The U.S. Food and Drug Administration today approved obinutuzumab for use in combination with chlorambucil to treat patients with previously untreated chronic lymphocytic leukaemia (CLL).

CLL is a blood and bone marrow disease that usually gets worse slowly. According to the National Cancer Institute, 15,680 Americans will be diagnosed and 4,580 will die from the disease this year.

Obinutuzumab works by helping certain cells in the immune system attack cancer cells. Obinutuzumab is intended to be used with chlorambucil, another drug used to treat patients with CLL.

Obinutuzumab is the first drug with breakthrough therapy designation to receive FDA approval. This designation was requested by the sponsor and granted soon after the biologic license application to support marketing approval was submitted to the FDA. 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 also granted obinutuzumab priority review because the drug demonstrated the potential to be a significant improvement in safety or effectiveness in the treatment of a serious condition. And the FDA granted obinutuzumab orphan product designation because it is intended to treat a rare disease.

“[This] approval represents an important new addition to the treatments for patients with CLL,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “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.”

Obinutuzumab's approval for CLL is based on a study of 356 participants in a randomized open-label multicenter trial comparing obinutuzumab in combination with chlorambucil to chlorambucil alone in participants with previously untreated CLL. Participants receiving obinutuzumab in combination with chlorambucil demonstrated a significant improvement in progression free survival: an average of 23 months compared with 11.1 months with chlorambucil alone.

The most common side effects observed in participants receiving obinutuzumab in combination with chlorambucil were infusion-related reactions, a decrease in infection-fighting white blood cells (neutropenia), a low level of platelets in the blood (thrombocytopenia), low red blood cells (anemia), pain in the muscles and bones (musculoskeletal pain), and fever (pyrexia).

obinutuzumab is being approved with a boxed warning regarding Hepatitis B virus reactivation and a rare disorder that damages the material that covers and protects nerves in the white matter of the brain (progressive multifocal leukoencephalopathy). These are known risks with other monoclonal antibodies in this class and rare cases were identified in participants on other trials of obinutuzumab. Patients should be advised of these risks and assessed for Hepatitis B virus and reactivation risk.

Source: FDA