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

Chapter 2:indications and dosing of anticancer drug therapy in patients with impaired kidney function, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

This comprehensive review discusses the dosing strategies of cancer treatment drugs for patients with impaired kidney function, specifically those with chronic kidney disease (CKD), undergoing hemodialysis, and kidney transplant recipients. CKD patients often necessitate dose adjustments of chemotherapeutic agents, e.g., platinum preparations, pyrimidine fluoride antimetabolites, antifolate agents, molecularly targeted agents, and bone-modifying agents, to prevent drug accumulation and toxicity due to diminished renal clearance of the administered drugs and their metabolites. In hemodialysis patients, factors such as drug removal from hemodialysis and altered pharmacokinetics demand careful optimization of anticancer drug therapy, including dose adjustment and timing of administration. While free cisplatin is removed by hemodialysis, most of the tissue- and protein-bound cisplatin remains in the body and rebound cisplatin elevations are observed after hemodialysis. It is not recommended hemodialysis for drug removal, regardless of timing. Kidney transplant patients encounter unique challenges in cancer treatment, as maintaining the balance between reduction of immunosuppression, switching to mTOR inhibitors, and considering potential drug interactions with chemotherapeutic agents and immunosuppressants are crucial for preventing graft rejection and achieving optimal oncologic outcomes. The review underscores the importance of personalized, patient-centric approaches to anticancer drug therapy in patients with impaired kidney function.

Antineoplastic chemotherapy and immunosuppression in liver transplant recipients: Squaring the circle?

BACKGROUND

Malignancies are a major cause of late death after liver transplantation (LT). In LT recipients presenting a malignancy, antineoplastic chemotherapy is central part of the therapeutic arsenal, but management of both immunosuppressive and antineoplastic chemotherapy can be very challenging. The aim of the present retrospective study was to describe a recent single center cohort of LT recipients treated with antineoplastic cytotoxic chemotherapy.

METHODS

All LT recipients who received antineoplastic chemotherapy in our center between 2005 and 2021 were included.

RESULTS

The study population included 72 antineoplastic chemotherapy courses in 69 patients. There was a majority of men (81.9%); median age at LT was 54.9 (range 1-68) and was 63.0 (18-79) at the diagnosis of malignancy. Lung carcinomas (23.6%), head and neck carcinomas (20.8%), lymphomas (16.7%), and recurrent hepatocellular carcinoma (HCC) (8.3%) were the most frequent malignancies. Neoadjuvant (30.6%), adjuvant (12.5%) or palliative (54.2%) chemotherapy was performed. Immunosuppressive regimen was modified from a calcineurin inhibitor (CNI)-based to an everolimus-based regimen (63.5% of CNI discontinuation). Median survival after diagnosis of malignancy was 22.5 months and 5-year survival was 30.1%. Chemotherapy regimen was considered optimal in 81.9% of the cases. Multivariate analysis disclosed that non-PTLD N+ stage malignancy (HR = 5.52 95%CI [1.40;21.69], p = .014), non-PTLD M+ stage malignancy (HR = 10.55 95%CI [3.20;34.73], p = .0001), and suboptimal chemotherapy (HR = 2.73 95%CI [1.34;5.56], p = .005) were significantly associated with poorer prognosis. No rejection episode occurred during chemotherapy.

CONCLUSIONS

The present study is the first one focused on antineoplastic chemotherapy in LT recipients. Our results suggest that immunosuppressive drugs and antineoplastic chemotherapy can be managed satisfactorily in most cases but this needs confirmation from larger cohorts.

mTOR inhibitors in pediatric liver transplant recipients

BACKGROUND

During the past decade, mTOR inhibitors (mTORi), everolimus and sirolimus, have been increasingly used after adult liver transplantation (LT). The aim of the present study was to describe the use of mTORi in pediatric LT recipients.

METHODS

All pediatric LT recipients who received mTORi before December 2017 from 4 European pediatric LT centers were included and analyzed.

RESULTS

The present retrospective study included 30 patients; 21 were male (70%), median age was 9.3 years (range: 1.2-17.1 years) at mTORi introduction. Main indications for mTORi introduction were pre-existing liver malignancy (43.3%), calcineurin inhibitor (CNI) nephrotoxicity (26.7%), or rejection (23.4%). At last follow-up, mTORi CNIs were withdrawn in 10 patients (10/29, 34.5%). The median dose of mTORi was 1.8 mg/day (range: 0.3-5.0) or 0.058 mg/kg/day (range: 0.01-0.26), and the median trough level was 5.1 μg/L (range: 1.0-15.5). After a median follow-up of 2.8 years (range: 0.2-10.0), 50.0% of the patients presented with at least one adverse event. The main adverse events included hyperlipidemia, proteinuria, dermatitis, and mucitis. Overall mTORi discontinuation rate was 23.3% (10.0% because of adverse event). Introduction of mTORi had no significant impact on renal function.

CONCLUSION

Our results suggest that mTORi can be used in pediatric LT recipients in different clinical situations, both to reinforce immunosuppressive therapy, and to reduce CNI and related toxicity.

