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

Severe Aplastic Anemia (SAA) Clinical Trial

Official title:

A Phase 1/2 Study of REGN7257 (Anti-Interleukin 2 Receptor Subunit Gamma [IL2RG] Monoclonal Antibody) in Patients With Severe Aplastic Anemia That Is Refractory to or Relapsed on Immunosuppressive Therapy

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04409080
• Other study ID #: R7257-RAA-1947
• Secondary ID: 2020-002031-2920
• Status: Recruiting
• Phase: Phase 1/Phase 2
• Start date: January 13, 2021
• Est. completion date: May 10, 2026

Study information

• Verified date: January 2024
• Source: Regeneron Pharmaceuticals
• Contact: Clinical Trials Administrator
• Phone: 844-734-6643
• Email: clinicaltrials[@]regeneron.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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])

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 33
• Est. completion date: May 10, 2026
• Est. primary completion date: January 15, 2026
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Key Inclusion Criteria:

1. Part A: SAA that is IST-refractory or IST-relapsed, as defined in the protocol

2. Part B: SAA that is IST-relapsed, as defined in the protocol

3. Hematopoietic stem cell transplantation (HSCT) is not available or suitable as a treatment option or has been refused by the patient

4. Adequate hepatic and renal function as defined in the protocol

Key Exclusion Criteria:

1. Diagnosis of Fanconi anemia or other congenital bone marrow failure syndrome as defined in the protocol

2. Evidence of myelodysplastic syndrome as defined in the protocol

3. Paroxysmal nocturnal hemoglobinuria (PNH) with evidence of clinically significant hemolysis (eg, treatment indicated) or history of PNH-associated thrombosis

4. Treatment with a T cell-depleting agent (eg, ATG or alemtuzumab) within 6 months prior to dosing

5. Treatment with a calcineurin inhibitor (eg, cyclosporine) within 4 weeks prior to dosing for patients enrolled in Part A

6. 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

7. HIV, hepatitis B or hepatitis C positive by serological testing at the screening visit as defined in the protocol

8. Active tuberculosis, latent tuberculosis infection (LTBI) or history incompletely-treated tuberculosis or LTBI

9. Active infection as defined in the protocol

Note: Other protocol-defined inclusion/ exclusion criteria apply

Related Conditions & MeSH terms

• Anemia
• Anemia, Aplastic
• Severe Aplastic Anemia (SAA)

Intervention

Drug:
• REGN7257
Administered by intravenous (IV) infusion, in Part A and B.

Locations

Country	Name	City	State
France	Hopital Saint-Louis - APHP	Paris	Ile-de-France
Korea, Republic of	Gachon University Gil Hospital	Incheon	Gyeonggi
Korea, Republic of	Ewha Womans University Medical Centre	Seoul	Seoul Capital Area
Korea, Republic of	Samsung Medical Center	Seoul	Seoul Capital Area
Korea, Republic of	Seoul National University Hospital	Seoul	Seoul Capital Area
Korea, Republic of	The Catholic University of Korea, Seoul St. Marys Hospital	Seoul	Seoul Capital Area
United Kingdom	St James's University Hospital	Leeds	West Yorkshire
United Kingdom	King's College Hospital, London	London
United States	Cleveland Clinic Foundation	Cleveland	Ohio
United States	The University of Texas MD Anderson Cancer Center	Houston	Texas

Sponsors (1)

Lead Sponsor	Collaborator
Regeneron Pharmaceuticals

Countries where clinical trial is conducted

United States,  France,  Korea, Republic of,  United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Incidence of adverse events (AEs)	Part A	12 months post-treatment, approximately 52 weeks
Primary	Incidence of serious adverse events (SAEs)	Part A	12 months post-treatment, approximately 52 weeks
Primary	Incidence and severity of treatment-emergent adverse events (TEAEs)	Part A	12 months post-treatment, approximately 52 weeks
Primary	Incidence of serious adverse events (SAEs)	Part B	Through the end of study visit, approximately 78 weeks
Primary	Incidence and severity of treatment-emergent adverse events (TEAEs)	Part B	Through the end of study visit, approximately 78 weeks
Primary	Overall response rate (ORR)	Part B	At 6 months, approximately 26 weeks
Secondary	ORR	Parts A and B	At 3 months, approximately 12 weeks
Secondary	Complete response (CR)	Parts A and B	At 3 months, approximately 12 weeks
Secondary	Partial response (PR)	Parts A and B	At 3 months, approximately 12 weeks
Secondary	Time to best response	Part A	Up to 12 months
Secondary	Time to best response	Part B	Up to 18 months
Secondary	Time to first response	Part A	Up to 12 months
Secondary	Time to first response	Part B	Up to 18 months
Secondary	Any clinical response	Part A	Until the end of study, approximately week 52
Secondary	Any clinical response	Part B	Until the end of study, approximately week 78
Secondary	Platelet transfusions per month over time	Part A	Up to 12 months
Secondary	Platelet transfusions per month over time	Part B	Up to 18 months
Secondary	Red blood cell transfusions per month over time	Part A	Up to 12 months
Secondary	Red blood cell transfusions per month over time	Part B	Up to 18 months
Secondary	Changes in lymphocyte cell counts	Part A	Up to 12 months
Secondary	Changes in lymphocyte cell counts	Part B	Up to 18 months
Secondary	Changes in neutrophil cell counts	Part A	Up to 12 months
Secondary	Changes in neutrophil cell counts	Part B	Up to 18 months
Secondary	Changes in hemoglobin cell counts	Part A	Up to 12 months
Secondary	Changes in hemoglobin cell counts	Part B	Up to 18 months
Secondary	Changes in reticulocyte cell counts	Part A	Up to 12 months
Secondary	Changes in reticulocyte cell counts	Part B	Up to 18 months
Secondary	Changes in platelet cell counts	Part A	Up to 12 months
Secondary	Changes in platelet cell counts	Part B	Up to 18 months
Secondary	Changes in the whole blood immune cell subsets (T cells)	Part A	Up to 12 months
Secondary	Changes in the whole blood immune cell subsets (T cells)	Part B	Up to 18 months
Secondary	Changes in the whole blood immune cell subsets (B cells)	Part A	Up to 12 months
Secondary	Changes in the whole blood immune cell subsets (B cells)	Part B	Up to 18 months
Secondary	Changes in the whole blood immune cell subsets [Natural killer (NK) cells]	Part A	Up to 12 months
Secondary	Changes in the whole blood immune cell subsets (NK cells)	Part B	Up to 18 months
Secondary	Drug concentrations in serum over time	Part A	Up to 12 months
Secondary	Drug concentrations in serum over time	Part B	Up to 18 months
Secondary	Incidence of treatment-emergent anti-drug antibody (ADA) over time	Part A	Up to 12 months
Secondary	Incidence of treatment-emergent ADA over time	Part B	Up to 18 months