Concentration-Controlled Everolimus (Certican): Combination with Reduced Dose Calcineurin Inhibitors

Cardiovascular effects of immunosuppression agents

Immunosuppressive medications are widely used to treat patients with neoplasms, autoimmune conditions and solid organ transplants. Key drug classes, namely calcineurin inhibitors, mammalian target of rapamycin (mTOR) inhibitors, and purine synthesis inhibitors, have direct effects on the structure and function of the heart and vascular system. In the heart, immunosuppressive agents modulate cardiac hypertrophy, mitochondrial function, and arrhythmia risk, while in vasculature, they influence vessel remodeling, circulating lipids, and blood pressure. The aim of this review is to present the preclinical and clinical literature examining the cardiovascular effects of immunosuppressive agents, with a specific focus on cyclosporine, tacrolimus, sirolimus, everolimus, mycophenolate, and azathioprine.

Target of rapamycin inhibitors (TOR-I; sirolimus and everolimus) for primary immunosuppression in kidney transplant recipients

BACKGROUND

Kidney transplantation is the therapy of choice for many patients with end-stage kidney disease (ESKD) with an improvement in survival rates and satisfactory short term graft survival. However, there has been little improvement in long-term survival. The place of target of rapamycin inhibitors (TOR-I) (sirolimus, everolimus), which have different modes of action from other commonly used immunosuppressive agents, in kidney transplantation remains uncertain. This is an update of a review first published in 2006.

OBJECTIVES

To evaluate the short and long-term benefits and harms of TOR-I (sirolimus and everolimus) when used in primary immunosuppressive regimens for kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 20 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs in which drug regimens, containing TOR-I commenced within seven days of transplant, were compared to alternative drug regimens, were included without age restriction, dosage or language of report.

DATA COLLECTION AND ANALYSIS

Three authors independently assessed study eligibility, risk of bias, and extracted data. Results were reported as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model. The certainty of the evidence was assessed using GRADE MAIN RESULTS: Seventy studies (17,462 randomised participants) were included; eight studies included two comparisons to provide 78 comparisons. Outcomes were reported at six months to three years post transplant. Risk of bias was judged to be low for sequence generation in 25 studies, for allocation concealment in 23 studies, performance bias in four studies, detection bias in 65 studies, attrition bias in 45 studies, selective reporting bias in 48 studies, and for other potential bias in three studies. Risk of bias was judged to be at high risk of bias for sequence generation in two studies, allocation concealment in two studies, performance bias in 61 studies, detection bias in one study, attrition bias in four studies, for selective reporting bias in 11 studies and for other potential risk of bias in 46 studies. Compared with CNI and antimetabolite, TOR-I with antimetabolite probably makes little or no difference to death (RR 1.31, 95% CI 0.87 to 1.98; 19 studies) or malignancies (RR 0.86, 95% CI 0.50 to 1.48; 10 studies); probably increases graft loss censored for death (RR 1.32, 95% CI 0.96 to 1.81; 15 studies), biopsy-proven acute rejection (RR 1.60, 95% CI 1.25 to 2.04; 15 studies), need to change treatment (RR 2.42, 95% CI 1.88 to 3.11; 14 studies) and wound complications (RR 2.56, 95% CI 1.94 to 3.36; 12 studies) (moderate certainty evidence); but reduces CMV infection (RR 0.43, 95% CI 0.29 to 0.63; 13 studies) (high certainty evidence). Compared with antimetabolites and CNI, TOR-I with CNI probably makes little or no difference to death (RR 1.06, 95% CI 0.84 to 1.33; 31 studies), graft loss censored for death (RR 1.09, 95% CI 0.82 to 1.45; 26 studies), biopsy-proven acute rejection (RR 0.95, 95% CI 0.81 to 1.12; 24 studies); and malignancies (RR 0.83, 95% CI 0.64 to 1.07; 17 studies); probably increases the need to change treatment (RR 1.56, 95% CI 1.28 to 1.90; 25 studies), and wound complications (RR 1.56, 95% CI 1.28 to 1.91; 17 studies); but probably reduces CMV infection (RR 0.44, 95% CI 0.34 to 0.58; 25 studies) (moderate certainty evidence). Lower dose TOR-I and standard dose CNI compared with higher dose TOR-I and reduced dose CNI probably makes little or no difference to death (RR 1.07, 95% CI 0.64 to 1.78; 9 studies), graft loss censored for death (RR 1.09, 95% CI 0.54 to 2.20; 8 studies), biopsy-proven acute rejection (RR 0.87, 95% CI 0.67 to 1.13; 8 studies), and CMV infection (RR 1.42, 95% CI 0.78 to 2.60; 5 studies) (moderate certainty evidence); and may make little or no difference to wound complications (RR 0.95, 95% CI 0.53 to 1.71; 3 studies), malignancies (RR 1.04, 95% CI 0.36 to 3.04; 7 studies), and the need to change treatments (RR 1.18, 95% CI 0.58 to 2.42; 5 studies) (low certainty evidence). Lower dose of TOR-I compared with higher doses probably makes little or no difference to death (RR 0.84, 95% CI 0.67 to 1.06; 13 studies), graft loss censored for death (RR 0.92, 95% CI 0.71 to 1.19; 12 studies), biopsy-proven acute rejection (RR 1.26, 95% CI 1.10 to 1.43; 11 studies), CMV infection (RR 0.87, 95% CI 0.63 to 1.21; 9 studies), wound complications (RR 0.92, 95% CI 0.66 to 1.29; 7 studies), and malignancy (RR 0.84, 95% CI 0.54 to 1.32; 10 studies) (moderate certainty evidence); and may make little or no difference to the need to change treatments (RR 0.91, 95% CI 0.78 to 1.05; 10 studies) (low certainty evidence). It is uncertain whether sirolimus and everolimus differ in their effects on kidney function and lipid levels because the certainty of the evidence is very low based on a single small study with only three months of follow-up.

