Belatacept for Simultaneous Calcineurin Inhibitor and Chronic Corticosteroid Immunosuppression Avoidance: Two-Year Results of a Prospective, Randomized Multicenter Trial

Abstract

Background and objectives: Immunosuppressive therapy in kidney transplantation is associated with numerous toxicities. CD28-mediated T-cell costimulation blockade using belatacept may reduce long-term nephrotoxicity, compared with calcineurin inhibitor-based immunosuppression. The efficacy and safety of simultaneous calcineurin inhibitor avoidance and rapid steroid withdrawal were tested in a randomized, prospective, multicenter study.

Design, setting, participants, & measurements: This study reports the 2-year results of a randomized clinical trial of 316 recipients of a new kidney transplant. All kidney transplants were performed using rapid steroid withdrawal immunosuppression. Recipients were randomized in a 1:1:1 ratio to receive belatacept with alemtuzumab induction, belatacept with rabbit anti-thymocyte globulin (rATG) induction, or tacrolimus with rATG induction. The composite end point consisted of death, kidney allograft loss, or an eGFR of <45 ml/min per 1.73 m2 at 2 years.

Results: The composite end point was observed for 11 of 107 (10%) participants assigned to belatacept/alemtuzumab, 13 of 104 (13%) participants assigned to belatacept/rATG, and 21 of 105 (21%) participants assigned to tacrolimus/rATG (for belatacept/alemtuzumab versus tacrolimus/rATG, P=0.99; for belatacept/rATG versus tacrolimus/rATG, P=0.66). Patient and graft survival rates were similar between all groups. An eGFR of <45 ml/min per 1.73 m2 was observed for nine of 107 (8%) participants assigned to belatacept/alemtuzuab, eight of 104 (8%) participants assigned to belatacept/rATG, and 20 of 105 (19%) participants assigned to tacrolimus/rATG (P<0.05 for each belatacept group versus tacrolimus/rATG). Biopsy sample-proven acute rejection was observed for 20 of 107 (19%) participants assigned to belatacept/alemtuzuab, 26 of 104 (25%) participants assigned to belatacept/rATG, and seven of 105 (7%) participants assigned to tacrolimus/rATG (for belatacept/alemtuzumab versus tacrolimus/rATG, P=0.006; for belatacept/rATG versus tacrolimus/rATG, P<0.001). Gastrointestinal and neurologic adverse events were less frequent with belatacept versus calcineurin-based immunosuppression.

Conclusions: Overall 2-year outcomes were similar when comparing maintenance immunosuppression using belatacept versus tacrolimus, and each protocol involved rapid steroid withdrawal. The incidence of an eGFR of <45 ml/min per 1.73 m2 was significantly lower with belatacept compared with tacrolimus, but the incidence of biopsy sample-proven acute rejection significantly higher.

Clinical trial registry name and registration number: Belatacept Early Steroid Withdrawal Trial, NCT01729494.

Keywords: immunosuppression; kidney transplantation; transplant outcomes.

Copyright © 2021 by the American Society of Nephrology.

Figures

Graphical abstract

Figure 1.

Study flow diagram. ITT, intention to treat; rATG, rabbit anti-thymocyte globulin.

Figure 2.

Kaplan–Meier estimates of freedom from secondary end point, patient and graft survival, and biopsy sample–proven acute rejection (BPAR) at 2 years. (A) Primary composite outcome, (B) patient survival, (C) death-censored graft survival, and (D) freedom from biopsy sample–proven acute cellular rejection. Group A, alemtuzumab/belatacept; group B, rATG/belatacept; group C, rATG/tacrolimus.