Three-Year Outcomes of a Randomized, Double-Blind, Placebo-Controlled Study Assessing Safety and Efficacy of C1 Esterase Inhibitor for Prevention of Delayed Graft Function in Deceased Donor Kidney Transplant Recipients.

Background And Objectives: Delayed graft function is related to ischemia-reperfusion injury and may be complement dependent. We previously reported from a randomized, placebo-controlled trial that treatment with C1 esterase inhibitor was associated with a shorter duration of delayed graft function and higher eGFR at 1 year. Here, we report longer-term outcomes from this trial.

Design, Setting, Participants, & Measurements: This is a analysis of a phase 1/2, randomized, controlled trial enrolling 70 recipients of deceased donor kidney transplants at risk for delayed graft function (NCT02134314). Subjects were randomized to receive C1 esterase inhibitor 50 U/kg (=35) or placebo (=35) intraoperatively and at 24 hours. The cumulative incidence functions method was used to compare graft failure and death over 3.5 years. eGFR slopes were compared using a linear mixed effects model.

Results: Three deaths occurred among C1 esterase inhibitor-treated patients compared with none receiving placebo. Seven graft failures developed in the placebo group compared with one among C1 esterase inhibitor-treated recipients; the cumulative incidence of graft failure was lower over 3.5 years among C1 esterase inhibitor-treated recipients compared with placebo (=0.03). Although no difference in eGFR slopes was observed between groups ( for group-time interaction =0.12), eGFR declined in placebo-treated recipients (-4 ml/min per 1.73 m per year; 95% confidence interval, -8 to -0.1) but was stable in C1 esterase inhibitor-treated patients (eGFR slope: 0.5 ml/min per 1.73 m per year; 95% confidence interval, -4 to 5). At 3.5 years, eGFR was 56 ml/min per 1.73 m (95% confidence interval, 42 to 70) in the C1 esterase inhibitor group versus 35 ml/min per 1.73 m (95% confidence interval, 21 to 48) in the placebo group, with an estimated mean eGFR difference of 21 ml/min per 1.73 m (95% confidence interval, 2 to 41 ml/min per 1.73 m).

Conclusions: Treatment of patients at risk for ischemia-reperfusion injury and delayed graft function with C1 esterase inhibitor was associated with a lower incidence of graft failure.