Recommendations of everolimus use in liver transplant

Mammalian target of rapamycin (mTOR) inhibitors, everolimus (EVL) and sirolimus are immunosuppressive agents with a minor nephrotoxic effect, limited to the development of proteinuria in some cases. The combination of EVL and low-dose tacrolimus has proven to be as safe and effective as standard therapy with tacrolimus for the prevention of acute cellular rejection. Early initiation of EVL-based immunosuppressive regimens with reduced exposure to calcineurin inhibitors has been shown to significantly improve renal function of LT recipients during induction and maintenance phases, with comparable efficacy and safety profiles. In patients with established kidney failure, initiating EVL may enable clinicians to reduce calcineurin inhibitors exposure, thereby contributing to the improved renal function of these patients. Although there is not sufficient evidence to recommend their use to prevent the recurrence of hepatocellular carcinoma and the progression of de novo tumours, they are used in this context in routine clinical practice.

Modification of immunosuppressive therapy as risk factor for complications after liver transplantation

Management of complications post-liver transplantation (LT) includes immunosuppressive manipulations with the aim to reduce the overall burden of immunologic suppression and compensate for renal, cardiovascular, metabolic toxicities, and for the increased oncologic risk. Two approaches can be implemented to reduce immunosuppression-related adverse events: upfront schedules tailored to the pretransplant individual patient's risk profile versus downstream modifications in the event of immunosuppression-related complications. Upfront strategies are supported by evidence originating from prospective randomized trials and consist of triple/quadruple schedules whereby calcineurin inhibitors (CNI)-exposure is reduced with combination of anti-CD25 monoclonal antibodies, antimetabolites and corticosteroids. Quadruple regimens allow for staggering of CNI introduction and higher renal function in the early term, but their superiority in the long term has not yet been established. A more recent upfront schedule contemplates early (4 weeks) introduction of mammalian target of rapamycin inhibitor (mTORi) everolimus and allows for reduction of CNI up to 4 years posttransplantation. Incorporation of mTORi has the potential to prolong time to recurrence for patients with hepatocellular carcinoma. However, as suggested by the available evidence, downstream immunosuppressive manipulations are more frequently adopted in clinical practice. These encompass CNI replacement and immunosuppression withdrawal. Switching CNI to mTORi monotherapy is the option most commonly adopted to relieve renal function and compensate for posttransplant malignancies. Its impact is dependent on interval from transplantation and underlying severity of renal impairment. Introduction of mTORi is associated with longer overall survival for patients with extrahepatic posttransplant malignancies, but results are awaited for recurrences of hepatocellular carcinoma. Immunosuppression withdrawal seems feasible (70%) in very long term survivors (>10 years), but is not associated with reversal of immunosuppression-related complications. Awaiting novel immunosuppressive drug categories, integration of upfront strategies with the aim to reduce CNI-exposure and a low threshold for adjustment in the posttransplant course are both advisable to improve long-term outcomes of LT.

Conversion From Sirolimus to Everolimus in Long-Term Liver Graft Recipients

Immunosuppression by inhibition of the mechanistic target of rapamycin (mTOR) is a promising approach after liver transplantation. The mTOR inhibitor sirolimus was used in selected liver graft recipients despite safety concerns and lack of approval. Everolimus is another mTOR inhibitor approved after liver transplantation. It is currently unknown, whether conversion of sirolimus to everolimus is safe in long-term liver graft recipients. Long-term liver graft recipients treated with sirolimus were converted to everolimus. A systematical analysis of biochemical and clinical data before and after conversion was performed. Sixteen patients were included (female/male, 8/8). Median (range) age at conversion was 66 years (49-78 years), and patients were converted at a median (range) of 10.1 years (4.0-22.3 years) after liver transplantation. In the majority of patients, no dose adjustment was needed after conversion. No rejection and no cytomegalovirus replication episodes were observed. Furthermore, no differences were found with respect to kidney function, diabetes mellitus, or blood pressure before and after conversion. Bilirubin serum concentration was lower, whereas aspartate aminotransaminase, alanine aminotransferase, and triglycerides serum concentrations were higher after conversion to everolimus. Neither clinical- nor graft-associated significant complications were observed after conversion from sirolimus to everolimus in long-term liver graft recipients. Everolimus-based immunosuppression may be offered to patients after liver transplantation formerly treated with sirolimus.

Everolimus and Malignancy after Solid Organ Transplantation: A Clinical Update

Malignancy after solid organ transplantation remains a major cause of posttransplant mortality. The mammalian target of rapamycin (mTOR) inhibitor class of immunosuppressants exerts various antioncogenic effects, and the mTOR inhibitor everolimus is licensed for the treatment of several solid cancers. In kidney transplantation, evidence from registry studies indicates a lower rate of de novo malignancy under mTOR inhibition, with some potentially supportive data from randomized trials of everolimus. Case reports and small single-center series have suggested that switch to everolimus may be beneficial following diagnosis of posttransplant malignancy, particularly for Kaposi's sarcoma and nonmelanoma skin cancer, but prospective studies are lacking. A systematic review has shown mTOR inhibition to be associated with a significantly lower rate of hepatocellular carcinoma (HCC) recurrence versus standard calcineurin inhibitor therapy. One meta-analysis has concluded that patients with nontransplant HCC experience a low but significant survival benefit under everolimus monotherapy, so far unconfirmed in a transplant population. Data are limited in heart transplantation, although observational data and case reports have indicated that introduction of everolimus is helpful in reducing the recurrence of skin cancers. Overall, it can be concluded that, in certain settings, everolimus appears a promising option to lessen the toll of posttransplant malignancy.

