On November 13, 2013 the U.S. Food and Drug Administration (FDA) announced that it had approved a new drug called Imbruvica (ibrutinib) for the treatment of a rare type of non-Hodgkin lymphoma called mantle cell lymphoma (MCL). Only about six percent of all Americans with non-Hodgkin lymphoma have this form.
MCL is quite aggressive. Generally, when it is discovered it has already spread to the bone marrow, lymph nodes and other organs.
The drug Imbruvica works by inhibiting an enzyme which is required by the cancer in order to grow and spread.
Imbruvica is intended for use in patients who have already tried at least one other treatment.
Two other drugs are also approved for the treatment of MCL: Millenium Pharmaceutical’s Velcade, which was approved in 2006; and Summit’s Revlimid, which received approval earlier this year.
Imbruvica is the second drug to be designated as breakthrough therapy. In July 2012, the passage of The Food and Drug Administration Safety and Innovation Act gave the agency the ability assign this designation at the request of the sponsor if preliminary data suggest that it may provide a significant improvement over existing treatments for very serious illnesses.
According to Dr. Richard Pazdur, director of the Office of Hematology and Oncology Products at the FDA’s Center for Drug Evaluation and Research, the FDA cooperated with the drug manufacturer to speed up the drug’s review and approval process because the FDA has a commitment to making new treatments available to those with rare diseases. The accelerated approval process allows promising new drugs to get into the hands of seriously ill patients much sooner without them having to wait for the confirmatory clinical trials to be completed.
The FDA also gave Imbruvia priority review and orphan-product designation. It received priority review because of its potential to provide a much safer or effective treatment for serious disease. It received its orphan-product status because it is targeted towards treating a rare disease.
Imbruvica received expedited approval for the treatment of MCL based upon a study in which 111 patients were administered the drug every day until their disease worsened or they could no longer tolerate the side effects. Almost 66 percent of the patients had cancer which either shrank or disappeared completely after being treated with the drug. It has not been established yet whether the drug helped with survival or disease symptoms.
The most commonly reported side effects with Imbruvica were: low platelet levels, decreased white blood cells, anemia, diarrhea, constipation, vomiting, upset stomach, decreased appetite, musculoskeletal pain, fatigue, swelling, bruising, rash, shortness of breath, upper respiratory tract infection and abdominal pain. Other side effects included bleeding, infections, kidney problems and the development of other cancers.
Inbruvica is being marketed for the treated of MCL by Pharmacyclics in Sunnyvale, CA and Janssen Biotech, Inc. in Raritan, NJ.
By Nancy Schimelpfening
Fast Track, Breakthrough Therapy, Accelerated Approval and Priority Review – FDA