A Study to Find Out How Safe REGN5668 is and How Well it Works In Adult Women When Given With Either Cemiplimab, or Cemiplimab + Fianlimab, or Ubamatamab

NCT04590326 | Recruiting Phase 1 FDA Drug

• 2 other identifiers: R5668-ONC-19382022-501904-83-00
• Study Type: interventional
• Target: 612
• Locations: 4 countries
• Sites: 24

Brief Summary

This study is researching an investigational drug called REGN5668 :

• alone or,
• combined with cemiplimab (also known as REGN2810) or,
• combined with both cemiplimab and fianlimab (also known as REGN3767), or
• combined with ubamatamab (also known as REGN4018), with or without sarilumab. The main purposes of this study are to:
• Learn about the safety and profile of any side effects from the study drugs and to determine the highest, safe dose that can be given to participants with ovarian cancer or cancer of the uterus
• Look for signs that the study drugs can treat ovarian cancer or cancer of the uterus This study has 2 parts. The purpose of Part 1 (Escalation) is to find the highest, safe dose of the study drug(s). The purpose of Part 2 (Expansion) is to use the doses chosen in Part 1. Participants with cancer of the uterus will only participate in Part 2. The study is looking at several other research questions, including:
• Side effects that may be experienced by participants taking REGN5668 alone and/or in combination with cemiplimab, cemiplimab and fianlimab, or ubamatamab
• How REGN5668 works in the body either alone and/or in combination with cemiplimab, cemiplimab and fianlimab, or ubamatamab
• How much of the study drugs (REGN5668, cemiplimab, fianlimab, ubamatamab) are in the blood
• To see if REGN5668 in combination with cemiplimab, cemiplimab and fianlimab, or ubamatamab works to treat cancer

Conditions

Ovarian Cancer; Fallopian Tube Cancer; Primary Peritoneal Cancer; Endometrial Cancer

Keywords

Progressive; Recurrent; Refractory; Serum CA-125 levels >= 2x ULN

Outcome Measures

Primary Outcomes (8)

• Incidence of Dose Limiting Toxicities (DLT)

  Dose escalation phase, Module 1

  42 days

• Incidence of DLTs

  Dose escalation phase, Module 2

  21 days post combination administration

• Incidence of Treatment-Emergent Adverse Events (TEAEs)

  Primary: Dose escalation phase Secondary: Dose expansion phase

  Through study completion, up to 5 years

• Incidence of Serious Adverse Events (SAEs)

  Primary: Dose escalation phase Secondary: Dose expansion phase

  Through study completion, up to 5 years

• Incidence of deaths

  Primary: Dose escalation phase Secondary: Dose expansion phase

  Through study completion, up to 5 years

• Incidence of laboratory abnormalities (Grade 3 or higher per National Cancer Institute Common Terminology Criteria for Adverse Events [NCI-CTCAE] version 5.0 [v5.0])

  Primary: Dose escalation phase Secondary: Dose expansion phase

  Through study completion, up to 5 years

• Concentrations of REGN5668 in serum when dosed alone and in combination with cemiplimab or ubamatamab

  Primary: Dose escalation phase

  Through study completion, up to 5 years

• Objective Response Rate (ORR) defined by Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 (Eisenhauer, 2009) of REGN5668 in combination with cemiplimab, cemiplimab + fianlimab, or ubamatamab (separately by cohort and combination)

  Primary: Dose expansion phase

  Through study completion, up to 5 years

Secondary Outcomes (11)

• ORR based on RECIST 1.1

  Through study completion, up to 5 years

• Best Overall Response (BOR) based on RECIST 1.1

  Through study completion, up to 5 years

• Duration Of Response (DOR) based on RECIST 1.1

  Through study completion, up to 5 years

• Disease Control Rate (DCR) based on RECIST 1.1

  Through study completion, up to 5 years

• Progression-Free Survival (PFS) based on RECIST 1.1

  Through study completion, up to 5 years

Study Arms (2)

Module 1

EXPERIMENTAL

REGN5668 in combination with cemiplimab, or cemiplimab + fianlimab

Drug: REGN5668; Drug: Cemiplimab; Drug: Cemiplimab + Fianlimab [Fixed Dose Combination (FDC)]

Module 2

EXPERIMENTAL

REGN5668 and ubamatamab

Drug: REGN5668; Drug: Ubamatamab; Drug: Sarilumab

Interventions

REGN5668 DRUG

Administer per the protocol

Module 1; Module 2

Cemiplimab DRUG

Administer per the protocol

Also known as: REGN2810, Libtayo®

Module 1

Ubamatamab DRUG

Administer per the protocol

Also known as: REGN4018

Module 2

Sarilumab DRUG

Administer per the protocol

Also known as: Kevzara®

Module 2

Cemiplimab + Fianlimab [Fixed Dose Combination (FDC)] DRUG

Administer per the protocol

Module 1

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Ovarian Cancer Cohorts Only: Has histologically or cytologically confirmed diagnosis of advanced epithelial ovarian cancer (except carcinosarcoma), primary peritoneal, or fallopian tube cancer that has received at least 1 line of platinum-based systemic therapy as defined in the protocol
• Expansion cohorts only: Has at least 1 lesion that is measurable by RECIST 1.1 as described in the protocol.
• Has a serum CA-125 level ≥2x ULN (in screening, not applicable to endometrial cohorts)
• Has adequate organ and bone marrow function as defined in the protocol
• Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
• Has a life expectancy of at least 3 months
• Endometrial Cancer Cohorts Only: histologically confirmed endometrial cancer that has progressed or recurrent after prior anti-PD-1 therapy and platinum-based chemotherapy as described in the protocol

