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.     

Experience with belatacept rescue therapy in kidney transplant recipients

In kidney transplant recipients with chronic graft dysfunction, long‐term immunosuppression with calcineurin inhibitors (CNIs) or mTOR inhibitors (mTORi) can be challenging due to adverse effects, such as nephrotoxicity and proteinuria. Seventy‐nine kidney transplant recipients treated with CNI‐based or mTORi‐based maintenance immunosuppression who had CNI‐induced nephrotoxicity or severe adverse events were switched to belatacept. Mean time from transplantation to belatacept conversion was 69.0 months. Mean estimated glomerular filtration rate (eGFR) ± standard deviation at baseline was 26.1 ± 15.0 ml/min/1.73 m², increasing to 34.0 ± 15.2 ml/min/1.73 m² at 12 months postconversion (P < 0.0005). Renal function improvements were also seen in patients with low eGFR (<25 ml/min/1.73 m²) or high proteinuria (>500 mg/l) at conversion. The Kaplan–Meier estimates for patient and graft survival at 12 months were 95.0% and 85.6%, respectively. The discontinuation rate due to adverse events was 7.9%. One case of post‐transplant lymphoproliferative disorder occurred at 17 months postconversion. For comparison, a historical control group of 41 patients converted to mTORi‐based immunosuppression because of biopsy‐confirmed CNI‐induced toxicity was examined; eGFR increased from 27.6 ± 7.2 ml/min/1.73 m² at baseline to 31.1 ± 11.9 ml/min/1.73 m² at 12 months (P = 0.018). Belatacept‐based immunosuppression may be an alternative regimen for kidney transplant recipients with CNI‐ or mTORi‐induced toxicity.     

Effect of mammalian target of rapamycin inhibitors on cytomegalovirus infection in kidney transplant recipients receiving polyclonal antilymphocyte globulins: a propensity score‐matching analysis

Mammalian target of rapamycin inhibitors (mTORi) prevents cytomegalovirus (CMV) infection in kidney transplant (KT) patients. From May 2010 to December 2013, all KT recipients were retrospectively analysed. Maintenance immunosuppression regimen was divided into mTORi or calcineurin inhibitors (CNI)‐based regimen. Since June 2011, CMV‐seropositive recipients (R+) treated with high‐intensity immunosuppression and mTORi did not receive anti‐CMV prophylaxis. We analysed 350 consecutive patients, of which 95 (27%) received mTORi and 255 (73%) CNI‐based immunosuppression. A Cox‐regression multivariate analysis showed that the use of mTORi‐based immunosuppression during all follow‐up reduced the risk of CMV infection (HR 0.36, 95% CI 0.15–0.89, P = 0.028) and confirmed in a propensity score‐matched cohort (HR 0.4, 95% CI 0.1–0.9, P = 0.047). Early discontinuation of mTORi increased the risk of CMV infection (HR 3.2; 95% CI 1.7–6.0) in univariate analysis. The incidence of CMV infection was not higher among CMV R+ patients on mTORi and requiring high‐intensity immunosuppression when CMV prophylaxis was not given. The use of mTORi protected for CMV infection in KT patients, allowing to avoid antiviral prophylaxis for R+ patients receiving high‐intensity immunosuppression. The increased risk of CMV infection after early discontinuation of mTORi warrants further research.     

An overview of the efficacy and safety of everolimus in adult solid organ transplant recipients

As the risk of graft loss due to acute rejection has declined, the goal of post-transplant management has switched to long-term preservation of organ function. Minimizing calcineurin inhibitor (CNI)-related nephrotoxicity is a key component of this objective. Everolimus is a mammalian target of rapamycin inhibitor/proliferation-signal inhibitor with potent immunosuppressive and anti-proliferative effects. It has been widely investigated in large randomized clinical studies that have shown it to have similar anti-rejection efficacy compared with standard-of-care regimens across organ transplant indications. With demonstrated potential to facilitate the reduction of CNI therapy and preserve renal function, everolimus is an alternative to the current standard-of-care CNI-based regimens used in de novo and maintenance solid organ transplantation recipients.Here, we provide an overview of the evidence from the everolimus clinical study program across kidney, liver, heart, and lung transplants, as well as other key data associated with its use in CNI reduction strategies in adult transplant recipients.     

