The U.S. Food and Drug Administration has approved a supplemental biologics license application for Gazyva (obinutuzumab) in combination with chlorambucil for the treatment of 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.
In 2013, the drug became the first drug to be approved by the FDA that had been granted Breakthrough Therapy Designation (OT 12/10/13 issue). The latest approval is based on data that found significant improvements across multiple clinical endpoints when the drug was used in combination with chlorambucil compared with use of rituximab plus chlorambucil and compared with use of chlorambucil alone.
That latest data is from Stage 2 of a Phase III, multicenter, open-label, randomized study (CLL11), which included 663 previously untreated patients with CLL who had co-existing medical conditions. Those patients received Gazyva plus chlorambucil or rituximab plus chlorambucil. The first stage of that trial included 589 patients with previously untreated CLL, which compared use of Gazyva plus chlorambucil with Gazyva alone.
The results showed:
* Patients who received Gazyva plus chlorambucil had a median progression-free survival of 26.7 months compared with 14.9 months for the patients receiving the rituximab combination;
* 26.1% of the patients receiving the Gazyva combination had a complete response compared with 8.8% of the patients who received rituximab combination; and
* At two years, the rate of death for patients receiving Gazyva plus chlorambucil was 9% compared with 20% for those who received chlorambucil alone. (Median overall survival has not yet been reached.)
Side effects for Gazyva include: hepatitis B reactivation, progressive multifocal leukoencephalopathy, infusion reactions, tumor lysis syndrome, infections, and low white blood cell counts. The most common side effects are infusion reactions, low white blood cell counts, low platelet counts, low red blood cell counts, fever, cough, nausea, and diarrhea.