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A Phase 3, Randomized, Double-blind Trial of Pembrolizumab (MK-3475) Plus Enzalutamide Versus Placebo Plus Enzalutamide in Participants With Metastatic Castration-Resistant Prostate Cancer (mCRPC) (KEYNOTE-641)

Status
Completed
Phases
Phase 3
Study type
Interventional
Source
EU CTIS
Registry ID
CTIS2022-500785-10-00
Acronym
MK-3475-641
Enrollment
420
Registered
2023-01-24
Start date
2019-08-23
Completion date
2025-08-20
Last updated
2025-09-10

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

Conditions

Metastatic Castration-Resistant Prostate Cancer

Brief summary

Overall Survival (OS), 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 (BICR)

Detailed description

Time to Initiation of the First Subsequent Anti-Cancer Therapy or Death (TFST), Prostate-specific Antigen (PSA) Response Rate, Prostate-specific Antigen (PSA) Undetectable Rate, Objective Response Rate (ORR) 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 (BICR), Duration of Response (DOR) 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 (BICR), Time to Prostate-specific Antigen (PSA) Progression, Time to Radiographic Soft Tissue Progression per Soft Tissue Rules of 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 (BICR), Time to Pain Progression (TTPP), Time to First Symptomatic Skeletal-Related Event (SSRE), Number of Participants Who Experienced At Least One Adverse Event (AE), Number of Participants Who Discontinued Study Treatment Due to an Adverse Event (AE

Interventions

DRUGENZALUTAMIDE
DRUGKEYTRUDA 25 mg/mL concentrate for solution for infusion

Sponsors

Merck Sharp & Dohme LLC
Lead SponsorINDUSTRY

Eligibility

Sex/Gender
Male
Age
18 Years to No maximum

Design outcomes

Primary

MeasureTime frame
Overall Survival (OS), 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 (BICR)

Secondary

MeasureTime frame
Time to Initiation of the First Subsequent Anti-Cancer Therapy or Death (TFST), Prostate-specific Antigen (PSA) Response Rate, Prostate-specific Antigen (PSA) Undetectable Rate, Objective Response Rate (ORR) 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 (BICR), Duration of Response (DOR) 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 (BICR), Time to Prostate-specific Antigen (PSA) Progression, Time to Radiographic Soft Tissue Progression per Soft Tissue Rules of 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 (BICR), Time to Pain Progression (TTPP), Time to First Symptomatic Skeletal-Related Event (SSRE), Number of Participants

Countries

Austria, Bulgaria, Czechia, France, Germany, Hungary, Ireland, Italy, Netherlands, Poland, Spain

Outcome results

None listed

Source: EU CTIS · Data processed: Feb 4, 2026