Risdiplam (EVRYSDI®) is an oral survival of motor neuron 2 (SMN2) premRNA splicing modifier approved by the EMA and MHRA for the treatment of patients aged ≥2 months, with a clinical diagnosis of Type 1, 2 or 3 spinal muscular atrophy (SMA) or 1–4 copies of SMN2.

SUNFISH (NCT02908685) is a two-part, randomised, placebocontrolled, double-blind study in a broad population of patients aged 2–25 years with Type 2/3 SMA. Part 2 assesses the efficacy and safety of the Part 1-selected dose of risdiplam versus placebo in Type 2 and non-ambulant Type 3 SMA. Participants were treated with risdiplam or placebo for 12 months; all participants then received risdiplam until Month 24. At Month 24, patients were offered the opportunity to enter the openlabel extension.

The primary outcome of Part 2 – change from baseline to Month 12 in the 32-item Motor Function Measure total score in patients treated with risdiplam (n=120) versus placebo (n=60) – was met. Gains observed with risdiplam at Month 12 were maintained or improved upon at Month 24. At Month 24, there were no treatment-related safety findings leading to withdrawal. Here we present efficacy and safety data of patients who have received risdiplam for 36 months.