Neoplastic disease after liver transplantation: Focus on de novo neoplasms

De novo neoplasms account for almost 30% of deaths 10 years after liver transplantation and are the most common cause of mortality in patients surviving at least 1 year after transplant. The risk of malignancy is two to four times higher in transplant recipients than in an age- and sex-matched population, and cancer is expected to surpass cardiovascular complications as the primary cause of death in transplanted patients within the next 2 decades. Since exposure to immunosuppression is associated with an increased frequency of developing neoplasm, long-term immunosuppression should be therefore minimized. Promising results in the prevention of hepatocellular carcinoma (HCC) recurrence have been reported with the use of mTOR inhibitors including everolimus and sirolimus and the ongoing open-label prospective randomized controlled SILVER. Study will provide more information on whether sirolimus-containing vs mTOR-inhibitor-free immunosuppression is more efficacious in reducing HCC recurrence.

Renal function improvement in liver transplant recipients after early everolimus conversion: A clinical practice cohort study in Spain

A national, multicenter, retrospective study was conducted to assess the results obtained for liver transplant recipients with conversion to everolimus in daily practice. The study included 477 recipients (481 transplantations). Indications for conversion to everolimus were renal dysfunction (32.6% of cases), hepatocellular carcinoma (HCC; 30.2%; prophylactic treatment for 68.9%), and de novo malignancy (29.7%). The median time from transplantation to conversion to everolimus was 68.7 months for de novo malignancy, 23.8 months for renal dysfunction, and 7.1 months for HCC and other indications. During the first year of treatment, mean everolimus trough levels were 5.4 (standard deviation [SD], 2.7) ng/mL and doses remained stable (1.5 mg/day) from the first month after conversion. An everolimus monotherapy regimen was followed by 28.5% of patients at 12 months. Patients with renal dysfunction showed a glomerular filtration rate (4-variable Modification of Diet in Renal Disease) increase of 10.9 mL (baseline mean, 45.8 [SD, 25.3] versus 57.6 [SD, 27.6] mL/minute/1.73 m(2) ) at 3 months after everolimus initiation (P < 0.001), and 6.8 mL at 12 months. Improvement in renal function was higher in patients with early conversion (<1 year). Adverse events were the primary reason for discontinuation in 11.2% of cases. The probability of survival at 3 years after conversion to everolimus was 83.0%, 71.1%, and 59.5% for the renal dysfunction, de novo malignancy, and HCC groups, respectively. Everolimus is a viable option for the treatment of renal dysfunction, and earlier conversion is associated with better recovery of renal function. Prospective studies are needed to confirm advantages in patients with malignancy.

mTOR inhibitor therapy: Does it prevent HCC recurrence after liver transplantation?

Prevention of hepatocellular carcinoma (HCC) recurrence after liver transplantation is a clinical priority. The importance of the mammalian target of rapamycin (mTOR) pathway in cell growth and survival makes it a logical target for antitumor strategies, as borne out by clinical data in various types of malignancy. A number of studies have indicated that the mTOR inhibitors everolimus and sirolimus suppress cell proliferation and tumor growth in animal models of HCC. Coadministration of an mTOR inhibitor could permit lower dosing of chemotherapeutic agents in HCC management, and trials in non-transplant HCC population are exploring combined used with various agents including sorafenib, the vascular endothelial growth factor inhibitor bevacizumab and conventional agents. In terms of a preventive effect after liver transplantation for HCC, data from retrospective studies and non-randomized prospective analyses in which patients received an mTOR inhibitor with concomitant calcineurin inhibitor therapy have indicated that HCC recurrence rates and overall survival may be improved compared to a standard calcineurin inhibitor regimen. Meta-analyses have supported these findings, but controlled trials are required before any firm conclusions can be drawn. In two of the three randomized trials which have assessed de novo mTOR inhibitor therapy after liver transplantation, there was a numerically lower rate of HCC recurrence by one year post-transplant in patients given an mTOR inhibitor versus the control arm, but absolute numbers were low. Overall, based on the available data from retrospective studies, meta-analyses, and post-hoc assessments of randomized trials, it appears advisable to consider mTOR inhibition-based immunosuppression after transplantation for HCC, particularly in patients who exceed the Milan criteria. Prospective data are awaited.

Conversion to everolimus dramatically improves the prognosis of de novo malignancies after liver transplantation for alcoholic liver disease

De novo malignancies are a main cause for late death after liver transplantation (LT). Everolimus (ERL) is an immunosuppressive agent with antitumoral properties. The aim of the present retrospective study was to identify prognostic factors, including conversion to ERL, for patients presenting non-cutaneous de novo solid organ malignancy after LT for alcoholic cirrhosis. The study population consisted of 83 patients (presenting 100 tumors, including 75% of upper aerodigestive tract cancers), among the 398 patients who underwent LT for alcoholic cirrhosis in our center. After diagnosis, ERL was introduced in 38 patients and calcineurin-inhibitor was discontinued in 64.1% of them. Tumor stage was a significant prognostic factor with a one-yr survival at 82.6% for early stages, 63.4% for intermediate stages (N+) and 27.4% for disseminated diseases (p < 0.001). Associated relative risk factor was 2.202 (95% CI 1.044-4.644) for intermediate stages and 5.743 (95% CI 2.436-13.541) for metastatic stages. One- and five-yr survival was 77.4% and 35.2% in ERL group vs. 47.2% and 19.4% in the non-ERL group, respectively (p = 0.003). The relative risk factor for ERL was 0.447 (95%CI 0.257-0.778). Our results strongly suggest that conversion to ERL improves the prognosis of de novo malignancies after LT for alcoholic cirrhosis. Prospective studies are needed to confirm this benefit.

