Long Term Outcomes of Transplant Recipients Comparing Belatacept vs. Tacrolimus: A UNOS Database Analysis.

Calcineurin inhibitors have been the choice for maintenance immunosuppression (IS) in kidney transplant recipients (KTR), but they are associated with nephrotoxicity and metabolic side effects. We aim to compare the long-term outcomes of KTR on belatacept (bela) versus tacrolimus (tac) IS, in all KTRs and various subgroups. Using the UNOS-STAR files, we identified adult first-KTR from 2010 to 2022. Patients were categorized based on maintenance-IS at index transplant admission by creating a propensity score matched cohort at 1:5 rate using several clinical characteristics. Primary outcomes included patient death, graft failure (GF), and death-censored graft failure (DCGF). Secondary outcomes included delayed graft function (DGF), acute-rejections (AR) within a year, and serum creatinine (Cr) at 1-year. The propensity-matched cohort included KTRs on bela (N = 2612) and tac (N = 12760). There was no significant difference in the hazard ratio of death (1.03 [0.92, 1.14]), GF (1.07 [0.97, 1.17]), or DCGF (1.11 [0.98, 1.25]). A sensitivity analysis comparing a propensity-matched cohort of bela + tac (n = 2033) versus tac (n = 9004); demonstrated significantly reduced risks of death (0.87 [0.76-1.00], p = 0.043) and GF (0.73 [0.64-0.83] p < 0.001) compared to those on Tac alone. In conclusion, bela + tac seems to be a nephron-sparing and rejection-lowering IS regimen with overall improved graft and patient outcomes when compared to the current standard of tacrolimus. Larger Randomized Controlled studies are needed.