New drug duo aims to shrink Hard-to-Treat prostate tumors

NCT ID NCT03972657

Recruiting now Disease control Sponsor: Regeneron Pharmaceuticals Source: ClinicalTrials.gov ↗

First seen Jun 27, 2026 · Last updated Jul 10, 2026 · Updated 2 times

Summary

This study tests a new drug called REGN5678, given alone or with another drug (cemiplimab), in men with advanced prostate cancer that no longer responds to hormone therapy. The goal is to see if the combination can safely shrink tumors by helping the immune system attack cancer cells. About 345 participants will take part across two phases: first to find the right dose, then to measure tumor response.

What this could mean

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

Active substance: REGN5678 (Nezastomig) and cemiplimab (Libtayo)
What this could lead to: If successful, this could provide a new treatment option for men with advanced prostate cancer that has stopped responding to standard therapies.
What could go wrong: This is an early-phase trial (phase 1/2) with a small number of participants, so safety and effectiveness are not yet proven. Side effects from the immune-boosting drugs could be serious.

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

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Conditions

The condition(s) this trial relates to.

castration-resistant prostate carcinoma clear cell renal carcinoma metastatic prostate carcinoma nonpapillary renal cell carcinoma renal cell carcinoma

As listed by the trial registrant

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

CLEAR CELL RENAL CELL CARCINOMA (CCRCC) METASTATIC CASTRATION-RESISTANT PROSTATE CANCER (MCRPC)

Contacts and locations

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Study contacts

Contact

Phone: •••-•••-•••• Email: •••••@•••••

Locations

Banner MD Anderson Cancer Center
RECRUITING

Gilbert, Arizona, 85234, United States
Columbia University - The Trustees of Columbia University in the City of New York
RECRUITING

New York, New York, 10032, United States
Emily Couric Clinical Cancer Center
RECRUITING

Charlottesville, Virginia, 22908, United States
Henry Ford Health
RECRUITING

Detroit, Michigan, 48202, United States
Icahn School of Medicine at Mount Sinai
RECRUITING

New York, New York, 10029, United States
James Cancer Hospital and Solove Research Institute
RECRUITING

Columbus, Ohio, 43210, United States
John Wayne Cancer Institute (JWCI)
RECRUITING

Santa Monica, California, 90404, United States
Lifespan Cancer Institute
RECRUITING

Providence, Rhode Island, 02903, United States
MD Anderson Cancer Center
RECRUITING

Houston, Texas, 77030, United States
Massachusetts General Hospital
RECRUITING

Boston, Massachusetts, 02114, United States
Mayo Clinic
RECRUITING

Phoenix, Arizona, 85054, United States
Mayo Clinic
RECRUITING

Rochester, Minnesota, 55905, United States
Mayo Clinic Jacksonville
RECRUITING

Jacksonville, Florida, 32224, United States
Moffitt Cancer Center - McKinley Drive
RECRUITING

Tampa, Florida, 33612, United States
Montefiore Medical Center
RECRUITING

New York, New York, 10461, United States
NYU Langone Health Perlmutter Cancer Center
RECRUITING

New York, New York, 10016, United States
Oregon Health & Science University (3485 S. Bond)
RECRUITING

Portland, Oregon, 97239, United States
Providence Portland Medical Center
WITHDRAWN

Portland, Oregon, 97213, United States
Sarah Cannon Research Institute (SCRI)
RECRUITING

Denver, Colorado, 80218, United States
Thomas Jefferson University Hospital
RECRUITING

Philadelphia, Pennsylvania, 19107, United States
University of Arizona
RECRUITING

Tucson, Arizona, 85724, United States
University of Rochester Medical Center (URMC) - Wilmot Cancer Institute (WCI) (James P. Wilmot Cancer Center) - Rochester
RECRUITING

Rochester, New York, 14642, United States
West Virginia University
RECRUITING

Morgantown, West Virginia, 26506, United States
Yale University Hospital
RECRUITING

New Haven, Connecticut, 06510, United States

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