ASH 2021 | Beti-cel gene therapy for transfusion-dependent β-thalassemia: 7-year follow up data

Patients with transfusion-dependent β-thalassemia (TDT), a severe genetic disease caused by mutations in the β-globin gene, require lifelong blood transfusions due to significantly reduced hemoglobin (Hb) production. As well a being highly burdensome, chronic transfusions carry the risk of progressive multi-organ damage due to iron overload. Betibeglogene autotemcel (beti-cel) is an ex vivo gene therapy that adds functional copies of a modified form of the β-globin gene, addressing the underlying deficit in TDT and thus, reducing or eliminating the need for transfusions. A number of studies evaluating the safety and efficacy of beti-cel have shown that treatment results in transfusion independence (TI) for at least 1 year in the majority of patients. Patients enrolled in the completed Phase I/II studies (NCT01745120, NCT02151526), and ongoing Phase III studies (NCT02906202, NCT03207009) were eligible for the LTF-303 long-term follow-up study after a minimum of 2 years of follow up. Alexis Thompson, MD, MPH, Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, presents the results of LTF-303 (NCT02633943) with up to 7 years of follow up. Of the 51 patients enrolled in the study, TI was achieved by 68% of those treated in a Phase I/II study and 86% treated in Phase III, where a refined transduction process was introduced. TI was maintained for an average of 32.3 months and median gene therapy–derived Hb was stable over time. Additionally, effective restoration of iron homeostasis led to reductions in iron burden over time in patients achieving TI. Overall, these long-term data demonstrate the potentially curative nature of beti-cel and support its continued clinical development. This press briefing was recorded at the American Society of Hematology (ASH) 2021 Annual Meeting and Exposition in Atlanta, GA.