CMSC 2012: Alemtuzumab Efficacy in RRMS Patients Who Relapsed on Prior Therapy

SAN DIEGO — The monoclonal antibody, alemtuzumab, significantly reducesthe number of relapses and the accumulation of disability in patients with relapsing-remitting multiple sclerosis (RRMS) who had relapsed on prior therapy, according to research presented at the Fourth Cooperative Meeting of the Consortium of Multiple Sclerosis Centers (CMSC) and America’s Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS).

Alemtuzumab is a monoclonal antibody that selectively targets CD52, a protein found on T and B cells, resulting in a depletion of the autoimmune cells thought to be responsible for the inflammatory process in MS. Alemtuzumab is currently under regulatory review for the treatment of relapsing MS.

Edward J. Fox, MD, of the University of Texas Medical Branch in Round Rock, Texas, and colleagues conducted the international, multicenter, 2-year Comparison of Alemtuzumab and Rebif® Efficacy in Multiple Sclerosis II (CARE-MS II) study involving 840 patients with RRMS aged 18 to 55 years with an Expanded Disability Status Scale (EDSS) of 5 or less who had relapsed while on prior therapy for at least 6 months. Patients were either treated with intravenously administered alemtuzumab 12 mg/day on 5 consecutive days at the beginning of the study and then for 3 consecutive days 1 year later or with 44 mcg of subcutaneously administered IFNbeta-1a three times per week for the duration of the study.

Prior treatment primarily consisted of IFNbeta or glatiramer acetate. Compared with IFNbeta-1a-treated patients, relapse rates were statistically significantly reduced by 49 percent in alemtuzumab-treated patients. The risk of 6-month sustained accumulation of disability was also statistically significantly reduced by 42 percent in alemtuzumab-treated patients compared with those who received IFNbeta-1a.

Infusion-associated reactions did occur with alemtuzumab treatment. While infections were common in both groups, the incidence of infections in the alemtuzumab group was higher in alemtuzumab-treated patients, but infections were generally mild-to-moderate in severity. An autoimmune thyroid-related adverse event was observed in 15.9 percent of alemtuzumab-treated patients compared with 5.0 percent in the IFNbeta-1a patients. A further 0.9 percent of alemtuzumab-treated patients developed immune thrombocytopenia. These incidents were identified early by way of a monitoring program and were controlled using conventional therapies.

“Alemtuzumab significantly reduced both relapses and the accumulation of disability compared to IFNbeta-1a in a population of RRMS patients who had relapsed on prior therapy. The safety profile was consistent with previous alemtuzumab studies,” the authors concluded.

This research was supported by Genzyme, a Sanofi Company, and Bayer Healthcare Pharmaceuticals.