FDA expands approved use of Imbruvica for rare form of Non-Hodgkin Lymphoma

The U.S. Food and Drug Administration today expanded the approved use of Imbruvica (ibrutinib) for patients with Waldenström’s macroglobulinemia (WM), a rare form of cancer that begins in the body’s immune system. The drug received a breakthrough therapy designation for this use.
A type of non-Hodgkin lymphoma, WM usually gets worse slowly over time and causes abnormal blood cells, known as B lymphocytes (B-cells), to grow within the bone marrow, lymph nodes, liver, and spleen. In WM, abnormal B-cells also overproduce a protein known as immunoglobulin M or IgM (macroglobulin) that may lead to excess bleeding, problems with vision and with the nervous system.
According to the National Cancer Institute, approximately 70,800 Americans were diagnosed and 18,990 died from non-Hodgkin lymphomas in 2014. Imbruvica works by blocking the enzyme that allows the abnormal B-cells in WM to grow and divide.
“Today’s approval highlights the importance of development of drugs for supplemental indications,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “Continued research has discovered new uses of Imbruvica.”
The FDA based its approval of Imbruvica for WM on a clinical study of 63 previously treated participants. All study participants received a daily 420 milligram orally administered dose of the medication until disease progression or side effects became intolerable. Results showed 62 percent of participants had their cancer shrink after treatment (overall response rate). At the time of the study, the duration of response ranged from 2.8 months to approximately 18.8 months.
The product’s new use is being approved more than two months ahead of its prescription drug user fee goal date of April 17, 2015, the date the FDA was scheduled to complete review of the drug application.