Belatacept-based regimens versus a cyclosporine A-based regimen in kidney transplant recipients: 2-year results from the BENEFIT and BENEFIT-EXT studies. Transplantation. 2010;90:1528-1535. [PMID: 21076381 DOI: 10.1097/tp.0b013e3181ff87cd]

Belatacept Post Kidney Transplantation

Objective:

To review the use of belatacept as an alternative to calcineurin inhibitor-based regimens for maintenance immunosuppression in renal transplant recipients.

Data Sources:

To provide an extensive overview of the pharmacology, pharmacokinetics, efficacy, and safety of belatacept, a MEDLINE/PubMed search (1980–December 2011) was performed for all articles evaluating belatacept's properties and patient outcomes, as well as abstracts from recent meetings, using key words belatacept, pharmacology, efficacy, pharmacokinetics, and safety.

Study Selection/Data Extraction:

Phase 2 and 3 studies in humans describing use, adverse reactions, pharmacology, pharmacokinetics, efficacy, and safety of belatacept were identified and reviewed. Other articles were identified through PubMed.

Data Synthesis:

Belatacept, a costimulation blocker, is a biologic recombinant fusion protein that has been shown to prevent acute cellular rejection in kidney transplant recipients and preserve renal function. It was recently approved by the FDA as an antirejection immunosuppressant agent for use in kidney transplant recipients. It is the first biologic agent used for maintenance immunosuppression. It acts as an antagonist to CD80 and CD86 receptors located on the surface of antigen presenting cells, thereby blocking CD28 T-cell activation and, thus, preventing acute rejection. In comparison with patients receiving other current therapies, patients on belatacept have demonstrated superior renal function with comparable outcomes in patient and graft survival.

Conclusions:

Belatacept has potential for use as an alternative to current maintenance immunosuppression regimens, with potentially fewer adverse effects.

Donor-specific HLA antibodies in a cohort comparing everolimus with cyclosporine after kidney transplantation

Donor-specific HLA antibodies (DSA) have a negative impact on kidney graft survival. Therefore, we analyzed the occurrence of DSA and antibody-mediated rejection (AMR) in patients from two prospective randomized trials in our center. At 3-4.5 months posttransplant 127 patients were randomized to continue cyclosporine or converted to everolimus therapy. The presence of DSA was prospectively assessed using Luminex assays. AMR was defined according to the Banff 2009 classification. Antibody screening was available in 126 patients with a median follow-up of 1059 days. Seven out of 65 (10.8%) patients on cyclosporine developed DSA after a median of 991 days. In comparison, 14/61 patients (23.0%) randomized to everolimus developed DSA after 551 days (log-rank: p = 0.048). Eight patients on everolimus compared to two patients on cyclosporine developed AMR (log-rank: p = 0.036). Four of 10 patients with AMR-all in the everolimus group-lost their graft. A multivariate regression model revealed everolimus, >3 mismatches and living donor as significant risk factors for DSA. Acute rejection within the first year, >3 mismatches, everolimus and living donor were independent risk factors for AMR. This single center analysis demonstrates for the first time that everolimus-based immunosuppression is associated with an increased risk for the development of DSA and AMR.

Our evolving understanding of late kidney allograft failure

PURPOSE OF REVIEW

Dramatic improvement in short-term results after kidney transplantation has fostered a change in focus for clinical research: further improvement in patient outcomes requires better understanding of late allograft failure.

RECENT FINDINGS

As recently as a decade ago, with clinicians and investigators besot by the mistaken assumption that 'rejection' was under control, most late allograft failure was attributed to calcineurin inhibitor nephrotoxicity. Application of newer laboratory-based techniques (C4d staining, solid-phase antibody assays, and molecular profiling) has resulted in a major shift in understanding late graft failure. New data from both clinic and laboratory indicate immunologic injury, perhaps potentiated by drug minimization, as the predominant cause of late allograft failure.

SUMMARY

This review traces our evolving understanding of the problem and what looks to be a paradigm change that offers new promise of effective intervention to improve long-term outcomes.

