Peginterferon beta-1a in multiple sclerosis: 2-year results from ADVANCE

Objective: To evaluate the efficacy and safety of subcutaneous peginterferon beta-1a over 2 years in patients with relapsing-remitting multiple sclerosis in the ADVANCE study. Methods: Patients were randomized to placebo or 125 mu g peginterferon beta-1a every 2 or 4 weeks. For Year 2 (Y2), patients originally randomized to placebo were re-randomized to peginterferon beta-1a every 2 weeks or every 4 weeks. Patients randomized to peginterferon beta-1a in Year 1 (Y1) remained on the same dosing regimen in Y2. Results: Compared with Y1, annualized relapse rate (ARR) was further reduced in Y2 with every 2 week dosing (Y1: 0.230 [95% CI 0.183-0.291], Y2: 0.178 [0.136-0.233]) and maintained with every 4 week dosing (Y1: 0.286 [0.231-0.355], Y2: 0.291 [0.231-0.368]). Patients starting peginterferon beta-1a from Y1 displayed improved efficacy versus patients initially assigned placebo, with reductions in ARR (every 2 weeks: 37%, p<0.0001; every 4 weeks: 17%, p=0.0906), risk of relapse (every 2 weeks: 39%, p<0.0001; every 4 weeks: 19%, p=0.0465), 12-week disability progression (every 2 weeks: 33%, p=0.0257; every 4 weeks: 25%, p=0.0960), and 24-week disability progression (every 2 weeks: 41%, p=0.0137; every 4 weeks: 9%, p=0.6243). Over 2 years, greater reductions were observed with every 2 week versus every 4 week dosing for all endpoints and peginterferon beta-1a was well tolerated. Conclusions: Peginterferon beta-1a efficacy is maintained beyond 1 year, with greater effects observed with every 2 week versus every 4 week dosing, and a similar safety profile to Y1. Clinicaltrials.gov Registration Number: NCT00906399.