News Release

Biogen Idec's baminercept alfa shows promise in patients with rheumatoid arthritis

Investigational compound designed to disrupt autoimmune cascade

Peer-Reviewed Publication

Offspring PR

Paris, France – June 12, 2008 -- Biogen Idec will present data on baminercept alfa (BG9924, LTßR-Ig), the first dual-mechanism, lymphotoxin-ß; (LT-ß;) and LIGHT pathway inhibitor in development for the treatment of autoimmune diseases, including rheumatoid arthritis (RA), during the 2008 European League Against Rheumatism (EULAR) Annual European Congress of Rheumatology at the Le Palais de Congrés de Paris. Three abstracts will be presented, including one podium presentation highlighting the Phase IIa preliminary safety and efficacy data as well as two poster presentations. The Phase IIa data suggest baminercept alfa is well tolerated. DAS, EULAR and other efficacy measures were improved in patients receiving baminercept alfa vs. patients receiving placebo and persisted up to eight weeks after the final baminercept alfa injection.

Podium presentation

  • "Preliminary safety and efficacy of Baminercept alfa (BG9924, LTßR-Ig) in the treatment of rheumatoid arthritis" – (Presentation OP-0122 – Thursday, June 12, 13:30 CEST, Ternes Session Room)

Poster presentations

  • "Long-term safety assessment of Baminercept alfa (BG9924, LTßR-Ig) in Cynomolgus monkeys – (Poster FRI0156– Friday, June 13, 11:45 – 13:30 CEST)
  • "Treatment of cynomolgus monkeys with Baminercept alfa (BG9924, LTßR-Ig) results in modulation of a specialized vasculature implicated in lymphocyte trafficking to areas of chronic inflammation" – (Poster SAT0040 – Saturday, June 14, 10:15 – 12:00 CEST)

"We are excited to take part in the Annual European Congress of Rheumatology and to share promising results for baminercept alfa," said Ajay Nirula, Director of Medical Research at Biogen Idec. "We are committed to developing new treatment options for those living with RA and are encouraged that results from the Phase IIa study suggest that innovative targeting of a new pathway may be effective in treating this disease."

Phase IIa Data Results

The Phase IIa blinded, multicenter, placebo-controlled trial was designed to assess the safety, pharmacokinetics, pharmacodynamics and efficacy of baminercept with methotrexate, a standard RA therapy, at different dose ranges. Patients (n=47) were randomized in a dose-escalating fashion to receive placebo or one of six doses of baminercept, ranging from 0.01 mg/kg to 3.0 mg/kg once weekly for four weeks, followed by eight weeks of observation. Patients had to have received methotrexate for at least three months prior to enrollment and continued to receive a stable dose of methotrexate throughout the study period.

Study results suggested improvement in the majority of ACR core set measurements (a series of standard measurement criteria for RA symptom and disease improvement) in patients given baminercept compared with placebo. At day 35, patients given baminercept showed an average 60 percent improvement from baseline in swollen joint count and 47 percent improvement in tender joint count, compared with 4.6 percent and 6.7 percent with placebo, respectively. Improvements in these ACR measures persisted for eight weeks after the final baminercept dose. Similar levels of improvements were observed at day 35 in several other standard markers of inflammation and disease progression. ACR scores and other measures improved in a dose dependent manner, with the greatest improvements reported in the groups receiving 1.0 mg/kg and 3.0 mg/kg.

The most common adverse event in patients receiving baminercept was headache. Transient mild-to-moderate flu-like symptoms were observed in 9 patients (25 percent) within 24 hours after the first dose of baminercept. However, these symptoms responded well to paracetamol (acetaminophen) and tended not to recur with subsequent doses. No serious, drug-related adverse events were reported in this study.

Based on the results of the Phase IIa study, Biogen Idec has initiated two Phase IIb trials to study baminercept alfa in combination with methotrexate in patients with moderate to severe RA. 1.) the REACT study for patients with an inadequate response to treatment with DMARD therapy (disease-modifying antirheumatic drug), which completed enrollment earlier this year, and 2.) the RESPOND study for patients having an inadequate response to a TNF inhibitor (biologic therapies that target the TNF pathway). A decision to enter into Phase III development will be made sometime towards the end of 2008 pending analysis of the results of Phase IIb studies.

Rheumatoid Arthritis and the LT- Pathway

In patients with RA, certain immune cells malfunction and attack the joints, causing painful and chronic inflammation as well as destruction of cartilage, tendons and bones. As in other autoimmune diseases, the immune system mistakes healthy cells for foreign invaders. Though the exact cause of RA is unknown, new research is uncovering the immunologic and genetic factors that play important roles in triggering and perpetuating inflammation of the joints.

As shown in preclinical studies, baminercept alfa is thought to inhibit the function of LT- and LIGHT, two critical components of the LT- pathway implicated in the progression of RA and other autoimmune diseases. These molecules are novel members of the TNF superfamily, distinct from TNF- and lymphotoxin- targeted by some biologics indicated for RA. Autoimmune diseases are in part characterized by the inappropriate emergence of organized immune cell collections, or lymphoid structures, at sites of inflammation or in immune system tissues. Baminercept alfa is thought to act by inhibiting the formation and maintenance of lymphoid structures and the consequent activation of aberrant immune effector cells implicated in the pathogenesis of autoimmune diseases such as RA. By blocking inappropriate signals from cell-surface LT- and LIGHT ligands, baminercept alfa may help restore a normal immune environment.

The LT- pathway was discovered at Biogen Idec, and baminercept alfa is a wholly-owned Biogen Idec molecule that was discovered in collaboration with academic scientists. Baminercept alfa is one of several programs in the company's research and development efforts in rheumatology.

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About Biogen Idec

Biogen Idec creates new standards of care in therapeutic areas with high unmet medical needs. Founded in 1978, Biogen Idec is a global leader in the discovery, development, manufacturing, and commercialization of innovative therapies. Patients in more than 90 countries benefit from Biogen Idec's significant products that address diseases such as lymphoma, multiple sclerosis, and rheumatoid arthritis. For product labeling, press releases and additional information about the company, please visit www.biogenidec.com.

Safe Harbor

This media alert contains "forward-looking statements" regarding Biogen Idec's development of baminercept alfa that are based on current expectations and assumptions that are subject to risks and uncertainties. Only a small number of research and development programs result in commercialization of a product. Factors which could cause actual results to differ materially from Biogen Idec's current expectations include the risk that results observed in the Phase IIa trial may not be predictive of the results to be obtained in the additional studies that would be necessary to demonstrate baminercept alfa to have a positive benefit-risk profile in the treatment of patients with RA. In addition, the company may not be able to meet applicable regulatory standards or regulatory authorities may fail to approve baminercept alfa; and the company may encounter other unexpected hurdles. For further information regarding factors, risks and uncertainties relating to Biogen Idec's drug research and development and other activities, please refer to the filings Biogen Idec has made with the Securities and Exchange Commission, including the "Risk Factors" section of Biogen Idec's Quarterly and Annual Reports, copies of which may be obtained at www.biogenidec.com. Biogen Idec assumes no obligation to update and specifically disclaims any duty to update the information in this press release for any reason, except as required by law, even as new information becomes available or other events occur in the future. All forward-looking statements in this press release are qualified in their entirety by this cautionary statement.


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