De novo belatacept in clinical vascularized composite allotransplantation

Most immunosuppressive regimens used in clinical vascularized composite allotransplantation (VCA) have been calcineurin inhibitor (CNI)‐based. As such, most recipients have experienced CNI‐related side effects. Costimulation blockade, specifically CD28/B7 inhibition with belatacept, has emerged as a clinical replacement for CNI‐based immunosuppression in kidney transplantation. We have previously shown that belatacept can be used as a centerpiece immunosuppressant for VCA in nonhuman primates, and subsequently reported successful conversion from a CNI‐based regimen to a belatacept‐based regimen after clinical hand transplantation. We now report on the case of a hand transplant recipient, whom we have successfully treated with a de novo belatacept‐based regimen, transitioned to a CNI–free regimen. This case demonstrates that belatacept can provide sufficient prophylaxis from rejection without chronic CNI‐associated side effects, a particularly important goal in nonlifesaving solid organ transplants such as VCA.     

Alternatives to immediate release tacrolimus in solid organ transplant recipients: When the gold standard is in short supply

Given the current climate of drug shortages in the United States, this review summarizes available comparative literature on the use of alternative immunosuppressive agents in adult solid organ transplant recipients including kidney, pancreas, liver, lung, and heart, when immediate-release tacrolimus (IR-TAC) is not available. Alternative options explored include extended-release tacrolimus (ER-TAC) formulations, cyclosporine, belatacept, mammalian target of rapamycin inhibitors, and novel uses of induction therapy for maintenance immunosuppression. Of available alternatives, only ER-TAC formulations are of non-inferior efficacy compared to IR-TAC when used de novo or after conversion in stable kidney transplant recipients (KTRs). All other alternatives were associated with higher rates of biopsy-proven rejection, but improved tolerance from classic adverse effects of IR-TAC including nephrotoxicity and development of diabetes. While most alternative therapies are approved in KTRs, access via third-party payors is an obstacle in non-KTRs. In the setting of IR-TAC shortage, alternate therapeutic options may be plausible depending on the organ population and individual patient situation to ensure appropriate, effective immunosuppression for each patient.     

Immunosuppression and the Risk of Post-Transplant Malignancy Among Cadaveric First Kidney Transplant Recipients

The success of renal transplantation may be counterbalanced by serious adverse medical events. The effect of immunosuppression on the incidence of de novo neoplasms among kidney recipients should be monitored continuously. Using data from the Scientific Registry of Transplant Recipients, we studied the association of induction therapy by immunosuppression with antilymphocyte antibodies, with the development of de novo neoplasms. The study population included more than 41 000 recipients who received a cadaveric first kidney transplant after December 31, 1995, and were followed through February 28, 2002. Using Cox regression models, we estimated time to development of two types of malignancy: de novo solid tumors and post-transplant lymphoproliferative disorder (PTLD). We made adjustments for several patient demographic factors and comorbidities. Induction therapy was significantly associated with a higher relative risk (RR) of PTLD (RR = 1.78, p < 0.001), but not with a greater likelihood of de novo tumors (RR = 1.07, p = 0.42). Treatment with maintenance tacrolimus vs. cyclosporine showed a significantly different RR of developing de novo tumors for recipients with induction than for those not receiving induction (p = 0.024). These new estimates of the magnitude of malignancy risk associated with induction therapy may be useful for clinical practice.     

De novo sirolimus-based regimen in Thai renal transplant recipients

BACKGROUND: Calcineurin inhibitor (CNI) toxicity is a common cause of chronic allograft nephropathy. Although de novo sirolimus (SRL) with CNI minimization may provide better graft function, studies in Asian recipients are lacking. AIM: We sought to determine the 1-year outcomes of renal transplant patients who received a de novo SRL-based regimen with CNI minimization. PATIENTS AND METHODS: A single-center, prospective study of de novo SRL-based, reduced-dose cyclosporine regimen was performed from 2004 to 2007. The control group was a historical cohort of a cyclosporine-based regimen (cyclosporine, prednisolone, and mycophenolate mofetil). The 1-year outcome parameters included renal function, rate of acute rejection, biopsy-proven CNI toxicity, graft and patient survivals. RESULTS: The SRL-based regimen achieved 100% 1-year graft and patient survivals. The renal function was comparable between the SRL-based and CNI-based regimens (serum creatinine 1.32 +/- 0.45 and 1.45 +/- 0.43 mg/dL; P = .27). The rate of biopsy-proven acute rejection was comparable (9.5% and 13%; P = .68). The SRL-based regimen had a higher rate of biopsy-proven CNI toxicity (28.5% and 9.7%; P = .03). CONCLUSIONS: De novo SRL-based regimen with CNI minimization provides excellent transplant outcomes. The strategy to minimize or withdraw CNIs may achieve excellent graft function. A prospective study targeting lower CNI trough levels in Asian transplant recipients is required.     

