FDA Drug Approval Summary: Alemtuzumab as Single-Agent Treatment for B-Cell Chronic Lymphocytic Leukemia

Abstract

On September 19, 2007, the U.S. Food and Drug Administration granted regular approval and expanded labeling for alemtuzumab (Campath); Genzyme Corporation, Cambridge, MA) as single-agent treatment for B-cell chronic lymphocytic leukemia (B-CLL). Alemtuzumab was initially approved in 2001 under accelerated approval regulations. Conversion to regular approval was based on a single study submitted to verify clinical benefit. Efficacy and safety were demonstrated in an open-label, international, multicenter, randomized trial of 297 patients with previously untreated, Rai stage I-IV B-CLL experiencing progression of their disease. Patients were randomized to either alemtuzumab, 30 mg i.v. over 2 hours three times per week on alternate days for a maximum of 12 weeks, or chlorambucil, 40 mg/m(2) orally every 28 days for a maximum of 12 months. The progression-free survival time, the primary study endpoint, was significantly longer in the alemtuzumab arm than in the chlorambucil arm. Both the overall and complete response rates were also significantly higher in the alemtuzumab arm. No differences in survival were observed. There were no new safety signals identified in patients receiving alemtuzumab. The most serious, and sometimes fatal, toxicities of alemtuzumab are cytopenias, infusion reactions, and infections.