Cytokinetics said today it has halted development of its lead drug tirasemtiv after it failed a Phase III trial in patients with amyotrophic lateral sclerosis (ALS).
Without offering details, Cytokinetics said tirasemtiv missed its primary endpoint in the Phase III VITALITY-ALS (Ventilatory Investigation of Tirasemtiv and Assessment of Longitudinal Indices after Treatment for a Year in ALS) by failing to show change from baseline in slow vital capacity (SVC) following 24 weeks of double-blind, placebo-controlled treatment.
Cytokinetics added that the decline in SVC from baseline to 24 weeks was smaller in patients who received any dose of tirasemtiv in VITALITY-ALS than the decline seen in patients receiving placebo.
And while the largest differences from placebo were seen in patients randomized to the mid- and high-dose groups of tirasemtiv who could tolerate and remain on their target dose, the company acknowledged that those differences were not statistically significant.
Tirasemtiv also missed the study’s secondary endpoints, which were assessed at 48 weeks after the start of treatment. Those secondary endpoints included:
- Change from baseline in the score of the three respiratory items of the ALS Functional Rating Scale Revised (ALSFRS-R) (i.e., the sum of items 10, 11 and 12) at 48 weeks;
- Slope of the mega-score of muscle strength at 48 weeks;
- Time to the first occurrence of a decline from baseline in percent predicted SVC ≥۲۰ percentage points or the onset of respiratory insufficiency or death through 48 weeks;
- Time to the first occurrence of a decline in SVC to ≤۵۰% predicted or the onset of respiratory insufficiency or death through 48 weeks;
- Change from baseline in the ALSFRS-R total score at 48 weeks;
- Time to the first use of mechanical ventilatory assistance or death through 48 weeks.
“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,” Robert I. Blum, Cytokinetics’ president and CEO, said in a statement.
Cytokinetics Halts Development of ALS Candidate Tirasemtiv after Phase III Failure
