Efficacy and safety of belatacept in heart transplant recipients.

Belatacept (BELA) pharmacokinetic (PK) studies informed dosing strategies used in phase 3 studies, where fixed mg/kg dosing compared a less intensive (LI) and more intensive (MI) regimen. The LI regimen was preferred due to a better risk/benefit profile. We compared PK parameters observed in the BELA Early Steroid Withdrawal Trial (BEST) with previous reports. BELA trough samples were analyzed using a validated quantitative enzyme-linked immunoassay. Clearance (CL) was estimated with Bayesian estimation using a published BELA population PK model. Significantly higher CL was observed in subjects <60 years old and African American (AA) patients, leading to decreased BELA exposure. No differences in allometrically scaled CL were observed by BMI or sex; however, overall BELA exposure was greater in males. There were no differences in exposure in subjects with rejection; however, subjects with infection had significantly higher exposure. BELA PK was not different between alemtuzumab and rabbit-antithymocyte globulin induction groups without steroids, but overall drug exposure was higher than previously reported in trials co-administering with basiliximab and steroids. Future studies to optimize BELA dosing strategies are warranted as BELA exposure in this analysis exceeded Phase 3 target thresholds. Trial Registration: ClinicalTrials.gov identifier: NCT01729494.

Belatacept (BTC), a fusion protein, selectively inhibits T-cell co-stimulation by binding to the CD80 and CD86 receptors on antigen-presenting cells (APCs) and has been used as immunosuppression in adult renal transplant recipients. However, data regarding its use in heart transplant (HT) recipients are limited. This retrospective cohort study aimed to delineate BTC's application in HT, focusing on efficacy, safety, and associated complications at a high-volume HT center. A retrospective cohort study was conducted of patients who underwent HT between January 2017 and December 2021 and subsequently received BTC as part of their immunosuppressive regimen. Twenty-one HT recipients were identified. Baseline characteristics, history of rejection, and indication for BTC use were collected. Outcomes included renal function, graft function, allograft rejection and mortality. Follow-up data were collected through December 2023. Among 776 patients monitored from January 2017 to December 2021 21 (2.7%) received BTC treatment. Average age at transplantation was 53 years (±12 years), and 38% were women. BTC administration began, on average, 689 [483, 1830] days post-HT. The primary indications for BTC were elevated pre-formed donor-specific antibodies in highly sensitized patients (66.6%) and renal sparing (23.8%), in conjunction with reduced calcineurin inhibitor dosage. Only one (4.8%) patient encountered rejection within a year of starting BTC. Graft function by echocardiography remained stable at 6 and 12 months posttreatment. An improvement was observed in serum creatinine levels (76.2% of patients), decreasing from a median of 1.58 to 1.45 (IQR [1.0-2.1] to [1.1-1.9]) over 12 months (p=.054). eGFR improved at 3 and 6 months compared with 3 months pre- BTC levels; however, this was not statistically significant (p=.24). Treatment discontinuation occurred in seven patients (33.3%) of whom four (19%) were switched back to full dose CNI. Infections occurred in 11 patients (52.4%), leading to BTC discontinuation in 4 patients (19%). In this cohort, BTC therapy was used as alternative immunosuppression for management of highly sensitized patients or for renal sparing. BTC therapy when combined with CNI dose reduction resulted in stabilization in renal function as measured through renal surrogate markers, which did not, however, reach statistical significance. Patients on BTC maintained a low rejection rate and preserved graft function. Infections were common during BTC therapy and were associated with medication pause/discontinuation in 19% of patients. Further randomized studies are needed to assess the efficacy and safety of BTC in HT recipients.

