FDA Approves Obinutuzumab (Gazyva) for Chronic Lymphocytic Leukemia

The US Food and Drug Administration (FDA) today approved obinutuzumab (Gazyva) for the treatment of chronic lymphocytic leukemia, to be used in combination with chlorambucil. Earlier this year, the drug received a breakthrough therapy designation. 

Obinutuzumab is the first drug with this designation to receive FDA approval. At the request of the sponsor, a breakthrough therapy designation can be given to a drug by the FDA, if preliminary clinical evidence indicates the drug could offer a substantial improvement over available therapies.

Obinutuzumab (formerly GA101) is a third-generation type II anti-CD20 antibody that acts as an immunomodulator. The drug selectivity binds to the extracellular domain of the human CD20 antigen on malignant human B cells.

“Today’s approval represents an important new addition to the treatments for patients with CLL,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research, in a press release. “This approval reflects the promise of the breakthrough therapy designation program, allowing us to work collaboratively with companies to expedite the development, review, and availability of important new drugs.”

The approval of obinutuzumab for CLL is based on a randomized, open-label multicenter trial, involving 356 previously untreated CLL patients, that compared obinutuzumab/chlorambucil to chlorambucil alone.

Participants receiving the obinutuzumab/chlorambucil combination had a significant improvement in progression-free survival compared with patients receiving chlorambucil alone (23 months vs 11.1 months).

The most common adverse events observed in patients receiving obinutuzumab/chlorambucil were neutropenia, infusion-related reactions, anemia, thrombocytopenia, pyrexia, and musculoskeletal pain.

The new drug contains a boxed warning regarding hepatitis B virus reactivation (patients should be assessed for this) and progressive multifocal leukoencephalopathy. These are known risks with other monoclonal antibodies in this class. Physicians should advise patients of these risks.

Obinutuzumab is marketed by Genentech, a member of the Roche Group.