JSP191 Antibody Targeting Conditioning in SCID Patients

Jasper Therapeutics

Status and phase: Enrolling; Phase 2; Phase 1

Conditions: SCID

Treatments: Biological: Humanized anti-CD117 Monoclonal Antibody (JSP191)

Study type: Interventional

Funder types: Industry

Identifiers

NCT02963064

JAS-BMT-CP-001

Details and patient eligibility

About

A Phase 1/2 study to evaluate the safety, tolerability, and efficacy of an antibody conditioning regimen, known as JSP191, in patients with Severe Combined Immune Deficiency undergoing blood stem cell transplantation

Full description

A Phase 1/2 study to evaluate the safety, tolerability, and efficacy of an antibody conditioning regimen, known as JSP191, in patients with SCID undergoing blood stem cell transplantation. Blood Stem Cell transplantation offers the only potentially curative therapy for SCID.

The biological conditioning regimen, JSP191, is an antibody that binds to CD117. CD117 is the receptor for Stem Cell Factor on blood forming cells. CD117 binding to Stem Cell Factor is critical for survival and maintenance of blood forming stem cells. The binding of JSP191 to CD117 blocks CD117 from binding to Stem Cell Factor on blood forming stem cells. In the absence of CD117/Stem Cell Factor binding, hematopoietic stem cells that are currently occupying the bone marrow niches in SCID patients exit from the bone marrow.

Enrollment: 40 estimated patients

Sex: All

Ages: 3 months to 12 years old

Volunteers: No Healthy Volunteers

Inclusion and exclusion criteria

Key Inclusion Criteria:

1. Typical SCID as defined by Primary Immune Deficiency Treatment Consortia including but not limited to the following subtypes:

   1. T-, B+, NK-: IL-2Rcγ deficient, JAK3-deficient (no longer enrolling)
   2. T-, B-, NK+: RAG1/2 deficient, Artemis-deficient
   3. T-, B+, NK+: IL7Rα deficient, CD3 subunit deficient, CD45 deficient (no longer enrolling) OR Variant SCID with absent or low T cell function, Omenn syndrome, Leaky SCID, Reticular dysgenesis, Adenosine deaminase deficiency, and Purine nucleoside phosphorylase deficiency may be included after consultation with the medical monitor.

2. Patients with human leukocyte antigen (HLA) matched related or unrelated donors

3. Adequate end organ function as defined in study protocol

4. Age ≤ 12 years

5. Prior donor of appropriate age (≥ 5 years old) available for re-collection of stem cells

6. Previous allogeneic Hematopoietic Cell Transplantation HCT (≥ 6 months post initial transplant) with poor graft function

Key Exclusion Criteria:

1. Patients with any acute or uncontrolled infections
2. Patients receiving any other investigational agents, or concurrent biological, chemotherapy, or radiation therapy
3. Patients with active malignancies
4. Active GVHD within 6 months prior to enrollment, or on immunosuppressive therapy for GVHD

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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40 participants in 1 patient group

Blood Stem Cell Transplant w/ anti-CD117 conditioning

Experimental group

Description:

The study will enroll two groups: Group A: previously transplanted SCID patients; Group B: newly diagnosed SCID. The study plans to assess JSP191 in different dose cohorts. Patients will receive a single dose of intravenous JSP191 antibody followed by monitoring for antibody clearance. Once the antibody has cleared below a certain level, patients will receive stem cell transplant and be monitored for hematopoietic recovery.

Treatment:

Biological: Humanized anti-CD117 Monoclonal Antibody (JSP191)