Ibrutinib (USAN, also known as PCI-32765 and marketed under the name Imbruvica) is an anticancer drug targeting B-cell malignancies. It is an orally-administered, selective and covalent inhibitor of the enzyme Bruton's tyrosine kinase (BTK).
Ibrutinib is an orally bioavailable, small-molecule inhibitor of Bruton's tyrosine kinase (BTK) with potential antineoplastic activity. Upon oral administration, ibrutinib binds to and irreversibly inhibits BTK activity, thereby preventing both B-cell activation and B-cell-mediated signaling. This leads to an inhibition of the growth of malignant B cells that overexpress BTK. BTK, a member of the src-related BTK/Tec family of cytoplasmic tyrosine kinases, is required for B cell receptor signaling, plays a key role in B-cell maturation, and is overexpressed in a number of B-cell malignancies. The expression of BTK in tumor cells is also associated with increased proliferation and survival.
Ibrutinib was developed by Pharmacyclics, Inc and Johnson & Johnson's Janssen Pharmaceutical division for additional B-cell malignancies including diffuse large B-cell lymphoma and multiple myeloma.
It was approved by the US Food and Drug Administration (FDA) in November 2013 for the treatment of mantle cell lymphoma and in February 2014 for the treatment of chronic lymphocytic leukemia. In January 2015, ibrutinib was approved by the FDA for treatment of Waldenström's macroglobulinemia, a form of non-Hodgkin's lymphoma.
According to the Wall Street Journal in January 2016 ibrutinib, a specialty drug, cost US$116,600 to $155,400 a year wholesale in the United States. In spite of discounts and medical insurance, the prohibitive price causes some patients to not fill their prescriptions. The company marketing the drug, AbbVie, acquired it in May 2015, projecting global sales of US$1 billion in 2016 and $5 billion in 2020.