Eyre TA, Preston G, Kagdi H, et al. - Researchers undertook a protocol-led, retrospective, cohort study, RETRO-idel, to determine the efficacy as well as the safety of idelalisib (IDL; an oral first-in-class phosphatidylinositol 3-kinase delta inhibitor) in combination with rituximab [IDL-R] in patients suffering from chronic lymphocytic leukaemia in routine clinical practice in the UK and Ireland. Participants were 110 patients [n = 27 front-line (1L)] treated with IDL-R. The best overall response rate (intention-to-treat) obtained was 88·2% (1L 96·3%, relapsed/refractory 85·5%). A median event-free survival of 20·3 months was reported and time-to-next treatment was noted to be 29·2 months. A 3-year overall survival of 56·1% was achieved. Findings revealed that IDL-R has a clear efficacy in routine practice. No new safety signals emerged, however, careful management of recognized toxicities is needed.