The US Food and Drug Administration today designated ibrutinib (Imbruvica™, Pharmacyclics, Sunnyvale, CA) as a breakthrough therapy for the treatment of mantle cell lymphoma (MCL), an aggressive cancer of the blood.

Ibrutinib works by inhibiting the enzyme that causes the cancer to spread; it is the third drug approved to treat MCL, a rare form of non-Hodgkin lymphoma, and is indicated for patients who have received at least one prior therapy. Bortozemib (Velcade®) and lenalidomide (Revlimid®) were previously approved for treatment of the disease in 2006 and 2013, respectively.

Related: Hematologic Cancers Resource Center

“[Ibrutinib’s] approval demonstrates the FDA’s commitment to making treatments available to patients with rare diseases,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “The agency worked cooperatively with the companies to expedite the drug’s development, review and approval, reflecting the promise of the Breakthrough Therapy Designation program.”

Ibrutinib is being approved by the FDA’s accelerated approval program, which allows for earlier patient access based on clinical data that shows a significant predictive benefit to patients, even before confirmatory clinical trials have been conducted. In this case, the study included 111 patients who received ibrutinib daily until disease progression or adverse events became intolerable. Approximately 66% of participants had their cancer shrink or completely disappear; an improvement in survival or disease-related symptoms has not yet been determined.

Common adverse events experienced with ibrutinib include thrombocytopenia, diarrhea, neutropenia, anemia, fatigue, musculoskeletal pain, edema, upper respiratory infection, nausea, bruising, dyspnea, constipation, rash, abdominal pain, vomiting, and decreased appetite.

For more information about this approval, please visit: http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm374761.htm