Study description: A post hoc analysis of AFFIRM data evaluated sustained Expanded Disability Status Scale (EDSS) change as a potential indicator of neurological improvement and as an outcome measure in MS clinical studies. To detect functional improvement, patients with sustained decreases in EDSS were compared with those who were either unchanged or deteriorated in EDSS. Analyses were performed in patients with a baseline EDSS score ≥2.0. An EDSS score ≥2.0 was selected as the cutoff in the current analyses because it reflects a level of impairment or disability from which improvement could be more reliably measured in a population of patients with MS similar to those enrolled in AFFIRM.

Study limitations:

  • Because this post hoc analysis is retrospective in nature, there are no prospectively defined endpoints
  • Post hoc analyses are performed after the study completion and cannot be used to demonstrate statistically significant differences between treatment groups

Treating with TYSABRI showed a 69% increase in cumulative probability of sustained disability improvement1

  • The cumulative probabilities of sustained improvement in neurological disability at 2 years, defined as a ≥1.0-point decrease in EDSS score that was sustained for 12 weeks, were estimated using the Kaplan-Meier method1

Study funded by Biogen.