Everolimus immunosuppression reduces the serum expression of fibrosis markers in liver transplant recipients

AIM: To evaluate the expression of serum fibrosis markers in liver transplantation (LT) recipients on everolimus monotherapy compared to patients on an anti-calcineurin regimen.

METHODS: This cross-sectional case-control study included LT patients on everolimus monotherapy (cases) (E) (n = 30) and matched controls on an anti-calcineurin regimen (calcineurin inhibitors, CNI), paired by etiology of liver disease and time since LT (n = 30). Clinical characteristics, blood tests and elastography were collected. Serum levels of transforming growth factor-β (TGF-β), angiopoietin-1, tumor necrosis factor (TNF), platelet derived growth factor, amino-terminal propeptide of type III procollagen (PIIINP), hyaluronic acid (HA), VCM-1 (ng/mL), interleukin (IL)-10, interferon-inducible protein 10 (IP-10), vascular endothelial growth factor and hepatocyte growth factor (HGF) (pg/mL) were determined by enzyme-linked immunosorbent assay. Expression of these markers between E and CNI was compared. Stratified analysis was done according to factors that may influence liver fibrosis. Variables are described with medians (interquartillic range) or percentages.

RESULTS: A total of 60 patients [age: 59 (49-64), hepatitis C virus (HCV): n = 21 (35%), time from LT: 73 mo (16-105)] were included. Patients had been on everolimus for a median of 15 mo. No differences in inflammatory activity, APRI test or liver elastography were found between the groups. No significant differences were observed between the groups in serum levels of PIIINP, metalloproteinase type = 1, angiopoietin, HGF, IP-10, TNF-α, IL-10 and vascular cell adhesion molecule. Patients on E had a lower expression of TGF-β [E: 12.7 (3.7-133.6), CNI: 152.5 (14.4-333.2), P = 0.009] and HA [E: 702.89 (329.4-838.2), CNI: 1513.6 (691.9-1951.4), P = 0.001] than those on CNI. This difference was maintained in the stratified analysis when recipient age is more than 50 years (TFG-β1: P = 0.06; HA: P = 0.005), in patients without active neoplasia (TFG-β1, P = 0.009; HA: P = 0.01), according to time since LT (> than 5 years, TFG-β1: P = 0.001; HA: P = 0.002), related to previous history of biliary complications (HA: P = 0.01) and HCV recurrence (HA: P = 0.004). Liver transplant recipients with everolimus monotherapy had less serum expression of TGF-β y HA than matched patients with anti-calcineurins. This difference remains when classifying patients according to donor age and time since LT. Due to the small sample size, when examining patients with a prior history of biliary complications or recurrent HCV, the difference was non-significant but trends towards the lower expression of TFG-β1 in the everolimus group. Mammalian target of rapamycin (mTOR) plays a role in the transformation of quiescent hepatocellular stellate cell to their active profibrotic state, and experimental models have demonstrated the potential activity of mTOR inhibition in attenuating fibrogenesis.

CONCLUSION: This study supports a possible role of everolimus in liver fibrosis modulation after LT in a clinical setting and suggests that tailoring immunosuppression could avoid fibrosis progression in the allograft.

PI3Kδ inhibition augments the efficacy of rapamycin in suppressing proliferation of Epstein-Barr virus (EBV)+ B cell lymphomas

Posttransplant lymphoproliferative disorder (PTLD) continues to be a devastating and potentially life-threatening complication in organ transplant recipients. PTLD is associated with EBV infection and can result in malignant B cell lymphomas. Here we demonstrate that the PI3K/Akt/mTOR pathway is highly activated in EBV+ B cell lymphoma lines derived from patients with PTLD. Treatment with the mTORC1 inhibitor Rapamycin (RAPA) partially inhibited the proliferation of EBV+ B cell lines. Resistance to RAPA treatment correlated with high levels of Akt phosphorylation. An mTORC1/2 inhibitor and a PI3K/mTOR dual inhibitor suppressed Akt phosphorylation and showed a greater anti-proliferative effect on EBV+ B lymphoma lines compared to RAPA. EBV+ B cell lymphoma lines expressed high levels of PI3Kδ. We demonstrate that PI3Kδ is responsible for Akt activation in EBV+ B cell lymphomas, and that selective inhibition of PI3Kδ by either siRNA, or a small molecule inhibitor, augmented the anti-proliferative effect of RAPA on EBV+ B cell lymphomas. These results suggest that PI3Kδ is a novel, potential therapeutic target for the treatment of EBV-associated PTLD and that combined blockade of PI3Kδ and mTOR provides increased efficacy in inhibiting proliferation of EBV+ B cell lymphomas.

Irreversible liver failure: treatment by transplantation: part 3 of a series on liver cirrhosis

BACKGROUND

Liver transplantation is the only established, causally directed treatment for irreversible chronic or acute liver failure.

METHODS

This review is based on papers retrieved by a selective search in the PubMed database, the index of randomized controlled trials of the European Society of Organ Transplantation, and the Cochrane database, along with an analysis of data from the authors' own center.

