FDA OKs Risdiplam for Treatment of Spinal Muscular Atrophy

Officials with the FDA have approved risdiplam (Evrysdi; Genentech) for the treatment of spinal muscular atrophy (SMA) in adults and children 2 months and older, according to a press release.

According to Genentech, risdiplam, which is a liquid medicine, is the first SMA therapy that can be administered daily at home by mouth or feeding tube.

The approval is based on data from 2 clinical trials, in which risdiplam demonstrated clinically meaningful improvements in motor function in patients across varying ages and levels of disease severity, including types 1, 2, and 3 SMA.

In the FIREFISH study, risdiplam was evaluated in symptomatic infants aged 2 to 7 months. According to the findings, 41% of infants treated with the therapeutic dose achieved the ability to sit without support for at least 5 seconds, as measured by the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III). Ninety percent of infants were alive without permanent ventilation at 12 months of treatment and reached 15 months of age or older, according to the study.

The SUNFISH study, which is the first and only placebo-controlled trial to include adults with types 2 and 3 SMA, evaluated risdiplam in children and adults aged 2 to 25 years. According to the results, children and adults treated with risdiplam experienced a clinically meaningful and statistical-significant improvement in motor function at 12 months (1.55 point mean difference; p=0.0156) compared with placebo (1.36 points [95% CI: 0.61, 2.11]; -0.19 points [95% CI: -1.22, 0.84], respectively), as measured by a change from baseline in the Motor Function Measure-32 total score.

Overall, risdiplam demonstrated a favorable efficacy and safety profile, with the safety profile established across both trials. The most commonly reported adverse effects (AEs) were fever, diarrhea, and rash in later-onset SMA. In infantile-onset SMA, the most common AEs were similar and also included upper respiratory tract infection, pneumonia, constipation, and vomiting. There were no treatment-related safety findings leading to withdrawal in either study.

“Throughout their lives, many people with SMA may lose their ability to perform critical movements, which can impact the ability to independently participate in aspects of daily life and even be life altering,” Kenneth Hobby, president of Cure SMA, said in a statement. “The approval of Evrysdi is an eagerly awaited milestone for our community. We appreciate Genentech’s commitment to reflecting the full scope of the real-world SMA population in their clinical trial program and developing a treatment that can be administered at home.”

According to Genentech, risdiplam will be available in the United States within 2 weeks for direct delivery to patients’ homes through Accredo Health Group Inc, an Express Scripts specialty pharmacy.

Reference

FDA Approves Genentech’s Evrysdi (risdiplam) for Treatment of Spinal Muscular Atrophy (SMA) in Adults and Children 2 Months and Older. News Release. Genentech; August 7, 2020. Accessed August 7, 2020. https://www.gene.com/media/press-releases/14866/2020-08-07/fda-approves-genentechs-evrysdi-risdipla