Background.Compared with calcineurin inhibitor–based immunosuppression, belatacept (BELA)-based treatment has been associated with better renal function but higher acute rejection rates. This phase 2 study (NCT02137239) compared the antirejection efficacy of BELA plus everolimus (EVL) with tacrolimus (TAC) plus mycophenolate mofetil (MMF), each following lymphocyte-depleting induction and rapid corticosteroid withdrawal.Methods.Patients who were de novo renal transplant recipients seropositive for Epstein-Barr virus were randomized to receive BELA+EVL or TAC+MMF maintenance therapy after rabbit antithymocyte globulin induction and up to 7 d of corticosteroids. The primary endpoint was the rate of biopsy-proven acute rejection at month 6.Results.Because of an unanticipated BELA supply constraint, enrollment was prematurely terminated at 68 patients, of whom 58 were randomized and transplanted (intention-to-treat [ITT] population: n = 26, BELA+EVL; n = 32, TAC+MMF). However, 25 patients received BELA+EVL‚ and 33 received TAC+MMF (modified ITT population). In the ITT population, the 6-mo biopsy-proven acute rejection rates were 7.7% versus 9.4% in the BELA+EVL versus TAC+MMF group. The corresponding 24-mo biopsy-proven acute rejection rates were 19.2% versus 12.5% in the ITT population and 16.0% versus 15.2% in the mITT population; all events were Banff severity grade ≤IIA and similar between groups. One patient in each group experienced graft loss unrelated to acute rejection. The 24-mo mean unadjusted estimated glomerular filtration rates were 71.8 versus 68.7 mL/min/1.73 m2 in the BELA+EVL versus TAC+MMF groups. Posttransplant lymphoproliferative disorder was reported for 1 patient in each group. No deaths or unexpected adverse events were observed.Conclusions.A steroid-free maintenance regimen of BELA+EVL may be associated with biopsy-proven acute rejection rates comparable to TAC+MMF.

Purpose: Beta cell replacement, via islet or solid organ pancreas transplant, remains the best strategy to restore insulin independence in patients with Type 1 diabetes mellitus (T1DM). Insulin independence beyond ten years is limited, with calcineurin inhibitors (CNI) contributing to beta cell toxicity and impairing renal function. Here, we report long-term results for multimodal beta cell replacement including islet and pancreas after islet (PAI) transplant with CNI-free immunosuppression (IS) regimens based on Belatacept (BELA) and Efalizumab (EFA). Methods: Ten non-uremic patients with severe T1DM received their first islet cell transplant between 2007 and 2009 with CNI-sparing IS based on BELA (n=5) or EFA (n=5). Patients were monitored for a mean of 12.9 ± 1.1 years from islet transplant for beta cell function and renal function. Following islet failure, patients were considered for repeat islet infusion and/or PAI transplant. Circulating immunologic phenotype was characterized in the first year. Results: Seven of 10 patients (70%) maintained insulin independence with normalization of HbA1c (3 BELA, 4 EFA) at 10 years post-islet transplant; four patients (2 EFA, 2 BELA) achieved long-term insulin independence after one islet infusion and three additional patients (2 EFA, 1 BELA) following PAI transplantation (Figure 1, Figure 2). Six of 10 (60%) remain insulin independent currently, at a mean follow-up of 13.3 ± 1.1 years from islet transplant. Eight of 10 patients (80%) maintained renal function with less than 30% decrease in GFR and without progression to stage 4 or stage 5 CKD (Figure 2). One patient progressed to stage 4 CKD following initiation of tacrolimus for PAI, and another progressed to stage 5 CKD after islet failure and return to full insulin dependence. Patients receiving EFA demonstrated profound expansion of circulating CD4+Foxp3+ regulatory T cells (Tregs). One patient (EFA-4) demonstrated Tregs comprising 68% of all circulating CD4+ T cells, and remains insulin independent despite discontinuing all immunosuppression, thus demonstrating the first reported case of operational tolerance in islet transplantation. Conclusions: Our results describe a multi-modal, personalized approach to beta-cell replacement. In our series, repeat islet transplant is ineffective at maintaining long-term insulin independence. PAI results in durable insulin independence but is associated with deterioration of renal function secondary to CNI dependence. EFA-based immunosuppression resulted in significant expansion of Tregs following transplantation, with one islet recipient establishing operational tolerance.Juvenile Diabetes Research Foundation (4-2004-372). NIH P30 (DK63720). NIH UO1 (AIO65193). CRC UL1 (RR024131). NIH T32 (AI125222).

