TUESDAY, May 28, 2019 -- The first gene therapy has been approved to treat children younger than 2 years with spinal muscular atrophy (SMA), the U.S. Food and Drug Administration announced Friday.
Zolgensma (onasemnogene abeparvovec-xioi), an adeno-associated virus vector-based gene therapy, targets the cause of SMA by delivering a fully functional copy of the human SMN1 gene into the target motor neuron cells. According to the FDA, a one-time intravenous administration of the drug yields expression of the SMN protein in a child's motor neurons, which improves movement, function, and survival. Dosing is based on patient weight, with a recommended dosage of 1.1 × 1.014 vector genomes per kilogram of body weight. Zolgensma is administered as an intravenous infusion for 60 minutes.