Two promising MS drugs move toward marketplace.

Promising results from multicenter clinical trials of two new agents for relapsing-remitting MS were announced at the American Neurological Association's annual meeting in San Francisco on October 10.

Copaxone (coe-PAX-ohn), or copolymer-I, produced by TEVA Pharmaceutical Industries (Israel and Kulpsville, Pa.), reduces the frequency of relapses (or exacerbations), and interferon beta-1a, produced by Biogen, Inc. of Cambridge, Mass., reduces the frequency of relapses and slows the progression of disability, according to the respective principal investigators of the two clinical trials.

Both TEVA and Biogen intend to continue complete data analysis of their studies and to apply to the U.S. Food and Drug Administration for approval to market these products, a process that often takes a year or more.

"We're highly encouraged," said Mike Dugan, president of the National Multiple Sclerosis Society. "We're proud of our contributions to the Copaxone clinical trial and to the early research on interferons that contributed to beta interferon therapies. Now, we're urging all the responsible parties to act on these results as quickly as they can without sacrificing safety."

Dr. Kenneth Johnson, principal investigator of the Copaxone trials, reported that daily subcutaneous (under the skin) injections of this drug resulted in a 24 percent reduction in the relapse rate over two years. The study took place at 11 U.S. medical centers and involved 251 people with relapsing-remitting MS and disability scores of 0 (no symptoms, no disability) to 5 (serious enough to impair full daily activity but able to walk a short distance without aid).

There were no significant differences between treated and control groups as far as time to progression of MS by a full disability-scale point or level of disability were concerned. Data from MRI examinations, collected at only one of the 11 centers, are still being analyzed.

The most common side effect associated with Copaxone was injection-site reactions. In addition, some people experienced brief post-injection flushing, shortness of breath and chest tightness.

Biogen's interferon beta-1a

Dr. Lawrence Jacobs, chief investigator of the Biogen studies, reported that intramuscular (into the muscle) injections once a week reduced the relapse rate 31 percent in the two-year study. In addition, 36.2 percent of people on placebo had progressed one full level on the Expanded Disability Status Scale after two years while only 22.6 percent of the treated people had progressed one level.

At the start of the study, participants had disability scores from 1 (minimal symptoms, no disability) to 3.5 (minimal to moderate disability, fully able to walk) on this scale.

The trial, which was conducted at five U.S. medical centers, also measured changes in brain lesions as seen on gadolinium-enhanced MRI. Here, the data showed a significant reduction in the size and number of active lesions in people on the drug, as compared to those who received placebo injections.

The drug's side effects included transient flu-like reactions - fever, malaise, and muscle aches. Skin reactions at the injection sites were about the same in both the active drug and the placebo groups, suggesting that problems did not stem from the active drug.