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

Summary

The main purpose of this study is to determine the safety, tolerability (how the body reacts to the drug[s]) and effectiveness (ability to treat the cancer) of REGN5678 (Nezastomig) alone, or in combination with cemiplimab. The study has 2 parts. The goal of Part 1 (dose escalation) is to determine a safe dose(s) of REGN5678 when it is given alone or in combination with cemiplimab. The goal of Part 2 (dose expansion) is to use the REGN5678 drug dose(s) found in Part 1 to see how well REGN5678 alone or in combination with cemiplimab works to shrink tumors.

Shortened from the sponsor's brief summary. View official record on ClinicalTrials.gov

Conditions studied

• Metastatic Castration-Resistant Prostate Cancer (mCRPC)
• Clear Cell Renal Cell Carcinoma (ccRCC)

Eligibility basics and study details

Study type

Interventional

Phase

Phase 1/2

Ages

18 years and older

Sex

All

Healthy volunteers

Not accepted

Sponsor

Regeneron Pharmaceuticals

Last updated on ClinicalTrials.gov

July 9, 2026

These are the basic criteria only. The full inclusion and exclusion criteria are on the official record, and the study team decides who can take part.

US recruiting sites