The Efficacy and Safety of Belatacept in Heart Transplant Recipients

Background: Arterial stiffness and phase angle (PhA) have gained importance as a diagnostic and prognostic parameter in the management of cardiovascular disease. There are few studies regarding the differences in arterial stiffness and body composition between renal transplant recipients (RTRs) receiving belatacept (BELA) vs. calcineurin inhibitors (CNI). Therefore, we investigated the differences in arterial stiffness and body composition between RTRs treated with different immunosuppressants, including BELA. Methods: In total, 325 RTRs were enrolled in the study (mean age 52.2 years, M −62.7%). Arterial stiffness was determined with an automated oscillometric device. All body composition parameters were assessed, based on bioelectrical impedance analysis (BIA), and laboratory parameters were obtained from the medical files of the patients. Results: We did not detect any significant difference in terms of arterial stiffness and PhA in RTRs undergoing different immunosuppressive regimens, based on CsA, Tac, or BELA. Age was an essential risk factor for greater arterial stiffness. The PhA was associated with age, BMI, time of dialysis before transplantation, and kidney graft function. Conclusion: No significant differences in arterial stiffness and PhA were observed in RTRs under different immunosuppressive regimens. While our data provide additional evidence for arterial stiffness and PhA in RTRs, more research is needed to fully explore these cardiovascular risk factors and the impact of different immunosuppressive regimens.

Belatacept in Kidney Transplant Recipients With Failed Allografts for the Prevention of Humoral Sensitization: A Pilot Randomized Controlled Trial.

Belatacept-based immunosuppression: A calcineurin inhibitor-sparing regimen in heart transplant recipients.

Pharmacokinetic immunosuppressive drug monitoring poorly correlates with clinical outcomes after solid organ transplantation. A promising method for pharmacodynamic monitoring of tacrolimus (TAC) in T cell subsets of transplant recipients might be the measurement of (phosphorylated) p38MAPK, ERK1/2 and Akt (activated downstream of the T cell receptor) by phospho-specific flow cytometry. Here, blood samples from n = 40 kidney transplant recipients (treated with either TAC-based or belatacept (BELA)-based immunosuppressive drug therapy) were monitored before and throughout the first year after transplantation. After transplantation and in unstimulated samples, p-p38MAPK and p-Akt were inhibited in CD8+ T cells and p-ERK in CD4+ T cells but only in patients who received TAC-based therapy. After activation with PMA/ionomycin, p-p38MAPK and p-AKT were significantly inhibited in CD4+ and CD8+ T cells when TAC was given, compared to pre-transplantation. Eleven BELA-treated patients had a biopsy-proven acute rejection, which was associated with higher p-ERK levels in both CD4+ and CD8+ T cells compared to patients without rejection. In conclusion, phospho-specific flow cytometry is a promising tool to pharmacodynamically monitor TAC-based therapy. In contrast to TAC-based therapy, BELA-based immunosuppression does not inhibit key T cell activation pathways which may contribute to the high rejection incidence among BELA-treated transplant recipients.

Regulatory T cells (Tregs) are considered key players in the prevention of allograft rejection in transplanted patients. Belatacept (BLT) is an effective alternative to calcineurin inhibitors that appears to preserve graft survival and function; however, the impact of this drug in the homeostasis of Tregs in transplanted patients remains controversial. Here, we analyzed the phenotype, function, and the epigenetic status of the Treg-specific demethylated region (TSDR) in FOXP3 of circulating Tregs from long-term kidney transplant patients under BLT or Cyclosporine A treatment. We found a significant reduction in the proportion of CD4+CD25hiCD127lo/−FOXP3+ T cells in all patients compared to healthy individual (controls). Interestingly, only BLT-treated patients displayed an enrichment of the CD45RA+ “naïve” Tregs, while the expression of Helios, a marker used to identify stable FOXP3+ thymic Tregs remained unaffected. Functional analysis demonstrated that Tregs from transplanted patients displayed a significant reduction in their suppressive capacity compared to Tregs from controls, which is associated with decreased levels of FOXP3 and CD25. Analysis of the methylation status of the FOXP3 gene showed that BLT treatment results in methylation of CpG islands within the TSDR, which could be associated with the impaired Treg suppression function. Our data indicate that analysis of circulating Tregs cannot be used as a marker for assessing tolerance toward the allograft in long-term kidney transplant patients. Trial registration number IM103008.

