Pharmacyclics first-in-class BTK inhibitor Imbruvica (ibrutinib) received expanded approval by the US Food and Drug Administration (FDA) for chronic lymphocytic leukemia (CLL) in July. Imbruvica, a selective inhibitor of Bruton's tyrosine kinase, which slows the development of B-cell malignancies, was approved in 2013 for mantle cell lymphoma, and in early 2014, it was given accelerated approval for CLL, based on a phase 1/2b clinical trial of 48 CLL patients. In July, the FDA expanded the approval to CLL patients with a deletion in chromosome 17, a form of CLL that responds poorly to standard treatment. The expanded approval, which was announced two months ahead of the application's Prescription Drug User Fee Act (PDUFA) date, was based on a trial with 391 previously treated patients, 127 of whom had the chromosome 17 deletion. It's been a particularly good year for CLL with three other CLL drugs receiving approval through the FDA's breakthrough drug designation since last November: Roche's Gazyva (obinutuxumab), GlaxoSmithKline and Genmab's Arzerra (ofatumumab) and Gilead's Zygelig (idelalisib).