Gene Therapy Potentially Curative for β-Thalassemia

FRIDAY, March 11, 2022 (HealthDay News) — A one-time infusion of betibeglogene autotemcel (beti-cel) gene therapy yields high levels of transfusion independence in children and adults with transfusion-dependent β-thalassemia and a non-β⁰/β⁰ genotype, according to a study published in the Feb. 3 issue of the New England Journal of Medicine.

Franco Locatelli, M.D., Ph.D., from the University of Rome, and colleagues conducted an open-label phase 3 study to examine the efficacy and safety of beti-cel in adult and pediatric populations with transfusion-dependent β-thalassemia and a non-β⁰/β⁰ genotype. Twenty-three patients were enrolled, underwent myeloablation with busulfan, and then received intravenous beti-cel. Patients were followed for a median of 29.5 months.

The researchers found that 20 of the 22 patients (91 percent) who could be evaluated had transfusion independence, including six of seven (86 percent) who were younger than 12 years. During transfusion independence, the average hemoglobin level was 11.7 g/dL. In patients with transfusion independence, the median level of gene therapy-derived adult hemoglobin with a T87Q amino acid substitution was 8.7 g/dL at 12 months after beti-cel infusion. Four patients had at least one adverse event considered to be related or possibly related to beti-cel; all except one were nonserious. There were no cases of cancer.

“These data suggest that in most patients with transfusion-dependent β-thalassemia and a non-β⁰/β⁰ genotype, one-time infusion of beti-cel is potentially curative through transfusion independence and the attainment of near normal hemoglobin levels,” the authors write.

Several authors disclosed financial ties to biopharmaceutical companies, including Bluebird Bio, which funded the study.

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