Fatal cytokine-release syndrome in a patient receiving toripalimab: a case report

Immune checkpoint inhibitors, a type of immunotherapy, have demonstrated optimal treatment efficacy in inducing durable antitumor responses in various cancers. Cytokine-release syndrome is a rare immune-related adverse event induced by immune checkpoint inhibitors. In our case, a patient with hypopharyngeal squamous cell carcinoma received toripalimab combined with chemotherapy. On the fourth day post treatment, the patient developed fever and hypotension. Laboratory examination indicated myelosuppression, acute kidney injury and disseminated intravascular coagulation. Meanwhile, serum cytokine levels of IL-6, IL-8, IL-10, IL-1β, IFN-γ and the level of hypersensitive C-reactive protein were markedly elevated. The patient was diagnosed with cytokine release syndrome, which progressed rapidly and led to the patient's demise on the fifth day post treatment.Immune checkpoint inhibitors (ICIs) have shown revolutionary efficacy in the treatment of multiple cancers. Cytokine-release syndrome (CRS) is a common and lethally adverse event of chimeric antigen receptor T-cell therapy; however, this adverse effect is rare in ICI therapy. Presently, while ICI-associated CRS is reported almost exclusively in case reports, fatal outcomes are rarely observed. A patient with hypopharyngeal squamous cell carcinoma received toripalimab combined with chemotherapy. On the fourth day post treatment, the patient developed CRS, which progressed rapidly, and the patient died on the fifth day post treatment.