Safety and Efficacy of Eculizumab in High-risk TA-TMA

High-risk, complement-mediated, untreated transplant-associated thrombotic microangiopathy (hrTA-TMA) carries a very poor prognosis due to multiple organ dysfunction syndrome (MODS). The complement C5 inhibitor eculizumab has shown promising efficacy in children with hrTA-TMA, but has not been prospectively studied in adult allogeneic hematopoietic stem cell transplantation (HSCT) recipients. The investigators plan to conduct the first multicenter prospective study in adults to evaluate eculizumab as an early targeted intervention for hrTA-TMA. The investigators hypothesize that eculizumab will more than double the survival rate of hrTA-TMA in adult HSCT recipients compared with untreated hrTA-TMA patients from our previous study, who will serve as historical controls. Inclusion criteria are a confirmed diagnosis of TA-TMA with at least one of the following hrTA-TMA features: random urine protein-to-creatinine ratio (rUPCR) ≥2 mg/mg, multiple organ dysfunction syndrome (MODS), or elevated plasma IL-10 (≥2× upper limit of normal). The primary endpoint is survival at 6 months after diagnosis of hrTA-TMA. Secondary endpoints are the cumulative incidence of MODS at 6 months after diagnosis of hrTA-TMA, and 1-year post-transplant survival. The eculizumab regimen consists of an intensive loading dose, an induction dose, and a maintenance dose, with a total treatment duration of up to 24 weeks. This study aims to investigate the safety and efficacy of eculizumab in the treatment of high-risk TA-TMA.