Alemtuzumab-Treated Patients with RRMS Demonstrate Durable Slowing of Brain Volume Loss Over 5 Years Despite Most Being Treatment-Free for 4 Years: CARE-MS I and II Extension Study (S51.001)

OBJECTIVE: To examine alemtuzumab’s effect on brain volume loss (BVL) over 5 years in the ongoing CARE-MS extension study (NCT00930553). BACKGROUND: Patients with active relapsing-remitting MS (RRMS) who were treatment-naive (CARE-MS I; NCT00530348) or who had an inadequate response (≥1 relapse) to a prior therapy at baseline (CARE-MS II; NCT00548405) demonstrated improved efficacy outcomes following treatment with alemtuzumab versus SC IFNB-1a over 2 years, including significant slowing of BVL. Efficacy on clinical and MRI endpoints was durable through 5 years. DESIGN/METHODS: Patients who received 2 annual courses of alemtuzumab in the core CARE-MS studies continued in the extension study, in which they could receive as-needed alemtuzumab retreatment for relapse or radiological activity. MRI scans were assessed at baseline and annually thereafter. BVL was derived by relative brain parenchymal fraction change. RESULTS: 349 (95[percnt]) CARE-MS I and 393 (93[percnt]) CARE-MS II alemtuzumab patients entered the extension study. Of those, 91[percnt] and 93[percnt] remained on study, 68[percnt] and 60[percnt] received no alemtuzumab retreatment since the initial 2 courses at core study baseline and Month 12, and 2[percnt] and 8[percnt] received another disease-modifying therapy. Median yearly BVL decreased progressively over 4 years in CARE-MS I, remaining low in Year 5 (Year 1: -0.59[percnt], Year 2: -0.25[percnt], Year 3: -0.19[percnt], Year 4: -0.15[percnt], Year 5: -0.20[percnt]). In CARE-MS II, median yearly BVL slowed over 3 years and remained low in Years 4 and 5 (Year 1: -0.48[percnt], Year 2: -0.22[percnt], Year 3: -0.10[percnt], Year 4: -0.19[percnt], Year 5: -0.07[percnt]). CONCLUSIONS: Slowing of BVL with alemtuzumab was maintained over 5 years, despite most patients not receiving alemtuzumab retreatment for 4 years. Based on these findings, alemtuzumab may provide a unique treatment approach with durable efficacy in the absence of continued treatment for RRMS patients. STUDY SUPPORTED BY: Genzyme, a Sanofi company, and Bayer Healthcare Pharmaceuticals.