Durable Efficacy of Alemtuzumab in Patients With Highly Active Relapsing-Remitting Multiple Sclerosis Who Relapsed on a Prior Therapy (P7.269)

OBJECTIVE: Evaluate alemtuzumab efficacy/safety over 3 years in the patient subset with highly active relapsing-remitting multiple sclerosis (MS) despite prior therapy. BACKGROUND: In the 2-year, phase 3 CARE-MS II study (NCT00548405), alemtuzumab significantly reduced relapses, disability, and magnetic resonance imaging (MRI) lesions versus subcutaneous interferon beta-1a in patients with highly active disease at baseline (蠅2 relapses in the year before randomization and 蠅1 baseline gadolinium [Gd]-enhancing lesion). DESIGN/METHODS: Patients received alemtuzumab 12 mg infusions at baseline and month 12, and retreatment if indicated in an ongoing extension study (NCT00930553). Improved Expanded Disability Status Scale (EDSS) score defined as 蠅0.5-point decrease from core study baseline. Sustained accumulation of disability (SAD) is 蠅1-point EDSS score increase (蠅1.5-point if baseline EDSS=0). MS disease freedom was defined as absence of MRI (new Gd-enhancing lesions and new/enlarging T2 lesions) and clinical (SAD and relapse) disease activity. RESULTS: Of 103 patients with highly active disease in the CARE-MS II alemtuzumab arm, 92 entered the extension study; 17 (18.5[percnt]) received a third treatment course in Year 3. Annualized relapse rate decreased from 0.33 in the core study to 0.08 in Year 3. EDSS scores were improved (46.2[percnt]) or stable (24.2[percnt]) in 70.3[percnt] of patients through Year 3; 83[percnt] were free from 6-month SAD at Year 3. The majority (64.7[percnt]) was free of MRI activity at Year 3. Yearly median percent change in brain parenchymal fraction slowed from -0.263[percnt] in Year 2 to -0.006[percnt] in Year 3. In Year 3, 19.6[percnt] of patients were MS disease activity-free. No new safety signals emerged in the study group. CONCLUSIONS: Alemtuzumab demonstrated durable improvements in clinical and MRI outcomes in patients with highly active disease at Year 3, despite most patients receiving their last treatment course 2 years prior. Study Supported by: Genzyme, a Sanofi company, and Bayer Healthcare Pharmaceuticals