A case of immune thrombocytopaenia induced by pembrolizumab in a metastatic melanoma patient with a history of immune-mediated pure red cell aplasia

Abstract

Immune checkpoint blocking agents such as the Programmed cell death-1 (PD1)-antagonist pembrolizumab have been approved for the treatment of metastatic melanoma [ [1] Robert C. Schachter J. Long G.V. Arance A. Grob J.J. Mortier L. et al. Pembrolizumab versus ipilimumab in advanced melanoma. N Engl J Med. 2015; 372: 2521-2532https://doi.org/10.1056/NEJMoa1503093 Crossref PubMed Scopus (4050) Google Scholar ]. Owing to its mechanism of action, this drug restores tumour-specific T-cell response and may induce various types of immune-related adverse events (irAEs) [ [2] Abdel-Wahab N. Shah M. Suarez-Almazor M.E. Adverse events associated with immune checkpoint blockade in patients with cancer: a systematic review of case reports. PLoS One. 2016; 11: e0160221https://doi.org/10.1371/journal.pone.0160221 Crossref PubMed Scopus (302) Google Scholar ]. Haematological toxicities are rare, and cytopenia of autoimmune origin remain exceptional. Herein, we report the occurrence of successive haematologic adverse events in a patient treated with pembrolizumab for a metastatic melanoma including an immune-mediated pure red cell aplasia (PRCA) followed by an immune thrombocytopaenia (IT).