Actively Recruiting

Phase 1
Phase 2
Age: 18Years +
MALE
NCT02861573

Study of Pembrolizumab (MK-3475) Combination Therapies in Metastatic Castration-Resistant Prostate Cancer (MK-3475-365/KEYNOTE-365)

Led by Merck Sharp & Dohme LLC · Updated on 2026-02-17

1200

Participants Needed

21

Research Sites

609 weeks

Total Duration

On this page

AI-Summary

What this Trial Is About

The purpose of this study is to assess the safety and efficacy of pembrolizumab (MK-3475) combination therapy in participants with metastatic castration resistant prostate cancer (mCRPC). There will be ten cohorts in this study: Cohort A will receive pembrolizumab + olaparib, Cohort B will receive pembrolizumab + docetaxel + prednisone, Cohort C will receive pembrolizumab + enzalutamide, Cohort D will receive pembrolizumab + abiraterone + prednisone Cohort E will receive pembrolizumab+lenvatinib, Cohort F will receive pembrolizumab+lenvatinib, Cohort G will receive pembrolizumab/vibostolimab coformulation (MK-7684A), Cohort H will receive pembrolizumab/vibostolimab coformulation, Cohort I will receive pembrolizumab+carboplatin+etoposide in Arm 1 and carboplatin+etoposide in Arm 2 and Cohort J will receive belzutifan in Arm1 and Pembrolizumab+belzutifan in Arm 2. Outcome measures will be assessed individually for each cohort.

CONDITIONS

Official Title

Study of Pembrolizumab (MK-3475) Combination Therapies in Metastatic Castration-Resistant Prostate Cancer (MK-3475-365/KEYNOTE-365)

Who Can Participate

Age: 18Years +
MALE

Eligibility Criteria

Eligible

You may qualify if you...

  • Male with histologically or cytologically confirmed prostate adenocarcinoma, with or without neuroendocrine features depending on cohort
  • Able to provide tumor tissue biopsy or archival specimen as required by cohort
  • Evidence of prostate cancer progression within 6 months prior to screening, except for de novo neuroendocrine prostate cancer participants
  • Ongoing androgen deprivation therapy with serum testosterone below 50 ng/dL, started at least 4 weeks before first study dose and continuing during study (except for certain neuroendocrine participants)
  • Stable bone resorptive therapy for at least 4 weeks before first study dose if applicable
  • Agreement to use contraception or abstain from heterosexual intercourse during treatment and specified time after last dose depending on drug
  • Eastern Cooperative Oncology Group (ECOG) performance status 0, 1, or 2 as specified per cohort
  • Prior treatments as required per cohort, such as docetaxel, abiraterone acetate, enzalutamide, or chemotherapy, with specified treatment durations and intervals
Not Eligible

You will not qualify if you...

  • Prior anticancer monoclonal antibody within 4 weeks before study therapy or unresolved side effects from prior antibody treatment
  • Chemotherapy, targeted therapy, abiraterone, enzalutamide, or radiation therapy within 2 weeks before study therapy or unresolved side effects
  • Participation in another investigational study within 4 weeks before randomization
  • Immunodeficiency or systemic steroid or immunosuppressive therapy within 7 days before randomization
  • Treatment with therapeutic radiopharmaceuticals for prostate cancer within 4 weeks prior to study
  • Active autoimmune disease requiring systemic treatment within past 2 years
  • History or current pneumonitis or interstitial lung disease requiring steroids
  • Prior participation in pembrolizumab or related anti-PD-1/PD-L1 therapy trials
  • Known HIV infection or active Hepatitis B or C
  • Live vaccine within 30 days before first study dose
  • Active central nervous system metastases or carcinomatous meningitis
  • Superscan bone scan preventing evaluation of new metastases
  • Prior solid organ or bone marrow transplant
  • Specific cohort-related exclusions such as seizures, CYP3A4 inhibitor or inducer use, heart conditions, neuropathy, significant fluid accumulation, uncontrolled hypertension, liver disease, and others as detailed per cohort
  • Prior treatment with platinum-containing compounds for Cohort I

AI-Screening

AI-Powered Screening

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Trial Site Locations

Total: 21 locations

1

Call for Information (Investigational Site 2041)

Aurora, Colorado, United States, 80045

Actively Recruiting

2

Call for Information (Investigational Site 2091)

Cleveland, Ohio, United States, 44195

Actively Recruiting

3

Call for Information (Investigational Site 2094)

Portland, Oregon, United States, 97239

Actively Recruiting

4

Call for Information (Investigational Site 0008)

Pittsburgh, Pennsylvania, United States, 15232

Actively Recruiting

5

Call for Information (Investigational Site 0019)

Myrtle Beach, South Carolina, United States, 29572

Actively Recruiting

6

Call for Information (Investigational Site 2090)

Germantown, Tennessee, United States, 38138

Actively Recruiting

7

Call for Information (Investigational Site 0016)

Seattle, Washington, United States, 98109

Actively Recruiting

8

MSD Australia

North Ryde, Australia

Actively Recruiting

9

Merck Canada

Kirkland, Quebec, Canada, H9H 4M7

Actively Recruiting

10

MSD Denmark

Glostrup Municipality, Denmark

Actively Recruiting

11

MSD France

Paris, France

Actively Recruiting

12

MSD Ireland (Human Health) Ltd.

Dublin, Ireland

Actively Recruiting

13

MSD Italia S.r.l.

Rome, Italy

Actively Recruiting

14

MSD Comercializadora, S. de R.L. de C.V.

Mexico City, Mexico

Actively Recruiting

15

Merck Sharp & Dohme BV

Haarlem, Netherlands

Actively Recruiting

16

Merck Sharp & Dohme (New Zealand) Ltd.,

Auckland, New Zealand

Actively Recruiting

17

MSD Polska Sp. Z o.o.

Warsaw, Poland

Actively Recruiting

18

Merck Sharp and Dohme de Espana S.A.

Madrid, Spain

Actively Recruiting

19

MSD Sweden

Stockholm, Sweden

Actively Recruiting

20

Merck Sharp & Dohme Ilaclari Ltd. Sti

Istanbul, Turkey (Türkiye)

Actively Recruiting

21

Merck Sharp & Dohme Ltd.

London, United Kingdom

Actively Recruiting

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Research Team

T

Toll Free Number

CONTACT

How is the study designed?

Study Type

INTERVENTIONAL

Masking

NONE

Allocation

NON_RANDOMIZED

Model

PARALLEL

Primary Purpose

TREATMENT

Number of Arms

12

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