Durable Efficacy of Alemtuzumab Over 10 Years: Long-Term Follow-Up of Patients with RRMS from the CAMMS223 Study (P3.053)

OBJECTIVE: Evaluate 10-year efficacy and safety in treatment-naive patients who received alemtuzumab 12 mg in phase 2 CAMMS223, and enrolled in the ongoing CARE-MS extension study. BACKGROUND: In CAMMS223, in patients with active relapsing-remitting MS (RRMS), alemtuzumab showed superior efficacy versus SC IFNB-1a. During 3 randomized studies, efficacy was durable through 5 years, with most patients not receiving retreatment for 4 years. DESIGN/METHODS: In the CAMMS223 core study (NCT00050778), patients were randomized to receive 2 annual courses of alemtuzumab with a possible third course based on T-cell counts. Patients could enter the extension (NCT00930553) for additional follow-up and as-needed retreatment. Endpoints included annualized relapse rate (ARR) and 6-month sustained accumulation of disability (SAD)/confirmed disability progression (≥1-point Expanded Disability Status Scale [EDSS] increase [≥1.5-point if baseline EDSS=0]). RESULTS: Of 108 alemtuzumab 12-mg-treated patients in CAMMS223, 60 entered the extension; based on rising T-cell counts, 39 received a third course (25 after Year 3). 57 (95[percnt]) of extension patients were followed through Year 10; of these, 12[percnt] and 10[percnt] received 4 or 5 alemtuzumab courses, respectively. Through Year 10, low ARR was maintained (0.07), 76[percnt] were free from 6-month SAD, and 78[percnt] had stable or ≥1-point improved EDSS versus baseline. Serious adverse event (AE) incidence was low. Incidence of infusion-associated reactions decreased after first treatment course (98[percnt]). Annual incidence of infections decreased after Year 1 (55[percnt]). Incidence of thyroid AEs peaked in Year 3 (17[percnt]) and declined thereafter. CONCLUSIONS: Alemtuzumab demonstrated durable clinical efficacy through Year 10 despite most patients receiving ≤3 treatment courses. Safety findings were consistent with those of other alemtuzumab clinical trials. Based on these findings, alemtuzumab may provide a unique treatment approach with durable efficacy in the absence of continued treatment for patients with RRMS. STUDY SUPPORTED BY: a Sanofi company, and Bayer Healthcare Pharmaceuticals. Disclosure: Dr. Coles has received personal compensation for activities with Genzyme. Dr. Habek has nothing to disclose. Dr. Bass has received personal compensation for activities with Sanofi-Genzyme, Novartis, Teva Neuroscience, Biogen Idec, Ascend Therapeutics, Quest. Dr. Brinar has nothing to disclose. Dr. Vladic has nothing to disclose. Dr. Margolin has received personal compensation for activities with Genzyme as an employee. Dr. Lu has received personal compensation for activities with Genzyme as a consultant. Dr. Fox has received research support from Biogen, Chugai, Eli Lily, EMD Serono, Genzyme, Novartis, Opexa, Roche.