Data from Phase III clinical trial of TYSABRI presented at ECTRIMS

Biogen Idec (NASDAQ: BIIB) and Elan Corporation, plc (NYSE: ELN) today announced data presented at the 25th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) showing the potential of TYSABRI^® (natalizumab) to redefine successful multiple sclerosis (MS) therapy. These data were from observational studies and retrospective analyses of the Phase III AFFIRM clinical trial, demonstrating that TYSABRI:

• Significantly improves measures of physical and cognitive disability using the Multiple Sclerosis Functional Composite (MSFC) in patients from the AFFIRM trial with baseline impairment;
• Promoted regeneration or stabilization of damage to the myelin sheath, which can cause some of the symptoms seen in MS patients, as measured by advanced MRI technology; and
• Shows improvement in quality of life as reported by patients.

"MS patients should expect more from an MS therapy and studies such as these demonstrate the potential for TYSABRI to satisfy their expectations," said Michael Panzara, M.D., M.P.H., vice president and chief medical officer of neurology, Biogen Idec. “These data presented at ECTRIMS show that, for many MS patients, TYSABRI may lead to improvement in a broad range of physical and cognitive symptoms.”

“The strong efficacy profile demonstrated in clinical trials is enhanced further from these and other important TYSABRI data presented at ECTRIMS," said Carlos Paya, M.D., Ph.D., president, Elan Corporation. “TYSABRI is the first approved MS therapy with reported data suggesting some signs of the progression of MS can be stopped, whether measured by clinical, radiological or patient-reported measures.”

TYSABRI significantly improves physical and cognitive function

This post-hoc analysis from the Phase III AFFIRM trial was conducted using the MSFC, a measure of disability that assesses aspects of neurologic dysfunction in MS not captured by Expanded Disability Status Scale (EDSS), to evaluate the effects of TYSABRI on disability improvement in patients with baseline impairment. Baseline impairment was defined when a patient experienced at least one of the following:

• Taking more than five seconds on the timed 25-foot walk (T25FW; ambulation);
• Taking more than 21 seconds on the 9-hole peg test (9-HPT; upper extremity function); or
• Providing fewer than 55 correct sums on the paced auditory serial addition test (PASAT-3; cognitive function).

The MSFC was administered to patients every 12 weeks; change from baseline to two years was a prespecified secondary endpoint. In the study, 460 patients received TYSABRI and 225 received placebo.

Results showed that TYSABRI significantly increased the proportion of patients who improved from baseline to two years on the T25FW>), 9-HPT>) and PASAT-3>) compared with placebo. The effect of TYSABRI remained significant for the T25FW, 9-HPT and PASAT-3 compared with placebo when improvement was defined as an improved change from baseline sustained for at least six, seven, or eight out of ten planned study visits.

“This data showing the ability of TYSABRI to improve both physical and cognitive function represents a new paradigm for defining success in MS therapies,” said Frederick E. Munschauer, III, M.D., Irvin and Rosemary Smith professor, University of New York, Buffalo, New York.

Natalizumab improves disability on the Multiple Sclerosis Functional Composite in a randomized, double-blind, placebo-controlled study of patients with relapsing multiple sclerosis (poster P434).

TYSABRI stabilizes and restores damage to the myelin sheath

Results from the study showed TYSABRI promoted regeneration and stabilization of damage done to the myelin sheath, as measured Voxel-Wise MTR (VWMTR), an advanced MRI technology, when compared with those receiving interferon beta-1a IM and healthy subjects.

In the study, 77 MS patients who received TYSABRI were followed for 12 months along with 21 MS patients who received interferon beta-1a IM and 17 age-matched and sex-matched healthy volunteers. TYSABRI significantly promoted remyelination when compared to patients treated with interferon beta-1a IM and healthy volunteers. There was no significant difference in decreasing VWMTR NABT volume over the follow-up between TYSABRI-treated patients and healthy volunteers. Relapsing-remitting patients on both therapies showed higher remyelination potential and less evident demyelination than relapsing secondary progressive MS patients.

Evolution of Voxel-Wise magnetization transfer ratio in natalizumab and interferon beta-1a IM treated patients with multiple sclerosis. A case-control study (poster P721).

TYSABRI patients report improvement in physical and psychological well-being

This ongoing, one-year longitudinal observational study assesses health outcomes from patients’ perspectives before the start of TYSABRI treatment and after the third, sixth and 12^th infusions. The Multiple Sclerosis Impact Scale-29 (MSIS-29) will be used to assess the impact of TYSABRI on disease-specific quality of life. Over a six-month period, the study showed patients receiving TYSABRI experienced a consistent improvement in both their physical and psychological well-being, suggesting that TYSABRI may improve overall quality of life of MS patients over time.