# Envarsus Versus Advagraf in De Novo Kidney Transplant Recipients: A Comparative Pharmacokinetic Study

## TL;DR

This study compares two once-daily tacrolimus formulations in kidney transplant patients, finding that Envarsus provides higher early drug exposure and requires lower maintenance doses than Advagraf.

## Contribution

The study provides real-world pharmacokinetic data comparing Envarsus and Advagraf in de novo kidney transplant recipients.

## Key findings

- Envarsus achieved higher trough concentrations and dose-normalized exposure than Advagraf at 48 hours.
- Envarsus required lower daily doses while maintaining similar trough levels over 3 months.
- Early overexposure was more frequent with Envarsus, suggesting the need for careful monitoring and possibly lower starting doses.

## Abstract

Background: Comparative real-world data on the pharmacokinetics of once-daily tacrolimus formulations in de novo kidney transplantation remain limited. We compared tacrolimus exposure and dosing requirements with Envarsus and Advagraf during the early post-transplant period. Methods: We conducted a prospective, observational, single-center study including adult de novo kidney transplant recipients treated with once-daily tacrolimus as either Envarsus or Advagraf. The immunosuppressive protocol was based on thymoglobulin induction, with delayed initiation of tacrolimus at an initial dose of 0.15 mg/kg/day, prednisone, and sirolimus as the third immunosuppressive agent. Trough concentrations (C0), daily dose, and dose-normalized trough exposure (C0/D) were assessed at 48 h and over 3 months (days 7, 14, 30, 60, and 90). Dose adjustments were guided by therapeutic drug monitoring and Bayesian individualization to achieve target trough ranges (6–10 ng/mL during month 1; 5–7 ng/mL thereafter). Clinical effectiveness and safety outcomes were evaluated through month 3. Results: Ninety recipients were included (Advagraf n = 43; Envarsus n = 47). At 48 h, Envarsus achieved higher trough concentrations and higher C0/D than Advagraf (C0: 10.7 vs. 7.7 ng/mL; C0/D: 1.30 vs. 0.75 (ng/mL)/mg; both p < 0.001). From week 1 to month 3, trough concentrations were similar between groups (week 1: 8.5 vs. 8.5 ng/mL, p = 0.968; month 3: 5.7 vs. 5.1 ng/mL, p = 0.234), but Envarsus required lower daily doses (week 1: 6.4 vs. 9.9 mg/day, p = 0.001; month 3: 3.2 vs. 4.1 mg/day, p = 0.021) and maintained higher C0/D (week 1: 1.53 vs. 1.00, p = 0.001; month 3: 1.94 vs. 1.57 (ng/mL)/mg, p = 0.012). At 48 h, infra-therapeutic troughs were less frequent with Envarsus (6.7% vs. 40.5%, p = 0.0001), while supra-therapeutic levels were more frequent (57.8% vs. 18.9%), and tacrolimus discontinuation due to high troughs occurred more often (23.4% vs. 7.0%, p = 0.032). Over 3 months, the proportion of measurements within the therapeutic range was similar (57.6% vs. 64.5%, p = 0.705). Efficacy and safety were similar between groups. Conclusions: In de novo kidney transplant recipients, Envarsus provides higher early tacrolimus exposure and consistently higher dose-normalized trough exposure than Advagraf, enabling lower maintenance doses while maintaining similar short-term effectiveness and safety. However, early overexposure was more frequent with Envarsus at 0.15 mg/kg/day, supporting careful early monitoring and consideration of lower starting doses.