatic HR+/HER2- breast cancer, which has not been previously treated with cytotoxic chemotherapy in the noncurative setting
* Has progressed on prior endocrine therapy and is now a chemotherapy candidate, meeting the characteristics in regard to previous treatments of one of the following 4 groups:
* Group 1: Has progressed on 2 or more lines of endocrine therapy for advanced/metastatic HR+/HER2-disease, with at least given in combination with a Cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. Prior treatment with mTOR and/or PI3-K inhibitors is allowed. OR
* GROUP 2a: Has progressed on 1 line of previous endocrine therapy for advanced/metastatic disease AND had a disease recurrence within 24 months of definitive surgery for the primary tumor and while on adjuvant endocrine therapy. Prior use of CDK4/6 inhibitors is required, either in the adjuvant and/or metastatic setting. Prior treatment with mTOR and/or PI3-K inhibitors is allowed. OR
* GROUP 2b: Has progressed within 12 months of starting 1 line of endocrine therapy with a CDK4/6 inhibitor for advanced/metastatic HR+/HER2- disease. OR
* GROUP 3: If no prior treatment with a CDK4/6 inhibitor, for advanced/metastatic disease and/or early stage disease (adjuvant), participants must have progressed within 6 months of starting 1 line of endocrine therapy with or without an mTOR…
Questions worth asking your doctor
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.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
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.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Progression-free Survival (PFS) per Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1) by Blinded Independent Central Review (BICR) in Participants With Combined Positive Score (CPS) ≥1