Novartis’ Itvisma (onasemnogene) has been approved by the US FDA to treat spinal muscular atrophy (SMA) in children aged two years and older, teenagers and adults with a confirmed mutation in the survival motor neuron 1 (SMN1) gene.
SMA is a rare, genetic neuromuscular disease caused by a mutated or missing SMN1 gene. Since the SMN1 gene is directly responsible for producing the SMN protein needed for muscle function, including movement, breathing and swallowing, problems with this gene can cause progressive and debilitating muscle weakness. Around 9,000 people in the US currently live with SMA.
Itvisma is designed to provide a functional copy of the SMN1 gene, thereby boosting SMN protein expression and improving motor function. While many other available SMA therapies need to be administered regularly, Itvisma can be given as a single injection that does not need to be adjusted for age or body weight.
“The FDA’s approval of intrathecal onasemnogene abeparvovec is a game-changing advance, expanding the use of transformational gene replacement therapy for SMA across age groups,” said John W Day, director of the Division of Neuromuscular Medicine at Stanford University School of Medicine.
“This achievement is not only a significant step forward for SMA – it also signals new possibilities for the broader field of neurological disorders and genetic medicine.”
The approval of Itvisma is based on data from two phase 3 studies, in which the treatment showed statistically significant improvements in motor function and stabilisation of motor abilities. These effects were sustained over 52 weeks of follow-up.
Kenneth Hobby, president of Cure SMA, said: “This new route of administration for a single dose of gene replacement therapy can mean so much more than what is measured by numbers on a functional motor scale – it could mean greater independence and freedom in activities of daily life.
“The SMA disease landscape has dramatically changed over the last six years, when the first gene therapy was approved. This is another welcome advancement.”