Laryngeal edema as a symptom of local cytokine release syndrome after BCMA-targeting CAR-T therapy for relapsed and refractory multiple myeloma.

Cytokine release syndrome (CRS) can be a major side effect of chimeric antigen receptor T-cell (CAR-T) therapy, and may occasionally become life-threatening in patients with factors such as high tumor burden or poor performance status. Among the many CRS events observed in B-cell maturation antigen (BCMA)-targeting CAR-T therapy, local symptoms (also called local CRS) are poorly understood due to their low frequency. Here, we present the case of a 54-year-old woman with refractory multiple myeloma exhibiting laryngeal edema as a local CRS. Before CAR-T therapy, she was diagnosed with progressive disease indicated by a left thyroid mass. After local irradiation, she received the BCMA-targeting CAR-T agent idecabtagene vicleucel (ide-cel). On day 2, the patient developed CRS, which resolved on treatment with tocilizumab. However, on day 4, laryngeal edema worsened, and was judged to be a local CRS. Intravenous dexamethasone rapidly reduced this edema. In conclusion, laryngeal edema rarely occurs as a local CRS, and to the best of our knowledge, has never been reported after ide-cel infusion. Dexamethasone was effective for reducing the local reaction that persisted after treatment of systemic symptoms with tocilizumab.