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# Cytokinetics Suspends ALS Drug Program After Phase 3 Data
- URL: https://www.fdaweb.com/cytokinetics-suspends-als-drug-program-after-phase-3-data/
- Published: 2017-11-21T12:00:00.000Z
- Updated: 2026-09-14T23:02:57.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5140178

Cytokinetics has suspended its *tirasemtiv* drug development program after receiving disappointing data from the VITALITY-ALS Phase 3 clinical trial in patients with amyotrophic lateral sclerosis (ALS). The company says the study did not meet the primary endpoint of change from baseline in “slow vital capacity” (SVC) that was evaluated at 24 weeks following randomization or any of the secondary endpoints. It says no new safety or tolerability findings were identified in the study.

“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,” Cytokinetics says. The largest differences, while not statistically significant, were observed in patients randomized to the mid- and high-dose groups who could tolerate and remain on their target dose, it explains.

Cytokinetics is hopeful that its next-generation fast skeletal muscle activator, CK-2127107, will see more promising results. “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,” it says. “CK-2127107 was derived from a different chemical structural class and was designed to have certain advantages relative to *tirasemtiv.* CK-2127107 appears to be more potent than *tirasemtiv* in preclinical models and in humans and appears better tolerated compared to *tirasemtiv.* CK-2127107 has demonstrated pharmacological activity that may lead to new therapeutic options for diseases associated with muscle weakness and fatigue.”