The 11-year long-term follow-up study from the randomized BENEFIT CIS trial

International audienceObjective: To assess outcomes for patients treated with interferon beta-1b immediately after clinicallyisolated syndrome (CIS) or after a short delay.Methods: Participants in BENEFIT (Betaferon/Betaseron in Newly Emerging MS for Initial Treatment)were randomly assigned to receive interferon beta-1b (early treatment) or placebo (delayedtreatment). After conversion to clinically definite multiple sclerosis (CDMS) or 2 years, patients onplacebo could switch to interferon beta-1b or another treatment. Eleven years after randomization,patients were reassessed.Results: Two hundred seventy-eight (59.4%) of the original 468 patients (71.3% of those eligible atparticipating sites) were enrolled (early: 167 [57.2%]; delayed: 111 [63.1%]). After 11 years, risk ofCDMS remained lower in the early-treatment arm compared with the delayed-treatment arm (p 50.0012), with longer time to first relapse (median [Q1, Q3] days: 1,888 [540, not reached] vs 931[253, 3,296]; p50.0005) and lower overall annualized relapse rate (0.21 vs 0.26; p50.0018). Only25 patients (5.9%, overall; early, 4.5%; delayed, 8.3%) converted to secondary progressive multiplesclerosis. Expanded Disability Status Scale scores remained low and stable, with no differencebetween treatment arms (median [Q1,Q3]: 2.0 [1.0, 3.0]). The early-treatment group had better PacedAuditory Serial Addition Task–3 total scores (p 5 0.0070). Employment rates remained high, andhealth resource utilization tended to be low in both groups.MRI metrics did not differ between groups.Conclusions: Although the delay in treatment was relatively short, several clinical outcomesfavored earlier treatment. Along with low rates of disability and disease progression in bothgroups, this supports the value of treatment at CIS.NCT01795872