Objective: To report interim results on patient-reported health-related quality-of-life (HRQoL) outcomes, function, and degree of disability over 8 months (M) in RRMS patients receiving alemtuzumab in clinical practice. Background: Alemtuzumab significantly improved clinical, MRI, and HRQoL outcomes versus SC IFNB-1a in RRMS patients in two phase 3 clinical trials, and remained efficacious in an extension over 6-year total follow-up. Real-world data on alemtuzumab use in clinical practice are limited. Design/Methods: PROMiS is an ongoing 1-year, real-world, prospective, non-interventional, online patient-reported outcomes (PRO) survey of RRMS patients in the USA who had initiated alemtuzumab. Patients were recruited from the MS One-to-One support program. PRO questionnaires were completed at baseline and at various intervals over 1 year: Multiple Sclerosis Impact Scale (MSIS-29; scale 0–100), and Multiple Sclerosis Performance Scale (MSPS; scale 0–41), both assessed at baseline, M4, M8, M12; Patient Determined Disease Steps (PDDS; scale 0–8; assessed at baseline, M6, M12). Higher scores indicate greater disability in functional health (MSPS and PDDS) or worse HRQoL (MSIS-29). Baseline characteristics, including treatment history, were collected. Results: The interim analysis included 171 patients (mean age 44.8 years; 72.5% female); 97.7% had received another MS therapy before initiating alemtuzumab. Mean MSIS-29 scores improved at M8 after alemtuzumab versus baseline (physical impact score, 43.0 versus 53.1; psychological impact score, 36.8 versus 49.4; both P Conclusions: Over 8M after alemtuzumab initiation, patients reported significant and clinically meaningful HRQoL improvements while functional health remained stable. It will be important for patients to complete the full alemtuzumab regimen (2 courses) to allow further assessment of treatment benefit. Disclosure: Dr. Khatri has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Acorda Therapeutics, Avanir Pharmaceuticals, Bayer, Biogen, EMD Serono, Genentech, Mallinckrodt, Novartis, Sanofi, Terumo BCT, and Teva. Dr. Morawski has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi. Dr. Chung has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi-Aventis Pharmaceuticals, Inc. Dr. Poole has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi. Dr. Hashemi has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi . Dr. Bury has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi Genzyme.