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Recruiting Phase 1, Phase 2 NCT04590326

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

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Clinical Trial Summary
NCT ID NCT04590326
Status Recruiting
Phase Phase 1, Phase 2
Sponsor Regeneron Pharmaceuticals
Condition Ovarian Cancer
Study Type INTERVENTIONAL
Enrollment 612 participants
Start Date 2020-12-08
Primary Completion 2027-03-25

Eligibility & Interventions

Sex Female only
Min Age 18 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
REGN5668CemiplimabUbamatamab

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

Phase 1 is the earliest stage of human testing — safety and dosage are the primary focus. Visits are frequent and medical supervision is intensive. You will be among the first people to receive this treatment.

This trial targets 612 participants in total. It began in 2020-12-08 with a primary completion date of 2027-03-25.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

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

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

Contact & Investigator

Central Contact

Clinical Trials Administrator

✉ clinicaltrials@regeneron.com

📞 844-734-6643

Principal Investigator

Clinical Trial Management

STUDY DIRECTOR

Regeneron Pharmaceuticals

Frequently Asked Questions

Who can join the NCT04590326 clinical trial?

This trial is open to female participants only, aged 18 Years or older, studying Ovarian Cancer. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT04590326 trial and what does that mean for participants?

Phase 1 trials are the first stage of human testing. The primary goal is to assess safety and determine appropriate dosage levels. Participants are closely monitored. These trials typically involve a small number of volunteers.

Is NCT04590326 currently recruiting?

Yes, NCT04590326 is actively recruiting participants. Contact the research team at clinicaltrials@regeneron.com for enrollment information.

Where is the NCT04590326 trial being conducted?

This trial is being conducted at Duarte, United States, Irvine, United States, Orange, United States, Tampa, United States and 11 additional locations.

Who is sponsoring the NCT04590326 clinical trial?

NCT04590326 is sponsored by Regeneron Pharmaceuticals. The principal investigator is Clinical Trial Management at Regeneron Pharmaceuticals. The trial plans to enroll 612 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: April 2026  ·  Data Methodology