July 1, 2026 —
The U.S. Food and Drug Administration has approved expanded use of Casgevy, Vertex Pharmaceuticals’ one-time gene editing therapy, for children as young as two years old with inherited blood disorders including sickle cell disease and transfusion-dependent beta thalassemia.
Casgevy was previously approved for patients aged 12 years and older. The expanded approval makes it the first gene editing therapy cleared for use in this younger pediatric population.
Casgevy is an ex vivo, autologous one-time therapy that uses CRISPR/Cas9 gene-editing technology to modify a patient’s haematopoietic stem cells. The process targets the BBCL11A gene to increase foetal haemoglobin production, helping red blood cells function more effectively and reducing complications associated with sickle cell disease.
Sickle cell disease is an inherited blood disorder in which abnormal hemoglobin causes red blood cells to become sickle-shaped, impairing oxygen delivery and leading to painful vaso-occlusive crises, organ damage, and other serious complications. Beta thalassemia is another inherited blood disorder in which patients cannot produce sufficient functional hemoglobin and may require regular red blood cell transfusions.
In a clinical study of children aged five to under 12 years with sickle cell disease, all eight evaluable patients experienced no severe vaso-occlusive crises for at least 12 consecutive months within the first 24 months after infusion.
In beta thalassemia, eight of nine evaluable children achieved transfusion independence for at least 12 consecutive months, with a median duration of 20.1 months.
The FDA approved the expanded indication 53 days after filing under the Commissioner’s National Priority Voucher program, a new fast-track review pathway designed to shorten the review time for selected drug applications.
The approval represents an important step for pediatric access to gene editing therapies in inherited blood disorders. For children with severe sickle cell disease or beta thalassemia, earlier intervention may offer the potential to reduce long-term complications and treatment burden, although careful long-term follow-up remains essential.
Other treatment options for sickle cell disease include hydroxyurea and bone marrow transplantation, but transplantation requires a suitable donor and can carry significant risks. Casgevy’s expanded pediatric approval adds a new option for younger patients and families facing serious inherited blood disorders with limited durable treatment choices.