Cyclosporine-based immunosuppressive strategies for kidney recipients: interim analysis of German data from the Multinational Observational Study (MOST)

INTRODUCTION: We collected data from kidney recipients with a functioning graft at German kidney transplant centers in order to analyze the efficacy of various cyclosporine (CsA)-based immunosuppressive strategies, the effects of different perioperative and maintenance regimens, and the impact of donor source on clinical outcome. METHODS: As part of the ongoing prospective Multinational Observational Study in Transplantation (MOST), data for both prospective and retrospective analysis were collected from kidney recipients over 18 years bearing a functioning graft that was transplanted at 21 German kidney transplant centers between 1987 and 2002. RESULTS: Data from 1223 renal graft recipients, including their CsA-based immunosuppressive regimens, were stratified as: 402 de novo patients (median 6.8 months posttransplant) and 821 patients on maintenance therapy (median 71 months posttransplant). Triple regimens with CsA + mycophenolate mofetil (MMF) + steroids (Ste) currently comprise the major perioperative immunosuppressive strategies in Germany (de novo 65%). IL-2 receptor antagonist (IL-2Ra) use is increasing (de novo 18%, maintenance 4%), while mono and dual regimen use de novo is declining (de novo 4%, maintenance 20%). Among 689 patients transplanted between 1987 and 2002 with outcome data, the mean incidence of acute rejection during the first posttransplant year was 21.6%. Rejection rates on initial therapy with CsA + MMF + Ste +/- antibodies (n = 517) averaged 17.8%. CONCLUSIONS: Between 1987 and 2002, CsA-based immunosuppression combined with MMF and Ste became the most commonly used strategy for both initial and maintenance therapy after kidney transplantation in Germany, yielding the low acute rejection rates particularly when combined with IL-2Ra.     

ASP2409, A Next‐Generation CTLA4‐Ig,Versus Belatacept in Renal Allograft Survival in Cynomolgus Monkeys

Belatacept is the first costimulatory blockade agent approved for maintenance immunosuppression in kidney transplant recipients. Clinical results have indicated that belatacept is associated with superior renal function and improved metabolic profile; however, higher incidence of acute rejection and posttransplant lymphoproliferative disorder are the shortcomings of this agent. In this study, ASP2409, a new cytotoxic T‐lymphocyte associated protein 4‐immunoglobulin possessing 14‐fold higher in vitro CD86 binding affinity than belatacept, was tested for renal allograft survival in cynomolgus monkeys. ASP2409 monotherapy dose‐dependently prolonged renal allograft survival. Low‐dose ASP2409 in combination with a subtherapeutic dose of tacrolimus showed much longer median survival time than monotherapy. Similar allograft survival results were observed in regimens based on high‐dose ASP2409, belatacept, and therapeutic‐dose tacrolimus. The results of renal allograft histopathology with high‐dose ASP2409‐based regimens were not inferior to the belatacept‐based regimen. Moreover, higher frequencies of FoxP3‐positive regulatory T cells in renal allografts were observed in ASP2409‐ and belatacept‐based regimens compared with tacrolimus‐based regimens. No serious side effects related to ASP2409 administration were found during the study. These data suggest that ASP2409 is a promising candidate for calcineurin inhibitor‐sparing or ‐avoidance regimens.     

Conversion from calcineurin inhibitor–based immunosuppression to mammalian target of rapamycin inhibitors or belatacept in renal transplant recipients

The calcineurin inhibitors (CNIs) remain the standard of care for maintenance immunosuppression following renal transplantation. CNIs have demonstrated their effectiveness in reducing acute cellular rejection; however, some evidence suggests that these compounds negatively affect native renal function and are associated with allograft injury in renal transplant recipients. CNIs have also been linked with hypertension, new‐onset diabetes after transplantation, tremor, and thrombotic microangiopathy, which have significant consequences for long‐term allograft function and patient health overall. Thus, converting patients to a non‐CNI‐based regimen may improve renal function and also provide extrarenal benefits. A number of studies have been conducted that explore CNI conversion strategies in renal transplant recipients in an effort to improve long‐term allograft function and survival. These include converting to alternative, non‐nephrotoxic, maintenance immunosuppressants, such as the mammalian target of rapamycin inhibitors (sirolimus and everolimus) and the costimulation blocker belatacept. In this review of literature, evidence for the potential renal and extrarenal benefits of conversion to these non‐CNI‐based regimens is evaluated. Clinical challenges, including the adverse event profiles of non‐CNI‐based regimens and the selection of candidates for conversion, are also examined.     