AUTHORS' CONCLUSIONS

In studies with follow-up to three years, TOR-I with an antimetabolite increases the risk of graft loss and acute rejection compared with CNI and an antimetabolite. TOR-I with CNI potentially offers an alternative to an antimetabolite with CNI as rates of graft loss and acute rejection are similar between interventions and TOR-I regimens are associated with a reduced risk of CMV infections. Wound complications and the need to change immunosuppressive medications are higher with TOR-I regimens. While further new studies are not required, longer-term follow-up data from participants in existing methodologically robust RCTs are needed to determine how useful immunosuppressive regimens, which include TOR-I, are in maintaining kidney transplant function and survival beyond three years.

Safety and efficacy of the early introduction of everolimus with reduced-exposure cyclosporine a in de novo kidney recipients

BACKGROUND

Everolimus and cyclosporine A (CsA) exhibit synergistic immunosuppressive activity when used in combination. We examined the safety and efficacy of the use of everolimus with a cyclosporine-sparing strategy in de novo renal transplant recipients.

METHODS

A comparative, parallel, randomized, open-label 1-year study has been performed in 148 patients from five transplant centers to compare the efficacy and tolerability of everolimus and reduced exposure CsA (the investigational group) or enteric-coated mycophenolate sodium and standard-exposure CsA (the control group) in combination with basiliximab and steroids. The eligible subjects were randomly assigned at 1 month after transplantation. Efficacy failure (biopsy-proven acute rejection, death, graft loss, or loss to follow-up), safety, and renal function were evaluated.

RESULTS

One graft loss has been reported in the control group and no patient death were reported in either group. The incidence of biopsy-proven acute rejection until 12 months after transplantation of the investigational group was 7.5%, compared to 11.1% of the control group (P=0.565). The mean estimated glomerular filtration rates of the investigational group at 12 months after transplantation was significantly higher (68.1 ± 16.8 ml/min/1.73 m(2)) than that of the control group (60.6 ± 15.8 ml/min/1.73 m(2); P=0.016). There was no significant difference (P>0.05) in the incidence of discontinuations and serious adverse events between the groups.

CONCLUSION

The results of this study provide the evidences that (1) the calcineurin inhibitor (CNI) minimization by the introduction of everolimus after 1-month posttransplantation keeps the incidences of acute rejection and additional risks as low as the conventional immunosuppression; (2) it allows minimizing CNI exposure, consequently reducing CNI nephrotoxicity and preserving renal function.

The use of sirolimus (rapamycin) in the management of refractory inflammatory bowel disease in children

BACKGROUND

Management of refractory inflammatory bowel disease (IBD) in children is challenging and once response to conventional medical therapy deviates from the expected, options are often limited. Sirolimus is commonly used in post-transplantation management and is used sparsely as rescue therapy in refractory Crohn's disease. In the present study, we report the efficacy of sirolimus as an adjuvant immunosuppressive therapy in a retrospective case review of a selected group of IBD children who were refractory to the conventional treatments.

METHODS

Medical records of children with refractory IBD unresponsive to conventional therapy and started on sirolimus between 2006 and 2012 were retrospectively reviewed. Clinical response, through Pediatric Ulcerative Colitis Activity Index (PUCAI) and Pediatric Crohn's Disease Activity Index (PCDAI), as well as intestinal inflammation, through specific histological scores, was evaluated.

RESULTS

The records of 14 patients were analyzed. Eleven of them had ulcerative colitis (UC) and 3 Crohn's disease (CD); mean age at diagnosis was 9.1 years (standard deviation 3.8). Of UC patients, 5 (45%) achieved clinical remission and 2 (18%) showed clinical response. All CD patients went into clinical remission. Mucosal healing was achieved by 5 children (45%) with UC and 2 (67%) with CD patients. One child with ulcerative colitis was weaned off adalimumab, while 2 children with CD were weaned off prednisolone and methotrexate successfully.