RESULTS

1199 liver transplantations were performed in Germany in 2011. The most common indications were alcoholic cirrhosis (28%), cirrhosis of other causes (24%), and intrahepatic tumors (20%). Among recipients, the sex ratio was nearly 1:1 and the median age was just under 50. Across Europe, the 1-, 5-, and 10-year survival rates after liver transplantation were 82%, 71% and 61%. In our own center, the Charité in Berlin, the corresponding rates were 90.4%, 79.6% and 70.3%, based on an experience of 100 to 120 cases per year. The current rate of functioning transplants five years after liver transplantation is 52.6% in Germany and 66.2% internationally. Standard immunosuppression consists of a calcineurin inhibitor, tacrolimus or cyclosporine A, and steroids. Early complications include primary functional failure of the transplant, hemorrhage, thrombosis, acute rejection, and biliary complications. Over the long term, complications that can impair the outcome include chronic rejection, biliary strictures, cardiovascular and metabolic adverse effects, nephrotoxicity, neurotoxicity, and opportunistic infections and malignancies.

CONCLUSION

Liver transplantation is a successful and well-established form of treatment that is nonetheless endangered by a shortage of donor organs and other structural and organizational difficulties.

Current and Future Treatment Strategies for Patients with Advanced Hepatocellular Carcinoma: Role of mTOR Inhibition

Hepatocellular carcinoma (HCC) is a common cancer that has the third highest cancer-related mortality rate worldwide. Although potentially curable by transplantation if detected early, the majority of cases are diagnosed at an advanced stage of disease for which limited treatment options are available. The only proven systemic therapy for advanced HCC is sorafenib, a multi-kinase inhibitor that has demonstrated modest efficacy and reasonable tolerability in patients with advanced HCC. Five years after the approval of sorafenib, no other agent has been proven to be beneficial in the first- or second-line setting in advanced HCC. While molecular studies have highlighted various potential targets in HCC, the mammalian target of rapamycin (mTOR) has emerged as an exciting target for cancer therapy including HCC. Laboratory data have linked the phosphatidylinositol 3-kinase/AKT/mTOR axis to various oncogenic processes, including survival and angiogenesis. Historically, mTOR inhibitors have been used for their immunosuppressive properties, but more recently they have been approved as anticancer agents. Retrospective HCC studies suggest that the inclusion of mTOR inhibition as part of an immunosuppressant regimen after transplantation may reduce HCC recurrence compared with other immunosuppressive agents such as calcineurin inhibitors. More recently, single-arm, phase I/II studies have shown that mTOR inhibitors also have activity as monotherapy in cases of recurrent HCC or de novo advanced HCC. This article will review the rationale for targeting the mTOR pathway in HCC, and the currently available clinical data supporting its development for HCC.

Antineoplastic effects of mammalian target of rapamycine inhibitors

Cancer after transplantation is the third cause of death and one of the more relevant comorbidities. Aim of this review is to verify the role of different pathogenetic mechanisms in cancer development in transplant patients and in general population as well. In particular has been outlined the different role exerted by two different families of drug as calcineurin inhibitor and mammalian target of rapamycin (mTOR) inhibitor. The role of mTOR pathways in cell homeostasis is complex but enough clear. As a consequence the mTOR pathway deregulation is involved in the genesis of several cancers. Hence the relevant role of mTOR inhibitors. The authors review the complex mechanism of action of mTOR inhibitors, not only for what concerns the immune system but also other cells as endothelial, smooth muscle and epithelial cells. The mechanism of action is still now not completely defined and understood. It implies the inhibition of mTOR pathway at different levels, but mainly at level of the phosphorylation of several intracellular kinases that contribute to activate mTOR complex. Many prospective and retrospective studies in transplant patients document the antineoplastic role of mTOR inhibition. More recently mTOR inhibitors proven to be effective in the treatment of some cancers also in general population. Kidney cancers, neuroendocrine tumors and liver cancers seem to be the most sensitive to these drugs. Best results are obtained with a combination treatment, targeting the mTOR pathway at different levels.

Everolimus in clinical practice in long-term liver transplantation: an observational study

INTRODUCTION

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been used in acute and chronic treatment of kidney and heart transplants. There is scarce information regarding its use in liver transplant recipients, although everolimus may be a useful alternative for selected cases.

OBJECTIVE

The objective of this study was to study the clinical, biochemical, and pathological features of patients to whom everolimus was added based upon defined clinical profiles.

STUDY DESIGN

This study was prospective observational ongoing study to evaluate the effectiveness and safety of everolimus alone or in combination with low doses of a calcineurin inhibitor (CNI). Chronic liver transplant recipients without contraindications to everolimus were defined based upon 7 profiles of complications. The initial everolimus dose (0.25 mg every 12 hours) was overlapped during conversion, measuring blood levels and evaluating clinical tolerance. Routine monitoring was performed to obtain immunosuppressant blood levels near the lower limit of the therapeutic range.

RESULTS

The 35 patients' including 17 men and 18 women, had an overall mean age of 61 ± 10 years with a mean follow-up of 34 months. The everolimus treatment lasted 20 months (range, 6-60). The indication for everolimus conversion were as follows: renal insufficiency (45.7%), no response to hepatitis C virus (HCV) treatment (42.9%), autoimmune hepatitis associated with interferon (8.5%), de novo autoimmune hepatitis (25.5%), de novo tumor (37.1%), neurotoxicity (14.3%), or side effects to rapamycin treatment (5.7%). Patients may have presented more than one indication. Effectiveness was assessed based upon improved liver (48.6%) or renal function (31.25% with renal insufficiency) or withdrawal of prednisone (100% of 10 patients receiving prednisone). CNI was withdrawn from 48.6% of patients due to de novo tumors or neurotoxicity. The side effect were as follows: anemia, leukopenia, or thrombocytopenia (11.4%) or dyslipidemia (27.3%). The survival rate was 94.3%.

