Guess the Therapy Answer December 10, 2025

What was the first ex-vivo lentiviral vector (LVV) gene therapy approved by the FDA for transfusion-dependent β-thalassemia?

Answer: betibeglogene autotemcel (beti-cel; marketed as Zynteglo)

See below for further reading on beti-cel:

Questions of Access: Gene Therapy’s Next Chapter in β-Thalassemia

Transfusion-dependent β-thalassemia (TDT) is a severe inherited blood disorder that requires lifelong blood transfusions for many patients. Although allogeneic stem cell transplant has offered a potential cure for patients, the global lack of matched donors can limit access for patients. Recently, gene therapy has emerged as a transformative option to address this gap—the FDA has approved 2 such therapies: bluebird bio’s beti-cel (Zynteglo) in 2022 and Vertex/CRISPR Therapeutics’ exa-cel (Casgevy) in 2024. Although they represent a huge step forward, their real-world rollout remains limited to select treatment centers. In this feature, CGTLive speaks with clinical experts Tami John, MD, and Shalini Shenoy, MD, MBBS, to explore early patient experiences, barriers to access, and the evolving landscape of gene therapy for TDT.

Study Suggests β-Thalassemia Gene Therapy May Help Improve Growth in Pediatric Patients

Data from a small cohort of pediatric patients with transfusion-dependent β-thalassemia (TDT) suggest that gene therapy may support improved growth outcomes, particularly in height-for-age metrics. The findings, presented at the EHA 2025 Congress, come from a poster by Jingyu Zhao, MPH, and colleagues at the Chinese Academy of Medical Sciences. Among the 9 patients treated with gene therapy between ages 5 and 16, a third showed improvements in height-for-age, and all achieved normal BMI-for-age within a year of treatment. Growth hormone, IGF-1, and zinc levels remained within normal range throughout follow-up, although vitamin D deficiencies were observed in over half of patients at 6 months. While serum ferritin levels showed no significant change, the findings offer early evidence that gene therapy’s benefits may extend beyond transfusion independence. The report adds to the evolving clinical landscape for TDT amid the rollout of beti-cel and exa-cel.