Everolimus in liver transplantation

Advancing immunosuppression in liver transplantation: A narrative review

Immunosuppression is essential to ensure recipient and graft survivals after liver transplantation (LT). However, our understanding and management of the immune system remain suboptimal. Current immunosuppressive therapy cannot selectively inhibit the graft-specific immune response and entails a significant risk of serious side effects, i.e., among others, de novo cancers, infections, cardiovascular events, renal failure, metabolic syndrome, and late graft fibrosis, with progressive loss of graft function. Pharmacological research, aimed to develop alternative immunosuppressive agents in LT, is behind other solid-organ transplantation subspecialties, and, therefore, the development of new compounds and strategies should get priority in LT. The research trajectories cover mechanisms to induce T-cell exhaustion, to inhibit co-stimulation, to mitigate non-antigen-specific inflammatory response, and, lastly, to minimize the development and action of donor-specific antibodies. Moreover, while cellular modulation techniques are complex, active research is underway to foster the action of T-regulatory cells, to induce tolerogenic dendritic cells, and to promote the function of B-regulatory cells. We herein discuss current lines of research in clinical immunosuppression, particularly focusing on possible applications in the LT setting.

Post-transplant-cyclophosphamide and short-term Everolimus as graft-versus-host-prophylaxis in patients with relapsed/refractory lymphoma and myeloma-Final results of the phase II OCTET-EVER trial

BACKGROUND

Conditioning regimens and the choice of immunosuppression have substantial impact on immune reconstitution after allogeneic hematopoietic stem cell transplantation (aHSCT). The pivotal mechanism to maintain remission is the induction of the graft-versus-tumor effect. Relapse as well as graft versus host disease remain common. Classic immunosuppressive strategies implementing calcineurin inhibitors (CNI) have significant toxicities, hamper the immune recovery, and reduce the anti-cancer immune response.

METHODS

We designed a phase II clinical trial for patients with relapsed and refractory lymphoid malignancies undergoing aHSCT using a CNI-free approach consisting of post-transplant cyclophosphamide (PTCy) and short-term Everolimus after reduced-intensity conditioning and matched peripheral blood stem cell transplantation. The results of the 19 planned patients are presented. Primary endpoint is the cumulative incidence and severity of acute GvHD.

RESULTS

Overall incidence of acute GvHD was 53% with no grade III or IV. Cumulative incidence of NRM at 1, 2, and 4 years was 11%, 11%, and 16%, respectively, with a median follow-up of 43 months. Cumulative incidence of relapse was 32%, 32%, and 42% at 1, 2, and 4 years after transplant, respectively. Four out of six early relapses were multiple myeloma patients. Overall survival was 79%, 74%, and 62% at 1, 2, and 4 years. GvHD-relapse-free-survival was 47% after 3 years.

CONCLUSIONS

Using PTCy and short-term Everolimus is safe with low rates of aGvHD and no severe aGvHD or cGvHD translating into a low rate of non-relapse mortality. Our results in this difficult to treat patient population are encouraging and warrant further studies.

The effect of miR-155-5p on M1 polarization of Kupffer cells and immune response during liver transplantation through regulating the expression of KDM5D

BACKGROUND

To explore the effect and its specific mechanism of miR-155-5p on M1 polarization of Kupffer cells (KCs) and immune response in liver transplantation (LT) through KDM5D.

METHODS

Primary KCs were isolated from Wistar rats and identified by cell culture, ink-swallowing test and flow cytometry. The cells identified as KCs were induced into LT acute rejection (AR) model cells by LPS/IFN-γ, flow cytometry was used for cell sorting and apoptosis detection. Enzyme-linked immunosorbent assay (ELISA) kit was used to detect the levels of inflammatory factors, macrophages and liver function markers. RT-qPCR detected the expression of miR-155-5p and KDM5D mRNA. The protein expression of KDM5D was detected by Western blot. Dual luciferase reporter gene experiment verified the targeting relationship between miR-155-5p and KDM5D.

