FDA approves oral treatment for spinal muscular atrophy

August 12, 2020

The US Food and Drug Administration (FDA) approved Evrysdi (risdiplam) to treat spinal muscular atrophy. It is the third drug approved to treat the condition.

The US Food and Drug Administration (FDA) has approved Evrysdi (risdiplam) from Genentech, Inc. to treat spinal muscular atrophy (SMA) in children aged 2 months and older.1 It is the third drug to treat SMA that has been approved by the FDA and the first oral drug. The approval was given orphan drug designation as well as a Rare Pediatric Disease Priority Review Voucher. Spinal muscular atrophy is a rare hereditary disease that causes muscle wasting and weakness. It is often fatal.

The efficacy of risdiplam was illustrated in 2 clinical studies. In an infantile-onset SMA study, efficacy was defined as the ability for a child to sit without support for at least 5 seconds and survival that didn’t require permanent ventilation. Following 12 months of treatment, 41% of the patients were able to sit without support for more than 5 seconds, which was a noticeable contrast with the natural progression of SMA. Following 23 months or more of treatment with risdiplam, 81% of the patients were alive without a need for permanent ventilation, which was another notable improvement over typical disease progression. The other later-onset SMA study looked at the score of a motor function test after a year of treatment. Participants who were given risdiplam had a mean increase in their score of 1.36 and the inactive treatment patients saw a mean decrease in the score of 0.19.

Side effects included diarrhea, rash, ulcers of the mouth area, joint pain, urinary tract infections, and fever. The infantile-onset study also reported vomiting, constipation, pneumonia, and upper respiratory tract infection. Risdiplam shouldn’t be taken with drugs that are multidrug and toxin extrusion substrates.

Reference

1. US Food and Drug Administration. FDA approves oral treatment for spinal muscular atrophy. US Food and Drug Administration. Published August 7, 2020. Accessed August 11, 2020. https://www.fda.gov/news-events/press-announcements/fda-approves-oral-treatment-spinal-muscular-atrophy