Understanding the positive benefit:risk profile of alemtuzumab in relapsing multiple sclerosis: perspectives from the Alemtuzumab Clinical Development Program

The introduction of high-efficacy therapies for relapsing-remitting multiple sclerosis has driven re-evaluation of treatment goals and benefit:risk considerations in treatment choice. In the alemtuzumab Phase II and III clinical trials, patients treated with alemtuzumab 12 mg versus subcutaneous interferon beta-1a demonstrated significantly reduced annualized relapse rates and improved magnetic resonance imaging outcomes, and were significantly more likely to achieve no evidence of disease activity and reduction in brain volume loss. In two of the studies, alemtuzumab-treated patients had a significantly reduced risk of 6-month confirmed disease worsening, compared with subcutaneous interferon beta-1a. Benefits were maintained throughout 5 years, with a majority of patients receiving no alemtuzumab retreatment or other disease-modifying therapy. Trial results support alemtuzumab's manageable, consistent safety profile in relapsing-remitting multiple sclerosis. Infusion-associated reactions, the most frequent adverse events (AEs), can be minimized by corticosteroid pretreatment, monitoring, and symptomatic management. Other AEs include infections and autoimmune events. Oral anti-herpes prophylaxis should be initiated on the first day of each alemtuzumab treatment course and continued according to local guidelines. Overall cancer risk was lower in the alemtuzumab clinical trials than in a reference population; however, continuing surveillance will determine if alemtuzumab may be associated with certain malignancies such as thyroid papillary carcinoma and melanoma, which are currently identified as potential risks. The post-approval risk management strategy includes a safety monitoring program. Autoimmune AEs (thyroid events, immune thrombocytopenia, nephropathies) can be detected in a timely manner with the monitoring program, which includes physician and patient education about the signs and symptoms, monthly renal and hematologic monitoring, and quarterly thyroid function monitoring for 48 months after the last alemtuzumab course. Education, vigilance by physicians and patients, and monthly laboratory monitoring are recommended to maintain alemtuzumab's positive benefit:risk profile.