You may not qualify if:

• Current or recent (as defined in the protocol) treatment with an investigational agent, systemic biologic therapy, or anti-cancer immunotherapy
• Has had another malignancy within the last 5 years that is progressing, requires active treatment, or has a high likelihood of recurrence as defined in the protocol
• Prior treatment with a Mucin 16 (MUC16)-targeted therapy
• Ovarian Expansion cohorts only: More than 5 prior lines of systemic therapy
• Has any condition that requires ongoing/continuous corticosteroid therapy as defined in the protocol within 1 week prior to the first dose of study drug
• Has ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments as defined in the protocol
• Has untreated or active primary brain tumor, CNS metastases, leptomeningeal disease, or spinal cord compression as defined in the protocol
• Has history of clinically significant cardiovascular disease as defined in the protocol
• Has known allergy or hypersensitivity to cemiplimab and/or components of study drug(s).

Sponsors & Collaborators

• Regeneron Pharmaceuticals: lead

Study Sites (24)

City of Hope Comprehensive Cancer Center

Duarte, California, 91010, United States

RECRUITING

The City of Hope Orange County Lennar Foundation Cancer Center

Irvine, California, 92618, United States

RECRUITING

Chao Family Comprehensive Cancer Center

Orange, California, 92868, United States

RECRUITING

H. Lee Moffitt Cancer Center

Tampa, Florida, 33612, United States

COMPLETED

Robert H. Lurie Comprehensive Cancer Center of Northwestern University

Chicago, Illinois, 60611, United States

RECRUITING

University of Chicago Medical Center

Chicago, Illinois, 60637, United States

RECRUITING

Massachusetts General Hospital

Boston, Massachusetts, 02114, United States

RECRUITING

Dana Farber Cancer Institute Brookline Avenue

Boston, Massachusetts, 02215, United States

RECRUITING

Karmanos Cancer Institute

Detroit, Michigan, 48201, United States

RECRUITING

Memorial Sloan Kettering Cancer Center

New York, New York, 10065, United States

RECRUITING

The Ohio State University Wexner Medical Center

Columbus, Ohio, 43210, United States

RECRUITING

Perelman School of Medicine at the University of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

RECRUITING

Seattle Cancer Care Alliance at South Lake Union - G3630

Seattle, Washington, 98109, United States

RECRUITING

Universitair Ziekenhuis Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

RECRUITING

Hopital Lyon Sud

Pierre-Bénite, Auvergne-Rhône, 69310, France

RECRUITING

Centre Georges Francois Leclerc

Dijon, Bourgogne-Franche-Comté, 21000, France

RECRUITING

Centre Francois Baclesse (CFB)

Caen, Normandy, 14076, France

RECRUITING

Institut Bergonie

Bordeaux, Nouvelle-Aquitaine, 33076, France

RECRUITING

Institut Gustave Roussy

Villejuif, 94805, France

RECRUITING

Hospital Clinico Universitario Santiago de Compostela

Santiago de Compostela, A Coruna, 15706, Spain

RECRUITING

Institut Catala dOncologia Girona

Girona, 17007, Spain

RECRUITING

Ciudad Universitaria

Madrid, 28040, Spain

RECRUITING

Hospital Universitario Fundacion Jimenez

Madrid, 28040, Spain

RECRUITING

Hospital Universitario 12 de Octubre Universidad Complutense de Madrid UCM

Madrid, 28041, Spain

RECRUITING

MeSH Terms

Conditions

Ovarian Neoplasms; Fallopian Tube Neoplasms; Endometrial Neoplasms; Recurrence

Interventions

cemiplimab; sarilumab

Condition Hierarchy (Ancestors)

Endocrine Gland Neoplasms; Neoplasms by Site; Neoplasms; Ovarian Diseases; Adnexal Diseases; Genital Diseases, Female; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Genital Neoplasms, Female; Urogenital Neoplasms; Genital Diseases; Endocrine System Diseases; Gonadal Disorders; Fallopian Tube Diseases; Uterine Neoplasms; Uterine Diseases; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Clinical Trial Management

  Regeneron Pharmaceuticals

  STUDY DIRECTOR

Central Study Contacts

Clinical Trials Administrator

CONTACT

844-734-6643; clinicaltrials@regeneron.com

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: October 9, 2020
• First Posted: October 19, 2020
• Study Start: December 8, 2020
• Primary Completion (Estimated): March 25, 2027
• Study Completion (Estimated): November 30, 2027
• Last Updated: November 21, 2025

Record last verified: 2025-08

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR, ANALYTIC CODE
• Time Frame: When Regeneron has: * received marketing authorization from major health authorities (e.g., FDA, European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc.) for the product and indication or has globally discontinued development of the product for all indications on or after April 2020 and has no plans for future development * made the study results publicly available (e.g., scientific publication, scientific conference, clinical trial registry) * the legal authority to share the data, and * ensured the ability to protect participant privacy
• Access Criteria: Qualified researchers can submit a proposal for access to individual patient or aggregate level data from a Regeneron-sponsored clinical trial through Vivli. Regeneron's Independent Research Request Evaluation Criteria can be found at: https://www.regeneron.com/sites/default/files/Regeneron-External-Data-Sharing-Policy-and-Independent-Research-Request-Evaluation-Criteria.pdf

Locations

FR (5); US (13); BE (1); ES (5)