A rare case of vascular rejection in a renal transplant recipient with nephrotic range proteinuria

Abstract:  In the post-cyclosporine A era, it has been reported that acute rejection after kidney transplantation is commonly revealed as an asymptomatic increase in the serum creatinine level. Nephrotic range proteinuria is observed in patients with recurrent or de novo glomerulonephritis, or with chronic transplant nephropathy and glomerulopathy in the late phase. Acute rejection occurring with nephrotic range proteinuria without a rise of serum creatinine has been rarely reported. Here, we report a rare case of vascular rejection in a renal transplant recipient with nephrotic range proteinuria. A 34-yr-old male renal transplant recipient presented with acute vascular rejection and early-onset nephrotic syndrome. Severe nephrotic range proteinuria was detected with a minimally elevated level of serum creatinine. Biopsy showed severe glomerulitis and vasculitis, which was relieved by conversion of the immunosupressant regimen. Severe proteinuria was a sign of acute vascular rejection with severe glomerulitis and vasculitis. Careful observation to ensure maintenance of immunosuppression is necessary in such cases.     

Incidence of donor‐specific antibodies in kidney transplant patients following conversion to an everolimus‐based calcineurin inhibitor‐free regimen

Scarce data exist regarding the incidence of donor‐specific antibodies (DSAs) in kidney transplant patients receiving everolimus‐based immunosuppression without calcineurin inhibitors (CNIs). The aim of this retrospective case–control study was to compare the incidence of de novo DSAs in patients converted to an everolimus‐based regimen without CNIs with that seen in patients maintained on CNIs. Sixty‐one DSA‐free kidney transplant patients who had been converted to an everolimus‐based regimen (everolimus group) were compared to 61 other patients maintained on CNIs‐based regimen (control group). Patients were matched according to age, gender, induction therapy, date of transplantation, and being DSA‐free at baseline. At last follow‐up, the incidence of DSAs was 9.8% in the everolimus group and 5% in the control group (p = ns). In the everolimus group, the increased incidence of DSAs between baseline and last follow‐up was statistically significant. Antibody‐mediated rejection occurred in 6.5% in the everolimus group and 0% in the CNIs group. The incidence of DSAs is numerically increased in kidney transplant patients treated with an everolimus‐based without CNIs. A study including a larger number of patients is required to determine whether a CNI‐free everolimus‐based immunosuppression significantly increases DSAs formation.     

Multicenter Randomized Prospective Trial of Steroid Withdrawal in Renal Transplant Recipients Receiving Basiliximab, Cyclosporine Microemulsion and Mycophenolate Mofetil

Corticosteroids withdrawal from immunosuppressive regimens has thus far been associated with increased risk of acute rejection episodes. In this study, basiliximab, a chimeric monoclonal interleukin-2 receptor antagonist, added to a maintenance regimen consisting of cyclosporine microemulsion and mycophenolate mofetil was studied for its effectiveness in allowing early corticosteroid withdrawal in de novo renal allograft recipients. Primary renal transplant recipients receiving basiliximab, cyclosporine-microemulsion, and mycophenolate mofetil, were randomized to either corticosteroid withdrawal at day four post-transplantation (n = 40) or standard steroid therapy (n = 43). The primary endpoint was the incidence of biopsy-proven acute rejection episodes. Randomized subjects who underwent transplantation and received at least one dose of basiliximab were analyzed in an intent-to-treat fashion. The incidence of biopsy-proven acute rejection at 12 months was not significantly different between the steroid withdrawal group (20%) and the standard treatment group (16%). Patient and graft survival was 100% in the steroid withdrawal group while one death in a patient with a functioning graft occurred in the standard steroid group. Seventy-two percent of the steroid withdrawal group remained off steroids at 6 months post-transplant. Allograft function and incidence of adverse events and infections were similar between the two groups. Rapid and early corticosteroid withdrawal among renal transplant recipients receiving basiliximab induction and daily therapy with cyclosporine-microemulsion and mycophenolate mofetil was not associated with an increased risk of acute rejection.     

