Gender effects on intramuscular interferon beta-1a in relapsing-remitting multiple sclerosis: analysis of 1406 patients

Background: We aimed to evaluate effects of gender on efficacy and safety of intramuscular (IM) interferon beta (IFNβ)-1a in patients with relapsing–remitting MS (RRMS) or clinically isolated syndromes (CIS) characteristic of early MS.Methods: Pooled data from 1406 (1027 women; 379 men) patients enrolled in five clinical studies of IM IFNβ-1a were analyzed. One analysis examined data for all patients treated with IM IFNβ-1a from all studies. Separate analyses were conducted of pooled IM IFNβ-1a-treated groups from all studies and pooled IFNβ-1a-treated and placebo-treated patients from the placebo-controlled studies. Outcome measures included time to first relapse, annualized relapse rate, time to disability progression, number of gadolinium-enhanced lesions, adverse events, laboratory evaluations, and neutralizing antibodies.Results: All efficacy assessments indicated similar treatment effects of IM IFNβ-1a in men and women with no significant treatment-by-gender interactions. Women reported more headach...