Biogen Idec, an independent biotechnology company, has announced results from several new analyses of Tysabri (natalizumab) data that demonstrate its effectiveness in reducing multiple sclerosis (MS) disease activity. This effect was particularly significant in people with relapsing MS who initiated treatment when they had lower Expanded Disability Status Scale (EDSS) scores as well as in those who have been treated for more than two years.

These data is being presented at the 29th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in Copenhagen, Denmark from October 2-5.

“These analyses build upon a growing body of evidence that demonstrates greater clinical benefits for people with MS when Tysabri is initiated earlier in the course of the disease, as well as when Tysabri is used for a longer duration in appropriate patients,” said Alfred Sandrock, MD, Ph.D., group senior vice president, Development Sciences and chief medical officer, Biogen Idec.

An analysis of data from the Tysabri Observational Programme (TOP), an ongoing observational, open-label, 10-year prospective study of relapsing-remitting MS (RRMS) patients, assessed patients who have been treated with Tysabri for at least four years. The analysis found that patients with less disability at baseline (EDSS score of <3.0 at baseline) had a significantly greater reduction in 12 month sustained disability progression in months 25-48 compared with months 0-24. Additionally, annualized relapse rates (ARR) in patients treated with Tysabri decreased from 2.03 at baseline to 0.19 during months 0-24 and 0.18 during months 25-48 (p<0.0001).

“Tysabri has advanced the treatment of RRMS patients with its established efficacy,” Sandrock added. “This analysis is encouraging because it provides new insight into the use of Tysabri beyond two years and suggests that effects of treatment are even better with longer use in appropriate patients.”

Tysabri is approved in more than 65 countries. Tysabri is approved in the United States as a monotherapy for relapsing forms of MS, generally for patients who have had an inadequate response to, or are unable to tolerate, an alternative MS therapy. In the European Union, it is approved for highly active relapsing-remitting MS (RRMS) in adult patients who have failed to respond to beta interferon or glatiramer acetate or have rapidly evolving, severe RRMS.

Tysabri has advanced the treatment of MS patients with its established efficacy. Data from the phase III AFFIRM trial, which was published in The New England Journal of Medicine, showed that after two years, Tysabri treatment led to a 68 per cent relative reduction (p<0.001) in the annualized relapse rate when compared with placebo and reduced the relative risk of disability progression by 42-54 per cent (p<0.001).

Biogen Idec uses cutting-edge science to discover, develop, manufacture and market therapies for serious diseases with a focus on neurology, immunology and hemophilia.