CRISPR Gene Therapy for Sickle Cell Is Now Approved for Young Children

On 2 July 2026, the U.S. Food and Drug Administration expanded approval of Casgevy — a landmark gene therapy that uses CRISPR gene editing — to children as young as two years old with sickle cell disease or transfusion-dependent beta thalassemia. Previously cleared for patients aged 12 and up, the therapy is now the first genetic treatment available for children this young for both conditions, opening the door to a potential one-time cure much earlier in life.

The timing matters medically. Both diseases inflict cumulative harm from the earliest years — repeated pain crises, organ damage and a lifetime dependence on transfusions — so reaching children before that damage accumulates could change the whole trajectory of their lives. Casgevy works by taking a patient’s own blood stem cells and using CRISPR/Cas9 to switch on the production of fetal hemoglobin, a form of the oxygen-carrying protein that keeps red blood cells from sickling and addresses the root cause of the disease.

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The clinical results behind the expansion are compelling. In the pediatric sickle cell group, all eight children studied (ages 5 to 11) went at least 12 consecutive months without a severe pain crisis within two years of treatment. Among children with transfusion-dependent beta thalassemia, eight of nine with evaluable data achieved a full year of transfusion independence, with a median duration of about 20 months. The treatment is intensive and not without side effects — mucositis, febrile neutropenia and reduced appetite were among the most common — and it requires specialized care, so it will not suit every family.

“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 Dr Haydar Frangoul, an investigator involved in the studies. For families who have watched children endure repeated hospitalizations, the prospect of a single treatment that addresses the underlying genetics — and can now be considered in early childhood — represents a profound shift in what a diagnosis of sickle cell disease can mean.