Belatacept Conversion Protocols and Outcomes in Kidney Transplant Recipients

Conversion from calcineurin inhibitor (CNI)-based to belatacept-based immunosuppression has become common; however, numerous protocols have emerged in lieu of a standardized protocol. The purpose of this study was to characterize belatacept conversion protocols from multiple centers and observe outcomes. This was a retrospective study that included Kaiser Permanente Southern California members. The primary outcome was rejection 6 months after conversion and secondary outcomes included change in serum creatinine and graft loss. Seventy-eight patients were included. Thirteen distinct protocols were identified from 8 different transplant centers. Protocols varied by initial dose, induction schedule, and CNI taper. The observed rate of rejection was 6%. There was a trend toward an association of rejection with lower tacrolimus exposure at the time of conversion and lower mycophenolic acid dosing postconversion. Graft survival was 88% and patient survival was 94%. There was a significant improvement in creatinine after conversion. Those with early conversions and creatinine >2.0 mg/dL at the time of conversion had the best response. A large variety of belatacept conversion protocols were identified. Protocols were defined by the initial dose, induction regimen, and CNI taper. Rejection rates were low and may be influenced by exposure to maintenance immunosuppression during and after conversion. Most patients showed stabilization and improvement in creatinine postconversion, with the largest effect in those with an early conversion and serum creatinine >2.0 mg/dL. •A large variety of belatacept conversion protocols are being used and vary by initial belatacept dose, induction frequency, and calcineurin inhibitor (CNI) tapering scheme.•Renal function improved significantly in those without postconversion rejection. On the contrary, those with rejection did not experience an improvement in renal function.•The most robust improvement in kidney function was seen in those converted within 1 year of transplant with a creatinine ≥2.0 mg/dL at the time of conversion.•Lower tacrolimus exposure at the time of conversion and lower mycophenolic acid dose tended to be associated with rejection.•Attention should be paid to CNI tapering regimen, CNI exposure, and maintenance mycophenolic acid dosing during conversion to prevent rejection.