Background In SELECTION, an extension study of SELECT evaluating the efficacy/safety of daclizumab high-yield process (DAC HYP) versus placebo, efficacy of DAC HYP in reducing clinical/radiological disease activity in relapsing-remitting multiple sclerosis (RRMS) patients demonstrated in SELECT was confirmed over 1–2 years.
Methods SELECTED is an ongoing, 6-year, single-arm, open-label study evaluating the efficacy/safety of 150 mg subcutaneous DAC HYP every 4 weeks in patients who completed SELECTION. An interim analysis was performed in January 2014, for patients with ≥3 years' continuous DAC HYP treatment.
Results Overall, 410 (90%) patients from SELECTION enrolled in SELECTED and 94 had been continuously treated at the time of the data-cut. Adjusted annualized relapse rate was 0.089 (95% confidence interval [CI]: 0.033–0.244) for weeks 96–120 and 0.047 (95% CI: 0.012–0.187) for weeks 120–144. In year 3, the adjusted mean number of new/newly enlarging T2 hyperintense lesions was 0.56 (95% CI: 0.24–1.32). Brain atrophy rate was reduced in year 3 from years 1–2 (mean annualized change: −0.3%). The safety profile in year 3 was similar to that observed in years 1–2.
Conclusions Efficacy of DAC HYP was sustained over 3 years in RRMS patients, supporting long-term maintenance therapy with DAC HYP.
Sponsors: Biogen, AbbVie Biotherapeutics.