Indications: Ibrutinib (Imbruvica) is approved for patients with Waldenström macroglobulinemia (WM), a rare form of non-Hodgkin lymphoma. It is also approved for mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL) with at least one prior therapy, and CLL with 17p deletion.

Dosing: For WM and CLL, 420 mg taken orally once a day. For MCL, the dose is 560 mg once a day. Ibrutinib comes in 140 mg capsules. It should not be used in patients with moderate or severe baseline hepatic impairment.

Pharmacokinetics: Ibrutinib is a small-molecule inhibitor of BTK that is metabolized primarily through cytochrome P450, CYP3A, and to a minor extent by CYP2D6. Its elimination half-life is 4 to 6 hours.

Drug Interactions: Avoid co-administration with strong and moderate CYP3A inhibitors.

Side Effects/Risks: The most common adverse reactions were thrombocytopenia, neutropenia, diarrhea, anemia, fatigue, musculoskeletal pain, bruising, nausea, upper respiratory tract infection, and rash. Check complete blood counts monthly and monitor patients for bleeding, fever, and infection.

More Information: The FDA initially granted ibrutinib accelerated approval in November 2013, first for use in patients with MCL who received 1 prior therapy, then added patients with CLL who were previously treated, and patients with CLL with a 17p deletion.

Source: Highlights of prescribing information: Imbruvica (ibrutinib). U.S. Food & Drug Administration website. http://www.accessdata.fda.gov/drugsatfda_docs/label/2015/205552s002lbl.pdf. Revised January 2015. Accessed February 20, 2015.