Similar Efficacy in Belatacept-Converted Kidney Transplant Recipients With Steroid-Avoiding Regimen.

Introduction: Belatacept offers a valuable alternative to calcineurin inhibitors (CNIs) for reducing toxicity in kidney transplant recipients (KTRs). No study has evaluated the efficacy and safety of late-conversion belatacept with steroid avoidance in KTRs.

Methods: This retrospective multicentric study evaluated the efficacy and safety of a belatacept-based steroid-avoiding therapy, in comparison with concomitant steroid use. The study included KTRs from 4-French transplant centers who were converted to belatacept at least 6 months posttransplantation.

Results: Overall, 512 KTRs were converted to belatacept in a median time of 38 (15.7-83.2) months after kidney transplantation (KT), including 199 patients without steroids after conversion (BelaS-). Median follow-up time was 78.9 (50.3-129.4) months. Compared with the 313 KTRs who had concomitant steroid use (BelaS+), BelaS- patients had a similar acute rejection (AR) rate (19 [6.1%] and 12 [6.0%] patients,  = 0.126, including 13 [68.4%] and 5 [41.7%] T cell-mediated rejection in BelaS+ and BelaS- patients, respectively), and a similar graft survival (graft loss occurred in respectively 23 [7.3%] and 9 [4.5%] patients in BelaS+ and BelaS- groups [ = 0.198]). However, patient mortality was higher among BelaS+ patients (16.6% vs. 3%,  < 0.001). Steroid use was an independent risk factor of mortality ( = 0.009) along with age ( = 0.0001) and diabetes ( = 0.001) at switch and the occurrence of severe infections with belatacept use ( = 0.0005). In addition, BelaS+ patients experienced a higher incidence of severe infections (cumulative incidence of 13.7 vs. 6.7 events/100-person-year), cytomegalovirus (CMV) disease ( < 0.001), infection by norovirus ( < 0.001), and hospitalization with COVID-19 ( < 0.001). BelaS+ patients were significantly more sensitized at conversion (donor-specific antibodies [DSA] in 21.8% vs. 6.6% in BelaS- patients,  < 0.001). DSA incidence remained stable after conversion. BelaS+ patients developed significantly more DSA (14 [4.9%] vs. 2 [1.0%],  < 0.001).

Conclusion: Avoiding steroids in KTRs who are late-converted to belatacept is associated with a similar efficacy along with lower mortality and reduced incidence of severe infections in selected low-sensitized patients.