Jasper Therapeutics, Inc. announced that additional follow-up data from Jasper's investigator-sponsored study of briquilimab (formerly known as JSP191) as a conditioning agent in the treatment of sickle cell disease (SCD) were presented in a plenary session focused on novel antibody-based conditioning regimens at the 2023 Tandem Meetings: Transplantation & Cellular Therapy Meetings of ASTCT and CIBMTR. Dr. John F. Tisdale, Director of the Cellular and Molecular Therapeutics Laboratory, National Heart, Lung, and Blood Institute, delivered the talk, titled Improving the Landscape for Curative Therapies in Sickle Cell Disease with Novel Conditioning Methods. The study is a Phase 1/2 clinical trial (NCT05357482) evaluating the addition of briquilimab, Jasper's anti-c-Kit monoclonal antibody, to an existing bone marrow transplantation regimen (NCT00061568) in individuals with SCD and beta thalassemia considered at high risk for complications from or ineligible for standard myeloablative hematopoietic stem cell transplant. The addition of briquilimab is being studied as a potential way to achieve a higher percentage
of healthy donor stem cell engraftment (donor chimerism) without increased toxicity. Initial data from this study were previously shared by Jasper via press release on January 3, 2023. In the plenary session presented by Dr. Tisdale, data results were as follows, with no graft-versus-host disease or briquilimab related severe adverse events observed: Donor myeloid chimerism- Patient 1: 100% at Day 100, Patient 2: 100% at Day 100, Patient 3: 100% at Day 30, Baseline hemoglobin (Hgb)- Patient 1: 8-9 g/dL, Patient 2: 9-10 g/dL, Patient 3: 8-9 g/dL, Hgb at most recent follow up- Patient 1: 12.6 g/dL, Patient 2: 11.4 g/dL, Patient 3: 14 g/dL.