2026 Update on Clinical Trials in β-Thalassemia.

Abstract

The therapeutic landscape of β-thalassemia has evolved rapidly over the past decade, shifting from a historical reliance on transfusion support and iron chelation toward disease-modifying and potentially curative therapies. This review summarizes the clinical development of novel treatments for both non-transfusion-dependent and transfusion-dependent β-thalassemia, including approved therapies, agents in active development, and programs that have been discontinued. Disease-modifying strategies have focused on improving ineffective erythropoiesis, correcting iron dysregulation, and restoring red blood cell metabolism. Luspatercept and mitapivat have demonstrated clinically meaningful improvements in hemoglobin levels and reduction of transfusion burden and are now approved in multiple jurisdictions. Additional pyruvate kinase activators, such as etavopivat, are undergoing clinical evaluation. Curative approaches have advanced substantially through gene addition, gene editing, and base editing technologies. Approved therapies, including betibeglogene autotemcel and exagamglogene autotemcel, have achieved high rates of durable transfusion independence, while emerging platforms aim to further improve efficacy, safety, and accessibility. At the same time, several promising approaches targeting fetal hemoglobin induction, iron metabolism, and ineffective erythropoiesis have failed to demonstrate sufficient clinical benefit despite preclinical proof of concept, highlighting the complexity of therapeutic development in β-thalassemia. Future priorities include refining patient selection, generating real-world and comparative effectiveness data, developing clinically meaningful response criteria, expanding pediatric access, and addressing the substantial cost and accessibility challenges associated with novel therapies.