CONCLUSIONS

Administration of everolimus to chronic liver transplants enhanced therapeutic options in the long term recipients when applied for predefined clinical indications and administrated with dose adjustments based on serial monitoring of exposure.

The metabolic and toxicological considerations for mTOR inhibitors in the treatment of hepatocarcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a major health problem worldwide. Several molecular pathways involved in HCC growth and progression have recently been identified. Rapamycin analogs are able to inhibit one of the most active oncogenic molecular pathways in HCC cells: the mammalian target of rapamycin (mTOR) pathway.

AREAS COVERED

In this review, the authors analyze the principal molecular features of the mTOR pathway and the use of rapamycin analogs in the treatment of hepatocarcinoma. The article also looks at the reoccurrence of HCC following liver transplantation as well as after the treatment of de novo neoplasms. Finally, the authors discuss the advantage of using a combined HCC pharmacological therapy to obtain a synergistic effect on tumor mass.

EXPERT OPINION

Among the available options for the treatment of advanced-stage HCC, mTOR pathway inhibitors show great promise. Once these agents have their safety and efficacy confirmed, in the treatment of liver disease, their use should be considered in patients affected by HCC. This should especially be the case for those who have had liver transplants or suffered with de novo tumors. Moreover, the authors believe that mTOR inhibitors could be used in a combined pharmacological approach to improve HCC molecular-targeted therapy by producing a multiple-level block of tumor intracellular signaling.

Conversion to everolimus in maintenance liver transplant patients: a multicenter, retrospective analysis

Data on the conversion of patients to everolimus after liver transplantation are sparse. A multicenter, retrospective study followed 240 maintenance liver transplant patients to analyze the current indications for everolimus conversion, the employed regimens and exposure levels, and the impact on efficacy and safety. The mean time from transplantation to the introduction of everolimus was 4.9 ± 5.2 years. The mean everolimus trough level was 7.3 ± 4.1 ng/mL at month 1 and 8.1 ± 4.7 ng/mL at month 12. At 12 months, 61.6% of the patients were no longer receiving calcineurin inhibitor (CNI) therapy. The mean estimated glomerular filtration rate (eGFR) according to the Cockcroft-Gault formula was 64.2 ± 30.0 mL/minute on day 0 and 68.4 ± 32.5 mL/minute at month 12 (P = 0.007). Among patients with baseline serum creatinine levels ≥ 130 μmol/L, the eGFR values were 44.3 ± 15.7 mL/minute on day 0 and 53.7 ± 26.0 mL/minute at month 12 (P = 0.003). Four patients (1.6%) developed mild or moderate biopsy-proven acute rejection. Adverse events led to everolimus discontinuation in 12.9% of the patients. After the initiation of everolimus, the mean white blood cell count decreased significantly, and the total cholesterol and triglyceride levels increased significantly. In this retrospective analysis of the largest cohort of maintenance liver transplant patients analyzed after their conversion to everolimus, more than 60% of the patients were kept free of CNIs with a very low risk of acute rejection and with an acceptable safety profile. Randomized trials in which maintenance liver transplant patients are switched to everolimus in response to clinical indications or preemptively are warranted.

Proliferation signal inhibitors and post-transplant malignancies in heart transplantation: practical clinical management questions

Although malignancy is a major threat to long-term survival of heart transplant (HT) recipients, clear strategies to manage immunosuppression in these patients are lacking. Several lines of evidences support the hypothesis of an anticancer effect of proliferation signal inhibitors (PSIs: mammalian target of rapamycin [mTOR] inhibitors) in HT recipients. This property may arise from PSI's ability to replace immunosuppressive therapies that promote cancer progression, such as calcineurin inhibitors or azathioprine, and/or through their direct biological actions in preventing tumor development and progression. Given the lack of randomized studies specifically exploring these issues in the transplant setting, a collaborative group reviewed current literature and personal clinical experience to reach a consensus aimed to provide practical guidance for the clinical conduct in HT recipients with malignancy, or at high risk of malignancy, with a special focus on advice relevant to potential role of PSIs.

Everolimus: a proliferation signal inhibitor with clinical applications in organ transplantation, oncology, and cardiology

Everolimus, a proliferation signal inhibitor in the mammalian target of rapamycin (mTOR) drug class, has many clinical applications, including in organ transplantation, oncology, and cardiology. It currently has United States Food and Drug Administration (FDA) approval for prophylaxis against rejection in de novo renal transplant recipients, treatment of renal cell carcinoma, and use as a drug-eluting stent. To review the pharmacology, pharmacokinetics, efficacy, and safety of everolimus, we performed a search of the MEDLINE database (January 1997-April 2010) for all English-language articles of in vitro and in vivo studies that evaluated everolimus, as well as abstracts from recent scientific meetings and the manufacturer. In transplantation, everolimus demonstrates immunosuppressive properties and has been used to prevent acute rejection in cardiac, liver, lung, and renal transplant recipients. It appears that this agent may be potent enough to allow for the minimization or removal of calcineurin inhibitors in the long-term management of renal transplant recipients. In oncology, everolimus has been proven effective for the management of treatment-resistant renal cell carcinoma. In cardiology, everolimus is available as a drug-coated stent and is used in percutaneous coronary interventions for prevention of restenosis. In transplant recipients and patients with renal cell carcinoma, everolimus appears to have an extensive adverse-event profile. The pharmacologic properties of everolimus differentiate this agent from other drugs used in these clinical areas, and its pharmacokinetic properties differentiate it from sirolimus.

