Two cases of durvalumab-induced Evans syndrome in biliary tract cancer.

We present two cases of Evans syndrome (ES) during durvalumab monotherapy after combination chemotherapy with durvalumab for advanced hilar cholangiocarcinoma. The patients were men aged 71 and 73 years with satisfactory performance status. They received eight cycles of gemcitabine, cisplatin, and durvalumab, followed by durvalumab monotherapy (five and six cycles, respectively) for a total of approximately 11 months. Subsequently, they developed autoimmune hemolytic anemia, characterized by reticulocytosis, indirect hyperbilirubinemia, elevated lactate dehydrogenase levels, and a positive direct Coombs test. Furthermore, their condition met the diagnostic criteria for ES, as they developed concomitant thrombocytopenia with antiplatelet antibodies. Both patients demonstrated hematological recovery with corticosteroid therapy, highlighting the efficacy of immunosuppression in managing this rare hematologic immune-related adverse event. Notably, the onset occurred during maintenance therapy after a prolonged latency of 11 months, underscoring the potential for delayed hematologic immune-related adverse events with programmed death-ligand 1 blockade. Corticosteroids remain the cornerstone of treatment, and high-dose pulse therapy may be necessary in refractory cases. In conclusion, recognition of durvalumab-induced ES is crucial for appropriate management.