Pharmacist Intervention Preventing Severe Cytokine Release Syndrome Induced by Immune Checkpoint Inhibitor Therapy: A Case Report.

Immune checkpoint inhibitors (ICIs) have significantly advanced cancer treatment, and their clinical indications continue to expand. At the same time, the importance of managing immune-related adverse events (irAEs) has been increasing, along with growing expectations for pharmacist involvement. Herein, we report a case in which prompt pharmacist intervention prevented the progression of cytokine release syndrome (CRS) following ICI therapy. A patient with lung adenocarcinoma received 4 cycles of carboplatin, pemetrexed, and pembrolizumab, followed by maintenance therapy with pemetrexed and pembrolizumab. During the first cycle of maintenance therapy, the patient presented with fever, chills, and fatigue. Despite antibiotic administration, the symptoms persisted. Given the low likelihood of infection and elevated laboratory markers such as ferritin and interleukin-6, CRS was suspected, and the patient was urgently admitted for corticosteroid therapy. However, the patient's respiratory condition deteriorated despite steroid administration. The attending pharmacist actively intervened by recommending additional laboratory tests, performing physical assessments, and suggesting therapeutic options. Following these interventions, the patient's symptoms improved, no further exacerbations occurred, and the patient was discharged. This case highlights the clinical significance of pharmacist intervention in managing ICI-related CRS.