In their official press release published on 21 November 2017, Cytokinetics Inc. announced that they will not be continuing work on tirasemtiv after disappointing results in the latest Phase 3 clinical trial. The trial, known under the acronym ‘VITALITY-ALS’, tested whether the drug has a beneficial effect on the breathing function and muscle strength of people with MND. This is very unfortunate news for everyone affected by the disease, however, Cytokinetics are already testing another compound with the hope that this will be more effective and better tolerated than tirasemtiv.
Tirasemtiv is a drug that aims to improve quality of life of people living with MND by increasing strength of their skeletal muscles (controlling body motion and posture) and therefore postponing muscle fatigue. It compensates for the missing nerve signal from a motor neurone to a muscle that instructs it to contract. Tirasemtiv activates a protein called troponin by increasing its sensitivity to calcium, which is crucial for muscle contraction. Continue reading