Cytokinetics falls on Phase III ALS readout for tirasemtiv

Cytokinetics Inc. (NASDAQ:CYTK) fell $2.85 (26%) to $8.25 on Tuesday after the company said it will suspend development of tirasemtiv as the candidate missed the primary and secondary endpoints in the Phase III VITALITY-ALS trial to treat amyotrophic lateral sclerosis.

On the trial's primary endpoint, tirasemtiv failed to significantly improve slow vital capacity (SVC) from baseline to week 24 vs. placebo. The fast skeletal muscle troponin activator also missed all secondary endpoints at week 48 vs. placebo, including the change from baseline in Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRS-R) respiratory components, slope of the mega-score of muscle strength, time to first occurrence of a decline from baseline in percent predicted SVC of at least 20 percentage points or the onset of respiratory insufficiency or death, and time to the first use of mechanical ventilatory assistance or death...