Biogen's injectable MS drug effective in trial

(Reuters) - Biogen Idec Inc said on Thursday that a late-stage clinical trial of an experimental multiple sclerosis treatment showed it to be safe and effective in cutting the annual rate of relapse in patients with the autoimmune disease.

The injectable treatment, peginterferon beta-1a, also known as Peg-Avonex, is designed to reduce the dosing schedule typical of standard interferon drugs such as Biogen's own Avonex, as it is designed to last longer in the body.

Biogen said the results "support peginterferon beta-1a as a potential treatment dosed every two weeks or every four weeks for relapsing-remitting multiple sclerosis."

The company said fewer patients relapsed on an every two-week dosing schedule than those on an every four-week schedule in the trial. The study included more than 1,500 patients with relapsing-remitting multiple sclerosis.

Both schedules of use worked at about the same rate to reduce the progression of disability with MS, an autoimmune disease that affects the brain and spinal cord, the company said.

Still, analysts are mainly focused on another multiple sclerosis drug in development by Biogen, BG-12, a pill that some expect could become the leading treatment for the disease.

David Ferreiro, an analyst at Oppenheimer, said in a research report that he expects peak sales of Peg-Avonex of around $830 million a year.

"We see the drug's convenience benefit as modest and expect a diminishing injectables market in the advent of BG-12, an oral with stronger efficacy than injectables," he said.

Biogen said it plans to submit the drug for approval in 2013 and Mark Schoenebaum, a research analyst at ISI Group, said in a note that he expects approval in 2014.

(Reporting By Caroline Humer; Editing by Nick Zieminski)