NCT04590326From ClinicalTrials.govRecruiting

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

A Phase 1/2 Study of REGN5668 (MUC16xCD28, a Costimulatory Bispecific Antibody) Administered in Combination With Other Agents in MUC16 + Malignancies

Ovarian Cancer
Fallopian Tube Cancer
Primary Peritoneal Cancer
Endometrial Cancer

At a glance

Phase: Phase 1
Study type: Interventional
Sponsor: Regeneron Pharmaceuticals
Enrolment target: 612
Started: 8 December 2020
Main results due: 8 November 2028
Study sites: 28
Registry updated: 24 September 2026

Can you take part?

Aged 18 years and over.
Women only.
You need the condition being studied — healthy volunteers are not accepted.

These are the headline rules only. Every study has a longer list, and whether you are eligible is decided by the research team at the site — never by this page.

Read the full eligibility criteria

Key Inclusion Criteria:

1. 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
2. Expansion cohorts only: Has at least 1 lesion that is measurable by RECIST 1.1 as described in the protocol.
3. Has a serum CA-125 level ≥2x ULN (in screening, not applicable to endometrial cohorts)
4. Has adequate organ and bone marrow function as defined in the protocol
5. Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
6. Has a life expectancy of at least 3 months
7. 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

Key Exclusion Criteria:

1. Current or recent (as defined in the protocol) treatment with an investigational agent, systemic biologic therapy, or anti-cancer immunotherapy
2. 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
3. Prior treatment with a Mucin 16 (MUC16)-targeted therapy
4. Ovarian Expansion cohorts only: More than 5 prior lines of systemic therapy
5. 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
6. Has ongoing or recent (within 5 years) evidence of significant autoimmune disease that required treatment with systemic immunosuppressive treatments as defined in the protocol
7. Has untreated or active primary brain tumor, CNS metastases, leptomeningeal disease, or spinal cord compression as defined in the protocol
8. Has history of clinically significant cardiovascular disease as defined in the protocol
9. Has known allergy or hypersensitivity to cemiplimab and/or components of study drug(s).

Note: Other protocol-defined Inclusion/Exclusion criteria apply

What this study is about

In the sponsor’s own words, from the registry.

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

Study sites(28)

City of Hope Comprehensive Cancer Center
Duarte, California, United States
Recruiting
The City of Hope Orange County Lennar Foundation Cancer Center
Irvine, California, United States
Recruiting
Chao Family Comprehensive Cancer Center
Orange, California, United States
Recruiting
H. Lee Moffitt Cancer Center
Tampa, Florida, United States
Completed
Robert H. Lurie Comprehensive Cancer Center of Northwestern University
Chicago, Illinois, United States
Recruiting
University of Chicago Medical Center
Chicago, Illinois, United States
Recruiting
Massachusetts General Hospital
Boston, Massachusetts, United States
Recruiting
Dana Farber Cancer Institute Brookline Avenue
Boston, Massachusetts, United States
Recruiting
Karmanos Cancer Institute
Detroit, Michigan, United States
Recruiting
Memorial Sloan Kettering Cancer Center
New York, New York, United States
Recruiting
The Ohio State University Wexner Medical Center
Columbus, Ohio, United States
Recruiting
Perelman School of Medicine at the University of Pennsylvania
Philadelphia, Pennsylvania, United States
Recruiting
Seattle Cancer Care Alliance at South Lake Union - G3630
Seattle, Washington, United States
Recruiting
Universitair Ziekenhuis Leuven
Leuven, Vlaams-Brabant, Belgium
Recruiting
Centro de Pesquisa em Oncologia PUCRS
Porto Alegre, Rio Grande do Sul, Brazil
Recruiting
Fundacao Pio XII - Hospital de Cancer de Barretos
Barretos, São Paulo, Brazil
Recruiting
Unimed Sorocaba
Sorocaba, São Paulo, Brazil
Recruiting
AC Camargo Cancer Center, Fundacao Antonio Prudente
São Paulo, Brazil
Recruiting
Hopital Lyon Sud
Pierre-Bénite, Auvergne-Rhône, France
Recruiting
Centre Georges Francois Leclerc
Dijon, Bourgogne-Franche-Comté, France
Recruiting
Institut Bergonie
Bordeaux, New Aquitaine, France
Recruiting
Centre Francois Baclesse (CFB)
Caen, Normandy, France
Recruiting
Institut Gustave Roussy
Villejuif, France
Recruiting
Hospital Clinico Universitario Santiago de Compostela
Santiago de Compostela, A Coruna, Spain
Recruiting
Institut Catala dOncologia Girona
Girona, Spain
Recruiting
Ciudad Universitaria
Madrid, Spain
Recruiting
Hospital Universitario Fundacion Jimenez
Madrid, Spain
Recruiting
Hospital Universitario 12 de Octubre Universidad Complutense de Madrid UCM
Madrid, Spain
Recruiting

Showing 28 of 28 sites. 27 of the 28 sites on this study are recruiting right now — a site can stop enrolling while the study as a whole is still open.

Source: ClinicalTrials.gov record NCT04590326. Trialion does not run this study, is not paid to refer anyone to it, and cannot enrol you. Eligibility is always decided by the research team at the site.

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