Malignancy after renal transplantation: the role of immunosuppression

Outcomes of kidney transplantation, in terms of graft and patient survival, have improved over the past few decades, partly as a result of the introduction of new immunosuppressive drugs. Many immunosuppressive agents are associated with an increased risk of cardiovascular events and an increased risk of cancer, however, which can compromise patient survival. Cancer is more common among solid-organ transplant recipients than it is in the general population or in patients on dialysis. In fact, malignancy is the third most common cause of death in renal transplant recipients. Immunosuppressive treatments used in renal transplant recipients can cause malignancy by supporting oncogenesis caused by certain viruses or by impairing immune surveillance thereby enabling faster tumor growth. In this Review, we describe the epidemiological and clinical characteristics of common tumor types occurring after kidney transplantation, and the etiopathogenetic factors that lead to their appearance, with a particular focus on the relationship between immunosuppressive treatment and malignancy. Immunosuppressive drugs associated with an increased risk of malignancy after transplantation are also discussed, as are immunosuppressive drugs that seem to have antioncogenic properties.

Tolerability of everolimus-based immunosuppression in maintenance liver transplant recipients

BACKGROUND

The aim of this study was to evaluate the tolerability of the conversion from calcineurin inhibitor (CNI) to everolimus (ERL) in maintenance liver transplant (LT) recipients.

METHODS

From January 2005 to March 2008, ERL was introduced after LT as maintenance immunosuppressive therapy because of (i) de novo or recurrent cancer after LT, (ii) pre-existing liver carcinoma on the liver explant or (iii) CNI toxicity. CNI dosage was progressively reduced until discontinuation.

RESULTS

The study population included 94 patients, of mean age 57 ± 10. The mean delay between LT and ERL introduction was 5 ± 5 yr. After a mean follow-up of 12 ± 7 months, 70% of the patients did present at least one side effect. The mean trough level of ERL was 6 μg/L at the end of follow-up. Main side effects included hyperlipidemia (37%), dermatitis (19%), mucositis (15%), and proteinuria (18%). Biopsy-proven acute rejection occurred in 9% of patients. Global ERL discontinuation rate was 21% (16% because of side effects).

CONCLUSIONS

The results of our experience indicate that conversion to ERL is associated with adverse effects in 70% of patients leading to drug discontinuation in 16% (and amenable to dose reduction in the remainders). Longer follow-up periods are necessary to capture the impact of ERL fully on renal function and survival in cancer patients.

Clinical recommendations for the use of everolimus in heart transplantation

Proliferation signal inhibitors (PSIs), everolimus (EVL), and sirolimus are a group of immunosuppressor agents indicated for the prevention of acute rejection in adult heart transplant recipients. Proliferation signal inhibitors have a mechanism of action with both immunosuppressive and antiproliferative effects, representing an especially interesting treatment option for the prevention and management of some specific conditions in heart transplant population, such as graft vasculopathy or malignancies. Proliferation signal inhibitors have been observed to work synergistically with calcineurin inhibitors (CNIs). Data from clinical trials and from the growing clinical experience show that when administered concomitantly with CNIs, PSIs allow significant dose reductions of the latter without loss of efficacy, a fact that has been associated with stabilization or significant improvement in renal function in patients with CNI-induced nephrotoxicity. The purpose of this article was to review the current knowledge of the role of PSIs in heart transplantation to provide recommendations for the proper use of EVL in cardiac transplant recipients, including indications, treatment regimens, monitoring, and management of the adverse events.

Indications and management of everolimus after liver transplantation

OBJECTIVE

Our aim was to assess our experience with the use and management of everolimus after orthotopic liver transplantation (OLT).

MATERIALS AND METHODS

Among the 759 patients who underwent transplantation from 1988 to 2008, 25 (3.2%) received immunosuppression with everolimus. Their mean age was 55.6 years. We analyzed indications for use, time between transplantation and introduction of everolimus, as well as its efficacy, side effects, and patient survival.

RESULTS

The indications for everolimus treatment were: extended hepatocellular carcinoma (HCC) in the explanted liver (n = 6; 24%); HCC recurrence during follow-up (n = 4; 16%); de novo tumor (n = 6; 24%); refractory rejection (n = 3; 12%); side effects of calcineurin inhibitors (CNI; n = 3; 12%); and other causes (n = 3; 12%). Mean time between OLT and everolimus treatment was 40 +/- 33 months (range, 10 days-178 months). Mean follow-up after conversion was 10 +/- 9 months (range, 1.5-25 months). More than half of the patients resolved the event for which the drug was indicated: 75% of patients with refractory rejection; 60% of those with renal insufficiency; and 100% of those converted for neurotoxicity or hepatotoxicity. Two patients with recurrent HCC and 1 with extended HCC died at a mean time of 10.5 months. The 6 cases of de novo tumors were operated and are healthy. Side effects were dyslipidemia in 8 and infection in 2. Five patients (20%) discontinued the drug.

CONCLUSIONS

In the early posttransplantation period, everolimus is indicated for refractory rejection or as prophylaxis for recurrence of extended tumors. In any time but especially in the late period, everolimus is indicated for patients with serious side effects due to a CNI or to a de novo tumor.