End-stage renal disease is a long-term irreversible decline in kidney function requiring renal replacement therapy: kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation, followed by immunosuppressive therapy (induction and maintenance therapy) to reduce the risk of kidney rejection and prolong graft survival. To review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect(®), Novartis Pharmaceuticals UK Ltd) and rabbit anti-human thymocyte immunoglobulin (rATG) (Thymoglobulin(®), Sanofi) as induction therapy, and immediate-release tacrolimus (TAC) (Adoport(®), Sandoz; Capexion(®), Mylan; Modigraf(®), Astellas Pharma; Perixis(®), Accord Healthcare; Prograf(®), Astellas Pharma; Tacni(®), Teva; Vivadex(®), Dexcel Pharma), prolonged-release tacrolimus (Advagraf(®) Astellas Pharma), belatacept (BEL) (Nulojix(®), Bristol-Myers Squibb), mycophenolate mofetil (MMF) (Arzip(®), Zentiva; CellCept(®), Roche Products; Myfenax(®), Teva), mycophenolate sodium (MPS) (Myfortic(®), Novartis Pharmaceuticals UK Ltd), sirolimus (SRL) (Rapamune(®), Pfizer) and everolimus (EVL) (Certican(®), Novartis) as maintenance therapy in adult renal transplantation. Clinical effectiveness searches were conducted until 18 November 2014 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science (via ISI), Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted until 18 November 2014 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Database (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and the American Economic Association's electronic bibliography (via EconLit, EBSCOhost). Included studies were selected according to predefined methods and criteria. A random-effects model was used to analyse clinical effectiveness data (odds ratios for binary data and mean differences for continuous data). Network meta-analyses were undertaken within a Bayesian framework. A new discrete time-state transition economic model (semi-Markov) was developed, with acute rejection, graft function (GRF) and new-onset diabetes mellitus used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death. Eighty-nine randomised controlled trials (RCTs), of variable quality, were included. For induction therapy, no treatment appeared more effective than another in reducing graft loss or mortality. Compared with placebo/no induction, rATG and BAS appeared more effective in reducing biopsy-proven acute rejection (BPAR) and BAS appeared more effective at improving GRF. For maintenance therapy, no treatment was better for all outcomes and no treatment appeared most effective at reducing graft loss. BEL + MMF appeared more effective than TAC + MMF and SRL + MMF at reducing mortality. MMF + CSA (ciclosporin), TAC + MMF, SRL + TAC, TAC + AZA (azathioprine) and EVL + CSA appeared more effective than CSA + AZA and EVL + MPS at reducing BPAR. SRL + AZA, TAC + AZA, TAC + MMF and BEL + MMF appeared to improve GRF compared with CSA + AZA and MMF + CSA. In the base-case deterministic and probabilistic analyses, BAS, MMF and TAC were predicted to be cost-effective at £20,000 and £30,000 per quality-adjusted life-year (QALY). When comparing all regimens, only BAS + TAC + MMF was cost-effective at £20,000 and £30,000 per QALY. For included trials, there was substantial methodological heterogeneity, few trials reported follow-up beyond 1 year, and there were insufficient data to perform subgroup analysis. Treatment discontinuation and switching were not modelled. High-quality, better-reported, longer-term RCTs are needed. Ideally, these would be sufficiently powered for subgroup analysis and include health-related quality of life as an outcome. Only a regimen of BAS induction followed by maintenance with TAC and MMF is likely to be cost-effective at £20,000-30,000 per QALY. This study is registered as PROSPERO CRD42014013189. The National Institute for Health Research Health Technology Assessment programme.

