Obinutuzumab: a review of its use in patients with chronic lymphocytic leukaemia

Obinutuzumab (Gazyva(®); Gazyvaro(®)) is an intravenously administered, glycoengineered, humanized, type II, anti-CD20 monoclonal antibody of the IgG1 subclass. It is available in the EU and the USA as combination therapy with oral chlorambucil in adults with previously untreated chronic lymphocytic leukaemia (CLL). In a multinational phase III study in this patient population, obinutuzumab plus chlorambucil significantly prolonged progression-free survival compared with oral chlorambucil alone and intravenous rituximab plus oral chlorambucil. Significant advantages with obinutuzumab plus chlorambucil over chlorambucil alone and rituximab plus chlorambucil were also observed in event-free survival, the time to a new anti-leukaemia treatment and overall response. The overall survival benefit with obinutuzumab plus chlorambucil is as yet unclear, although the most recent analysis suggests a benefit over chlorambucil alone. In the phase III study, obinutuzumab plus chlorambucil had a manageable tolerability profile in accordance with what would be expected for an anti-CD20 antibody. Neutropenia and infusion-related reactions were the most frequently reported grade 3 or higher treatment-emergent adverse events. In the majority of patients, infusion-related reactions were mild to moderate in severity and occurred predominantly during the first infusion and were managed by slowing or temporarily halting the infusion. Thus, current evidence suggests that obinutuzumab plus chlorambucil is a welcome addition to the treatment options currently available for adults with previously untreated CLL and is recommended by the National Comprehensive Cancer Network guidelines as the preferred first option for some, including those with comorbidities.