Objectives: To evaluate the time course of alemtuzumab’s effects on disability in comparison to SC IFNB-1a in RRMS patients who have had disease activity on prior therapy.
Methods: CARE-MS II was a 2-year, randomized (2:1), rater-blinded trial comparing alemtuzumab to IFNB-1a in 628 active RRMS patients who had ≥ 1 relapse while on therapy. Alemtuzumab was administered 12 mg/day intravenously on 5 days at study start and on 3 days 12 months later. SC IFNB-1a was administered 44 mcg 3 times weekly for 24 months. EDSS was assessed at baseline and quarterly by blinded raters. Change from baseline was tested with a repeated measures mixed-model with covariate adjustment for geographic region and baseline EDSS.
Results: Alemtuzumab patients were significantly better than SC IFNB-1a patients on mean change from baseline EDSS as early as Month 6, with a net difference of 0.27 (P = 0.0003). Alemtuzumab group mean EDSS score remained significantly lower than the IFNB-1a group at all subsequent time points through Month 24, (net treatment group differences: Month 9: 0.33, P <0.0001; Month 12: 0.25, P =0. 0023; Month 15: 0.24, P = 0.0073; Month 18: 0.35, P =0.0002; Month 21: 0.38, P <.0001; and Month 24: 0.41, P <0.0001). Alemtuzumab patients also showed significant mean improvement compared with baseline beginning at Month 6 (all P values < 0.05), while SC IFNB-1a patients showed significant mean worsening at most time points (all Pvalues < 0.05) except Months 3, 12, and 15.
Conclusions: Alemtuzumab treatment led to disability improvement that developed early and was durable through the 2-year study period.