End-stage renal disease is a long-term irreversible decline in kidney function requiring kidney transplantation, haemodialysis or peritoneal dialysis. The preferred option is kidney transplantation followed by induction and maintenance immunosuppressive therapy to reduce the risk of kidney rejection and prolong graft survival. To systematically review and update the evidence for the clinical effectiveness and cost-effectiveness of basiliximab (BAS) (Simulect,(®) Novartis Pharmaceuticals) and rabbit antihuman thymocyte immunoglobulin (Thymoglobuline,(®) Sanofi) as induction therapy and immediate-release tacrolimus [Adoport(®) (Sandoz); Capexion(®) (Mylan); Modigraf(®) (Astellas Pharma); Perixis(®) (Accord Healthcare); Prograf(®) (Astellas Pharma); Tacni(®) (Teva); Vivadex(®) (Dexcel Pharma)], prolonged-release tacrolimus (Advagraf,(®) Astellas Pharma); belatacept (BEL) (Nulojix,(®) Bristol-Myers Squibb), mycophenolate mofetil (MMF) [Arzip(®) (Zentiva), CellCept(®) (Roche Products), Myfenax(®) (Teva), generic MMF is manufactured by Accord Healthcare, Actavis, Arrow Pharmaceuticals, Dr Reddy's Laboratories, Mylan, Sandoz and Wockhardt], mycophenolate sodium, sirolimus (Rapamune,(®) Pfizer) and everolimus (Certican,(®) Novartis Pharmaceuticals) as maintenance therapy in children and adolescents undergoing renal transplantation. Clinical effectiveness searches were conducted to 7 January 2015 in MEDLINE (via Ovid), EMBASE (via Ovid), Cochrane Central Register of Controlled Trials (via Wiley Online Library) and Web of Science [via Institute for Scientific Information (ISI)], Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Health Technology Assessment (HTA) (The Cochrane Library via Wiley Online Library) and Health Management Information Consortium (via Ovid). Cost-effectiveness searches were conducted to 15 January 2015 using a costs or economic literature search filter in MEDLINE (via Ovid), EMBASE (via Ovid), NHS Economic Evaluation Databases (via Wiley Online Library), Web of Science (via ISI), Health Economic Evaluations Database (via Wiley Online Library) and EconLit (via EBSCOhost). Titles and abstracts were screened according to predefined inclusion criteria, as were full texts of identified studies. Included studies were extracted and quality appraised. Data were meta-analysed when appropriate. A new discrete time state transition economic model (semi-Markov) was developed; graft function, and incidences of acute rejection and new-onset diabetes mellitus were used to extrapolate graft survival. Recipients were assumed to be in one of three health states: functioning graft, graft loss or death. Three randomised controlled trials (RCTs) and four non-RCTs were included. The RCTs only evaluated BAS and tacrolimus (TAC). No statistically significant differences in key outcomes were found between BAS and placebo/no induction. Statistically significantly higher graft function (p < 0.01) and less biopsy-proven acute rejection (odds ratio 0.29, 95% confidence interval 0.15 to 0.57) was found between TAC and ciclosporin (CSA). Only one cost-effectiveness study was identified, which informed NICE guidance TA99. BAS [with TAC and azathioprine (AZA)] was predicted to be cost-effective at £20,000-30,000 per quality-adjusted life year (QALY) versus no induction (BAS was dominant). BAS (with CSA and MMF) was not predicted to be cost-effective at £20,000-30,000 per QALY versus no induction (BAS was dominated). TAC (with AZA) was predicted to be cost-effective at £20,000-30,000 per QALY versus CSA (TAC was dominant). A model based on adult evidence suggests that at a cost-effectiveness threshold of £20,000-30,000 per QALY, BAS and TAC are cost-effective in all considered combinations; MMF was also cost-effective with CSA but not TAC. The RCT evidence is very limited; analyses comparing all interventions need to rely on adult evidence. TAC is likely to be cost-effective (vs. CSA, in combination with AZA) at £20,000-30,000 per QALY. Analysis based on one RCT found BAS to be dominant, but analysis based on another RCT found BAS to be dominated. BAS plus TAC and AZA was predicted to be cost-effective at £20,000-30,000 per QALY when all regimens were compared using extrapolated adult evidence. High-quality primary effectiveness research is needed. The UK Renal Registry could form the basis for a prospective primary study. This study is registered as PROSPERO CRD42014013544. The National Institute for Health Research HTA programme.

