Locatelli F, Thompson AA, Kwiatkowski JL, et al. - In patients with transfusion-dependent β-thalassemia and a non–β0/β0 genotype, betibeglogene autotemcel (beti-cel) gene therapy led to a sustained HbA ^T87Q (adult hemoglobin with a T87Q amino acid substitution) level and a total hemoglobin level that was sufficiently high to allow transfusion independence in most cases, including those younger than 12 years of age.

• Beti-cel gene therapy consists of autologous CD34+ hematopoietic stem cells and progenitor cells transduced with the BB305 lentiviral vector encoding the β-globin (β ^A-T87Q ) gene.

• Adult and pediatric patients (n=23 patients in total) with transfusion-dependent β-thalassemia and a non–β0/β0 genotype underwent myeloablation with busulfan (with doses adjusted on the basis of pharmacokinetic analysis) and received beti-cel intravenously in this open-label, phase 3 study.

• Transfusion independence occurred in 91% of patients, and the average hemoglobin concentration during transfusion independence was 11.7 g per deciliter (range, 9.5 to 12.8).

• At 12 months post beti-cel infusion, 8.7 g per deciliter (range, 5.2 to 10.6) was noted to be the median level of gene therapy–derived HbA ^T87Q in cases who had transfusion independence.

• Beti-cel showed a safety profile consistent with that of busulfan-based myeloablation.

• No cases of cancer were reported.