OncoMatch/Clinical Trials/NCT03972657
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
Is NCT03972657 recruiting? Yes, currently enrolling (May 2026). This Phase 1/2 trial studies multiple treatments including REGN5678 and Cemiplimab for metastatic castration-resistant prostate cancer (mcrpc).
Treatment: REGN5678 · Cemiplimab — 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 alone or in combination with cemiplimab 2. How REGN5678 alone or in combination with cemiplimab works in the body 3. How much REGN5678 and/or cemiplimab are present in the blood 4. To see if REGN5678 alone or in combination with cemiplimab works to reduce the size of the tumor by helping the immune system destroy the tumor
Check if I qualifyExtracted eligibility criteria
Cancer type
Prostate Cancer
Renal Cell Carcinoma
Disease stage
Metastatic disease required
Prior therapy
Must have received: second-generation antiandrogen (abiraterone, enzalutamide, apalutamide, darolutamide) — metastatic and/or castration-resistant
one second-generation anti-androgen therapy (eg, abiraterone, enzalutamide, apalutamide, or darolutamide)
Must have received: PSMA-targeting radioligand (177Lu-PSMA-617) — metastatic and/or castration-resistant
177Lu-PSMA-617 radiotherapy, or another lutetium-based PSMA targeted radioligand
Must have received: anti-PD-1 therapy — metastatic
Prior treatment must include an anti-Programmed Death-1 (receptor) [PD-1]/Programmed Death-Ligand 1 (PD-L1) therapy
Must have received: anti-CTLA-4 therapy (ipilimumab) — metastatic
either ipilimumab and/or a tyrosine kinase inhibitor
Must have received: tyrosine kinase inhibitor — metastatic
either ipilimumab and/or a tyrosine kinase inhibitor
Cannot have received: systemic therapy
Has received treatment with an approved systemic therapy within 3 weeks of dosing
Cannot have received: systemic biologic therapy
Has received any previous systemic biologic therapy within 5 half-lives of first dose of study therapy
Cannot have received: PSMA-targeting therapy
Exception: PSMA targeting radioligand (eg. 177Lu-PSMA-617) in mCRPC
Has received prior PSMA-targeting therapy with the exception of a PSMA targeting radioligand (eg. 177Lu-PSMA-617) in mCRPC
Cannot have received: anti-cancer immunotherapy
Exception: sipuleucel-T
Dose Escalation: Has had prior anti-cancer immunotherapy (other than sipuleucel-T) within 5 half-lives prior to study therapy
Cannot have received: anti-cancer immunotherapy
Dose Expansion (mCRPC only): Has had prior anti-cancer immunotherapy, as described in the protocol
Structured fields extracted by AI. May contain errors — verify against the official protocol.
US trial sites
- Banner MD Anderson Cancer Center · Gilbert, Arizona
- Mayo Clinic · Phoenix, Arizona
- University of Arizona · Tucson, Arizona
- John Wayne Cancer Institute (JWCI) · Santa Monica, California
- Sarah Cannon Research Institute (SCRI) · Denver, Colorado
Showing up to 5 US sites. See all sites on ClinicalTrials.gov →
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