CONCLUSION

Our data provide evidence that sirolimus seems to be effective as rescue therapy in a subgroup of children with severe IBD refractory to conventional therapies by inducing both clinical remission and mucosal healing.

Everolimus therapy is associated with reduced lipoprotein-associated phospholipase A2 (Lp-Pla2) activity and oxidative stress in heart transplant recipients

BACKGROUND

Several studies demonstrated decreased severity and incidence of cardiac allograft vasculopathy (CAV) in heart transplant recipients receiving immunosuppressive therapy with everolimus. However, data regarding the influence of everolimus on risk factors predisposing to CAV are hitherto limited. We here systematically evaluated cardiovascular risk factors in heart transplanted patients, who underwent conversion to everolimus or were maintained on conventional therapy with calcineurin inhibitors (CNI).

METHODS

50 Patients receiving everolimus and 91 patients receiving CNI in addition to mycophenolate mofetil and low-dosed steroids were included in the study. CAV risk factors were determined in plasma or urine using standard enzymatic or immunochemical methods.

RESULTS

No significant differences were observed between both groups with regard to lipid (total, LDL- and HDL-cholesterol), metabolic (glucose, insulin), inflammatory (C-reactive protein, IL-6, myeloperoxidase) and cardiac (troponin I, NT-proBNP) risk factors. However, significantly lower activity of lipoprotein-associated phospholipase A2 (Lp-PLA2) and a negative correlation between the Lp-PLA2 activity and the everolimus concentration were observed in plasmas from everolimus-treated patients. Conversion to everolimus significantly lowered Lp-PLA2 activity in heart transplant recipients. Studies in vitro revealed reduced Lp-PLA2 expression in hepatocytes and macrophages pre-exposed to everolimus. In addition, reduced plasma markers of oxidative stress including oxidized LDL, 8-iso-prostaglandin F2α and protein carbonyls were noted in heart transplant recipients receiving everolimus therapy.

CONCLUSION

Our results suggest that everolimus specifically lowers plasma activity and cellular production of Lp-PLA2 and thereby dampens oxidative stress. These effects may additionally contribute to the reduced CAV incidence observed in heart transplant recipients receiving everolimus therapy.

Parsimonious discovery of synergistic drug combinations

Combination therapies that enhance efficacy or permit reduced dosages to be administered have seen great success in a variety of therapeutic applications. More fundamentally, the discovery of epistatic pathway interactions not only informs pharmacologic intervention but can be used to better understand the underlying biological system. There is, however, no systematic and efficient method to identify interacting activities as candidates for combination therapy and, in particular, to identify those with synergistic activities. We devised a pooled, self-deconvoluting screening paradigm for the efficient comprehensive interrogation of all pairs of compounds in 1000-compound libraries. We demonstrate the power of the method to recover established synergistic interactions between compounds. We then applied this approach to a cell-based screen for anti-inflammatory activities using an assay for lipopolysaccharide/interferon-induced acute phase response of a monocytic cell line. The described method, which is >20 times as efficient as a naïve approach, was used to test all pairs of 1027 bioactive compounds for interleukin-6 suppression, yielding 11 pairs of compounds that show synergy. These 11 pairs all represent the same two activities: β-adrenergic receptor agonists and phosphodiesterase-4 inhibitors. These activities both act through cyclic AMP elevation and are known to be anti-inflammatory alone and to synergize in combination. Thus we show proof of concept for a robust, efficient technique for the identification of synergistic combinations. Such a tool can enable qualitatively new scales of pharmacological research and chemical genetics.

Everolimus-based, calcineurin-inhibitor-free regimen in recipients of de-novo kidney transplants: an open-label, randomised, controlled trial

BACKGROUND

Non-nephrotoxic immunosuppressive strategies that allow reduction of calcineurin-inhibitor exposure without compromising safety or efficacy remain a goal in kidney transplantation. Immunosuppression based on the mammalian-target-of-rapamycin inhibitor everolimus was assessed as a strategy for elimination of calcineurin-inhibitor exposure and optimisation of renal-graft function while maintaining efficacy.

METHODS

In the ZEUS multicentre, open-label study, 503 patients (aged 18-65 years) who had received de-novo kidney transplants were enrolled. After initial treatment with ciclosporin, based on trough concentrations, and enteric-coated mycophenolate sodium (1440 mg/day, orally), corticosteroids (≥5 mg/day prednisolone or equivalent, orally), and basiliximab induction (20 mg, intravenously, on day 0 [2 h before transplantation], and on day 4), 300 (60%) patients were randomly assigned at 4·5 months in a 1:1 ratio to undergo calcineurin-inhibitor elimination (everolimus-based regimen that was based on trough concentrations [6-10 ng/mL] and enteric-coated mycophenolate sodium [1440 mg/day] with corticosteroids), or continue standard ciclosporin-based treatment. Randomisation was done by use of a central, validated system that automated the random assignment of treatment groups to randomisation numbers. The primary objective was to show better renal function (glomerular filtration rate [GFR]; Nankivell formula) with the calcineurin-inhibitor-free everolimus regimen at 12 months after transplantation. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00154310.