Three-year outcomes from BENEFIT-EXT: a phase III study of belatacept versus cyclosporine in recipients of extended criteria donor kidneys

Recipients of extended-criteria donor (ECD) kidneys have poorer long-term outcomes compared to standard-criteria donor kidney recipients. We report 3-year outcomes from a randomized, phase III study in recipients of de novo ECD kidneys (n = 543) assigned (1:1:1) to either a more intensive (MI) or less intensive (LI) belatacept regimen, or cyclosporine. Three hundred twenty-three patients completed treatment by year 3. Patient survival with a functioning graft was comparable between groups (80% in MI, 82% in LI, 80% in cyclosporine). Mean calculated GFR (cGFR) was 11 mL/min higher in belatacept-treated versus cyclosporine-treated patients (42.7 in MI, 42.2 in LI, 31.5 mL/min in cyclosporine). More cyclosporine-treated patients (44%) progressed to GFR <30 mL/min (chronic kidney disease [CKD] stage 4/5) than belatacept-treated patients (27-30%). Acute rejection rates were similar between groups. Posttransplant lymphoproliferative disorder (PTLD) occurrence was higher in belatacept-treated patients (two in MI, three in LI), most of which occurred during the first 18 months; four additional cases (3 in LI, 1 in cyclosporine) occurred after 3 years. Tuberculosis was reported in two MI, four LI and no cyclosporine patients. In conclusion, at 3 years after transplantation, immunosuppression with belatacept resulted in similar patient survival, graft survival and acute rejection, with better renal function compared with cyclosporine. As previously reported, PTLD and tuberculosis were the principal safety findings associated with belatacept in this study population.

Current landscape for T-cell targeting in autoimmunity and transplantation

In recent years, substantial advances in T-cell immunosuppressive strategies and their translation to routine clinical practice have revolutionized management and outcomes in autoimmune disease and solid organ transplantation. More than 80 diseases have been considered to have an autoimmune etiology, such that autoimmune-associated morbidity and mortality rank as third highest in developed countries, after cardiovascular diseases and cancer. Solid organ transplantation has become the therapy of choice for many end-stage organ diseases. Short-term outcomes such as patient and allograft survival at 1 year, acute rejection rates, as well as time course of disease progression and symptom control have steadily improved. However, despite the use of newer immunosuppressive drug combinations, improvements in long-term allograft survival and complete resolution of autoimmunity remain elusive. In addition, the chronic use of nonspecifically targeted immunosuppressive drugs is associated with significant adverse effects and increased morbidity and mortality. In this article, we discuss the current clinical tools for immune suppression and attempts to induce long-term T-cell tolerance induction as well as much-needed future approaches to produce more short-acting, antigen-specific agents, which may optimize outcomes in the clinic.

Calcineurin inhibitors in kidney transplantation: friend or foe?

PURPOSE OF REVIEW

The utilization of calcineurin inhibitors (CNI) in kidney transplantation has dramatically improved short-term outcomes but significant gains in long-term outcomes have proved elusive. Nephrotoxicity is the major problem associated with CNIs and is responsible for the disappointing progress seen in long-term graft survival. In this review, we assess CNI efficacy as well as the latest strategies employed to limit long-term CNI nephrotoxicity.

RECENT FINDINGS

Three CNI sparing strategies - CNI withdrawal, CNI avoidance, and CNI minimization - are evaluated with discussion of key studies such as the Efficacy Limiting Toxicity Elimination-Symphony and Spare-the-Nephron studies. Recent breakthroughs in transplant immunosuppression are discussed such as the BENEFIT and BENEFIT-EXT studies, which have led to the recent US Food and Drug Administratrion approval of belatacept, a novel T-cell costimulation blocker.

SUMMARY

For now, CNIs remain the proven standard of care in modern immunosuppression. However, some novel agents may challenge the role CNIs play in kidney transplantation in the very near future.

Allospecific CD154 + T-cytotoxic memory cells as potential surrogate for rejection risk in pediatric intestine transplantation

Clinical end-points dictate large trial enrollments and exclude children with the rare intestine transplant procedure (ITx), who experience higher drug-related morbidity. We evaluate the novel rejection-risk parameter, allo-(antigen)-specific CD154 + TcMs (i) as surrogates for ACR using Prentice's criteria, (ii) for association with immunosuppression targets to determine Fleming's surrogate end-point designation, and (iii) as time-to-event end-point in a simulated comparison of alemtuzumab (NCT#01208337, n = 14) and rabbit anti-human thymocyte globulin (rATG, n = 16) among 30 children with ITx. CD154 + TcM were measured in MLR before, and at 1-60 and 61-200 days after ITx (NCT#01163578). CD154 + TcM correlate significantly with rejection severity (Spearman r = 0.685, p = 2.03E-5) and associate with biopsy-proven ITx rejection with sensitivity/specificity of 94%/84% [corrected] independent of immunosuppressant. Previously stated sensitivity of 90% is incorrect. [corrected]. The rejection-risk threshold of CD154 + TcM resolves rapidly in 200-day follow-up (46 ± 20 vs. 158 ± 59 days, p = 0.009, K-M) with alemtuzumab, which demonstrates lower 90-day ACR incidence (50% vs. 69%, p=NS, Fisher's exact), and is associated with accelerated prednisone minimization to ≤2.5 mg/day, compared with rATG (120 ± 28 vs. 180 ± 30 days, p = 0.027, K-M). As a surrogate end-point, time-to-rejection-risk resolution measured with CD154 + TcM portends 50% reduction in sample sizes in a simulated trial of alemtuzumab vs. rATG. Rejection-risk assessment with CD154 + TcM may enable informed immunosuppression minimization, and preliminary efficacy comparisons in pediatric ITx.

