Refractory insulin resistance and hemophagocytic lymphohistiocytosis following enfortumab vedotin treatment: A case report.

The increasing incidence of urothelial carcinoma, coupled with advancements in its therapeutic landscape, has resulted in improved survival rates for patients. This, in turn, has led to a growing population of patients requiring specialized oncological care, with Enfortumab vedotin (EV) emerging as a pivotal treatment for metastatic urothelial carcinoma. While EV is associated with hyperglycemia, ketoacidosis is exceedingly rare. To the best of our knowledge, the link between EV and hemophagocytic lymphohistiocytosis (HLH) has not yet been explored. A 56-year-old patient diagnosed with metastatic urothelial carcinoma underwent EV treatment as a third-line treatment after progression following treatment with cisplatin/gemcitabine and pembrolizumab. Notably, after receiving two doses of EV, the patient exhibited refractory insulin resistance, leading to ketoacidosis. Subsequently, HLH emerged, necessitating a treatment regimen involving dexamethasone and etoposide. Despite intensive efforts, the patient experienced septic shock, resulting in death. The present case report highlights refractory insulin resistance and ketoacidosis, followed by reactive HLH, in the context of EV therapy. The limited literature on these complications demonstrates the need for further research to improve the understanding of the underlying mechanisms. With growing evidence of the efficacy of EV and evolving survival rates in urothelial carcinoma, healthcare professionals must remain vigilant for potential adverse effects, ensuring early recognition and optimal patient care.