Onset of efficacy as early as 2 months and maintained over 2 years
Study description: A post hoc analysis of the AFFIRM pivotal trial was performed to look at time to onset of clinical effects following initiation of TYSABRI® (natalizumab). ARR was calculated at 3-month intervals.a,b
Study limitations:
aAnnualized relapse rates per 3-month interval were calculated as the total number of relapses divided by total person-years observed within the interval.
bRelapses were defined as new or recurrent neurologic symptoms not associated with fever or infection that lasted ≥24 hours and were accompanied by new neurologic signs found by the examining neurologist.
cPost hoc subgroup analysis of data from AFFIRM defined highly active disease as ≥2 relapses in the year before study entry and ≥1 T1 Gd+ MRI lesion at study entry. A total of 209 patients (148 TYSABRI and 61 placebo) in AFFIRM met the criteria for highly active MS.
This study was funded by Biogen.