Ibrutinib (Imbruvica), an orally administered kinase inhibitor, is now approved by the Food and Drug Administration to treat chronic graft-versus-host disease (GVHD) after other treatments have failed. This is the first drug approved specifically for chronic GVHD. Ibrutinib was previously approved for the treatment of certain types of chronic lymphocytic leukemia, Waldenstrom's macroglobulinemia, and marginal zone lymphoma. Ibrutinib inhibits Bruton's tyrosine kinase, which prevents malignant B cells from proliferating and surviving.

Patients who receive stem cell transplants from blood or bone marrow frequently develop chronic GVHD, in which the transplanted cells attack the person's own healthy cells. This condition can be life threatening. The safety and efficacy of ibrutinib in chronic GVHD was studied in an open-label, multicenter, single-arm trial of 42 patients with chronic GVHD who continued to have symptoms such as mouth ulcers and skin rashes even after receiving cortisone, the standard treatment. Sixty-seven percent of patients experienced symptom improvement after receiving ibrutinib. For 48% of these patients, improvement lasted five months or longer.

Ibrutinib's adverse effect profile has not changed with this new indication. Serious adverse effects include hemorrhage, infections, cytopenias, atrial fibrillation, hypertension, second primary malignancies, tumor lysis syndrome, and embryo-fetal toxicity. Common adverse effects include fatigue, bruising, diarrhea, thrombocytopenia, muscle spasms, stomatitis, nausea, bleeding, anemia, and pneumonia. Because of the possibility of drug interactions, dose adjustments are needed if ibrutinib is coadministered with certain inhibitors of the cytochrome P-450 (CYP) isoenzyme, CYP3A. Specific information regarding dose modifications can be found in the drug's labeling.

Nurses should tell patients receiving ibrutinib to read the medication guide that comes with each new prescription, as this will have the most up-to-date information about adverse effects. For complete prescribing information for ibrutinib, see http://www.accessdata.fda.gov/drugsatfda_docs/label/2017/205552s017lbl.pdf.