REGN4336 and REGN5678 for Advanced Prostate Cancer

This study is looking at two investigational immunotherapy drugs, REGN4336 and REGN5678, for men with advanced prostate cancer that has spread (metastatic) and is no longer responding to standard hormone therapy (castration-resistant). Researchers want to find out if REGN4336 is safe and how well it works, both alone and when given with REGN5678. The first part of the study will determine a safe dose. To join, you must be an adult male with this type of prostate cancer that has progressed recently, and your PSA level must be at least 4 ng/mL. The study will track side effects and how well the drugs shrink tumors over time.

Study design
This is an interventional study planning to enroll 228 adult male participants. It has two parts, with the first part focused on finding a safe dose of the drugs.
What's involved
Not specified in the trial record.
Compensation
Not stated in the trial record.
Follow-up
Participants will be monitored for side effects for up to 5 years after treatment.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT05125016

A Trial to Find Out if REGN4336 is Safe and How Well it Works Alone and in Combination With REGN5678 for Adult Participants With Advanced Prostate Cancer

Recruiting
PHASE1Ages 18+InterventionalTreatment
Regeneron Pharmaceuticals
~228 participants
Updated 2026-05-05 on ClinicalTrials.gov
What's tested:REGN4336REGN5678

At a glance

Recruiting sites
13 of 14 listed sites are recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Incidence of Dose-Limiting Toxicities (DLTs)
Measured over up to 21 days
+6 more outcomes measured
Metastatic Castration-resistant Prostate Cancer
14 sites across 11 states
Pennsylvania4
California1
Connecticut1
Kentucky1
Maryland1
New Jersey1
New York1
North Carolina1
  • Clinical Trial Management · STUDY_DIRECTOR · Regeneron Pharmaceuticals

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  • Incidence of Dose-Limiting Toxicities (DLTs)up to 21 days

    Dose escalation

  • Incidence and severity of Treatment-Emergent Adverse Events (TEAEs)Up to 5 years

    Dose escalation

  • Incidence and severity of Serious Adverse Events (SAEs)Up to 5 years

    Dose escalation

  • Incidence and severity of Adverse Events of Special Interest (AESIs)Up to 5 years

    Dose escalation

  • REGN4336 monotherapy concentrations in serumUp to 5 years

    Dose escalation

  • REGN4336 concentrations in serum in combination with REGN5678Up to 5 years

    Dose escalation

  • Composite Response Rate (CRR) of ≥50% decline of prostate specific antigen (PSA) and/or confirmed radiographic response of complete response (CR) or partial response (PR)Up to 5 years

    Dose expansion