Obinutuzumab for chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a frequent hematological malignancy that is incurable using standard approaches. Two anti-CD20 monoclonal antibodies (mAb), rituximab and ofatumumab, have been approved for CLL treatment. A new glycoengineered type II humanized anti-CD20 mAb, obinutuzumab (GA101), has been developed and demonstrates increased activity against B-cell malignancies by inducing direct cell death and better antibody-dependent cellular cytotoxicity. In a recent randomized Phase III study in patients with newly diagnosed CLL and coexisting conditions, obinutuzumab plus chlorambucil demonstrated significant improvement in progression-free survival and several other outcome parameters, in contrast to rituximab plus chlorambucil. Grade 3-4 infusion-related reactions and neutropenia occurred more frequently in patients who received obinutuzumab compared with those who received rituximab; however, the rate of serious infections was similar. Obinutuzumab represents a promising new option for patients with CLL and must be investigated with other chemotherapy regimens or with new targeted agents.