Seven months after picking up full rights to BG-12 through the acquisition of Fumapharm AG, Biogen Idec Inc. launched a Phase III program of the immunomodulator in multiple sclerosis.

The Cambridge, Mass.-based company designed two pivotal studies, which already started internationally and are expected to begin in the U.S. later this year, to evaluate the effect of BG-12 on the relapse rate on patients with relapsing-remitting MS. The start of those studies marks "an important milestone in terms of our ongoing efforts in MS," said Amy Brockelman, Biogen spokeswoman.

Biogen, which already markets the MS drugs Avonex, a once-weekly interferon beta-1a injection, and Tysabri (natalizumab), an alpha-4 antagonist administered by infusion, is focusing on "developing multiple options across the range" of MS treatment, Brockelman said.

BG-12, an oral fumarate derivative, demonstrated in Phase II studies an ability to act as an immunomodulator with a mechanism of action that combines cytoprotective and anti-inflammatory properties. Results from a 257-patient Phase II trial showed that those treated with 720 mg of BG-12 per day had a 69 percent reduction in the mean number of new gadolinium-enhancing lesions compared to placebo, as assessed monthly from weeks 12 through 24.

For the Phase III program, more than 2,000 patients will be enrolled to test two doses of BG-12 against placebo. The DEFINE (Determination of the Efficacy and Safety of Oral Fumarate in Relapsing-Remitting MS) study is expected to involve about 1,000 patients randomized to receive either BG-12 daily, at 400 mg or 720 mg, or placebo. The primary endpoint will be the "portion of relapsing patients at two years" vs. placebo, Brockelman told BioWorld Today.

The CONFIRM (Comparator and an Oral Fumarate in Relapsing-Remitting MS) study, meanwhile, is structured similarly, though it will include the addition of a comparator arm. Patients in that trial will be randomized to receive daily one of the two oral doses of BG-12 or placebo or 20 mg of Copaxone (glatiramer acetate) given by subcutaneous injection. The primary endpoint will be the relapse rate among patients at two years.

Data from both trials are "expected to be complementary," she said. Results also will measure the progression of disability and certain MRI assessments.

Though Biogen hopes patient enrollment progresses quickly, Brockelman said it's "premature to speculate" on a timeline for completing the studies and advancing through the regulatory process.

An estimated 1 million people worldwide suffer from MS, with about 700,000 with relapsing disease. And with more than half of MS patients not receiving treatment, "there's certainly a large population that's looking for an additional therapeutic option," she said.

Biogen began working on BG-12 in 2003 through a collaboration with Fumapharm, of Lucerne, Switzerland, and decided to consolidate those rights by acquiring Fumapharm for an undisclosed cash payment last year. That transaction also added psoriasis drug, Fumaderm, to Biogen's pipeline.

Beyond BG-12, other MS therapies in Biogen's development pipeline include Rituxan (rituximab), a B-cell targeted therapy in Phase II. Rituxan is partnered with San Francisco-based Genentech Inc., and previously gained approval in rheumatoid arthritis and non-Hodgkin's lymphoma. The company is working with Fremont, Calif.-based PDL BioPharma Inc. to develop daclizumab, a Phase II-stage antibody designed to bind to the IL-2 receptor on activated T cells, and licensed rights last year CDP323, an oral alpha-4 integrin inhibitor discovered by Brussels, Belgium-based UCB. Shares of Biogen (NASDAQ:BIIB) closed at $49.50 Tuesday, down 52 cents.