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# FDA OKs Casgevy for Younger Children
- URL: https://www.fdaweb.com/fda-oks-casgevy-for-younger-children/
- Published: 2026-07-06T12:00:00.000Z
- Updated: 2026-09-14T13:42:08.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5161391

FDA has approved a supplemental indication for Vertex Pharmaceuticals’ Casgevy (exagamglogene autotemcel) for patients aged 2 and older with either sickle cell disease (SCD) with recurrent vaso-occlusive crises (VOCs) or transfusion-dependent β thalassemia (TDT). An agency [notice](https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapy-young-children-sickle-cell-disease?ref=fdaweb.com) says it’s the first gene therapy approved for patients aged 2 years and older with SCD.

Casgevy was previously approved to treat patients aged 12 years and older with SCD with recurrent VOCs or TDT.

Casgevy is described as a gene therapy consisting of the patient’s (autologous) hematopoietic stem cells, administered as a one-time single dose for intravenous infusion. The cells are edited using CRISPR/Cas9, a type of genome editing technology, and then engrafted in the body’s bone marrow. CRISPR/Cas9 can be directed to a specific spot in DNA, where it cuts the genetic material so that DNA can be accurately removed, added, or replaced.

The safety and effectiveness of Casgevy in patients aged 5 years to less than 12 years with SCD were evaluated in a clinical trial involving 11 patients. A trial of 15 patients evaluated the treatment’s safety and effectiveness in patients aged 5 years to less than 12 years with TDT.

“Based on product characteristics and clinical study data,” FDA says, “extrapolation to the younger pediatric age population was granted to expand the indication to 2 years of age and above for both conditions.”

The most common adverse reactions were mucositis and febrile neutropenia in patients with SCD and TDT, and decreased appetite in patients with SCD. Additionally, the prescribing information contains warnings for neutrophil engraftment failure, delayed platelet engraftment, hypersensitivity reactions, and off-target genome editing risk.

The approval decision came 53 days after filing and was the eighth approval selected for the National Priority Voucher program, the agency says. FDA granted Casgevy orphan drug, regenerative medicine advanced therapy, and fast-track designations.