Haematological toxicities with immunotherapy in patients with cancer: a systematic review and meta-analysis

•Incidence of PD-[L]1 inhibitor's haematological toxicity is presently unknown and under-reported.•We have performed a systematic review and meta-analysis of 47 trials among solid tumours.•Anaemia, neutropenia, febrile neutropenia and thrombocytopenia were 9.8, 0.9, 2.8 and 0.4%.•The risk of anaemia with anti-PD-(L)1 agents is not negligible, while that of neutropenia was rare.•Clinicians should check the complete blood cell count before every cycle of therapy.