FINDINGS

118 (76%) of 155 everolimus-treated patients and 117 (81%) of 145 ciclosporin-treated patients completed treatment with study drug up to 12 months after transplantation. At this timepoint, the everolimus regimen was associated with a significant improvement in GFR versus the ciclosporin regimen (71·8 mL/min per 1·73 m(2) vs 61·9 mL/min per 1·73 m(2), respectively; mean difference 9·8 mL/min per 1·73 m(2), 95% CI -12·2 to -7·5). Rates of biopsy-proven acute rejection were higher in the everolimus group than in the ciclosporin group after randomisation (15 [10%] of 154 vs five [3%] of 146; p = 0·036), but similar for the full study period (23 [15%] vs 22 [15%]). Compared with the ciclosporin regimen, higher mean lipid concentrations, slightly increased urinary protein excretion, and lower haemoglobin concentrations were noted with the everolimus regimen; thrombocytopenia, aphthous stomatitis, and diarrhoea also occurred more often in the everolimus group. A higher incidence of hyperuricaemia was noted with ciclosporin.

INTERPRETATION

Early elimination of calcineurin inhibitor by use of everolimus-based immunosuppression improved renal function at 12 months while maintaining efficacy and safety, indicating that this strategy may facilitate improved long-term outcomes in selected patients.

FUNDING

Novartis Pharma.

Early (fifth day) vs. late (sixth month) steroid withdrawal in renal transplant recipients treated with Neoral(®) plus Rapamune(®): four-yr results of a randomized monocenter study

The most advisable timing for steroid withdrawal (CSWD) after renal transplantation (Tx) is still an open issue. This randomized study has compared early CSWD (at day 5) with late (at month 6) in patients under Neoral + Sirolimus. The primary end point was the percentage of success in CSWD at month 48. Ninety-six transplants from deceased donors were randomized to withdraw steroids either early (n = 49) or late (n = 47). At four yr, the two strategies were comparable for: success in CSWD (65% in both), graft survival (95% and 98%), patient survival (92% and 96%) creatininemia (1.7 ± 0.3 and 1.6 ± 0.4 mg/dL), side effects, being still on Sirolimus + Neoral (69% and 74%), reversibility of rejection (AR) (all cases), severity of AR (grade 1A/1B: 81% and 63%). The major differences were incidence of AR: at month twelve (48% vs. 30%, p < 0.04), at 48 (53% and 33%, p < 0.03); timing of AR (72 ± 86 d vs. 202 ± 119 d, p < 0.0001). The timing of CSWD influences neither the rate of successful CSWD nor the long-term results. However, early suspension causes a higher AR rate, mostly arising within month one, but always responsive to steroids. Yet, the early appearance of AR can make patient management easier and safer.

Long-term outcome of very early cyclosporine minimization and de novo everolimus therapy in kidney transplant recipients: a pharmacokinetic guided approach

BACKGROUND

Cyclosporine (CsA) nephrotoxicity is an important cause of chronic allograft dysfunction. Clinical information concerning the impact of very early CsA dose reduction in kidney transplant recipients is limited. We have examined the long-term outcomes of very early CsA dose reduction. This is synchronized with de novo everolimus and steroid therapy.

METHODS

We enrolled 10 de novo kidney transplant recipients to receive CsA (target C(0) 250-350 ng/mL) and prednisolone as initial therapy. CsA dosage was reduced by 50% at posttransplant day 7. Everolimus (target trough level, 3-8 ng/mL) was concomitantly started at the day of CsA reduction. Full pharmacokinetic studies of everolimus and CsA were studied at the period of 4-8 weeks after CsA reduction. CsA was then gradually reduced to maintain a trough level of 50-100 ng/mL and/or C(max) <600 ng/mL.

RESULTS

The mean follow-up was 51.2 ± 3.45 months. The nadir serum creatinine was 1.03 ± 0.33 mg/dL. The mean initial estimated glomerular filtration rate (eGFR) was 97.97 ± 23.36 mL/min. The mean initial trough everolimus was 5.2 ± 1.5 ng/mL. The eGFR at 1 year, 3 years, and last follow-up was 82 ± 25, 80 ± 21, and 80 ± 25 mL/min, respectively. Patient and graft survival was 100%.

CONCLUSION

Very early CsA dose reduction synchronized with de novo everolimus therapy was associated with good long-term patient and graft survival in kidney transplant recipients. This intervention can lead to 75% CsA minimization and is associated with very good GFR by the modification of Diet in Renal Disease Formula at year 4.

