New Tysabri Analysis Shows Improved Walking Speed in Significant Number of MS Patients

Biogen Idec has announced that a post hoc analysis of data from the AFFIRM study shows Tysabri (natalizumab) significantly increased the proportion of relapsing-remitting multiple sclerosis (RRMS) patients with confirmed improvement in walking speed (CIWS) relative to placebo at 2 years.

Additional data from observational registry studies show that switching to Tysabri after experiencing a multiple sclerosis (MS) relapse while taking interferon beta (IFNβ) or glatiramer acetate (GA) reduced the risk of future relapses and treatment discontinuation. These data were presented at the 66th American Academy of Neurology (AAN) annual meeting in Philadelphia, Pa. (26 April–3 May 2014).

“We know that MS has a significant impact on ambulation — a key concern for many people living with this disease — which is why we analysed data from AFFIRM to evaluate the potential impact of Tysabri on walking speed,” said Alfred Sandrock, MD, PhD, group senior vice president and chief medical officer at Biogen Idec. “TYSABRI was associated with a 20% increase in walking speed, a clinically relevant improvement, in a significantly greater number of patients compared to placebo.”

Walking Speed Impacted with TYSABRI

AFFIRM was a 2-year, randomised, multi-center, placebo-controlled, double-blind study of 942 patients with RRMS that evaluated the effect of Tysabri on the progression of physical disability and the rate of clinical relapses. A post-hoc analysis of AFFIRM assessed the impact of TYSABRI on the proportion of patients with CIWS compared to placebo. CIWS was defined as ≥20% increase in walking speed from baseline in the timed 25-foot walk (T25FW) confirmed 12 weeks later.

Results show that, over the course of 2 years, CIWS was significantly associated with improvement in patient-reported physical functioning. Treatment with Tysabri increased the proportion of patients with CIWS at year two by 79% compared to placebo (Tysabri, 12.3%; placebo 6.9%; p=0.0133). These effects were more significant and occurred earlier in patients with more advanced disability — with CIWS being increased by as much as five-fold compared to placebo at one year.

While many MS clinical trials measure disability progression, which includes a measure of ambulation by the Expanded Disability Status Scale (EDSS), these data from AFFIRM suggest that CIWS may be a more sensitive endpoint in capturing improved ambulation in RRMS patients.