Treatment of systemic lupus erythematosus: new advances in targeted therapy

Treatment for systemic lupus erythematosus (SLE) has traditionally been restricted to broad-based immunosuppression, with glucocorticoids being central to care. Recent insights into lupus pathogenesis promise new, selective therapies with more favorable side effect profiles. The best example of this is belimumab, which targets the B cell cytokine BLyS and has now received Food and Drug Administration (FDA) approval for its use in SLE. Strategies targeting other cytokines, such as interleukin 6 (IL-6) and interferon (IFN)-α, are also on the horizon. Blockade of costimulatory interactions between immune cells offers another opportunity for therapeutic intervention, as do small molecule inhibitors that interfere with cell signaling pathways. We review here the current strategies for SLE treatment, with particular focus on therapies now in active pharmaceutical development. We will also discuss new understandings in lupus pathogenesis that may lead to future advances in therapy.

Belatacept: a new biologic and its role in kidney transplantation

OBJECTIVE

To review the pharmacology, efficacy, safety, and role of belatacept in maintenance immunosuppression in adult kidney transplant recipients (KTR).

DATA SOURCES

PubMed, EMBASE, International Pharmaceutical Abstracts, Web of Knowledge (1990-November 2011), and Google were searched using the terms belatacept, kidney or renal, and transplant.

STUDY SELECTION AND DATA EXTRACTION

Relevant articles (English language and human subjects) were reviewed. Selected studies included 3 Phase 2 and 2 Phase 3 trials. Data were compared with Food and Drug Administration (FDA) briefing documents and belatacept full prescribing information.

DATA SYNTHESIS

Belatacept, a cytotoxic T-lymphocyte-associated antigen 4-immunoglobulin, is the first marketed intravenous maintenance immunosuppressant. It is approved for use in combination with basiliximab induction, mycophenolate mofetil, and corticosteroids to prevent rejection in adult KTR. Belatacept exhibits linear pharmacokinetics and first-order elimination. The less intensive regimen used in Phase 3 trials is approved by the FDA. In low-moderate immunologic risk KTR, short-term patient and allograft survival appear comparable with that seen with cyclosporine, with improved renal function despite more frequent and severe early acute rejection. Preliminary data from Phase 2 corticosteroid-avoidance and conversion trials suggest that better renal function, acceptable rejection rates, and comparable patient and allograft survival may be achieved with belatacept compared with calcineurin inhibitors (CNIs). Common adverse effects of belatacept include anemia, neutropenia, urinary tract infection, headache, and peripheral edema. While a more favorable cardiovascular and metabolic profile and lack of requirement for therapeutic drug monitoring are attractive, a higher frequency of posttransplant lymphoproliferative disorder is concerning. Belatacept drug costs are significantly higher than those of standard CNI- or sirolimus-based regimens.

CONCLUSIONS

Belatacept provides a new option for maintenance immunosuppression in adult KTR. Further research is needed to compare its efficacy and safety with standard tacrolimus-based regimens, to evaluate whether increased drug costs are offset by long-term improvements in patient and allograft survival, and to establish its role in the immunosuppression armamentarium.

Three-year outcomes from BENEFIT, a randomized, active-controlled, parallel-group study in adult kidney transplant recipients

The clinical profile of belatacept in kidney transplant recipients was evaluated to determine if earlier results in the BENEFIT study were sustained at 3 years. BENEFIT is a randomized 3 year, phase III study in adults receiving a kidney transplant from a living or standard criteria deceased donor. Patients were randomized to a more (MI) or less intensive (LI) regimen of belatacept, or cyclosporine. 471/666 patients completed ≥3 years of therapy. A total of 92% (MI), 92% (LI), and 89% (cyclosporine) of patients survived with a functioning graft. The mean calculated GFR (cGFR) was ∼21 mL/min/1.73 m(2) higher in the belatacept groups versus cyclosporine at year 3. From month 3 to month 36, the mean cGFR increased in the belatacept groups by +1.0 mL/min/1.73 m(2) /year (MI) and +1.2 mL/min/1.73 m(2) /year (LI) versus a decline of -2.0 mL/min/1.73 m(2) /year (cyclosporine). One cyclosporine-treated patient experienced acute rejection between year 2 and year 3. There were no new safety signals and no new posttransplant lymphoproliferative disorder (PTLD) cases after month 18. Belatacept-treated patients maintained a high rate of patient and graft survival that was comparable to cyclosporine-treated patients, despite an early increased occurrence of acute rejection and PTLD.

