Tirasemtiv fails Phase III study for amyotrophic lateral sclerosis

The VITALITY-ALS (Ventilatory Investigation of Tirasemtiv and Assessment of Longitudinal Indices after Treatment for a Year in ALS), an international Phase III clinical trial of tirasemtiv in patients with amyotrophic lateral sclerosis (ALS), did not meet the primary endpoint of change from baseline in slow vital capacity (SVC) which was evaluated at 24 weeks following randomization or any of the secondary endpoints in the trial which were evaluated at 48 weeks. No new safety or tolerability findings related to tirasemtiv were identified in VITALITY-ALS.

Serious adverse events were similar between patients who received tirasemtiv or placebo but more patients discontinued double-blind treatment on tirasemtiv than on placebo primarily due to non-serious adverse events related to tolerability. The decline in SVC from baseline to 24 weeks was smaller in patients who received any dose of tirasemtiv in VITALITY-ALS compared to the decline in patients receiving placebo. The largest differences from placebo were observed in patients randomized to the mid- and high-dose groups of tirasemtiv who could tolerate and remain on their target dose, although those differences were not statistically significant.