FDA Approves First Gene Therapy Technology to Treat Children With Sickle Cell Disease

WASHINGTON — The Food and Drug Administration Wednesday granted supplemental approval for a breakthrough CRISPR gene therapy medication, making it the first available to treat young children with sickle cell disease.

Casgevy (exagamglogene autotemcel) was first approved in December 2023 as the first medication capable of treating sickle cell disease and transfusion-dependent beta-thalassemia, another hemoglobin-related condition.

It was originally approved for patients aged 12 or older. With Wednesday’s supplemental approval, it is now available to children as young as 2 years old.

The treatment is now expected to offer a much earlier window to prevent lifelong organ damage caused by SCD.

SCD poses major threats to young children, leading to the proliferation of misshapen and rigid red blood cells that can clog small blood vessels, leading to tissue and bone pain, called vaso-occlusive crises.

Similarly, TDT affects blood cells, resulting in severe anemia that requires continuous blood transfusions to manage.

In an FDA statement announcing the supplemental approval, Acting Deputy Director of the Office of Therapeutic Products at the Center for Biologics Evaluation and Research Megha Kaushal, M.D., MSc, said: “These disorders carry a heavy burden for children and their families, affecting growth, development, and long-term health in profound ways.”

Kaushal underlined that treating children aged 2-5 opens a “critical window” to fend off irreversible organ damage and offset developmental harms.

The treatment involved an autologous stem cell transplant, starting with the collection of a child’s own blood-forming stem cells for later use.

Scientists then used CRISPR technology to splice and reorder the genetic information within these stem cells at the molecular level, thereby modifying the DNA.

Editing the genetic code this way boosts the production of fetal hemoglobin, which produces the healthy oxygen-carrying red blood cells that healthy babies have and that aren’t susceptible to sickle cell defects.

These modified cells are returned to the child and produce a brand-new, healthy blood supply.

Extremely high success rates have been recorded from this gene therapy.