RESULTS

The separated KCs adhered after being cultured for 24 h, had pseudopodia and phagocytosis, and the proportion of F4/80 positive cells was more than 90%. The expression of miR-155-5p was increased in LPS/IFN-γ-induced KCs. And knockdown of miR-155-5p inhibited H3K4me3 and H3K27me3 of TNF-α promoter, M1 polarization of KCs and the immune response of AR model cells by upregulating KDM5D. In animal experiments, knockdown of miR-155-5p was found to inhibit liver damage and immune response in rats with allogeneic orthotopic LT.

CONCLUSION

These results confirmed that miR-155-5p inhibited M1 polarization of KCs induced by LPS/IFN-γ, thereby alleviating AR and liver function impairment after LT by upregulating KDM5D.

Renal Protective Effect of Everolimus in Liver Transplantation: A Prospective Randomized Open-Label Trial

Supplemental Digital Content is available in the text.

Renal dysfunction is associated with poor long-term outcomes after liver transplantation. We examined the renal sparing effect of everolimus (EVR) compared to standard calcineurin inhibitor (CNI) immunosuppression with direct measurements of renal function over 24 months.

mTOR Inhibition and Clinical Transplantation: Liver

The evidence base concerning use of mammalian target of rapamycin (mTOR) inhibitor therapy after liver transplantation is evolving rapidly, clarifying their benefits and disadvantages in different clinical scenarios. The H2304 trial showed that starting everolimus at 1 month posttransplant, with reduced tacrolimus, achieves a sustained improvement in renal function versus standard tacrolimus-based therapy, with at least equivalent immunosuppressive efficacy. Randomized studies evaluating early discontinuation of calcineurin inhibitor (CNI) therapy after introduction of an mTOR inhibitor consistently demonstrated a substantial improvement in renal function versus standard CNI therapy. However, concomitant mycophenolic acid is advisable to avoid an increase in mild biopsy-proven acute rejection, and induction with an interleukin-2 receptor antagonist may also be helpful. High-quality robust data regarding prevention of posttransplant malignancies under mTOR inhibitors is lacking in liver transplantation, although there are some indications of benefit. In maintenance patients, robust data are limited regarding mTOR inhibitor initiation in response to deteriorating renal function or other indications but late conversion (>1 year) appears ineffective. Rates of mTOR inhibitor discontinuation due to adverse events are high, affecting at least a quarter of patients. In conclusion, the evidence base for use of mTOR inhibitors early posttransplant to support CNI reduction now convincingly demonstrates a renal advantage, but adequate adjunctive immunosuppression is essential to preserve efficacy.

Everolimus with or without mycophenolate mofetil in a liver transplantation setting: a single-center experience

Background

This study evaluated the efficacy, safety, and impact on renal function of everolimus in patients after liver transplantation (LT) with or without mycophenolate mofetil (MMF).

Methods

We evaluated LT recipients with calcineurin inhibitor (CNI)-related renal dysfunction after everolimus initiation. Laboratory data, including evaluation of renal function based on glomerular filtration rate (GFR) at baseline (i.e., everolimus initiation) and at the end of follow up, were analyzed.

Results

Fifty consecutive patients started taking everolimus at 30 months post-LT (range: 1-240), 6 as monotherapy and 44 in combination with MMF. After 30.5 months (range: 6-112), all patients were alive, without any biochemical evidence of a rejection episode or recurrence of hepatocellular carcinoma. The mean GFR, based on the Modification of Diet in Renal Disease equation, was 53±13 mL/min at baseline and 59±12 mL/min at the end of follow up (P=0.031). Eleven (22%) of the patients had GFR <60 mL/min at baseline but returned to GFR >60 mL/min by the end of follow up. In multivariate analysis, the time between the development of renal dysfunction and everolimus initiation was the only factor independently associated with GFR improvement (odds ratio [OR] 0.85, 95% confidence interval [95%CI] 0.76-0.96; P=0.007). Everolimus was stopped in 11 patients (22%) at the end of follow up because of adverse events.

Conclusion

A CNI-free everolimus-based regimen was effective in LT recipients with renal dysfunction and was associated with an improvement in GFR.

