Clinically significant bleeding with immune checkpoint inhibitors: A retrospective cohort study

Immune checkpoint inhibitors (ICIs) have changed the clinical outcomes of many malignancies. ICIs have been approved for the treatment of multiple malignancies including melanoma, non–small-cell lung cancer (NSCLC) and renal cell cancer. ICIs target programmed cell death receptor-1 or ligand-1 (PD-1/PD-L1) and lymphocyte-associated protein 4 to activate the immune system against cancer cells [ [1] Onoi K. Chihara Y. Uchino J. Shimamoto T. Morimoto Y. Iwasaku M. et al. Immune checkpoint inhibitors for lung cancer treatment: a review. J Clin Med. 2020; 9 Crossref PubMed Scopus (26) Google Scholar ]. Haematological immune-related adverse events (hem-irAEs) are rare compared with the involvement of other organ systems and include immune thrombocytopenia (ITP), acute haemolytic anaemia (HA), aplastic anaemia and haemophagocytic lymphohistiocytosis [ 2 Michot J.M. Bigenwald C. Champiat S. Collins M. Carbonnel F. Postel-Vinay S. et al. Immune-related adverse events with immune checkpoint blockade: a comprehensive review. Eur J Cancer. 2016; 54: 139-148 Abstract Full Text Full Text PDF PubMed Scopus (1129) Google Scholar , 3 Michot J.M. Lazarovici J. Tieu A. Champiat S. Voisin A.L. Ebbo M. et al. Haematological immune-related adverse events with immune checkpoint inhibitors, how to manage?. Eur J Cancer. 2019; 122: 72-90 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 4 Delanoy N. Michot J.M. Comont T. Kramkimel N. Lazarovici J. Dupont R. et al. Haematological immune-related adverse events induced by anti-PD-1 or anti-PD-L1 immunotherapy: a descriptive observational study. Lancet Haematol. 2019; 6: e48-e57 Abstract Full Text Full Text PDF PubMed Scopus (92) Google Scholar ]. Several studies have suggested that activated T cells against normal blood cells may contribute to pathogenesis [ [5] Pang X. Su X. Zhang Z. Cui Y. Immune thrombocytopenia of haematological immune-related adverse events in cancer immunotherapy: most and mighty. Eur J Cancer. 2020; 131: 16-17 Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar ]. Given the scarcity of studies examining the clinical impact of hem-irAEs on outcomes of cancer patients, we hereby report our experience.