Cytokinetics (NASDAQ:CYTK) is facing an ugly day after its announcement that a Phase 3 clinical trial, VITALITY-ALS, evaluating tirasemtiv in patients with amyotrophic lateral sclerosis (ALS) failed to achieve the primary endpoint of a change in slow vital capacity (SVC) at week 24 versus baseline. None of the secondary endpoints were met either.
The decline in SVC from baseline to week 24 was smaller in the treatment group compared to placebo and the largest differences were observed in the mid-dose and high-dose tirasemtiv cohorts but the differences were not statistically significant.
Serious adverse events were similar between the treatment and control groups. There were more discontinuations in the tirasemtiv cohorts due to tolerability issues.
CEO Robert Blum says, “While we are deeply disappointed by the results of VITALITY-ALS, we remain committed to people with ALS who are fighting this devastating disease and who need new therapies to slow the decline of respiratory function and muscle strength that are key hallmarks of disease progression. We have decided to suspend the development of tirasemtiv. While we believe that VITALITY-ALS demonstrated pharmacologic activity for the mechanism of action, we also believe that limitations of tirasemtiv may be addressed with our next-generation fast skeletal muscle activator, CK-2127107. Based on previous Phase 1 clinical studies, we believe CK-2127107 will be better tolerated and potentially more effective than tirasemtiv in patients with ALS and look forward to Phase 2 trial results in 2018.
Complete results from VITALITY-ALS will be presented on December 8 at the International ALS/MND Symposium in Boston.
Nov. 21, 2017