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RecruitingNCT03564340Updated Sep 25, 2026

Study of REGN4018 (Ubamatamab) Administered Alone or in Combination With Cemiplimab in Adult Patients With Recurrent Ovarian Cancer or Other Recurrent Mucin-16 Expressing (MUC16+) Cancers

A Phase 1/2 interventional study of Ubamatamab and Cemiplimab in Recurrent Ovarian Cancer, Recurrent Fallopian Tube Cancer and Recurrent Primary Peritoneal Cancer, sponsored by Regeneron Pharmaceuticals. Recruiting at 54 sites in 10 countries. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-25.

Sponsored by Regeneron Pharmaceuticals · Phase 1/2, Interventional, and Treatment

From the registry’s dates

  • Started May 2018; still recruiting 8 years 5 months later.
Updated Sep 25, 20261 site addedGo to Updates ↓
Phase
Phase 1/2
Study type
Interventional
Enrollment
890
Allocation
Non-randomized
Ages
18 Years and older
Sex
Female
01

Study summary

The main purpose of this study is to:

  • Learn about the safety of ubamatamab and to find out what dose of ubamatamab can be given alone or with cemiplimab to patients with ovarian cancer or cancer of the uterus
  • The study will also look at the levels of ubamatamab and/or cemiplimab in the body and measure how well the body can remove the study drug(s). This is called pharmacokinetics
  • The study will also look at any signs that ubamatamab alone or with cemiplimab can treat recurrent advanced ovarian cancer or cancer of the uterus
  • To find out how safe and tolerable pretreatment is in combination with ubamatamab and to see how well it works to prevent or minimize Cytokine Release Syndrome (CRS)
02

Conditions studied

  • Recurrent Ovarian Cancer
  • Recurrent Fallopian Tube Cancer
  • Recurrent Primary Peritoneal Cancer
  • Recurrent Endometrial Cancer
  • Endometrial Cancer
  • Low-grade Serous Ovarian Cancer
03

In context

Ovarian Neoplasms

3,381 studies on the registry are indexed under Ovarian Neoplasms; 790 are open to participants now.

This study's planned enrollment of 890 is above the median of 54 across 2,548 interventional studies indexed under Ovarian Neoplasms.

Browse Ovarian Neoplasms studies →

Lead sponsor

Regeneron Pharmaceuticals is the lead sponsor of 411 studies on the registry; 90 are open to participants now.

Of its 125 completed or terminated interventional studies of FDA-regulated products, 79 (63%) have results posted.

Browse Regeneron Pharmaceuticals studies →

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
Female
Accepts healthy volunteers
No

Eligibility criteria

Key Inclusion Criteria:

  1. Ovarian Cancer Cohorts Only: Patients with or cytologically confirmed diagnosis of advanced, epithelial ovarian cancer (except carcinosarcoma), primary peritoneal, or fallopian tube cancer who have all of the following:

    1. serum CA-125 level ≥2 x (ULN) (in screening, not required for low-grade serous carcinoma)
    2. has received at least 1 line of platinum-containing therapy or must be platinum-intolerant (applicable for dose escalation and non-randomized dose expansion cohorts)
    3. documented relapse or progression on or after the most recent
    4. no standard therapy options likely to convey clinical benefit
  2. Adequate organ and bone marrow function as defined in the protocol
  3. of at least 3 months
  4. Randomized phase 2 expansion cohort (Ovarian Cancer only): Platinum-resistant ovarian cancer patients who have had 2 to 4 lines of platinum-based therapy as defined in the protocol.

  5. Endometrial Cancer Cohorts Only: histologically confirmed endometrial cancer that has progressed or recurrent after prior anti-Programmed Cell Death Ligand 1 () therapy and platinum-based chemotherapy:

    1. MUC16 positivity of tumor cells ≥25% by immunohistochemistry (IHC), as defined in the protocol
    2. 1-4 prior lines of systemic therapy, as described in the protocol

Key Exclusion Criteria:

  1. Prior treatment with anti-Programmed Cell Death (PD-1)/PD-L1 therapy, as described in the protocol
  2. Ovarian Cancer Expansion cohorts only: More than 4 prior lines of cytotoxic chemotherapy (does not apply to low-grade serous ovarian cancer cohort)
  3. Prior treatment with a MUC16 - targeted therapy
  4. Untreated or active primary brain tumor, central nervous system (CNS) , or spinal cord compression, as described in the protocol
  5. History and/or current cardiovascular disease, as defined in the protocol
  6. Severe and/or uncontrolled hypertension at screening. Patients taking anti-hypertensive medication must be on a stable anti-hypertensive regimen

Note: Other protocol-defined Inclusion/Exclusion Criteria apply

Terms in these criteria, in plain language(6)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Histologically or cytologically confirmed

The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).

