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

NCT ID: NCT03972657

Last Updated: 2025-11-06

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

PHASE1/PHASE2

Total Enrollment

345 participants

Study Classification

INTERVENTIONAL

Study Start Date

2019-08-12

Study Completion Date

2027-11-15

Brief Summary

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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

Detailed Description

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Conditions

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

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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mCRPC - dose escalation cohort

REGN5678 with or without cemiplimab

Group Type EXPERIMENTAL

REGN5678

Intervention Type DRUG

Administered as per the protocol

Cemiplimab

Intervention Type DRUG

Administered as per the protocol

mCRPC - dose expansion cohort

REGN5678 with or without cemiplimab

Group Type EXPERIMENTAL

REGN5678

Intervention Type DRUG

Administered as per the protocol

ccRCC - dose escalation cohort

REGN5678 with or without cemiplimab

Group Type EXPERIMENTAL

REGN5678

Intervention Type DRUG

Administered as per the protocol

Cemiplimab

Intervention Type DRUG

Administered as per the protocol

ccRCC - dose expansion cohort

REGN5678 with or without cemiplimab

Group Type EXPERIMENTAL

REGN5678

Intervention Type DRUG

Administered as per the protocol

Interventions

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REGN5678

Administered as per the protocol

Intervention Type DRUG

Cemiplimab

Administered as per the protocol

Intervention Type DRUG

Other Intervention Names

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Nezastomig REGN2810 LIBTAYO

Eligibility Criteria

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Inclusion Criteria

mCRPC cohorts (men):

1. Men with histologically or cytologically confirmed adenocarcinoma of the prostate without pure small cell carcinoma.
2. PSA value at screening ≥4 ng/mL that has progressed within 6 months prior to screening as defined in the protocol.
3. Has received ≥2 lines prior systemic therapy approved in the metastatic and/or castration-resistant setting (in addition to Androgen Deprivation Therapy \[ADT\]) including at least:

1. one second-generation anti-androgen therapy (eg, abiraterone, enzalutamide, apalutamide, or darolutamide)
2. 177Lu-PSMA-617 radiotherapy, or another lutetium-based PSMA targeted radioligand, as described in the protocol

ccRCC cohorts (men and women):

1. Histologically or cytologically confirmed RCC with a clear-cell component.
2. Diagnosis of metastatic ccRCC with at least one measurable lesion via RECIST 1.1 criteria
3. Has progressed on or after ≥1 line prior systemic therapy approved in the metastatic setting. Prior treatment must include an anti-Programmed Death-1 (receptor) \[PD-1\]/Programmed Death-Ligand 1 (PD-L1) therapy and either ipilimumab and/or a tyrosine kinase inhibitor

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, as described in the protocol
2. Has received any previous systemic biologic therapy within 5 half-lives of first dose of study therapy, as described in the protocol
3. Has received prior PSMA-targeting therapy with the exception of a PSMA targeting radioligand (eg. 177Lu-PSMA-617) in mCRPC
4. Dose Escalation: Has had prior anti-cancer immunotherapy (other than sipuleucel-T) within 5 half-lives prior to study therapy.
5. Dose Expansion (mCRPC only): Has had prior anti-cancer immunotherapy, as described in the protocol
6. 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
7. Ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments, as described in the protocol
8. 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
9. Uncontrolled infection with Human Immunodeficiency Virus (HIV), hepatitis B or hepatitis C infection; or diagnosis of immunodeficiency
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Regeneron Pharmaceuticals

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Principal Investigators

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Clinical Trials Management

Role: STUDY_DIRECTOR

Regeneron Pharmaceuticals

Locations

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Banner MD Anderson Cancer Center

Gilbert, Arizona, United States

Site Status RECRUITING

Mayo Clinic

Phoenix, Arizona, United States

Site Status RECRUITING

University of Arizona

Tucson, Arizona, United States

Site Status RECRUITING

John Wayne Cancer Institute (JWCI)

Santa Monica, California, United States

Site Status RECRUITING

Sarah Cannon Research Institute (SCRI)

Denver, Colorado, United States

Site Status RECRUITING

Yale University Hospital

New Haven, Connecticut, United States

Site Status RECRUITING

Mayo Clinic Jacksonville

Jacksonville, Florida, United States

Site Status RECRUITING

Moffitt Cancer Center - McKinley Drive

Tampa, Florida, United States

Site Status RECRUITING

Massachusetts General Hospital

Boston, Massachusetts, United States

Site Status RECRUITING

Mayo Clinic

Rochester, Minnesota, United States

Site Status RECRUITING

NYU Langone Health Perlmutter Cancer Center

New York, New York, United States

Site Status RECRUITING

Icahn School of Medicine at Mount Sinai

New York, New York, United States

Site Status RECRUITING

Columbia University - The Trustees of Columbia University in the City of New York

New York, New York, United States

Site Status RECRUITING

Montefiore Medical Center

New York, New York, United States

Site Status RECRUITING

University of Rochester Medical Center (URMC) - Wilmot Cancer Institute (WCI) (James P. Wilmot Cancer Center) - Rochester

Rochester, New York, United States

Site Status RECRUITING

Providence Portland Medical Center

Portland, Oregon, United States

Site Status WITHDRAWN

Oregon Health & Science University (3485 S. Bond)

Portland, Oregon, United States

Site Status RECRUITING

Thomas Jefferson University Hospital

Philadelphia, Pennsylvania, United States

Site Status RECRUITING

Lifespan Cancer Institute

Providence, Rhode Island, United States

Site Status RECRUITING

MD Anderson Cancer Center

Houston, Texas, United States

Site Status RECRUITING

Emily Couric Clinical Cancer Center

Charlottesville, Virginia, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Clinical Trials Administrator

Role: CONTACT

844-734-6643

Other Identifiers

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R5678-ONC-1879

Identifier Type: -

Identifier Source: org_study_id

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