Alemtuzumab: Long-Term Efficacy and Safety in Multiple Sclerosis

Alemtuzumab is an investigational humanized monoclonal antibody that selectively targets CD52, leading to long-term depletion of T-lymphocytes and B-lymphocytes. A phase II study involving 334 patients with relapsing-remitting multiple sclerosis (RRMS) demonstrated superior clinical efficacy of alemtuzumab over interferon β-1a given three times weekly (N Engl J Med 2008; 359:1786). Now, researchers have conducted a manufacturer-supported extension study to assess longer-term treatment effect and safety.

The original trial lasted 36 months, with 334 patients with RRMS enrolled from 2002 through 2004. However, one patient died of immune thrombocytopenia (ITP), resulting in an alemtuzumab dosing suspension between 2005 and 2008. Therefore, fewe…