About the study

The primary objective of the study is: Dose Escalation: • To assess the safety, tolerability, and pharmacokinetics (PK) and to determine recommended phase 2 dosing regimen (RP2DR) of REGN4336 separately as monotherapy or in combination with cemiplimab Dose Expansion: • To assess preliminary anti-tumor activity of REGN4336 as monotherapy or in combination with cemiplimab as measured by objective response rate (ORR) per modified Prostate Cancer Working Group (PCWG3) criteria The secondary objectives of the study are: Dose Escalation: • To assess preliminary anti-tumor activity of REGN4336 as monotherapy or in combination with cemiplimab as measured by ORR per modified PCWG3 criteria Dose Expansion: - To characterize the safety profile in each expansion cohort - To characterize the PK of REGN4336 as monotherapy or in combination with cemiplimab In both Dose Escalation and Dose Expansion: - To assess preliminary anti-tumor activity of REGN4336 as monotherapy or in combination with cemiplimab as measured by prostate specific antigen (PSA) decline - To evaluate immunogenicity of REGN4336 in Module 1 and immunogenicity of REGN4336 and cemiplimab in Module 2

Who can take part?

You may be eligible to participate in the study if you meet the following criteria:

Inclusion criteria

1. Histologically or cytologically confirmed adenocarcinoma of the prostate without pure small cell carcinoma
2. Metastatic, castration-resistant prostate cancer (mCRPC) with PSA value at screening ≥4 ng/mL that has progressed within 6 months prior to screening as defined in the protocol
3. Has progressed upon or intolerant to ≥2 lines prior systemic therapy approved in the metastatic and/or castration-resistant setting (in addition to androgen deprivation therapy [ADT]) including at least one second-generation anti-androgen therapy (e.g. abiraterone, enzalutamide, apalutamide, or darolutamide) Key

Exclusion criteria

1. Has received treatment with an approved systemic therapy within 3 weeks of dosing or has not yet recovered (ie, grade ≤1 or baseline) from any acute toxicities
2. Has received any previous systemic biologic therapy within 5 half-lives of first dose of study therapy
3. Has received prior PSMA-targeting therapy
4. Any condition that requires ongoing/continuous corticosteroid therapy (>10 mg prednisone/day or anti-inflammatory equivalent) within 1 week prior to the first dose of study therapy
5. Ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments
6. Encephalitis, meningitis, neurodegenerative disease (with the exception of mild dementia that does not interfere with activities of daily living [ADLs]) or uncontrolled seizures in the year prior to first dose of study therapy
7. Uncontrolled infection with human immunodeficiency virus (HIV), hepatitis B or hepatitis C infection; or diagnosis of immunodeficiency NOTE: Other protocol defined Inclusion/Exclusion Criteria apply

For a full list of inclusion/exclusion criteria, please visit ClinicalTrials.gov

Study locations

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How to apply

Determine if a study site for this clinical trial is near you. Contact the study to apply.