Calcineurin Inhibitor Minimization,Conversion, Withdrawal,and Avoidance Strategies in Renal Transplantation: A Systematic Review and Meta‐Analysis

Despite their clinical efficacy, concerns about calcineurin inhibitor (CNI) toxicity make alternative regimens that reduce CNI exposure attractive for renal transplant recipients. In this systematic review and meta‐analysis, we assessed four CNI immunosuppression strategies (minimization, conversion, withdrawal, and avoidance) designed to reduce CNI exposure and assessed the impact of each on patient and allograft survival, acute rejection and renal function. We evaluated 92 comparisons from 88 randomized controlled trials and found moderate‐ to high‐strength evidence suggesting that minimization strategies result in better clinical outcomes compared with standard‐dose regimens; moderate‐strength evidence indicating that conversion to a mammalian target of rapamycin inhibitor or belatacept was associated with improved renal function but increased rejection risk; and moderate‐ to high‐strength evidence suggesting planned CNI withdrawal could result in improved renal function despite an association with increased rejection risk. The evidence base for avoidance studies was insufficient to draw meaningful conclusions. The applicability of the review is limited by the large number of studies examining cyclosporine‐based strategies and low‐risk populations. Additional research is needed with tacrolimus‐based regimens and higher risk populations. Moreover, research is necessary to clarify the effect of induction and adjunctive agents in alternative immunosuppression strategies and should include more comprehensive and consistent reporting of patient‐centered outcomes.     

A randomized,phase 1b study of the pharmacokinetics,pharmacodynamics, safety,and tolerability of bleselumab,a fully human,anti‐CD40 monoclonal antibody,in kidney transplantation

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of various doses of the anti‐CD40 monoclonal antibody bleselumab (ASKP1240) in de novo kidney transplant recipients receiving concomitant standard immunosuppression over 90 days posttransplant. Transplant recipients were randomized (1:1:1:1:1) to bleselumab 50 mg, 100 mg, 200 mg, or 500 mg, or placebo, in addition to standard maintenance immunosuppression. The primary pharmacokinetic endpoints were AUC_inf, C_max, and AUC_last. The primary pharmacodynamic endpoint was B cell CD40 receptor occupancy over time. Overall, 50 kidney transplant recipients were randomized; 45 received their randomized treatment (bleselumab [n = 37] or placebo [n = 8]). AUC_inf and AUC_last demonstrated a more than dose‐proportional increase in the range of 50‐500 mg, and C_max increased linearly with increasing dose. Maximal receptor occupancy for B cell CD40 was reached at all dose levels and was prolonged as dose increased. No kidney transplant recipients experienced cytokine release syndrome or a thromboembolic event. Treatment‐emergent anti‐bleselumab antibodies were found in one kidney transplant recipient in the bleselumab 50 mg group; these were detected only at Day 7. Overall, bleselumab demonstrated nonlinear pharmacokinetics and dose‐dependent prolonged B cell CD40 receptor occupancy and was well tolerated at all doses (ClinicalTrials.gov: NCT01279538).     

Disparate rates of acute rejection and donor‐specific antibodies among high‐immunologic risk renal transplant subgroups receiving antithymocyte globulin induction

Lymphocyte‐depleting induction lowers acute rejection (AR) rates among high‐immunologic risk (HIR) renal transplant recipients, including African Americans (AAs), retransplants, and the sensitized. It is unclear whether different HIR subgroups experience similarly low rates of AR. We aimed to describe the incidence of AR and de novo donor‐specific antibody (dnDSA) among HIR recipients categorized by age, race, or donor type. All received antithymocyte globulin (ATG) induction and triple maintenance immunosuppression. A total of 464 HIR recipients from 2007 to 2014 were reviewed. AR and dnDSA rates at 1 year for the entire population were 14% and 27%, respectively. AR ranged from 6.7% among living donor (LD) recipients to 30% in younger AA deceased donor (DD) recipients. De novo donor‐specific antibody at 1 year ranged from 7% in older non‐AA LD recipients to 32% in AAs. AA race remained as an independent risk factor for AR among DD recipients and for dnDSA among all HIR recipients. Development of both AR and dnDSA within the first year was associated with a 54% graft survival at 5 years and was an independent risk factor for graft loss. Despite utilization of recommended immunosuppression for HIR recipients, substantial disparities exist among subgroups, warranting further consideration of individualized immunosuppression in certain HIR subgroups.     

