REGN7257 in Adult Patients With Severe Aplastic Anemia That Is Refractory to or Relapsed on Immunosuppressive Therapy

NCT04409080 | Terminated Phase 1 FDA Drug

• 3 other identifiers: R7257-RAA-19472020-002031-292023-508601-24-00
• Study Type: interventional
• Target: 17
• Locations: 4 countries
• Sites: 10

Brief Summary

This study is researching an experimental drug called REGN7257 (called "study drug"). The study is focused on patients who have severe aplastic anemia (SAA), a disease of the bone marrow resulting in an impairment of the production of blood cells. The main purpose of this two-part study (Part A and Part B) is to test how safe and tolerable REGN7257 is in patients with SAA in which other Immunosuppressive therapies (ISTs) have not worked well. The study is looking at several other research questions to better understand the following properties of REGN7257:

• Side effects that may be experienced by participants taking REGN7257
• How REGN7257 works in the body
• How much REGN7257 is present in blood after dosing
• If REGN7257 works to raise levels of certain blood counts after treatment
• How quickly REGN7257 works to raise levels of certain blood counts
• In patients for whom REGN7257 works to raise levels of certain blood counts after treatment, how many continue to show such a response throughout the study
• If REGN7257 works to lower the number of platelet and red blood cell transfusions needed
• How REGN7257 changes immune cell counts and composition
• How the body reacts to REGN7257 and if it produces proteins that bind to REGN7257 (this would be called the formation of anti-drug antibodies \[ADA\])

Conditions

Severe Aplastic Anemia (SAA)

Keywords

Immunosuppressive therapy (IST); Refractory; Relapsed

Outcome Measures

Primary Outcomes (6)

• Incidence of adverse events (AEs)

  Part A

  12 months post-treatment, approximately 52 weeks

• Incidence of serious adverse events (SAEs)

  Part A

  12 months post-treatment, approximately 52 weeks

• Incidence and severity of treatment-emergent adverse events (TEAEs)

  Part A

  12 months post-treatment, approximately 52 weeks

• Incidence of serious adverse events (SAEs)

  Part B

  Through the end of study visit, approximately 78 weeks

• Incidence and severity of treatment-emergent adverse events (TEAEs)

  Part B

  Through the end of study visit, approximately 78 weeks

• Overall response rate (ORR)

  Part B

  At 6 months, approximately 26 weeks

Secondary Outcomes (33)

• ORR

  At 3 months, approximately 12 weeks

• Complete response (CR)

  At 3 months, approximately 12 weeks

• Partial response (PR)

  At 3 months, approximately 12 weeks

• Time to best response

  Up to 12 months

• Time to best response

  Up to 18 months

Study Arms (2)

Part A

EXPERIMENTAL

Part A: Single ascending dose (SAD) escalation cohorts

Drug: REGN7257

Part B

EXPERIMENTAL

Part B: Multiple REGN7257 dosages.

Drug: REGN7257

Interventions

REGN7257 DRUG

Administered by intravenous (IV) infusion, in Part A and B.

Part A; Part B

Eligibility Criteria

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

You may qualify if:

• Part A: SAA that is IST-refractory or IST-relapsed, as defined in the protocol
• Part B: SAA that is IST-relapsed, as defined in the protocol
• Hematopoietic stem cell transplantation (HSCT) is not available or suitable as a treatment option or has been refused by the patient
• Adequate hepatic and renal function as defined in the protocol

You may not qualify if:

• Diagnosis of Fanconi anemia or other congenital bone marrow failure syndrome as defined in the protocol
• Evidence of myelodysplastic syndrome as defined in the protocol
• Paroxysmal nocturnal hemoglobinuria (PNH) with evidence of clinically significant hemolysis (eg, treatment indicated) or history of PNH-associated thrombosis
• Treatment with a T cell-depleting agent (eg, ATG or alemtuzumab) within 6 months prior to dosing
• Treatment with a calcineurin inhibitor (eg, cyclosporine) within 4 weeks prior to dosing for patients enrolled in Part A
• Treatment with eltrombopag or investigational thrombopoietin receptor agonist, Granulocyte Colony-Stimulating Factor (G-CSF), or an androgen (eg, danazol), within 2 weeks prior to dosing
• HIV, hepatitis B or hepatitis C positive by serological testing at the screening visit as defined in the protocol
• Active tuberculosis, latent tuberculosis infection (LTBI) or history incompletely-treated tuberculosis or LTBI
• Active infection as defined in the protocol

Sponsors & Collaborators

• Regeneron Pharmaceuticals: lead

Study Sites (10)

Cleveland Clinic Foundation

Cleveland, Ohio, 44195, United States

Location

The University of Texas MD Anderson Cancer Center

Houston, Texas, 77030, United States

Location

Hopital Saint-Louis - APHP

Paris, Île-de-France Region, 75010, France

Location

Gachon University Gil Hospital

Incheon, Gyeonggi-do, 21565, South Korea

Location

Seoul National University Hospital

Seoul, Seoul Capital Area, 03080, South Korea

Location

Samsung Medical Center

Seoul, Seoul Capital Area, 06351, South Korea

Location

The Catholic University of Korea, Seoul St. Marys Hospital

Seoul, Seoul Capital Area, 06591, South Korea

Location

Ewha Womans University Medical Centre

Seoul, Seoul Capital Area, 07985, South Korea

Location

St James's University Hospital

Leeds, West Yorkshire, LS97TF, United Kingdom

Location

King's College Hospital, London

London, SE5 9RS, United Kingdom

Location

MeSH Terms

Conditions

Anemia, Aplastic; Recurrence

Condition Hierarchy (Ancestors)

Anemia; Hematologic Diseases; Hemic and Lymphatic Diseases; Bone Marrow Failure Disorders; Bone Marrow Diseases; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Clinical Trial Management

  Regeneron Pharmaceuticals

  STUDY DIRECTOR

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: May 26, 2020
• First Posted: June 1, 2020
• Study Start: January 13, 2021
• Primary Completion: October 17, 2024
• Study Completion: October 17, 2024
• Last Updated: October 24, 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 may request access to anonymized patient level data or aggregate study data 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, has the legal authority to share the data, and has made the study results publicly available (eg, scientific publication, scientific conference, clinical trial registry).

Locations

KR (5); FR (1); GB (2); US (2)