Study of REGN5678 Nezastomig Alone or With Cemiplimab for Adults With Metastatic Castration-Resistant Prostate Cancer and Clear Cell Renal Cell Carcinoma

What this Trial Is About

Researchers are evaluating the safety, tolerability, and effectiveness of the drug REGN5678 Nezastomig alone or combined with cemiplimab in adults with metastatic castration-resistant prostate cancer mCRPC and other tumors expressing PSMA. This Phase 12 study aims to find safe dosing in the first part and assess tumor shrinkage in the second part. Additional questions include side effects, drug behavior in the body, drug levels in blood, and tumor response through immune activation. Participants receive REGN5678 with or without cemiplimab following specific dosing protocols. The study has two parts dose escalation to identify safe dose levels, and dose expansion to evaluate effectiveness using doses found in part one. Both mCRPC and clear cell renal cell carcinoma ccRCC patients are included, with treatment given in parallel groups. Drugs are administered as per protocol throughout the trial. During the study, participants undergo regular assessments including safety monitoring for adverse events and laboratory abnormalities, blood tests to measure drug concentrations and antibodies, and imaging to evaluate tumor response using RECIST 1.1 criteria. The main outcomes include treatment-emergent adverse events, dose-limiting toxicities, and objective tumor response rates, tracked up to 5 years. The trial duration supports long-term safety and effectiveness evaluation.

A Trial to Find Out if REGN5678 (Nezastomig) is Safe and How Well it Works Alone or in Combination With Cemiplimab for Adult Participants With Metastatic Castration-Resistant Prostate Cancer and Other Tumors