Intratumoral immunotherapy with anti-PD-1 and TLR9 agonist induces systemic antitumor immunity without accelerating rejection of cardiac allografts

Immune checkpoint inhibitors, such as programmed cell death 1 (PD-1) blockades, have revolutionized the field of cancer immunotherapy. However, there is a growing concern whether PD-1 inhibitors can be administered safely to transplant recipients with advanced cancer, as the T cells activated by checkpoint inhibitors may become reactive not only toward tumor antigens but also toward donor alloantigen, thereby resulting in allograft rejection. Here, immunotherapy with anti-PD-1/toll like receptor 9 agonist was administered to C57BL/6 mice bearing a cardiac allograft that were receiving maintenance immunosuppression or a PI4KIIIβ inhibitor-based tolerogenic regimen. Intratumoral (i.t.), but not systemic, immunotherapy promoted potent anti-tumor responses, but did not accelerate allograft rejection. This effect was associated with a pro-immunogenic effect induced by i.t. immunotherapy resulting in systemic cellular and humoral immune anti-tumor responses. Furthermore, when the tumor and cardiac allograft shared major histocompatibility complex (MHC) antigens, i.t. immunotherapy promoted immune responses directed against tumor and the cardiac allograft resulting in allograft rejection. The anti-tumor effect was compromised by maintenance immunosuppression with cyclosporin A, indicating that an optimal balance between enhanced anti-tumor immunity and decreased transplant immunoreactivity is critical. A clinically relevant approach could be to temporarily withdraw maintenance immunosuppression and/or replace it with a PI4KIIIβ inhibitor–based tolerance-inducing regimen to allow for effective immunotherapy to take place.     

Belatacept Combined With Transient Calcineurin Inhibitor Therapy Prevents Rejection and Promotes Improved Long‐Term Renal Allograft Function

Belatacept, a T cell costimulation blocker, demonstrated superior renal function, lower cardiovascular risk, and improved graft and patient survival in renal transplant recipients. Despite the potential benefits, adoption of belatacept has been limited in part due to concerns regarding higher rates and grades of acute rejection in clinical trials. Since July 2011, we have utilized belatacept‐based immunosuppression regimens in clinical practice. In this retrospective analysis of 745 patients undergoing renal transplantation at our center, we compared patients treated with belatacept (n = 535) with a historical cohort receiving a tacrolimus‐based protocol (n = 205). Patient and graft survival were equivalent for all groups. An increased rate of acute rejection was observed in an initial cohort treated with a protocol similar to the low‐intensity regimen from the BENEFIT trial versus the historical tacrolimus group (50.5% vs. 20.5%). The addition of a transient course of tacrolimus reduced rejection rates to acceptable levels (16%). Treatment with belatacept was associated with superior estimated GFR (belatacept 63.8 mL/min vs. tacrolimus 46.2 mL/min at 4 years, p < 0.0001). There were no differences in serious infections including rates of cytomegalovirus or BK viremia. We describe the development of a costimulatory blockade‐based strategy that ultimately allows renal transplant recipients to achieve calcineurin inhibitor–free immunosuppression.     

Economic impacts of alternative kidney transplant immunosuppression: A national cohort study

Understanding the economic implications of induction and maintenance immunosuppression (ISx) is important in developing personalized kidney transplant (KTx) care. Using data from a novel integrated data set including financial records from the University Health System Consortium, Medicare, and pharmacy claims (2007-2014), we estimated the differences in the impact of induction and maintenance ISx regimens on transplant hospitalization costs and Medicare payments from KTx to 3 years. Use of thymoglobulin (TMG) significantly increased transplant hospitalization costs ($12 006; P = .02), compared with alemtuzumab and basiliximab. TMG resulted in lower Medicare payments in posttransplant years 1 (−$2058; P = .05) and 2 (−$1784; P = .048). Patients on steroid-sparing ISx incurred relatively lower total Medicare spending (−$10 880; P = .01) compared with patients on triple therapy (tacrolimus, antimetabolite, and steroids). MPA/AZA-sparing, mammalian target of rapamycin inhibitors-based, and cyclosporine-based maintenance ISx regimens were associated with significantly higher payments. Alternative ISx regimens were associated with different KTx hospitalization costs and longer-term payments. Future studies of clinical efficacy should also consider cost impacts to define the economic effectiveness of alternative ISx regimens.