FDA expands Casgevy label to younger children with sickle cell disease

FDA has expanded the indications for Casgevy (exagamglogene autotemcel) to include patients aged 2 years and older with sickle cell disease (SCD) and recurrent vaso-occlusive crises (VOCs), as well as those with transfusion-dependent β-thalassemia (TDT). Previously, both indications were approved only for patients aged 12 years and older.

Casgevy is an autologous hematopoietic stem cell gene therapy that uses CRISPR/Cas9 gene editing to increase fetal hemoglobin production, reducing red blood cell sickling in SCD and eliminating transfusion dependence in many patients with TDT.

By making this one-time therapy available to younger children, the expanded indications allow clinicians to consider potentially curative treatment earlier in the disease course, before years of recurrent VOCs, chronic anemia, or transfusion dependence lead to irreversible organ damage. Although treatment remains limited to carefully selected patients who can undergo stem cell collection, myeloablative conditioning, and infusion at specialized treatment centers, earlier referral to pediatric hematology and authorized gene therapy centers may become increasingly important.

The approval was supported by studies in children aged 5 to younger than 12 years. Among eight efficacy-evaluable patients with SCD, all remained free of protocol-defined severe VOCs for at least 12 consecutive months during the first 24 months after treatment. Among nine efficacy-evaluable patients with TDT, eight achieved transfusion independence for at least 12 consecutive months, with a median duration of 20.1 months.

FDA also extended the indication to children aged 2 to younger than 5 years by extrapolating efficacy from the 5- to younger-than-12-year population, supported by the therapy's mechanism, product characteristics, and the expectation of a similar treatment effect in younger children.

The most common adverse reactions were mucositis and febrile neutropenia in patients with SCD and TDT, and decreased appetite in patients with SCD. The prescribing information also includes warnings about neutrophil engraftment failure, delayed platelet engraftment, hypersensitivity reactions, and the potential for off-target genome editing. Treatment requires myeloablative conditioning before infusion.

"Earlier access to the transformative potential of this therapy will allow clinicians and families to consider treatment before years of cumulative damage from these life-shortening diseases take hold," said Haydar Frangoul, MD, MS, Medical Director of HCA Healthcare's Sarah Cannon Transplant and Cellular Therapy Program at TriStar Centennial Children's Hospital and an investigator in the Casgevy clinical development program.

Sources: FDA. (2026 July 1). FDA Approves First Gene Therapy for Young Children with Sickle Cell Disease; Vertex Pharmaceuticals. (2026 July 1). Vertex Announces US FDA Approval for Expanded Use of Casgevy for the Treatment of People Ages 2 Years and Older With Sickle Cell Disease or Transfusion-Dependent Beta Thalassemia