Febrile Neutropenia in a Patient with Non-Small Cell Lung Cancer Treated with the Immune-Checkpoint Inhibitor Nivolumab.

<strong>BACKGROUND</strong> Nivolumab is a human IgG4 monoclonal antibody against human programmed cell death 1 (PD-1). It has demonstrated efficacy against metastatic non-small cell lung cancer (NSCLC). Treatment with nivolumab is sometimes associated with immune-related adverse events (ir AEs) in patients. These specific ir AEs include pneumonitis, hypothyroidism, dermatitis, enterocolitis, hepatitis, and neuropathy. However, hematological toxicity is rare. <strong>CASE REPORT</strong> A 57-year-old man with lung adenocarcinoma, with brain and adrenal gland metastases, was therefore started on nivolumab therapy as third-line treatment. After administration of the second dose with nivolumab, grade 3 febrile neutropenia (FN) and grade 2 liver dysfunction developed in the patient. The patient was started to on intravenous antibiotics, granulocyte colony-stimulating factor (G-CSF), and corticosteroids. Neutrophil counts and liver function gradually improved, and corticosteroids were tapered over 6 weeks. However, the patient was re-treated with G-CSF because the neutrophil counts decreased again. <strong>CONCLUSIONS</strong> Care needs to be taken with such patients because neutropenia due to treatment with nivolumab can recur, as well as other ir AEs.