Jasper Therapeutics (JSPR) Reports Updated Data from Phase 1 Clinical Trial of JSP191

Jasper Therapeutics, Inc., (NASDAQ: JSPR) today announced updated efficacy, safety and pharmacokinetic data from its ongoing multicenter Phase 1 clinical trial of JSP191, the company’s first-in-class anti-CD117 monoclonal antibody, as a targeted, non-toxic conditioning regimen in older patients with myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) undergoing allogeneic hematopoietic (blood) cell transplantation.

Updated data from the multicenter study showed that conditioning with a single dose of JSP191 0.6 mg/kg prior to low dose radiation and fludarabine in preparation for transplantation was well tolerated and led to successful engraftment as evidenced by primary neutrophil recovery and full donor myeloid chimerism in twenty-four older patients (aged 62-79) with AML in complete response (CR) or MDS. Twenty patients were determined to be free from morphological relapse or disease progression at last follow up with four patients off study due to relapse or progression. Clearance of measurable residual disease (MRD) was observed in 12 of 20 evaluable patients at last follow up. One case of late-onset grade III-IV acute GI graft vs. host disease (GVHD) and one case of secondary graft failure were reported. No JSP191 related Significant Adverse Events, no cases of classical acute grade II-IV GVHD and no cases of transplant related mortality within 100 days were reported.

The findings were presented by lead investigator Lori Muffly, M.D., M.S., Assistant Professor of Medicine (Blood and Bone Marrow Transplantation) at Stanford Medicine, as a late-breaking abstract at the 2022 Transplantation & Cellular Therapy (TCT) Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for International Blood & Marrow Transplant Research (CIBMTR).

“We are excited about the progress of JSP191 as a targeted conditioning agent in patients with MDS or AML in CR undergoing hematopoietic stem cell transplant. These data show that JSP191 may be safely used on top of a standard conditioning regimen in older patients unable to tolerate myeloablative conditioning,” said Ronald Martell, President and CEO of Jasper Therapeutics. “We are looking forward to the start of a registration clinical study of JSP191 for transplant conditioning in MDS or AML in CR patients and the potential to bring safer and more effective conditioning to the growing population of older patients in need of blood stem cell transplant.”

The Phase I trial is an open-label, multicenter study evaluating the safety, tolerability and efficacy of adding JSP191 to the standard conditioning regimen of low-dose radiation and fludarabine in patients aged 60 or older with MDS or AML undergoing hematopoietic cell transplantation. Patients were ineligible for myeloablative conditioning. The primary outcome measure of the study is the safety and tolerability of JSP191 as a conditioning regimen up to one year following a donor cell transplant. Secondary endpoints include engraftment and donor chimerism, MRD clearance, non-relapse mortality, event-free survival, and overall survival.

For more information on the study, refer to Clinicaltrials.gov identifier NCT04429191

You May Also Be Interested In

• Aligos Therapeutics Inc. (ALGS) Presents Positive Data from the ALG-097558 Phase 1 Study
• Atlassian (TEAM) comes ahead of Street estimates in Q1 but shares tumble
• Aligos Therapeutics Inc. (ALGS) Presents Positive Data from the ALG-097558 Phase 1 Study