Efficacy and safety of de novo or early everolimus with low cyclosporine in deceased-donor kidney transplant recipients at specified risk of delayed graft function: 12-month results of a randomized, multicenter trial

Immediate or early use of proliferation signal inhibitor (PSI)/mammalian target of rapamycin (mTOR) inhibitor therapy can avoid high exposure to calcineurin inhibitors but concerns exist relating to the risk of delayed graft function (DGF) and impaired wound healing with the mTOR sirolimus. CALLISTO was a 12-month, prospective, multicenter, open-label study. Deceased-donor kidney transplant patients at protocol-specified risk of DGF were randomized to start everolimus on day 1 (immediate everolimus, IE; n = 65) or week 5 (delayed everolimus, DE; n = 74). Incidence of the primary endpoint (biopsy-proven acute rejection, BPAR; graft loss, death, DGF, wound healing complications related to transplant surgery or loss to follow-up) was 64.6% and 66.2% in the IE and DE groups, respectively, at month 12 (P = 0.860). The overall incidence of BPAR was 20.1%. Median estimated glomerular filtration rate was 48 ml/min/1.73 m(2) and 49 ml/min/1.73 m(2) in the IE and DE groups, respectively, at month 12. DGF and wound healing complications were similar between groups. Adverse events led to study drug discontinuation in 17 IE patients (26.2%) and 28 DE patients (37.8%) (NS). In conclusion, introduction of everolimus immediately or early posttransplant in DGF-risk patients is associated with good efficacy, renal function and safety profile. There seems no benefit in delaying initiation of everolimus.

Everolimus plus reduced-exposure CsA versus mycophenolic acid plus standard-exposure CsA in renal-transplant recipients

Everolimus allows calcineurin-inhibitor reduction without loss of efficacy and may improve renal-transplant outcomes. In a 24-month, open-label study, 833 de novo renal-transplant recipients were randomized to everolimus 1.5 or 3.0 mg/day (target troughs 3-8 and 6-12 ng/mL, respectively) with reduced-exposure CsA, or mycophenolic acid (MPA) 1.44 g/day plus standard-exposure CsA. Patients received basiliximab +/- corticosteroids. The primary endpoint was composite efficacy failure (treated biopsy-proven acute rejection, graft loss, death or loss to follow-up) and the main safety endpoint was renal function (estimated glomerular filtration rate [eGFR], by Modification of Diet in Renal Disease [MDRD]) at Month 12 (last-observation-carried-forward analyses). Month 12 efficacy failure rates were noninferior in the everolimus 1.5 mg (25.3%) and 3.0 mg (21.9%) versus MPA (24.2%) groups. Mean eGFR at Month 12 was noninferior in the everolimus groups versus the MPA group (54.6 and 51.3 vs 52.2 mL/min/1.73 m(2) in the everolimus 1.5 mg, 3.0 mg and MPA groups, respectively; 95% confidence intervals for everolimus 1.5 mg and 3.0 mg vs MPA: -1.7, 6.4 and -5.0, 3.2, respectively). The overall incidence of adverse events was comparable between groups. The use of everolimus with progressive reduction in CsA exposure, up to 60% at 1 year, resulted in similar efficacy and renal function compared with standard-exposure CsA plus MPA.

[Proliferation signal inhibitors: what therapeutic protocols are followed in 2009?]

Proliferation signal inhibitors (PSI) have been used in France for kidney transplants for some ten years. They provide a certain number of long-term benefits for kidney function in transplant patients due to their anti-proliferation and anti-tumour properties and absence of nephrotoxicity. Their use has been evaluated in therapeutic regimens aimed at reducing the nephrotoxicity associated with calcineurin inhibitors (CNI). Strategies based on minimizing the use of CNIs and therapy switches between 3 and 6 months have shown promising results, especially in terms of prevention of deterioration of kidney function. The best time to make the switch has not yet been defined with certainty, but predictors of success, preservation of good kidney function and absence of proteinuria have been established. Aside from cases of demonstrated CNI toxicity, a history or onset of de novo cancer is a situation in which this type of regimen can be considered.

Effect of itraconazole on the pharmacokinetics of everolimus administered by different routes in rats

The effect of itraconazole on the pharmacokinetics of everolimus was investigated in rats. Ten minutes after an intravenous or intraintestinal administration of itraconazole, everolimus was delivered intravenously (0.2 mg/kg) or intraintestinally (0.5 mg/kg). Blood concentrations of everolimus were measured up to 240 min, and pharmacokinetic parameters were calculated. Intraintestinally administered itraconazole (20 mg/kg) significantly increased the area under the concentration-time curve (AUC) of intraintestinally administered everolimus about 4.5-fold, but even at 50 mg/kg did not affect the AUC of intravenously administered everolimus. However, intravenously administered itraconazole (50 mg/kg) increased the AUC of both intraintestinally and intravenously administered everolimus approximately 2-fold. Using a value for hepatic blood flow from the literature (50 ml/min/kg), the apparent intestinal and hepatic extraction of everolimus without itraconazole was calculated as about 80% and 13%, respectively. Intraintestinally administered itraconazole (20 mg/kg) changed the apparent intestinal extraction by 0.26-fold from 0.829 to 0.215, but the hepatic availability of everolimus was almost unchanged after the intravenous or intraintestinal administration of itraconazole even at a dose of 50 mg/kg from 0.871 to 0.923 or 0.867, respectively. In conclusion, intraintestinally administered itraconazole dramatically increased the AUC of everolimus delivered intraintestinally by inhibiting the intestinal first-pass extraction of this drug.

