title: Spontaneous Iliopsoas Muscle Hemorrhage Secondary to Ibrutinib (Imbruvica; Pharmacyclics): Brief Report.
abstract: Ibrutinib (Imbruvica; Pharmacyclics) is the first Food and Drug Administration-approved inhibitor of Burton's tyrosine kinase (BTK). Attenuation of BTK signaling ultimately leads to inhibition of B-cell proliferation and apoptosis. After a series of clinical trials, the Food and Drug Administration approved ibrutinib in patients with relapsed chronic lymphocytic leukemia in 2014 and Waldenström's macroglobulinemia in 2015. Those trials included rare grade 3+ hemorrhagic events associated with ibrutinib. Herein, we report a unique presentation of back pain due to iliopsoas muscle hemorrhage in a patient with Waldenström's macroglobulinemia after initiation of ibrutinib.
authors.affiliation: Scripps Green Hospital, La Jolla, CA, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Sarcon
authors.affiliation: Scripps Green Hospital, La Jolla, CA, USA.
authors.forename: Gregory P
authors.initials: GP
authors.lastname: Botta
authors.affiliation: Scripps Green Hospital, La Jolla, CA, USA.
authors.forename: Nikunj
authors.initials: N
authors.lastname: Patel
authors.affiliation: Scripps Green Hospital, La Jolla, CA, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Saven
keywords: Imbruvica; hemorrhage; iliopsoas muscle