Jasper Therapeutics presents final results from Phase 1 study of briquilimab

Jasper Therapeutics announced positive final results from the Phase 1 study of briquilimab in combination with fludarabine and low-dose irradiation conditioning in older adults with acute myeloid leukemia, or AML, in complete remission or myelodysplastic syndromes, or MDS, undergoing allogeneic hematopoietic cell transplant. The study enrolled 32 adult patients with AML in CR, MDS, or AML not in CR. Following a 0.6 mg/kg infusion of briquilimab, serum levels were assessed to determine start of Flu at 30 mg/m 2/day on Transplant Day -4, -3, -2, and TBI 2-3 Gy on TD0. Peripheral blood grafts were infused on TD0. Primary endpoints were safety, tolerability, and briquilimab pharmacokinetics, and secondary endpoints included engraftment, chimerism, measurable residual disease clearance, acute graft-versus-host-disease, chronic GVHD, non-relapse mortality, regression-free survival, and overall survival at 1 year. Results from the study demonstrated that a regimen of briquilimab plus Flu/TBI led to successful engraftment of donor blood stem cell without the associated short and long-term toxicities that accompany busulfan-based regimens commonly used in transplant of donor or gene-corrected cells, and led to promising early minimum residual disease clearance. Further, briquilimab dosing resulted in predictable pharmacokinetics and allowed donor cell infusion 9-14 days after administration, and all patients who engrafted achieved neutrophil recovery before TD +26.