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

About the trial

Sponsor

Regeneron Pharmaceuticals

Tested

REGN5678 (drug), Cemiplimab (drug)

Dates

Started 2019-08-12; completion 2027-11-15

Results posted

Not yet

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. This study is looking at several other research questions, including: 1. Side effects that may be experienced by taking REGN5678 alon…

From ClinicalTrials.gov, last updated 2026-11-04. Full record, eligibility and contacts (opens in a new tab)

Industry funding

Regeneron Pharmaceuticals, Inc. reported $4.2M in research payments for this study in 2025 (543 payments).

Products named: Libtayo

Research payments usually go to hospitals, universities and research sites to run a study, not to the investigators personally. A payment is not evidence of wrongdoing.