(094) Evaluation of Efficacy and Safety of Eculizumab for the Treatment of Transplant-Associated Thrombotic Microangiopathy (TA-TMA): A Single Center Study

Poster Abstract:

Background: TA-TMA is a complication of hematopoietic cell transplant (HCT) associated with endothelial injury that can be caused by conditioning and immunosuppression. Endothelial injury can initiate and propagate the complement cascade. Ultimately, this activation can lead to hemolytic anemia, platelet activation, and formation of thrombi, leading to end-organ injury from ischemia. Eculizumab is a humanized monoclonal antibody that inhibits complement protein C5 used to treat TA-TMA. Due to the lack of standardized criteria and overlapping signs and symptoms with other complications of HCT, diagnosis proves to be challenging. To help bridge this gap in knowledge, the American Society for Transplantation and Cellular Therapy, Center for International Bone Marrow Transplant Research, Asia-Pacific Blood and Marrow Transplantation, and European Society for Blood and Marrow Transplantation have recently harmonized the diagnostic and prognostic features of TA-TMA and recommend clinical trial enrollment and directed therapy for those with high-risk TA-TMA. Additionally, while eculizumab is often used as the primary treatment, an optimal dosing strategy has not been well-defined for TA-TMA. With these updated guidelines, this project aims to evaluate the usage of eculizumab.

Objectives: To assess the efficacy and safety of eculizumab for TA-TMA in order to create a treatment pathway for The Mount Sinai Hospital (MSH).

Methods: This is a single-center, retrospective cohort analysis of patients who received eculizumab for TA-TMA at MSH. Medical records of patients ≥18 years old who received an allogeneic HCT and received at least one dose of eculizumab between January 1, 2019, and December 31, 2023, were reviewed. The primary objective was to determine the percentage of high-risk TA-TMA patients based on the 2023 Consensus Criteria. Secondary objectives included time to TA-TMA resolution as defined by tapering of eculizumab, mortality at 30-day and 90-day post-eculizumab initiation, rates of infection requiring intravenous (IV) antibiotics during eculizumab therapy, intensive care unit admissions, meningococcal vaccination adherence, antibiotic prophylaxis adherence at start of eculizumab, and recurrence of TA-TMA after tapering/discontinuation. Data will be analyzed using descriptive statistics appropriate for categorical and continuous data.

Results: Results pending.

Conclusions: Conclusions pending.

References (must also be included in final poster): Schoettler ML, Carreras E, Cho BS. Transplant Cell Ther. 2023;29(3):151-163.
Jodele S, Dandoy CE, Lane A, et.al. Blood. 2020;135 (13): 1049–1057.
Young JA, Pallas CR, Knovich MA. Bone Marrow Transplant. 2021; 56(8): 1805–1817.