Skip to main content
OpenTrials
Recruiting

NCT Number: NCT04590326

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

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

Recruiting

Interested in participating?

Request Info

Key information

Conditions

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

Age range

18 year and older

Sex eligibility

Female

Study type

Interventional

Phase

Phase 1 / Phase 2

Primary location

Universitair Ziekenhuis Leuven, Leuven, Vlaams-Brabant, Belgium

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Key Inclusion Criteria:

  • 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

Key Exclusion Criteria:

  • 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).

Note: Other protocol-defined Inclusion/Exclusion criteria apply

Treatment and study plan

REGN5668

Drug

Administer per the protocol

cemiplimab

Drug

Administer per the protocol

Other names: REGN2810, Libtayo®

Ubamatamab

Drug

Administer per the protocol

Other names: REGN4018

Sarilumab

Drug

Administer per the protocol

Other names: Kevzara®

Cemiplimab + Fianlimab [Fixed Dose Combination (FDC)]

Drug

Administer per the protocol

Primary outcomes

  1. Incidence of Dose Limiting Toxicities (DLT)

    Time frame: 42 days

    Dose escalation phase, Module 1

  2. Incidence of DLTs

    Time frame: 21 days post combination administration

    Dose escalation phase, Module 2

  3. Incidence of Treatment-Emergent Adverse Events (TEAEs)

    Time frame: Through study completion, up to 5 years

    Primary: Dose escalation phase Secondary: Dose expansion phase

  4. Incidence of Serious Adverse Events (SAEs)

    Time frame: Through study completion, up to 5 years

    Primary: Dose escalation phase Secondary: Dose expansion phase

  5. Incidence of deaths

    Time frame: Through study completion, up to 5 years

    Primary: Dose escalation phase Secondary: Dose expansion phase

  6. 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])

    Time frame: Through study completion, up to 5 years

    Primary: Dose escalation phase Secondary: Dose expansion phase

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

    Time frame: Through study completion, up to 5 years

    Primary: Dose escalation phase

  8. 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)

    Time frame: Through study completion, up to 5 years

    Primary: Dose expansion phase

Secondary outcomes

  1. ORR based on RECIST 1.1

    Time frame: Through study completion, up to 5 years

    Dose escalation phase

  2. Best Overall Response (BOR) based on RECIST 1.1

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  3. Duration Of Response (DOR) based on RECIST 1.1

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  4. Disease Control Rate (DCR) based on RECIST 1.1

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  5. Progression-Free Survival (PFS) based on RECIST 1.1

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  6. Cancer Antigen 125 (CA-125) change from baseline after treatment with REGN5668 in combinations with cemiplimab, cemiplimab + fianlimab, or ubamatamab (separately by cohort and combination)

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  7. Concentration of REGN5668 in serum over time when dosed alone and in combination with cemiplimab, cemiplimab + fianlimab, or ubamatamab

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  8. Presence or absence of anti-drug antibodies against REGN5668

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  9. Presence or absence of anti-drug antibodies against ubamatamab

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  10. Presence or absence of anti-drug antibodies against cemiplimab

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

  11. Presence or absence of anti-drug antibodies against fianlimab

    Time frame: Through study completion, up to 5 years

    Dose escalation and expansion phases

Study contacts

Contact information is provided by the study sponsor or research team.

Clinical Trials Administrator

CONTACT

[email protected]

844-734-6643

Sponsors and collaborators

Lead sponsor

Regeneron Pharmaceuticals

Industry

Registry information

Official study title

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

Important dates

Study start
2020
Primary completion
2027
Study completion
2027
First posted
Oct 19, 2020
Registry last updated
Nov 21, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.