Risdiplam Has Long-Term Efficacy and Safety in Treatment of Spinal Muscular Atrophy

New clinical trial data for risdiplam (Evrysdi; Genentech, San Franscisco, CA) shows long-term efficacy and safety of risdiplam for up to 3 years of treatment of spinal muscular atrophy (SMA). These data come from a broad population of people with SMA2 and SMA3. 

In the SUNFISH study (NCT02908685), the increase in Motor Function Measure 32 (MFM-32) total score from baseline previously observed at year 1 was maintained through year 3. Improvements on the Revised Upper Limb Module (RULM) and Hammersmith Functional Motor Scale Expanded (HFMSE) total scores compared with baseline were also sustained between year 1 and year 3. 

“The positive long-term efficacy and safety results for Evrysdi in this broad SMA population are important for physicians as they consider Evrysdi as a treatment option for their patients,” said Laurent Servais, MD, PhD, professor of pediatric neuromuscular diseases, MDUK Oxford Neuromuscular Centre. “In treating people with SMA, our aim is to enable or preserve their independence and patients in the SUNFISH study reported continuous improvement or stabilization in the level of help needed for daily living.”

Risdiplam was well-tolerated over the 3-year time period in the SUNFISH study. The overall rate of adverse events (AEs) in SUNFISH decreased over 3 years, and a trend towards a lower rate of serious adverse events (SAEs) was observed in the third year of treatment. Overall, AEs and SAEs were reflective of the underlying disease and no treatment-related AEs led to withdrawal from the study. 

SUNFISH is a 2-part, double-blind, placebo-controlled study in people age 2 to 25 years who have SMA2 or 3. Part 1 (n=51) determined the dose for the confirmatory Part 2 (n=180), which evaluated motor function with Motor Function Measure 32 (MFM-32) at 12 months. 

The data were presented at the Muscular Dystrophy Association (MDA) Clinical and Scientific Conference, March 13-16, 2022.