Genmab A/S has completed recruitment of patients in the pivotal study of Arzerra (ofatumumab) in the treatment of refractory chronic lymphocytic leukaemia (CLL). A total of 220 patients have been enrolled in the study including 100 patients refractory to fludarabine and alemtuzumab, 100 patients who are refractory to fludarabine and considered inappropriate candidates for alemtuzumab and 20 patients who did not qualify for either category.

Based on positive results from an interim analysis in this study, Genmab and GlaxoSmithKline submitted a Biologics License Application (BLA) to the US Food and Drug Administration (FDA) in January and a Marketing Authorization Application (MAA) to the European Medicines Agency (EMEA) in February.

The study includes patients with CLL refractory to both fludarabine and alemtuzumab, and patients who are refractory to fludarabine and considered inappropriate candidates for alemtuzumab due to bulky tumor masses in their lymph nodes. The study design calls for patients to receive eight weekly infusions of ofatumumab, followed by four monthly infusions. Patients receive 300 mg of ofatumumab at the first infusion and 2,000 mg of ofatumumab at each subsequent infusion. Disease status is assessed every four weeks until week 28 and then every three months until disease progression or month 24.

Ofatumumab is a novel, investigational, fully human monoclonal antibody that targets a membrane-proximal (close to the cell surface) small loop epitope (a portion of a molecule to which an antibody binds) on the CD20 molecule of B-cells.