Three-year Outcomes After Conversion From Monthly to Every 2-month Belatacept Maintenance Therapy in Kidney Transplant Recipients: Results From a Randomized Controlled Trial.

Maintenance immunosuppression with belatacept following kidney transplantation results in improved long-term graft function as compared with calcineurin inhibitors. However, broad application of belatacept has been limited, in part related to logistical barriers surrounding a monthly (q1m) infusion requirement. Methods: To determine whether every 2-mo (q2m) belatacept is noninferior to standard q1m maintenance, we conducted a prospective, single-center randomized trial in low-immunologic-risk, stable renal transplant recipients. Here, post hoc analysis of 3-y outcomes, including renal function and adverse events, are reported. Results: One hundred sixty-three patients received treatment in the q1m control group (n = 82) or q2m study group (n = 81). Renal allograft function as measured by baseline-adjusted estimated glomerular filtration rate was not significantly different between groups (time-averaged mean difference of 0.2 mL/min/1.73 m2; 95% confidence interval: -2.5, 2.9). There were no statistically significant differences in time to death or graft loss, freedom from rejection, or freedom from donor-specific antibodies (DSAs). During the extended 12- to 36-mo follow-up, 3 deaths, 1 graft loss occurred in the q1m group, compared with 2 deaths, and 2 graft losses in the q2m group. In the q1m group, 1 patient developed DSAs and acute rejection. In the q2m group, 3 patients developed DSAs and 2 associated with acute rejection. Conclusions: Based on the similar renal function and survival at 36 mo compared with q1m, q2m belatacept is a potentially viable maintenance immunosuppressive strategy in low immunologic risk kidney transplant recipients that may facilitate increased clinical utilization of costimulation blockade-based immunosuppression.

Post-transplant lymphoproliferative disorder risk and outcomes in renal transplant patients treated with belatacept immunosuppression.

Introduction: Post-transplant lymphoproliferative disorder (PTLD) is a rare but life-threatening malignancy that arises in the setting of immunosuppression (IS) after solid organ transplant. IS regimens containing belatacept have been associated with an increased risk of PTLD in Epstein-Barr virus (EBV)-seronegative renal transplant recipients, and the use of belatacept is contraindicated in this population. However, the impact of belatacept-based regimens on PTLD risk and outcomes in EBV-seropositive renal transplant recipients is less well characterized. Methods: A case-control study was conducted to investigate how combinatorial IS regimens impact the risk of PTLD and survival outcomes in renal transplant recipients at a large transplant center between 2010 and 2019. In total, 17 cases of PTLD were identified and matched 1:2 to controls without PTLD by age, sex, and transplanted organ(s). We compared baseline clinical characteristics, examined changes in IS regimen, viral loads, and renal function over time, and evaluated time-to-event analyses, including graft rejection and survival. Results: Cases of PTLD largely resembled matched controls in terms of baseline characteristics, although expected differences in EBV serostatus trended toward significance (42.9% of PTLD cases were donor-positive/recipient-negative vs. 8.3% controls, p = 0.063). PTLD cases were not more likely to have received belatacept than controls. Belatacept was not associated with graft rejection or failure, re-transplant, hospitalization, or decreased survival. Conclusions: Belatacept was not associated with an increased risk of PTLD, and was not associated with decreased survival in either PTLD cases or in the entire cohort. Our case-control study supports the concept that belatacept remains a safe and effective option for IS in EBV-seropositive renal transplant patients.

Impact of belatacept and tacrolimus on cytomegalovirus viral load control and relapse in moderate and high-risk cytomegalovirus serostatus kidney transplant recipients.

BACKGROUND: Belatacept improves long-term graft survival, but control of some primary viral infections may be impaired. We evaluated the impact of belatacept and tacrolimus on cytomegalovirus (CMV) viral control, remission and relapse in CMV high-risk and moderate-risk recipients. METHODS: Using a multistate Markov model, we evaluated viral load state transitions of 173 kidney transplant recipients with at least one episode of viremia within 1 year after transplant: state 1, undetectable/low viral load; state 2, moderate viremia; and state 3, severe viremia. RESULTS: Among high-risk recipients, belatacept-treated recipients exhibited a significantly higher probability of entering moderate viremia (.36; 95% CI = .31, .41) than tacrolimus-treated recipients (.20; 95% CI = .13, .29). The expected number of days in viremic states differed. High-risk belatacept-treated recipients persisted in moderate viremia for significantly longer (128 days, 95% CI = 110, 146) than did tacrolimus-treated recipients (70.0 days, 95% CI = 45.2, 100) and showed a trend of shorter duration in low/undetectable viral load state (172 days, 95% CI = 148, 195) than did tacrolimus-treated recipients (239 days, 95% CI = 195, 277). Moderate-risk recipients showed better viral load control and with no differences by immunosuppression. CONCLUSION: High-risk belatacept-treated recipients showed defects in sustaining viral control relative to tacrolimus-treated recipients. Avoidance of initial use belatacept in high-risk recipients or development of modified management protocols should be considered.

Abatacept as rescue immunosuppression after calcineurin inhibitor treatment failure in renal transplantation.

A majority of kidney transplant recipients receive calcineurin inhibitor-based immunosuppression. However, some do not tolerate calcineurin inhibitors and require other immunosuppressive strategies. Until recently, alternative approaches have been associated with inferior outcomes, but recent methods have effectively utilized belatacept in calcineurin inhibitor-intolerant patients. Though promising, belatacept uptake has been limited by higher acute rejection rates, unavailability due to production shortages, and logistical challenges as a result of intravenous infusion requirements. Interestingly, its predecessor abatacept is clinically available in subcutaneous formulation to treat autoimmune disorders but has not been used in clinical transplantation. Here we report on a series of 9 calcineurin inhibitor-intolerant transplant recipients converted to abatacept early after transplant as rescue immunosuppression during periods of belatacept unavailability. Retrospective review revealed successful allograft salvage and 100% patient and graft survival (median 115 months) after conversion to abatacept. Patients received abatacept for a median duration of 82 months with stable, long-term renal allograft function, a single cellular rejection episode, and no clinically apparent protective immunity concerns. Hence our findings suggest that future clinical studies utilizing abatacept either de novo or as conversion therapy in transplant recipients should be considered.