BREAST CANCER DRUG COULD BECOME THERAPY FOR ALS

SAN DIEGO, Nov. 13, 2001 — Tamoxifen, a commonly used breast cancer drug, could turn out to be an effective treatment for the neuromuscular disease amyotrophic lateral sclerosis (ALS).

At the annual Society for Neuroscience meeting in San Diego Monday, neurologist Benjamin Brooks described promising studies on the drug, and announced that he's begun a trial, funded by the Muscular Dystrophy Association, to fully evaluate its use in people with ALS.

Brooks, who directs the MDA/ALS Clinical Research Center at the University of Wisconsin in Madison, happened upon tamoxifen's promise when he began treating a patient who developed ALS and breast cancer almost simultaneously. Over several months, while the woman was receiving tamoxifen for her breast cancer, Brooks noticed that her ALS was taking an extremely slow course.

Normally, ALS stages a relentless attack against muscle-controlling nerve cells in the spinal cord, causing progressive muscle weakness and death within three to five years of diagnosis. But while receiving tamoxifen, Brooks’ patient largely maintained her muscle strength for more than four years.

Tamoxifen, Brooks noted, works by blocking the activity of protein kinase C (PKC), an enzyme involved in cell growth and gene regulation. Work by other scientists has shown that PKC activity is unusually high in the spinal cords of people with ALS, he said.

Brooks went on to test tamoxifen in mice with an ALS-like disease caused by a virus. Tamoxifen delayed symptoms in the mice by eight days and prolonged their survival by two weeks, he reported Monday.

With support from MDA, Brooks and his colleagues have begun a year-long clinical trial of tamoxifen in 80 people with ALS. They’re still recruiting candidates for the trial.