Six ALS Clinical Trials: Tirasemtiv

by Amy Madsen on Wed, 2013-05-01 09:23

Name: Tirasemtiv (CK-2017357)

How it works: Tirasemtiv, developed by Cytokinetics, is designed to increase the sensitivity of muscle fibers to calcium, resulting in a potential increase in muscle force generation.

Purpose of trial: To evaluate the safety, tolerability and effectiveness of tirasemtiv when taken with or without riluzole by people with ALS. (Riluzole — brand name Rilutek — is the only drug approved by U.S. Food and Drug Administration to treat ALS.)

Click image to enlarge:

Tirasemtiv (CK-2017357): (a) chemical structure of CK-2017357; (b) calcium dependence of the fast skeletal myofibril ATPase at two concentrations of CK-2017357 compared to vehicle control; (c) the dose response of CK-2017357-treated fast skeletal, slow skeleton, cardiac; (d) tropomyosin troponin. (Image courtesy of Nature.)

Type of trial: Tirasemtiv currently is being tested in a phase 2b, 400-person, multinational clinical trial in people with ALS. The trial is a project of the Northeast ALS Consortium (NEALS), an ALS research network.

Trial sites:

  1. Canada, Ireland and the United Kingdom
  2. Several states in the U.S.: California; Washington, D.C.; Florida; Georgia; Indiana; Iowa; Kansas; Maryland; Massachusetts; Michigan; Minnesota; Missouri; Nebraska; New Hampshire; New York; North Carolina; Ohio; Oregon; Pennsylvania; Texas; Virginia and West Virginia.

Outcome measures:

  1. The primary outcome measure is change in function as measured using the ALSFRS-R (ALS Functional Rating Scale-Revised).
  2. Secondary outcome measures are changes in breathing function, handgrip strength and fatigability.
  3. Blood tests will be performed to assess safety, and information about any side effects that occur also will be collected.

Currently recruiting? This study is currently recruiting participants.

Background info:

  1. Favorable results from three previous phase 2 trials of tirasemtiv in ALS were reported in a Dec. 7, 2012, Cytokinetics press release. In all three trials, treatment with tirasemtiv appeared to result in dose-dependent effects, including improved muscle and respiratory function. See also Safety, tolerability and pharmacodynamics of a skeletal muscle activator in amyotrophic lateral sclerosis.
  2. Read a manuscript (for a fee) describing tirasemtiv's mechanism of action: Activation of fast skeletal muscle troponin as a potential therapeutic approach for treating neuromuscular diseases.
  3. View a video about the rationale and background of the phase 2b clinical trial of tirasemtiv in ALS: BENEFIT-ALS: Blinded Evaluation of Neuromuscular Effects and Functional Improvement with Tirasemtiv in ALS 3-12-13.
  4. Cytokinetics also is testing tirasemtiv in myasthenia gravis and spinal muscular atrophy.

Additional info: For trial information, enrollment criteria and contact information, see Study of Safety, Tolerability and Efficacy of CK-2017357 in Amyotrophic Lateral Sclerosis (ALS).

To read about the other ALS clinical trials:

Note: The effect of these drugs on people with ALS is still unknown. Individuals are strongly advised not to use these drugs to treat ALS until they have been proven safe and effective, and have been approved for use in ALS. Always consult with your physician before adding any medications to your treatment plan. 

About Clinical Trials

About Clinical Trials

A clinical trial is a test, in humans, of an experimental treatment. Although it's possible that benefit may be derived from participating in a clinical trial, it's also possible that no benefit, or even harm, may occur.

MDA has no ability to influence who is chosen to participate in a clinical trial.

To learn more, see Learn About Clinical Studies and Being a Co-Adventurer, which is about neuromuscular disease clinical trials. To see a continuously updated database of clinical trials, go to

Amy Madsen
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