Cytokinetics drug helps ALS patients in small trial

LOS ANGELES (Reuters) - A small trial of Cytokinetics Inc's experimental drug for patients suffering from amyotropic lateral sclerosis, commonly known as Lou Gehrig's disease, found that it improved muscle response in some patients.

The patients in the Phase 2a trial were treated with either a single 500 mg dose of the drug, known as CK-2017357, or a 250 mg dose, as well as a placebo.

The Cytokinetics drug is designed to activate a protein called troponin in fast-twitch skeletal muscle tissue, allowing the muscle to contract with greater force. It is not a treatment for ALS, but is being studied as a potential therapy for improving patients' quality of life.

At six hours after receiving the higher dose, 29 of 65 trial patients assessed themselves as "better" in terms of muscle strength and fatigue, compared with 18 of 63 on placebo. At the same time, investigators assessed eight of 63 patients on placebo as better, compared with 15 of 62 after the 250 mg dose of CK-2017357 and 20 of 65 after 500 mg.

The results were correlated with blood plasma levels and increases in measures of endurance, said Dr. Jeremy Shefner, head of the neurology department at the Upstate Medical University at the State University of New York, and the trial's lead investigator, said in a telephone interview.

ALS is a progressive disease that attacks nerve cells in the brain and spinal cord, resulting in muscle weakness and atrophy, eventually leading to death.

"This is a disease for which there is absolutely no effective therapy," Dr. Shefner said. "To show that you had nearly 45 percent of patients feeling better on a drug after a single dose is quite an amazing finding."

The most common adverse side effect seen in the trial was dizziness, most of which was mild, although some patients on the higher dose of the drug experienced moderate dizziness.

Cytokinetics said it expects to launch in the first half of next year a mid-stage trial looking at multiple doses of the drug, possibly over a three-month period.

"We have to be mindful that we have only given ALS patients two separate single doses of this potential medication," Andrew Wolff, chief medical officer at Cytokinetics, said in a telephone interview. "We need to do some medium-term dosing ... just to be sure we understand the tolerability."

The company will hold an investor meeting and conference call at 0700 ET on Monday to discuss the trial results, which were presented at a medical meeting in Florida on Sunday.

Cytokinetics expects to have results in the first half of next year from another mid-stage trial of CK-2017357 in patients with leg pain caused by circulatory dysfunction, known as claudication.

(Reporting by Deena Beasley; Editing by Jan Paschal)