Your pathology report is the document that shows this.

ULN (upper limit of normal)

The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.

“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

PD-1, PD-L1 and checkpoint inhibitors

PD-1, PD-L1 and CTLA-4 are proteins that act as brakes on the immune system. Checkpoint inhibitors, such as pembrolizumab or nivolumab, block them so the immune system can attack a cancer.

PD-L1 can also be measured in a tumour sample. Some scores count stained tumour cells only (TPS); others also count certain immune cells (CPS). The study names the score and the minimum it uses.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Sequential assignment
Masking
None (open label)
Enrollment
890 participants (estimated)

Study arms

  • Experimental
    Monotherapy

    REGN4018 administration

    Drug: Ubamatamab · Drug: Sarilumab · Drug: Tocilizumab

  • Experimental
    Combination Therapy

    REGN4018 and cemiplimab administration

    Drug: Ubamatamab · Drug: Cemiplimab

Interventions

  • DrugUbamatamab

    Administered per the protocol

    Also known as: REGN4018

  • DrugCemiplimab

    Administered per the protocol

    Also known as: REGN2810, Libtayo®

  • DrugSarilumab

    Administered per the protocol

    Also known as: Kevzara®, REGN88, SAR153191

  • DrugTocilizumab

    Administered per the protocol

    Also known as: ACTEMRA®, Biosimilar

06

What researchers measure

Primary outcomes

  1. Number of participants with Dose-limiting toxicity (DLTs) for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: From Cycle 1, Day 1 up to 35 days

  2. Number of participants with DLTs for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: From Cycle 2, Day 1 up to 21 days

  3. Number of participants with Treatment-emergent adverse event (TEAE)s (including immune-related adverse events (imAEs)) for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  4. Number of participants with TEAEs (including imAEs) for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  5. Number of participants with serious adverse events (SAEs) for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  6. Number of participants with SAEs for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  7. Number of deaths for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  8. Number of deaths for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  9. Number of participants with laboratory abnormalities (grade 3 or higher per Common Terminology Criteria for Adverse Events [CTCAE]) for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  10. Number of participants with laboratory abnormalities (grade 3 or higher per CTCAE) for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  11. Concentration of ubamatamab in serum over time for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  12. Concentration of ubamatamab in serum over time for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  13. Objective response rate (ORR) defined by Response Evaluation Criteria in Solid Tumors (RECIST 1.1) for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  14. ORR defined by RECIST 1.1 for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

Secondary outcomes

  1. ORR based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation Phase

    Time frame: Up to 2 years

  2. ORR based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation Phase

    Time frame: Up to 2 years

  3. Number of participants with TEAEs (including imAEs) for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  4. Number of participants with TEAEs (including imAEs) for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  5. Number of participants with SAEs for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  6. Number of participants with SAEs for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  7. Number of deaths for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  8. Number of deaths for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  9. Number of participants with laboratory abnormalities (grade 3 or higher per CTCAE) for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  10. Number of participants with laboratory abnormalities (grade 3 or higher per CTCAE) for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  11. Concentration of ubamatamab in serum over time for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  12. Concentration of ubamatamab in serum over time for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  13. Change from baseline in quality of life (QoL) as measured by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 GHS/QoL score for ubamatamab monotherapy

    Dose Expansion Phase The EORTC-QLQ-C30 is a 30-item subject self-report questionnaire composed of both multi-item and single scales, including global health status/quality of life, functional Scales (physical, role, emotional, cognitive, and social) , symptom scales (fatigue, nausea and vomiting, and pain), and 6 single items (dyspnea, insomnia, appetite loss, constipation, diarrhea, and financial difficulties). Participants rate items on a 4-point scale, with 1 as "not at all" and 4 as "very much."