The pathogenesis and treatment of chronic allograft nephropathy

Despite improvements in immunosuppressive therapy, long-term allograft survival after kidney transplantation remains as low as 50%. Chronic allograft nephropathy (CAN) is a major cause of late graft loss in renal transplant recipients. The histopathologic signs of CAN-interstitial fibrosis, tubular atrophy, glomerulopathy and vasculopathy-are nonspecific; therefore, the 2007 Banff classification dispensed with the term CAN in favor of 'interstitial fibrosis and tubular atrophy without evidence of any specific etiology'. In this Review, however, the term CAN is used to describe a clinical syndrome that is characterized by progressive decline in renal function from 3 months after transplantation, accompanied by the development of proteinuria and hypertension. The pathogenesis of CAN is complex and incompletely understood, and involves several immunological and non-immunological factors. We discuss the contributory roles of acute rejection, donor age, anti-human-leukocyte-antigen antibodies, calcineurin inhibitor nephrotoxic effects, viral infection, hypertension and hyperlipidemia. The prevention and treatment of CAN needs multidisciplinary strategies. Early detection by means of protocol biopsy and calculation of glomerular filtration rate is the first step, followed by management of modifiable risk factors.

The use of everolimus in renal-transplant patients

Despite advances in immunosuppressive therapy, long-term renal-transplantation outcomes have not significantly improved over the last decade. The nephrotoxicity of calcineurin inhibitors (CNIs) is an important cause of chronic allograft nephropathy (CAN), the major driver of long-term graft loss. Everolimus is a proliferation signal inhibitor with a mechanism of action that is distinct from CNIs. The efficacy and tolerability of everolimus in renal-transplant recipients have been established in a wide range of clinical trials. Importantly, synergism between everolimus and the CNI cyclosporine (CsA) permits CsA dose reduction, enabling nephrotoxicity to be minimized without compromising efficacy. Currently, everolimus is being investigated in regimens where reduced exposure CNIs are used from the initial post-transplant period to improve renal function and prevent CAN. By inhibiting the proliferation of smooth muscle cells, everolimus may itself delay the progression or development of CAN. Although everolimus is associated with specific side effects, these can generally be managed. By targeting the main causes of short- and long-term graft loss, everolimus has a key role to play in renal transplantation, which is being explored further in a number of ongoing Phase III–IV trials.

Proliferation signal inhibitors and cardiac allograft vasculopathy

PURPOSE OF REVIEW

Cardiac allograft vasculopathy (CAV) is the leading cause of late morbidity and mortality in heart transplant patients and limits long-term survival. Immunosuppression following cardiac transplantation has traditionally comprised a calcineurin inhibitor in combination with mycophenolate mofetil or azathioprine and corticosteroids. This combination provides effective immunosuppression but does not prevent subsequent development of CAV. Proliferation signal inhibitors (such as sirolimus and everolimus), a new class of immunosuppressants, have recently been shown to be effective in attenuating the development of CAV following cardiac transplantation.

RECENT FINDINGS

In addition to immunosuppressive properties, proliferation signal inhibitors have important antiproliferative effects outside the immune system. Several ex-vivo and preclinical studies on animal models have demonstrated control of the vascular manifestations after cardiac transplantation. In clinical trials, proliferation signal inhibitors used as secondary immunosuppressive agents in place of azathioprine or mycophenolate prevented CAV progression and reduced the incidence of clinically significant cardiac events. Proliferation signal inhibitors are also effective as primary immunosuppressants, and, after complete calcineurin inhibitor withdrawal, mitigate the progression of CAV, improve calcineurin inhibitor-induced nephropathy and hypertension.

SUMMARY

Proliferation signal inhibitors are powerful immunosuppressive agents with antiproliferative properties that attenuate CAV and have the potential to improve long-term survival following cardiac transplantation.

A multicenter, randomized, double-blind trial of everolimus versus azathioprine and placebo to maintain steroid-induced remission in patients with moderate-to-severe active Crohn's disease

OBJECTIVES

A prospective study was undertaken to compare the efficacy of everolimus versus azathioprine or placebo in maintaining steroid-induced remission in active Crohn's disease (CD) and assess the safety and pharmacokinetics of everolimus.

METHODS

This was a randomized, double-blind, placebo-controlled, proof-of-concept study in adults with moderate-to-severe active CD. The patients received oral steroids for a rapid induction of remission plus everolimus 6 mg/day, azathioprine 2.5 mg/kg/day, or placebo as maintenance treatment. The main outcome measure was the treatment success, defined as a steroid-free remission by the end of month 3 and maintained until study cutoff without the use of prohibited efficacy treatments.

