Tacrolimus exposure in the real world: an analysis from the M ycophenolic acid O bservational RE nal transplant study

Tacrolimus exposure and renal function data to 36 months post‐transplant were analyzed from the prospective, observational M ycophenolic acid O bservational RE nal transplant ( MORE ) registry in which de novo kidney transplant patients were managed according to local practice. Tacrolimus trough ( C 0 ) concentration at month 12 was stratified as low (<6 ng/mL), moderate (6–8 ng/mL), or high (>8 ng/mL) in 724 patients. Estimated glomerular filtration rate (e GFR ) was stratified as low (<60 mL/min/1.73 m 2 ) or high (≥60 mL/min/1.73 m 2 ). High tacrolimus C 0 (>8 ng/mL) was observed in 47.7%, 34.1%, 26.8%, and 26.7% of patients at baseline and months 12, 24, and 36, respectively. Biopsy‐proven acute rejection was similar to month 36 regardless of tacrolimus C 0 category at month 12. Tacrolimus C 0 >8 ng/mL vs. <6 ng/mL at month 12 was predictive of low e GFR at month 24 (p = 0.023) with a nonsignificant trend at month 36 (p = 0.085). Infections (p < 0.013) and BK virus infection (p < 0.001) were most frequent in the low tacrolimus C 0 cohort. Neutropenia was most frequent in the high tacrolimus C 0 category (p = 0.010). In conclusion, over a quarter of patients were exposed to high tacrolimus C 0 to 36 months post‐transplant. Tacrolimus exposure did not affect rejection risk, but tacrolimus C 0 >8 ng/mL at month 12 was predictive of subsequent low e GFR compared to C 0 <6 ng/mL.