    Time frame: Baseline up to 2 years

  14. Change from baseline in quality of life (QoL) as measured by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ)-C30 GHS/QoL score for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Baseline up to 2 years

  15. Change from baseline in physical functioning as measured by the EORTC QLQ-C30 physical functioning score for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Baseline up to 2 years

  16. Change from baseline in physical functioning as measured by the EORTC QLQ-C30 physical functioning score for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Baseline up to 2 years

  17. Change from baseline in abdominal symptoms as measured by the Measure of Ovarian Symptoms and Treatment (MOST)-Abdominal index score for ubamatamab monotherapy

    Dose Expansion Phase excluding the Endometrial Cancer Cohort The MOST-24 is a 24-item questionnaire used to measure the impact of chemotherapy on symptoms (21 items) and well-being (3 items). The expected questionnaire completion time is less than 5 minutes. The prevalence of each MOST item at assessment time points can be summarized by providing the mean, standard deviation and proportions based on the MOST response format, a numeric rating scale with integers from zero to 10, with five verbal anchors: 'No trouble at all' (0), 'Mild' (1-3), 'Moderate' (4-6), 'Severe' (7-10), and 'Worst I can imagine' (10).

    Time frame: Baseline up to 2 years

  18. Change from baseline in abdominal symptoms as measured by the MOST-Abdominal index score for ubamatamab with cemiplimab

    Dose Expansion Phase Not applicable to Endometrial Cancer Cohort

    Time frame: Baseline up to 2 years

  19. Time to deterioration in GHS/QoL for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  20. Time to deterioration in GHS/QoL for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  21. Time to deterioration in physical functioning for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  22. Time to deterioration in physical functioning for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  23. Time to deterioration in abdominal symptoms for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Up to 2 years

  24. Time to deterioration in abdominal symptoms for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Up to 2 years

  25. Change from baseline in QoL as measured by EQ-5D for ubamatamab monotherapy

    Dose Expansion Phase

    Time frame: Baseline up to 2 years

  26. Change from baseline in QoL as measured by EQ-5D for ubamatamab with cemiplimab

    Dose Expansion Phase

    Time frame: Baseline up to 2 years

  27. ORR based on iRECIST for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  28. ORR based on iRECIST for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  29. Best overall response (BOR) based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  30. BOR based on iRECIST for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  31. BOR based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  32. BOR based on iRECIST for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  33. Duration of response (DOR) based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  34. DOR based on iRECIST for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  35. DOR based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  36. DOR based on iRECIST for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  37. Disease control rate based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  38. Disease control rate based on iRECIST for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  39. Disease control rate based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  40. Disease control rate based on iRECIST for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  41. Complete response (CR) rate based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  42. CR rate based on iRECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  43. CR rate based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  44. CR rate based on iRECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  45. Progression-free survival (PFS) based on RECIST 1.1 for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  46. PFS based on iRECIST for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  47. PFS based on RECIST 1.1 for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  48. PFS based on iRECIST for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  49. Cancer antigen-125 (CA-125) response for ubamatamab monotherapy

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

  50. CA-125 response for ubamatamab with cemiplimab

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

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

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

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

    Dose Escalation and Dose Expansion Phases

    Time frame: Up to 2 years

07

Study locations

49 of 54 sites recruiting
08

References and documents

Publications

  • Zhu M, Madia P, Crawford A, Brouwer-Visser J, Krueger P, Haber L, Peterman M, Uldrick TS, Miller E, Davis JD, Retter MW. Translational findings support regimen selection for first-in-human study of ubamatamab (MUC16 x CD3 bispecific antibody) in patients with recurrent ovarian cancer. Clin Transl Sci. 2024 Dec;17(12):e70082. doi: 10.1111/cts.70082. PubMed 39652449 ↗

Individual participant data

Plan to share: Yes — All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing.

Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, 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

Data sharing details ↗ · vivli.org

09

Updates

1 registry update since Sep 25, 2026
Sites
1 site added
Show site
  • The University of Texas MD Anderson Cancer Center · Houston, United States
Sep 25, 2026
Show all 1 update
  1. Sep 25, 2026
    1 site added
    Show site
    • The University of Texas MD Anderson Cancer Center · Houston, United States

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT03564340
Lead sponsor
Regeneron Pharmaceuticals
Responsible party
Sponsor
First posted
Jun 20, 2018
Start date
May 21, 2018
Primary completion
May 10, 2027 (estimated)
Completion
May 10, 2027 (estimated)
Last update
Sep 25, 2026

Study contacts

Clinical Trials Administrator
Contact
clinicaltrials@regeneron.com
844-734-6643
Clinical Trial Management
study director · Regeneron Pharmaceuticals

Oversight

Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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