Trial Testing Respiratory Muscle Drug for ALS Patients

(Aidan Jones, Flickr)

14 July 2015. Biopharmaceutical company Cytokinetics is beginning a late-stage clinical trial of a drug designed to slow the decline of respiratory muscle functions in people with amyotrophic lateral sclerosis, or ALS, a neurodegenerative disorder. In addition, Cytokinetics, in South San Francisco, California, received a $1.5 million grant from the ALS Association supporting the trial, and for collecting plasma samples from trial participants in a companion study identifying biomarkers associated with the disease.

ALS, also known as Lou Gehrig’s disease, is a progressive neurological disease that attacks the nerve cells controlling voluntary muscles, such as those in the arms, legs, and face. In ALS, muscles gradually weaken and waste away, leading to individuals losing their strength and their ability to move their arms, legs, and body. When diaphragm and chest wall muscles fail, people lose the ability to breathe without ventilatory support, often leading to death from respiratory failure.

Cytokinetics develops small molecule, or low molecular weight, treatments for disorders marked by compromised or declining muscle performance, particularly the ability of muscles to contact. The company is developing therapies for disorders involving skeletal muscles, such as those in the respiratory system affected by ALS. In addition, Cytokinetics is designing treatments for heart muscle conditions, such as heart failure, and disorders of smooth muscles, including those in the airways affected by asthma.

The company’s lead product is tirasemtiv, taken in tablet form, a small-molecule activator of troponin proteins that regulate calcium in skeletal and heart muscle contractions. The drug works by increasing troponin sensitivity to calcium, increasing the response to signals from nerve cells and muscle force, as well as reducing muscle fatigue. Cytokinetics says results of earlier trials and preclinical studies show tirasemtiv can slow the decline in slow vital capacity, a key measure of respiratory function in people with ALS.

The clinical trial plans to enroll some 445 individuals with ALS at 75 sites in North America and Europe, with so far one site in New York City identified. Participants will receive between 250 to 500 milligrams of tirasemtiv or a placebo each day for 48 weeks. Researchers conducting the trial will look primarily at changes in slow vital capacity in participants beginning at week 24, as well as related measures of respiratory function, such as need for assisted ventilation.

The trial is supported financially in part by ALS Association with a grant of $1.5 million to Cytokinetics. During the trial, clinicians will take blood plasma samples from participants for the Northeastern ALS Consortium repository, where researchers from Barrow Neurological Institute in Phoenix will analyze the samples to highlight biomarkers associated with ALS. Barrow Institute researchers are expected to integrate results of the plasma samples with clinical data from the trial patients to identify biomarkers of ALS progression and underlying disease mechanisms.

Read more:

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• Gene Therapy Biotech Raises $60M in Venture Funds
• Stem Cells Shown to Stop Decline for Some ALS Patients
• Clinical Trial Proposals Sought for ALS Treatments
• Calico Licenses Neurodegenerative Disease Compounds

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