Management of extravasations of enfortumab vedotin and pembrolizumab: a case report and mini review of the current literature

Following the EV-302/KEYNOTE-A39 study, the combination therapy of enfortumab vedotin and pembrolizumab (EV-P) has been established as a new first-line treatment for metastatic urothelial carcinoma. With increasing use, the documentation and publication of unexpected side effects and complications are essential to systematize procedures. We report on a 56-year-old patient who experienced an extravasation of EV-P during the first cycle due to dislocation of the port catheter from the cephalic vein. Extensive subcutaneous necrosis of the infraclavicular region required surgical debridement and application of a vacuum-assisted closure system, followed by secondary wound healing. The wound healed with a residual scar but no functional impairment or persistent pain. The therapy was resumed via a peripheral venous catheter, and the patient achieved a deep partial response. To our knowledge, this represents the first reported case of central venous EV-P extravasation (CTCAE grade 3) requiring surgical therapy. Because of its cytotoxic payload, EV in particular may pose a high risk of local complications in the context of extravasations.