for people ages 3 months and up (full criteria)
at San Francisco, California and other locations
study started
completion around
Principal Investigator
by Christopher Dvorak
Headshot of Christopher Dvorak
Christopher Dvorak



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

Official Title

A Phase 1/2 Study to Evaluate the Safety, Tolerability, and Efficacy of JSP191 for Hematopoietic Cell Transplantation Conditioning to Achieve Engraftment and Immune Reconstitution in Subjects With SCID


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 are depleted.


SCID, Immunodeficiency, Pediatric, Bone Marrow Transplantation, GVHD, Stem Cells, Chimerism, Transplant, BMT, Severe Combined Immunodeficiency, Antibodies, Monoclonal Antibodies, Humanized anti-CD117 Monoclonal Antibody (JSP191), Blood Stem Cell Transplant w/ anti-CD117 conditioning


You can join if…

Open to people ages 3 months and up

All patient groups must have:

  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
    2. T-, B-, NK+: RAG1/2 deficient, Artemis-deficient
    3. T-, B+, NK+: IL7Rα deficient, CD3 subunit deficient, CD45 deficient 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

You CAN'T join if...

  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


  • UCSF Benioff's Children's Hospital accepting new patients
    San Francisco California 94158 United States
  • Lucile Packard Children's Hospital accepting new patients
    Palo Alto California 94304 United States

Lead Scientist at UCSF

  • Christopher Dvorak
    My Research Interests are divided into 3 areas of focus: 1. Supportive Care (especially Invasive Fungal Infections) following Hematopoietic Stem Cell Transplantation 2. Transplantation for Severe Combined Immunodeficiency 3. Transplantation for Rare Leukemias (JMML and APL)


accepting new patients
Start Date
Completion Date
Jasper Therapeutics, Inc.
Phase 1/2 research study
Study Type
Expecting 40 study participants
Last Updated