Abatacept as maintenance therapy in kidney transplantation: a retrospective comparative study.

Belatacept use is increasinging in kidney transplantation, as it has demonstrated improved graft survival compared with calcineurin inhibitors. However, its intravenous administration and recurrent supply shortages may limit its use. Abatacept has a similar mechanism of action. Although widely used in rheumatology, its use in kidney transplantation remains poorly documented. This study aimed to compare the efficacy and safety of abatacept and belatacept as maintenance immunosuppressive therapy after kidney transplantation. We conducted a retrospective study including adult kidney transplant recipients who were switched to abatacept or belatacept between 2017 and 2023. The primary endpoint was the occurrence of rejection within the first year after conversion. A total of 74 patients were included: 21 in the abatacept group and 53 in the belatacept group. No significant difference was observed in rejection rates at 1 year (respectivily 9.5% vs. 9.4%; p > 0.999). Rates of viral and opportunistic infections were also comparable. These findings, which warrant confirmation in larger studies, suggest that abatacept is associated with acceptable safety outcomes relative to belatacept. Abatacept may thererefore be considered a potential alternative in selected situations, including drug shortage, limited venous access, pregnancy or the need for greater treatment autonomy.