Credit: Bill Branson
The US Food and Drug Administration (FDA) has approved a supplemental biologics license application for obinutuzumab (Gazyva) in combination with chlorambucil to treat patients with previously untreated chronic lymphocytic leukemia (CLL).
The approval adds to the drug’s label data from stage 2 of the CLL11 study, which showed that obinutuzumab plus chlorambucil offers significant clinical improvements when compared head-to-head with rituximab plus chlorambucil.
This includes progression-free survival (PFS), complete response (CR), and minimal residual disease (MRD) data from stage 2 of the study. In addition, overall survival data was added from stage 1, in which researchers compared obinutuzumab plus chlorambucil to chlorambucil alone.
The label now reflects that obinutuzumab plus chlorambucil improved PFS compared to rituximab plus chlorambucil. The median PFS was 26.7 months and 14.9 months, respectively (hazard ratio=0.42, P<0.0001).
Additionally, obinutuzumab plus chlorambucil nearly tripled the CR rate when compared to rituximab plus chlorambucil. The CR rates were 26.1% and 8.8%, respectively.
Of the patients who achieved a CR with or without complete recovery from abnormal blood cell counts, 19% (18/94) of patients in the obinutuzumab arm and 6% (2/34) in the rituximab arm were MRD negative in the bone marrow.
Forty-one percent (39/94) of patients in the obinutuzumab arm and 12% (4/34) in the rituximab arm were MRD-negative in the peripheral blood.
At nearly 2 years, the rate of death was 9% (22/238) for patients who received obinutuzumab plus chlorambucil and 20% (24/118) for those who received chlorambucil alone (hazard ratio=0.41). The median overall survival has not yet been reached.
About obinutuzumab
Obinutuzumab is an engineered monoclonal antibody designed to attach to CD20 on B cells. The drug attacks targeted cells both directly and together with the body’s immune system.
The prescribing information for obinutuzumab includes warnings that the drug can cause serious or life-threatening side effects. These include hepatitis B reactivation, progressive multifocal leukoencephalopathy, infusion reactions, tumor lysis syndrome, infections, and neutropenia.
The most common side effects of the drug are infusion reactions, neutropenia, thrombocytopenia, anemia, fever, cough, nausea, and diarrhea.
Obinutuzumab was FDA-approved for use in combination with chlorambucil to treat previously untreated CLL in November 2013. The drug (which is known as Gazyvaro in Europe) was approved by the European Commission for the same indication in July 2014.
Obinutuzumab was discovered by Roche Glycart AG, an independent research unit of Roche. In the US, the drug is part of a collaboration between Genentech and Biogen Idec.