Prevention of cardiovascular disease in adult recipients of kidney transplants

Although advances in immunosuppression, tissue typing, surgery, and medical management have made transplantation a routine and preferred treatment for patients with irreversible renal failure, successful transplant recipients have a greatly increased risk of premature mortality because of cardiovascular disease and malignancy compared with the general population. Conventional cardiovascular risk factors such as hyperlipidaemia, hypertension, and diabetes are common in transplant recipients, partly because of the effects of immunosuppressive drugs, and are associated with adverse outcomes. However, the natural history of cardiovascular disease in such recipients differs from that in the general population, and only statin therapy has been studied in a large-scale interventional trial. Thus, the management of this disease and the balance between management of conventional risk factors and modification of immunosuppression is complex.

Immunosuppressive monoclonal antibodies: current and next generation

Monoclonal antibodies (mAbs) are well-established therapeutics, as evidenced by the large number of Food and Drug Administration-approved mAbs for the treatment of cancers, and inflammatory or autoimmune diseases, and for the prevention and treatment of solid organ transplant rejection. Although, in many cases, mAbs have improved patient survival, they are also associated with an increased incidence of opportunistic infections. We review here the current and next generation of mAbs and the risks that infectious disease specialists should be aware of.

Targets of new immunosuppressants in renal transplantation

Although current immunosuppression is highly effective in avoiding acute rejection, it is associated with nephrotoxicity, cardiovascular morbidity, infection, and cancer. Thus, new drugs dealing with new mechanisms, as well as minimizing comorbidities, are warranted in renal transplantation. Few novel drugs are currently under investigation in Phase I, II, or III clinical trials. Belatacept is a humanized antibody that inhibits T-cell co-stimulation and has shown encouraging results in Phase II and III trials. Moreover, two new small molecules are under clinical development: AEB071 or sotrastaurin (a protein kinase C inhibitor) and CP-690550 or tasocitinib (a Janus kinase inhibitor). Refinement in selecting the best combinations for the new and current immunosuppressive agents is probably the main challenge for the next few years.

The effects of Cyclosporine A and azathioprine on human T cells activated by different costimulatory signals

Immunosuppression is an important treatment modality in transplantation and human diseases that are associated with aberrant T cell activation. There are considerable differences regarding the cellular processes targeted by the immunosuppressive drugs that are in clinical use. Drugs like azathioprine (Aza) mainly act by halting proliferation of fast dividing cells, whereas others like cyclosporine A (CsA) specifically target signaling pathways in T cells. Since the outcome of T cell responses critically depends on the quality and strength of costimulatory signals, this study has addressed the interplay between costimulation and the immunosuppressive agents CsA and Aza during the in vitro activation of human T cells. We used an experimental system that allows analyzing T cells activated in the presence of selected costimulatory ligands to study T cells stimulated via CD28, CD2, LFA-1, ICOS or 4-1BB. The mean inhibitory concentrations (IC₅₀) for Aza and CsA were determined for the proliferation of T cells receiving different costimulatory signals as well as for T cells activated in the absence of costimulation. CD28 signals but not costimulation via CD2, 4-1BB, ICOS or LFA-1 greatly increased the IC₅₀ for CsA. By contrast, the inhibitory effects of Aza were not influenced by T cell costimulatory signals. Our results might have implications for combining standard immunosuppressive drugs with CTLA-4Ig fusion proteins, which act by blocking CD28 costimulation.

The emerging role of Brazil in clinical trial conduct for transplantation

Brazil is a country with over 190 000 000 inhabitants and a health system composed of a large public, government managed system. Between 1999 and 2010 the number of deceased donors increased by 161%, from 3.8 to 9.9 pmp, and the number of solid organ transplants increased by 121%, from 2891 to 6402. This growth was a consequence of the creation of a well-organized national transplant program. Government funding, decentralization and educational investment in transplant coordinators and related professional were decisive. In 2009 Brazil was the second largest country in the absolute number of kidney transplants (n = 4259). There are significant region disparities in performance which are mainly due to the development status. Improvements in transplant and research regulations resulted in an increasing participation of Brazilian transplant centers in multicenter trials, reaching over 44 studies during the last 11 years. Brazilian centers have been involved in clinical trials using everolimus, sirolimus, fingolimod, mycophenolate mofetyl, mycophenolate sodium, tacrolimus modified-release, sotrastaurin, belatacept, JAK3 inhibitor CP690,550 and valganciclovir. The still increasing number of transplants performed every year along with more efficient regulatory and sanitary analysis, organized clinical research programs and reduction in region performance disparities will eventually increase even more the participation of Brazil in trials worldwide.