NEW YORK - Biogen Idec Inc.’s chief executive, George Scangos, was skeptical when he learned company researchers were pursuing a new treatment for Lou Gehrig’s disease. No one knows the cause of the illness that killed the famous baseball player more than 70 years ago, and no medicine has been shown to slow its advance for long.
Scangos changed his mind after he took charge of the Weston, Mass., company two years ago and reviewed data about dexpramipexole. The compound, which may slow the disease’s progression, is in the final stages of clinical trials required for Food and Drug Administration approval, with results expected this year.
“I don’t know any disease that’s in more need of therapy than ALS,’’ said Scangos, whose company is the world’s largest maker of drugs for multiple sclerosis. “It’s certainly risky, but the data speaks for itself. So we made a calculated bet.’’
ALS, or amyotrophic lateral sclerosis, affects about 30,000 people in the United States, causing nerve damage that leads muscles to shut down progressively over three to five years. Most patients die from respiratory failure.
Lou Gehrig, who played for the New York Yankees, retired from baseball in 1939 when he was diagnosed with the disease and died two years later.
There’s one ALS drug on the market, Sanofi’s Rilutek, but it provides only a modest benefit. Rilutek has US sales of about $50 million, said Eric Schmidt, a Cowen & Co. analyst.
The market for dexpramipexole could top $1 billion a year, Schmidt estimated. The company paid $80 million for a licensing deal in 2010 with Knopp Biosciences, which first developed the drug, and will pay an additional $265 million if certain regulatory and sales goals are met.
The compound looked promising enough in earlier trials by Knopp to attract the attention of Al Sandrock, Biogen Idec’s head of neurology research and a former physician who worked with ALS patients. It is designed to improve functioning of the mitochondria, the energy producers in cells, and to provide protection to neurons under stress.
Phase 2 trials showed that after 12 weeks, people on the highest dose had about a 35 percent slowing of ALS progression, compared with patients taking a placebo, said Merit Cudkowicz, principal investigator of the phase 2 and phase 3 trials and director of the ALS Multidisciplinary Clinic at Massachusetts General Hospital.
Patients given higher doses got better results. “It was a nice dose-dependent effect,’’ he said. “We didn’t expect that at 12 weeks.’’
Biogen Idec’s phase 3 trial, generally the last stage before review by regulators, enrolled its first patient in March 2011.
There have been as many as 20 consecutive failed studies of experimental medicines for ALS, Schmidt wrote in a February research note.
For some patients, Biogen Idec’s medicine is their best hope. “I’d be waiting at the pharmacy for it as soon as it’s FDA-approved,’’ said Laura Tuttle, a nurse who was diagnosed with ALS in 2009.
The data from the phase 3 trial are expected in the second half of this year, and the medicine is on a fast-track path with the FDA.
“This is far from a long shot,’’ Scangos said in January. “We are genuinely hopeful that we will be able to provide meaningful therapy’’ for thousands of patients.