The U.S. Food and Drug Administration has approved Gazyva (obinutuzumab, GA101) to be used in combination with chlorambucil to treat patients with previously untreated chronic lymphocytic leukemia (CLL). Gazyva, made by Genentech, is a monoclonal antibody that attaches to CD20 and attacks cells directly and with the body's immune system. It is the first drug to receive FDA approval that had been granted Breakthrough Therapy designation.
“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,” Richard Pazdur, MD, Director of the FDA's Office of Hematology and Oncology Products, said in a news release.
The FDA can designate a drug a breakthrough therapy at the request of the sponsor if preliminary clinical evidence indicates the drug may offer a substantial improvement over available therapies for patients with serious or life-threatening diseases. The FDA had also granted Gazyva priority review because the drug demonstrated potential to significantly improve the safety or effectiveness in the treatment of a serious condition. And, the FDA granted the drug orphan product designation because it is intended to treat a rare disease.
Gazyva's approval is based on a randomized open-label multicenter study comparing Gazyva in combination with chlorambucil with chlorambucil alone in patients with previously untreated CLL. The patients receiving the combination therapy demonstrated an average progression-free survival time of 23 months vs. 11.1 months for patients receiving chlorambucil alone.
The most common side effects observed in patients receiving Gazyva in combination with chlorambucil were infusion-related reactions, neutropenia, thrombocytopenia, anemia, musculoskeletal pain, and pyrexia.
The drug is being approved with a boxed warning regarding Hepatitis B virus reactivation and progressive multifocal leukoencephalopathy. Both are known risks with other monoclonal antibodies in this class, and rare cases were identified in patients on other Gazyva trials.
Marketing applications for the drug have also been submitted to the European Medicines Agency.