The FDA expanded Casgevy — the first-ever CRISPR/Cas9 gene-editing therapy — to children as young as 2 years old with severe sickle cell disease and transfusion-dependent beta thalassemia, slashing the previous age floor from 12. The decision came with real data: in the CLIMB SCD-151 trial, all eight evaluable patients ages 5 to 11 were free of vaso-occlusive crises for at least 12 consecutive months after a single infusion. "Earlier access to the transformative...