Idelalisib is no longer recommended as first line treatment for chronic lymphocytic leukaemia in patients who have 17p deletion or TP53 mutation, and it should not be initiated in patients with any evidence of ongoing systemic bacterial, fungal, or viral infection. Prophylaxis for Pneumocystis jirovecii pneumonia should be administered to all patients throughout idelalisib treatment., and patients should also be monitored for infection and have regular blood tests for white cell counts because low counts can increase their risk of infection. The SPC also has new information on dose modification guidance for management of neutropenia.