Disposition of everolimus in mdr1a-/1b- mice and after a pre-treatment of lapatinib in Swiss mice

The aim of this study was to document the in vivo transport of everolimus (inhibitor of mTOR) by P-glycoprotein (P-gp), and to investigate the influence of lapatinib (inhibitor of P-gp) on everolimus disposition. Pharmacokinetics of everolimus (0.25mg/kg) has been investigated after oral administration in mdr1a-/1b- mice compared to the wild type. Also, everolimus pharmacokinetics was characterized after oral administration on Swiss mice either alone or after 2 days of pre-treatment of lapatinib (200mg/kg). The influence of lapatinib pre-treatment on intestinal P-gp expression was investigated by Western blot analysis. The non-compartimental analysis was performed using Winonlin professional version 4.1 software (Pharsight, Mountain View, CA). The areas under the plasma concentration-time curve (AUC) were compared using Bailer's method. A significant 1.3-fold increase of everolimus AUC observed in mdr1a-/1b- mice suggested that everolimus is transported in vivo by intestinal P-gp in mice. In addition, a 2.6-fold significant increase of everolimus AUC with lapatinib pre-treatment as compared with the everolimus alone group was noticed. The elimination half-life was comparable (t(1/2)=5.3h vs. t(1/2)=4h). A 38.5% significant decrease of P-gp expression was observed in duodenum segment in lapatinib pre-treated group as compared with control group. In conclusion, lapatinib enhanced everolimus absorption by decreasing intestinal P-gp expression. An inhibition of CYP 450 could not be excluded. These results confirm the necessity of a therapeutic monitoring of everolimus combined with an inhibitor of the P-gp and CYP 450 like lapatinib in a future anti-tumor treatment.

The role of mTOR inhibitors in the management of posttransplant malignancy

Organ transplant recipients given mammalian target of rapamycin inhibitor (mTORi) have reduced incidence of de novo posttransplant malignancies (dNPTMs). Posttransplant Kaposi's sarcoma and nonmelanotic skin malignancies (NMSC) frequently undergo remission/regression after conversion to mTORi immunosuppression (IS), especially early, small, and low-grade lesions, whereas larger, aggressive, and metastatic skin tumors are less likely to respond. mTORi-based IS is effective and well tolerated in orthotopic liver transplant patients with hepatocellular carcinoma (HCC) achieving excellent survival and disease-free intervals, particularly with extended criteria tumors, although the evidence that mTORi prevents HCC recurrence after orthotopic liver transplantation is only suggestive. Regression of metastatic HCC and other tumors and various forms of posttransplant lymphoproliferative disease have occurred after mTOR conversion. Documentation of regression/remission of other solid-organ dNPTM (colon, stomach, breast, etc.) after mTORi conversion is essentially absent with only anecdotal reports lacking follow-up data. Unfortunately, there is not a single reported prospective clinical trial powered for looking at the effect of mTORi IS in transplant recipients. Nevertheless, reduced incidence of all of dNPTMs and remission/regression of the commonest posttransplant tumors with mTOR therapy are strong reasons to expand the use of mTORi.

Conversion to everolimus monotherapy in maintenance liver transplantation: feasibility, safety, and impact on renal function

We present the 12-month results of a prospective trial of conversion from calcineurin inhibitors (CNI) to everolimus (EVL) in maintenance liver transplant (LT) recipients. Forty (M:F = 28:12; 54.9 +/- 11 years) patients were enrolled at a mean interval of 45.5 +/- 31.2 months from transplantation. Conversion was with EVL at a dosage of 0.75 mg b.i.d., withdrawal of antimetabolites, and a 50%-per-week reduction of CNI to a complete stop within 4 weeks. The treatment success was conversion to EVL monotherapy at 12 months while failure was presence of CNI, death, and graft loss. Indication to conversion was deteriorating renal function in 36 (90%). At 12 months, patient- and graft survival were 100% and the success rate was 75% (30/40). Ten patients (25%) were failures: four (10%) for acute rejection; three hepatitis C virus-RNA positive patients (7.5%) for hypertransaminasemia; one (2.5%) for acute cholangitis; and two (5%) due to persistent pruritus and oral ulcers. In patients on EVL monotherapy, at 12 months the mean change of calculated creatinine clearance (cCrCl) was 4.03 +/- 12.6 mL/min and the only variable correlated with the probability of improvement was baseline cCrCl (P < 0.0001). Conversion from CNI to EVL is feasible in 75% of the cases and associated with improvement in renal function for patients with higher baseline cCrCl.

Everolimus: an update on the mechanism of action, pharmacokinetics and recent clinical trials

BACKGROUND

A growing body of evidence suggests that everolimus might offer effective immunosuppressive activity together with antiproliferative effects that may address some of the unmet needs in the long-term therapeutic management of the post-transplant patient.

OBJECTIVE

To summarize the emerging evidence for employing everolimus-based immunosuppression.

METHODS

A systematic review was conducted of the Medline, Embase and Renal Health Library (Cochrane Collaboration) databases, and of the summary publications from international transplant meetings and congresses during 2000-2008.

RESULTS

This article summarizes this analysis, with special focus on the pharmacokinetic characteristics of everolimus and on the results of its use in renal transplantation. Some data has also been included about the efficacy of the drug in other solid organ transplantation and in tumours.

CONCLUSIONS

Everolimus is an immunosuppressant drug with proven efficacy in transplantation. When used in combination with cyclosporin, better results are obtained in renal function with low cyclosporin doses. Adverse events related to this drug are frequent and lead to moderate dropout rates.