Neutrophil, Platelet Engraftment is Successful with Briquilimab in Patients with Sickle Cell Disease

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The targeted patient population included those with sickle cell disease or beta thalassemia who were considered at high risk for complications, or otherwise ineligible for standard myeloablative hematopoietic stem cell transplant.

The monoclonal antibody briquilimab (JSP191) demonstrated positive results while being investigated in combination with bone marrow transplantation in patients with sickle cell disease (SCD) and beta thalassemia. The ongoing objective is to determine if briquilimab could potentially facilitate a higher percentage of healthy donor stem cell engrafment while maintaing safety and avoiding increased toxicity.

The targeted patient population included those considered at high risk for complications, or otherwise ineligible for standard myeloablative hematopoietic stem cell transplant (HSCT).

“While stem cell infusion with healthy donor stem cells or gene-corrected cells are potentially curative options for SCD and beta thalassemia, they are both limited by the toxicity of current conditioning regimens using busulfan or melphalan, which are often cited as the most concerning safety risks for transplant patients and physicians,” Ronald Martell, President and CEO of Jasper Therapeutics said in a statement.

Jasper therapeutics announced that all 3 patients in the phase 1/2 trial with sickle cell disease had successful neutrophil engraftment at 12-16 days, as well as platelet engraftment at 8-17 days following treatment with briquilimab. At 60 days after allogenic stem cell transplant, the first 2 patients achieved complete donor myeloid chimerism.

Data also showed that by the 5 month follow up, the first patient to receive treatment with briquilimab had a total hemoglobin level of 13.3 g/dL, which exhibited an increase from the baseline level of 8-9 g/dL.

“With briquilimab, we hope to offer a highly targeted conditioning regimen to directly address conditioning toxicity as a barrier limiting the ability of patients to access curative hematopoietic stem cell therapies," Martell continued.

The study added briquilimab to a regimen that included alemtuzumab, low-dose irradation, sirolimus. The monoclonal antibody was administered before infusion of mobilized peripheral blood cells from human leukocyte antigen matched related donors. No severe adverse events related to briquilimab were reported.