#2237 Preliminary results of Protection of Renal Function after Conversion of fast IR-Tac Metabolizers to Envarsus® study (The Protect RENvarsus study)

Abstract Background and Aims As shown in a proof-of-concept study, renal function of fast immediate-release tacrolimus (IR-Tac) metabolizers can recover after conversion to prolonged-release tacrolimus (LCP-Tac), whereas slow Tac metabolizers showed no benefit over a 3-year follow-up [1]. The aim of this study is to test this hypothesis in a multi-center trial. Method In a multicenter European trial, we aim to enroll 300 renal transplant (RTx) recipients who were switched from IR-Tac to LCP-Tac one month or later after RTx. Metabolizer groups will be defined by calculation of the C/D ratio at one month after RTx: fast IR-Tac metabolizers (<1 ng/mL*1/mg) and slow (≥1) [2]. The development of renal function, acute rejections, infections, and the development of diabetes mellitus will be observed in a 5-year follow-up. Results A total of 265 patients have been included in this study to date. Preliminary data confirm that fast metabolizers who were switched to LCP-Tac at a median time of 2.0 months (range: 1.0-253.1 months) showed a recovery of renal function. In contrast, slow metabolizers showed a stable eGFR after switching to LCP-Tac at a median time of 13.2 months (range: 1.2-172.8 months) following RTx. The incidence of complications was low and comparable in both groups. Conclusion Preliminary data confirm that early conversion of fast IR-Tac metabolizers to LCP-Tac can improve renal function after RTx. The 5-year follow-up data will provide additional insight.