Phase 3 Trial for Experimental Drug Tirasemtiv Currently Recruiting Participants with ALS

Researchers are looking for people with amyotrophic lateral sclerosis (ALS) to participate in the phase 3 VITALITY-ALS clinical trial, sponsored by Cytokinetics, to test the experimental drug tirasemtiv.

Tirasemtiv is a skeletal muscle activator that is designed to increase the sensitivity of muscle fibers to calcium, which should cause these fibers to contract even if the signal from the nervous system is weaker than normal. It’s expected to result in a potential increase in muscle force generation.

The goals of the study are to determine the effect of tirasemtiv versus a placebo on respiratory function. Investigators will assess slow vital capacity (SVC), a measure of breathing function, as well as other measures of respiratory function and muscle strength.

The study, which is taking place at trial sites throughout the United States and Canada, is being conducted in three distinct parts:

  • In the first “open-label” part of the trial, all participants are treated with 125 mg of tirasemtiv, dosed twice daily.
  • Participants who complete the initial two weeks of treatment will enter the second part of the trial, in which each participant will be randomly assigned to receive either tirasemtiv or placebo for 48 weeks.
  • The final part of the trial, called the “withdrawal phase,” lasts four weeks. In it, half of the participants who were receiving tirasemtiv in the second part of the trial will be switched to placebo.

Participants must be 18 years or older, have received a diagnosis of ALS within 24 months of starting the trial and meet additional eligibility requirements. Those who are taking 50 milligrams of riluzole twice a day when they enter the trial will have their dose reduced to 50 milligrams once daily.

To learn more about this trial, including inclusion and exclusion criteria, visit and enter NCT02496767 into the search box.

About MDA

The Muscular Dystrophy Association is the world’s leading nonprofit health agency dedicated to saving and improving the lives of people with muscle disease, including muscular dystrophy, amyotrophic lateral sclerosis (ALS) and other neuromuscular diseases. It does so by funding worldwide research to find treatments and cures; by providing comprehensive health care services and support to MDA families nationwide; and by rallying communities to fight back through advocacy, fundraising and local engagement.

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Claire Orphan
Media Relations Manager