Leukopenia is common in corticosteroid (CS) free immunosuppressive (IS) regimens, possibly due to increased mycophenolic acid (MPA) exposure. This study evaluated the effect of MPA exposure on leukopenia and neutropenia in patients receiving belatacept (BELA) based regimens without calcineurin inhibitors or CS. Methods: The 0-12 hour area under the curve (AUC0-12h) of MPA was monitored in kidney-alone transplant recipients at 1 & 3 months post-transplant. Patients were on mycophenolate mofetil (MMF), CS-free, with either BELA (n=30) or tacrolimus (TAC; n=19) maintenance IS regimens. MPA exposure was estimated using a Bayesian estimator and a linear regression equation from Pawinski, et al (7.75 + 6.49C0 + 0.76C0.5 + 2.43C2). Target FK levels were 10-15ng/ml for the 1st month and 5-10ng/ml after. Leukopenia and neutropenia were defined as white blood cell count <3000cells/uL and absolute neutrophil count <1500cells/uL. Results: Risk of leukopenia and neutropenia increased with increased MPA AUC0-12h. An AUC0-12h>60ug*h/ml, calculated with Bayesian estimation, in BELA patients correlated with higher risk of neutropenia.Table: No Caption available.BELA patients with leukopenia or neutropenia >1 month post-transplant had a higher average 1st measured AUC0-12h than patients with neither (p=0.04).Figure: No Caption available.Similar results were not found in TAC patients, possibly due to insufficient sample size. The Bayesian and Pawinski methods provided comparable clinical guidance on when it may be appropriate to decrease MMF dose for AUC0-12h>60ug*h/ml in BELA and TAC patients (p=1). Conclusions: Risk of neutropenia increases with MPA AUC0-12h >60ug*h/ml in renal transplant patients on CS-free, BELA regimens. Elevated 1st measured MPA AUC0-12h predicts increased risk of adverse events >1 month in these patients. Estimates of MPA exposure by the Bayesian method agree with the Pawinski equation results in guiding clinical decisions for MMF dose changes.

It is unclear if new costimulatory blockade agents, such as the cytotoxic T lymphocyte-associated antigen 4-Ig molecule belatacept (BEL), promote or inhibit the potential for immunologic tolerance in transplantation. We therefore tested the in vitro effects of BEL on human regulatory T cells (Tregs) in mixed lymphocyte reactions (MLR) alone and in combination with maintenance agents used in transplant recipients. BEL, mycophenolic acid (MPA), and sirolimus, either alone or in combination, were added to healthy volunteer Treg-MLR, testing (a) H-TdR incorporation for inhibition of lymphoproliferation and (b) flow cytometry to analyze for newly generated CD4+ CD25(high) FOXP3+ Tregs in carboxyfluorescein succinimidyl ester-labeled MLR responders. In addition, the modulatory effects of putative Tregs generated in the presence of these drugs were also tested using the lymphoproliferation and flow cytometric assays. In comparison with medium controls, BEL dose-dependently inhibited both lymphoproliferation and Treg generation in human leukocyte antigen DR matched and mismatched MLRs either alone or in combination with MPA or sirolimus. However, MPA alone inhibited lymphoproliferation but significantly enhanced Treg generation at subtherapeutic concentrations (P<0.01). In addition, purified CD4+ CD127- cells generated in MLR in the presence of MPA and added as third component modulators in fresh MLRs significantly enhanced newly developed Tregs in the proliferating responder cells compared with those generated with BEL or medium controls. BEL alone and in combination with agents used in transplant recipients inhibits the in vitro generation of human Tregs. BEL might therefore be a less optimal agent for tolerance induction in human organ transplantation.

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