The U.S. Food and Drug Administration (FDA) has approved Itvisma (onasemnogene abeparvovec) for the treatment of patients ages two years and older with spinal muscular atrophy (SMA) with a confirmed mutation in the SMN1 gene. The gene therapy is administered intrathecally so that the one-time fixed dose does not have to be adjusted for age or body weight. Onasemnogene abeparvovec was previously approved as an intravenous formulation for children with SMA.
SMA is a group of genetic neuromuscular disorders that affect the motor neurons. The loss of motor neurons causes progressive muscle weakness and loss of movement due to muscle wasting. Many types of SMA mainly affect the muscles involved in walking, sitting, arm movement, and head control. Breathing and swallowing may also become difficult as the disease progresses in many types of SMA.
Onasemnogene abeparvovec is designed to address the genetic cause of SMA by providing a functional copy of the human SMN1 gene.
The FDA approval is largely based on data from the phase 3 STEER clinical trial and the open label phase 3b STRENGTH clinical trials. Onasemnogene abeparvovec demonstrated statistically significant improvements in motor function and stabilization of motor abilities. These improvements were sustained over 52 weeks of follow up.
Additionally, the safety profile was favorable and consistent with the most common adverse events including upper respiratory tract infection, pyrexia, common cold, and vomiting.
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To learn more about SMA and other rare musculoskeletal disorders, visit https://checkrare.com/diseases/musculoskeletal-diseases/