Eculizumab Prophylaxis for Systematic Rechallenging Gemcitabine in Gemcitabine-Induced Thrombotic Microangiopathy: A Case Report.

Gemcitabine-induced thrombotic microangiopathy (GITMA) is a rare yet devastating complication in patients receiving gemcitabine, especially at cumulative doses above 20,000 mg/m². We report the case of a 72-year-old woman with metastatic pancreatic adenocarcinoma who developed severe thrombotic microangiopathy (TMA) during gemcitabine and nab-paclitaxel therapy. Her initial presentation included thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury. A kidney biopsy confirmed TMA and, given the high likelihood this was related to gemcitabine, therapy was discontinued and the patient was transitioned to folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX). Although the patient stabilized with improved renal and hematologic parameters, her cancer progressed radiographically. Given her good performance status and the need for effective tumor control, a decision was made to rechallenge with gemcitabine under prophylactic terminal complement blockade. She received eculizumab 900 mg intravenously for 4 weekly doses, followed by reintroduction of gemcitabine and nab-paclitaxel. Over 4 treatment cycles given during a 3-month period, the patient showed no signs of GITMA recurrence, maintaining stable renal function and normal hemolysis markers. This case demonstrates the potential role of eculizumab in preventing recurrent GITMA, allowing continued gemcitabine-based therapy for metastatic pancreatic adenocarcinoma. Further research is warranted to define optimal dosing and timing of eculizumab and long-term outcomes.