Could keytruda tame tough prostate cancers?

NCT ID NCT04104893

Ongoing Disease control Sponsor: VA Office of Research and Development Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This phase 2 study tests pembrolizumab (Keytruda) in 40 men with metastatic castration-resistant prostate cancer that has specific genetic flaws (mismatch repair deficiency or CDK12 inactivation). The goal is to see if the drug can shrink tumors or slow the cancer. Researchers will also study tumor samples to understand why some men respond and others don't.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance: Pembrolizumab (Keytruda), a drug that helps the immune system attack cancer cells
What this could lead to: If successful, this could show that pembrolizumab is an effective treatment for certain men with advanced prostate cancer who have specific genetic changes.
What could go wrong: This is a small, early-phase trial with only 40 participants, so results may not apply to everyone. The drug may not shrink tumors or improve survival, and it can cause immune-related side effects.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for METASTATIC CASTRATION-RESISTANT PROSTATE CANCER are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

castration-resistant prostate carcinoma metastatic prostate carcinoma mismatch repair cancer syndrome 1 prostate cancer

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

METASTATIC CASTRATION-RESISTANT PROSTATE CANCER

Contacts and locations

Locations

Bay Pines VA Healthcare System, Pay Pines, FL

Bay Pines, Florida, 33744, United States
Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA

Philadelphia, Pennsylvania, 19104, United States
Durham VA Medical Center, Durham, NC

Durham, North Carolina, 27705, United States
Hunter Holmes McGuire VA Medical Center, Richmond, VA

Richmond, Virginia, 23249, United States
James J. Peters VA Medical Center, Bronx, NY

The Bronx, New York, 10468, United States
Jesse Brown VA Medical Center, Chicago, IL

Chicago, Illinois, 60612, United States
Manhattan Campus of the VA NY Harbor Healthcare System, New York, NY

New York, New York, 10010, United States
San Francisco VA Medical Center, San Francisco, CA

San Francisco, California, 94121, United States
VA Ann Arbor Healthcare System, Ann Arbor, MI

Ann Arbor, Michigan, 48105, United States
VA Greater Los Angeles Healthcare System, West Los Angeles, CA

West Los Angeles, California, 90073-1003, United States
VA Portland Health Care System, Portland, OR

Portland, Oregon, 97207-2964, United States
VA Puget Sound Health Care System Seattle Division, Seattle, WA

Seattle, Washington, 98108, United States
Washington DC VA Medical Center, Washington, DC

Washington D.C., District of Columbia, 20422-0001, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.