At the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting, Jacqueline Barrientos, MD, of the North Shore-LIJ Cancer Institute, Lake Success, NY, summarises the results of a phase 1b trial that evaluated the safety and efficacy of the PI3Kδ inhibitor, idelalisib, in combination with chemoimmunotherapeutic agents for the treatment of patients with previously treated chronic lymphocytic leukemia (CLL). Investigated combinations included idelalisib with rituximab; ofatumumab; bendamustine and rituximab; fludarabine; and chlorambucil.