Study of Pembrolizumab (MK-3475) Plus Enzalutamide Versus Placebo Plus Enzalutamide in Participan… (NCT03834493) | Clinical Trial Compass
CompletedPhase 3
Study of Pembrolizumab (MK-3475) Plus Enzalutamide Versus Placebo Plus Enzalutamide in Participants With Metastatic Castration-resistant Prostate Cancer (mCRPC) (MK-3475-641/KEYNOTE-641)
United States, Argentina, Australia1,244 participantsStarted 2019-07-28
Plain-language summary
The purpose of this study is to assess the efficacy and safety of the combination of pembrolizumab (MK-3475) and enzalutamide in the treatment of men with metastatic castration-resistant prostate cancer (mCRPC) who have not received chemotherapy for mCRPC, are abiraterone-naïve, or are intolerant to or progressed on abiraterone acetate. There are two primary study hypotheses.
Hypothesis 1: The combination of pembrolizumab plus enzalutamide is superior to placebo plus enzalutamide with respect to Overall Survival (OS).
Hypothesis 2: The combination of pembrolizumab plus enzalutamide is superior to placebo plus enzalutamide with respect to Radiographic Progression-free Survival (rPFS) per Prostate Cancer Working Group (PCWG)-modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as assessed by blinded independent central review.
Who can participate
Age range
18 Years
Sex
MALE
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 main inclusion and exclusion criteria include but are not limited to the following:
Inclusion Criteria:
* Has histologically- or cytologically-confirmed adenocarcinoma of the prostate without small cell histology
* Has prostate cancer progression while on androgen deprivation therapy (or post bilateral orchiectomy) within 6 months prior to randomization
* Has current evidence of metastatic disease documented by either bone lesions on bone scan and/or soft tissue disease by computed tomography/magnetic resonance imaging (CT/MRI)
* Has met one of the following criteria with regard to abiraterone acetate exposure: (1) is abiraterone-naïve; (2) received prior abiraterone acetate for the treatment of mHSPC or mCRPC, for a minimum of 4 weeks and not progressed while on treatment; or (3) received prior abiraterone acetate for the treatment of mHSPC or mCRPC and progressed on treatment after a minimum of 8 weeks treatment (minimum 14 weeks for those with bone progression)
* Has ongoing androgen deprivation with serum testosterone \<50 ng/dL (\<2.0 nM)
* Participants receiving bone resorptive therapy (including, but not limited to, bisphosphonate or denosumab) must have been on stable doses prior to randomization
* Participants must agree to the following during the study treatment period and for at least 90 days after the last dose of enzalutamide: Refrain from donating sperm, plus EITHER be abstinent OR must agree to use male condom
* Has provided newly obtained core or excisi…
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.
1This was a Phase 3 trial comparing pembrolizumab plus enzalutamide against enzalutamide alone for metastatic castration-resistant prostate cancer — has the full data been published yet, and what did the results show for overall survival and disease progression?
2Since the trial is completed, does the combination of pembrolizumab and enzalutamide look like it could be more effective than enzalutamide by itself, or did the results suggest the added immunotherapy didn't make a meaningful difference?
3Pembrolizumab is an immunotherapy that can cause immune-related side effects beyond what enzalutamide causes on its own — based on what came out of this trial, what were the most common or serious safety concerns seen when the two drugs were combined?
4Given that this trial has finished, is the pembrolizumab-plus-enzalutamide combination available to me now through standard care, an approved indication, or would I need to find a different study or access program?
5How does this combination trial compare to other current treatment options for metastatic castration-resistant prostate cancer — is enzalutamide alone, or a completely different regimen, potentially a better starting point for my specific situation?
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
Overall Survival (OS)
Timeframe: Up to 40 months (through database cut-off date of 12-Dec-2022)
2
Radiographic Progression-free Survival (rPFS) Per Prostate Cancer Working Group (PCWG)-Modified Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as Assessed by Blinded Independent Central Review
Timeframe: Up to 40 months (through database cut-off date of 12-Dec-2022)