RESULTS

Following an interim analysis, the study was terminated before enrollment was completed due to the lack of efficacy. The full intent-to-treat population comprised 138 patients. Only 96 patients who entered the study > or =7 months prior to data cutoff were included in the primary efficacy population. The treatment success was achieved in 13 of 38 everolimus patients, 22 of 36 azathioprine patients, and 8 of 22 placebo patients. Using the Kaplan-Meier estimates at month 7, the incidence of treatment success was 22.0% with everolimus group (95% confidence interval [CI] 6.7-37.3%, P= 0.610 vs placebo), 38.3% with azathioprine group (95% CI 20.6-55.9%, P= 0.500 vs placebo), and 28.8% with placebo group (95% CI 7.7-49.9%). The type and incidence of adverse events in the everolimus cohort were similar to those reported in the approved transplantation indications.

CONCLUSIONS

The safety and tolerability of everolimus (6 mg/day) in patients with active CD were comparable to azathioprine. At this dose, everolimus is not more efficacious in achieving a steroid-free remission in active CD than the comparators.

Use of Everolimus as a Rescue Immunosuppressive Therapy in Liver Transplant Patients With Neoplasms

Everolimus is a new immunosuppressant with antitumoral properties and few side effects, but limited use in liver transplantation. The aim of the present study was to evaluate the effect on survival and safety of everolimus in post liver transplantation neoplasms in a single center. Ten liver transplant recipients with a posttransplant diagnosis of neoplasm received everolimus during a median of 12.7 (5.5-27.5) months; median survival was 21.3 (7.5-40.5) months. The probability of survival of everolimus group was significantly greater than the observed in a historical cohort of 14 liver recipients with comparable tumors who did not receive everolimus (100%, 90%, 72% vs. 50%, 29%, 14%) at 6, 12, and 24 months, respectively (HR=4.6, 95% confidence interval: 1.3-16.4; P=0.008). During everolimus therapy no patients showed rejection. Renal function improved in three patients. Furthermore, severe adverse effects and infections were infrequent. In summary, everolimus seems safe for liver transplant recipients with cancer and may improve short-term survival, but further studies are needed to determine long-term benefits and safety.

Reversal of loss of glomerular filtration rate in children with transplant nephropathy after switch to everolimus and low-dose cyclosporine A

Until now there have been no good therapeutic options in children with biopsy-proven transplant nephropathy (TN) and loss of glomerular filtration rate (GFR) while receiving cyclosporine A (CsA), mycophenolate mofetil (MMF) and prednisolone (Pred). In 13 kidney transplanted children (mean age 13 yr, SD 4) with CsA/MMF/Pred immunosuppression, renal biopsy revealed significant TN. MMF was discontinued, CsA dose was reduced to 50% and Everolimus was started (1.6 mg/m(2)/day). Pred was stopped in 10 of 13 patients. The mean GFR was 55 mL/min/1.73 m(2) (SD 24) one yr before switch, 45 mL/min/1.73 m(2) (SD 16, p < 0.05) at the time of switch and 47 mL/min/1.73 m(2) (SD 18, p < 0.05) 12 months later. There were no severe side-effects or acute rejections. Lactate dehydrogenase, cholesterol, creatine kinase, and U-albumin/creatinine ratio did not increase significantly. After six months, the mean certican-C0 level was 4.0 microg/L (SD 1.5) and mean CsA-C0 level was 52 ng/mL (SD 23). The GFR of transplanted kidneys in children with TN improved by changing immunosuppression from CsA/MMF/Pred to everolimus and low-dose CsA.

Recommendations for the use of everolimus (Certican) in heart transplantation: results from the second German-Austrian Certican Consensus Conference

Everolimus (Certican; Novartis Pharma AG, Basel, Switzerland) represents the latest generation of proliferation signal inhibitors (PSIs). Everolimus is indicated for use as an immunosuppressive drug in renal and heart transplantation. This report reflects the recommendations of the second German-Austrian Certican Consensus Conference, held in January 2006, for the clinical use of everolimus.

Randomized exposure-controlled trials; impact of randomization and analysis strategies

AIMS

In the literature, five potential benefits of randomizing clinical trials on concentration levels, rather than dose, have been proposed: (i) statistical study power will increase; (ii) study power will be less sensitive to high variability in the pharmacokinetics (PK); (iii) the power of establishing an exposure-response relationship will be robust to correlations between PK and pharmacodynamics (PD); (iv) estimates of the exposure-response relationship are likely to be less biased; and (v) studies will provide a better control of exposure in situations with toxicity issues. The main aim of this study was to investigate if these five statements are valid when the trial results are evaluated using a model-based analysis.

