Ten‐year outcomes in a randomized phase II study of kidney transplant recipients administered belatacept 4‐weekly or 8‐weekly

In the phase II IM103‐100 study, kidney transplant recipients were first randomized to belatacept more‐intensive‐based (n = 74), belatacept less‐intensive‐based (n = 71), or cyclosporine‐based (n = 73) immunosuppression. At 3‐6 months posttransplant, belatacept‐treated patients were re‐randomized to receive belatacept every 4 weeks (4‐weekly, n = 62) or every 8 weeks (8‐weekly, n = 60). Patients initially randomized to cyclosporine continued to receive cyclosporine‐based immunosuppression. Cumulative rates of biopsy‐proven acute rejection (BPAR) from first randomization to year 10 were 22.8%, 37.0%, and 25.8% for belatacept more‐intensive, belatacept less‐intensive, and cyclosporine, respectively (belatacept more‐intensive vs cyclosporine: hazard ratio [HR] = 0.95; 95% confidence interval [CI] 0.47‐1.92; P = .89; belatacept less‐intensive vs cyclosporine: HR = 1.61; 95% CI 0.85‐3.05; P = .15). Cumulative BPAR rates from second randomization to year 10 for belatacept 4‐weekly, belatacept 8‐weekly, and cyclosporine were 11.1%, 21.9%, and 13.9%, respectively (belatacept 4‐weekly vs cyclosporine: HR = 1.06, 95% CI 0.35‐3.17, P = .92; belatacept 8‐weekly vs cyclosporine: HR = 2.00, 95% CI 0.75‐5.35, P = .17). Renal function trends were estimated using a repeated‐measures model. Estimated mean GFR values at year 10 for belatacept 4‐weekly, belatacept 8‐weekly, and cyclosporine were 67.0, 68.7, and 42.7 mL/min per 1.73 m(2), respectively (P<.001 for overall treatment effect). Although not statistically significant, rates of BPAR were 2‐fold higher in patients administered belatacept every 8 weeks vs every 4 weeks.