First Patient Enrolled in Extension Trial for Tirasemtiv to Treat ALS

Cytokinetics has enrolled the first patient in the VIGOR-ALS extension trial (NCT02936635), which will assess the effects of tirasemtiv in patients with amyotrophic lateral sclerosis (ALS) who participated in the Phase 3 VITALITY-ALS (NCT02496767) study.

Tirasemtiv is a novel skeletal muscle activator that triggers the muscle troponin complex, increasing its sensitivity to calcium. In preclinical studies and early clinical trials involving more than 1,000 people worldwide, tirasemtiv demonstrated improvements in skeletal muscle force in response to neuronal input and delays in disease onset, as well as a decrease in muscle fatigue.

Tirasemtiv is currently being evaluated for its safety, tolerability and effectiveness in the Phase 3 VITALITY-ALS trial, designed to confirm and extend findings on measures of respiratory function and muscle strength from prior studies.

The open-label VIGOR-ALS study, an extension of VITALITY-ALS, will assess the incidence of adverse reactions in patients as its primary endpoint.

Secondary endpoints include time to events such as the first use of assisted ventilation or respiratory insufficiency, and the change from baseline ALS functional rating scale-revised (ALSFRS-R) — a validated rating instrument for monitoring the progression of disability in patients with ALS.

After enrolling, patients will begin receiving tirasemtiv at 125 mg twice a day for up to four weeks, and will gradually increase to their maximum tolerated dose of 250 mg twice a day.

“People living with ALS desperately need new therapies, and VIGOR-ALS reflects our commitment to the patients that participated in VITALITY-ALS and who contributed enormously to the development of a potential new medicine for patients with ALS,” Dr. Fady I. Malik, MD, PhD, Cytokinetics’ executive vice president of R&D, said in a press release. “This trial will provide supplemental data on the effects of long-term use of tirasemtiv.”

ALS is estimated to affect around 30,000 people in the U.S. and similar numbers in Europe, with 6,000 new cases being diagnosed every year in the U.S. alone.

The U.S. Food and Drug Administration (FDA) granted orphan drug designation and fast track status to tirasemtiv. The European Medicines Agency (EMA) has also given the drug candidate orphan medicinal product designation for the potential treatment of ALS.