METHODS

Quantitative relationships between drug dose, concentration, biomarker and clinical end-point were defined using pharmacometric models. Three randomization schemes for exposure-controlled trials, dose-controlled (RDCT), concentration-controlled (RCCT) and biomarker-controlled (RBCT), were simulated and analysed according to the models.

RESULTS

(i) The RCCT and RBCT had lower statistical power than RDCT in a model-based analysis; (ii) with a model-based analysis the power for an RDCT increased with increasing PK variability; (iii) the statistical power in a model-based analysis was robust to correlations between CL and EC(50) or E(max); (iv) under all conditions the bias was negligible (<3%); and (v) for studies with equal power RCCT could produce either more or fewer adverse events compared with an RDCT.

CONCLUSION

Alternative randomization schemes may not have the proposed advantages if a model-based analysis is employed.

Calcineurin inhibitor-free immunosuppression using everolimus (Certican) in maintenance heart transplant recipients: 6 months' follow-up

BACKGROUND

Everolimus is a proliferation signal-inhibitor recently introduced in heart transplant recipients. To date, little is known about calcineurin inhibitor (CNI)-free immunosuppression using everolimus. This study reports the results of CNI-free immunosuppression using everolimus.

METHODS

During a continuous 9-month period, 60 heart transplant recipients were enrolled. Reasons for switching to everolimus were side effects associated with prior CNI immunosuppression. All patients underwent standardized switching protocols and completed 6 months of follow-up. Blood was obtained for lipid status, renal function, routine controls, and levels of immunosuppressive agents. Echocardiography and a physical examination were performed on Days 0, 14, 28, and then every 3 months.

RESULTS

After switching to everolimus, most patients recovered from the side effects associated with CNIs. Renal function improved significantly after 6 months (creatinine, 2.1 +/- 0.6 vs 1.5 +/- 0.9 mg/dl, p = 0.001; creatinine clearance, 42.2 +/- 21.6 vs 61.8 +/- 23.4 ml/[min x 1.73 m2], p = 0.018). Arterial hypertension improved after 3 months and remained decreased during the observation period. Tremor, peripheral edema, hirsutism, and gingival hyperplasia markedly improved. Adverse events occurred in 8 patients (13.3%), including interstitial pneumonia (n = 2), skin disorders (n = 2), reactivated hepatitis B (n = 1), and fever of unknown origin (n = 3).

CONCLUSION

Preliminary data suggest that CNI-free immunosuppression using everolimus is safe, with excellent efficacy in maintenance heart transplant recipients. Arterial hypertension and renal function improved significantly. CNI-induced side effects such as tremor, peripheral edema, hirsutism, and gingival hyperplasia markedly improved in most patients.

Conversion to everolimus in kidney transplant recipients: a safe and simple procedure

To date there is a substantial experience with rapamycin conversion in stable renal transplant recipients with respect to the procedure of conversion, initial doses, and target blood levels as well as adverse events, but in the case of Everolimus there is almost no experience with conversion and calcineurin inhibitor (CNI) withdrawal. We describe an initial experience among 32 renal transplant recipients who were converted to Everolimus with complete suspension of CNI in two Spanish transplant centers. Our results emphasised the procedure for conversion, the target levels, the adverse events, and the initial efficacy, over the first month after conversion. Our conclusions were that conversion from CNI to Everolimus was a simple, safe procedure with a predictable profile of adverse events, which were, in general, of mild intensity. There was a good correlation between initial dose and blood level. Initial doses of about 3 mg/d combined with rapid reduction in CNI exposure seemed to be adequate. The target range levels between 5 and 10 ng/mL seemed to be sufficient for complete CNI elimination, especially in patients also receiving antiproliferative drugs (such as mycophenolate mofetil or azathioprine) in whom levels near the lower end of the range might be adequate.

Chronic renal allograft dysfunction

The major causes of renal transplant loss are death from vascular, malignant or infectious disease, and loss of the allograft from chronic renal dysfunction associated with the development of graft fibrosis and glomerulosclerosis. Chronic allograft nephropathy (CAN) is the histologic description of the fibrosis, vascular and glomerular damage occurring in renal allografts. Clinical programs rely on monitoring change in serum creatinine for identification of patients at risk of CAN, but this change occurs late in the course of the disease, and underestimates the severity of pathologic change. CAN has several causes: ischemia-reperfusion injury, ineffectively or untreated clinical and subclinical rejection, and superimposed calcineurin inhibitor nephrotoxicity, exacerbating pre-existing donor disease. Once established, interstitial fibrosis and arteriolar hyalinosis lead to progressive glomerulosclerosis over the subsequent years. There have been a number of approaches to treatment aimed at reducing the impact of CAN, mostly centered around avoidance of calcineurin inhibitors through their elimination in all, or just selected, patients. These immunosuppression strategies combine corticosteroids with azathioprine or mycophenolate mofetil, and/or sirolimus and everolimus. Late identification of CAN in individual patients has meant that strategies for intervening to prevent chronic renal allograft dysfunction and subsequent graft loss tend to be "too little and far too late."