Ab initio Everolimus-based Versus Standard Calcineurin Inhibitor Immunosuppression Regimen in Liver Transplant Recipients

AIM

We designed a retrospective case-control study to determine the efficacy and feasibility of everolimus (EVR) combined with low-dose tacrolimus (Tac) ab initio versus standard-dose Tac after liver transplantation (LT).

METHODS

Seventy-one adult LT patients, receiving EVR and low-dose Tac without corticosteroids or induction therapy from postoperative day 1 (EVR group) were compared with a well-matched control group of 61 recipients treated with standard-dose Tac in association with antimetabolite.

RESULTS

Baseline characteristics for the two groups were comparable. The overall patient and graft survival rates were similar (P = .908). Liver function was stable during the follow-up. In the EVR group, biopsy-proven acute rejection occurred in two cases (2.8%), whereas chronic rejection occurred in one (1.4%). The EVR group experienced a better renal function already after 2 weeks (estimated glomerular filtration rate: 89.85 [36.46 to 115.3] mL/min/1.73 m2 vs. 68.77 [16.11 to 115.42] mL/min/1.73 m2; P = .013), which was also observed after a median time of 27 months (range, 0 to 82 months) from LT (estimated glomerular filtration rate: 80 [45 to 118.3] mL/min/1.73 m2 vs. 70.9 [45 to 88.4] mL/min/1.73 m2; P = .04). After a median time of 27 months, the EVR group showed lower incidence of arterial hypertension and insulin-dependent diabetes mellitus.

CONCLUSION

Ab initio EVR-based immunosuppression could be a valid option immediately after surgery in recipients at high-risk for post-LT renal impairment.

Everolimus for pediatric patients with acute graft-versus-host disease after hematopoietic stem cell transplantation: A pilot study

Acute graft-versus-host disease (aGVHD) is a significant cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Due to the poor prognosis for patients not responding to first-line steroids treatment, improvements in aGVHD therapy are needed. Everolimus is a promising candidate that combines immunosuppressive properties with anti-neoplastic effects. Here, we retrospectively reviewed the efficacy of everolimus with steroids as primary treatment in 13 patients with grade II to grade IV aGVHD after HSCT. Among them, 12 (92.3%) had complete response to everolimus with steroids without additional immunosuppressive agents. The median duration of therapy was 76 days (range 20-110). Asymptomatic hypertriglyceridemia was the most common therapy complication (69.2%), but treatment interruption was not needed. Thrombotic microangiopathy was rare (7.7%), but can be quickly solved by stopping everolimus and cyclosporine treatment. Other toxicities were manageable. Two patients developed chronic GVHD (15.4%), limited in one and extensive in the other. The overall survival was 76.9% with a median follow-up of 3.4 years after HSCT (range 0.7-5.7). Accordingly, everolimus with steroids were feasible for patients with aGVHD after HSCT as primary treatment. Further large-scale studies are required.

Revisiting Repurposing

Drug repurposing can be a cost-effective strategy to identify new small molecule-based therapies. Thus, drug repurposing significantly influences the discovery of therapeutics, particularly for rare and neglected diseases, which are often constrained by limited research and development funds. The push for translational science and access to drug discovery-associated resources such as high throughput screening instrumentation, assay development expertise, and Food and Drug Administration-approved drug libraries have intensified interest in drug repurposing. However, successful drug repurposing is highly challenging and subject to particular limitations. Despite these challenges, drug repurposing is a critical component to any comprehensive drug discovery strategy and has the capacity to benefit a wide variety of therapeutically underserved diseases.

Management of Immunosuppression in Liver Transplantation

Liver transplantation outcomes have significantly improved over the past few decades owing largely to the introduction of effective immunosuppression medications. Further comprehension of the unique immune microenvironment of the liver has led to the development of newer molecular targeted therapeutics. Understanding the mechanism of action and adverse effect profiles of these medications is crucial for appropriate management of posttransplant patients. In this review, the author describes the immunologic response elicited by liver transplantation, chronicles the various immunosuppressant drug classes, discusses the evidence behind their use, and evaluates the management of special subpopulations of posttransplantation patients.

Safety and Efficacy of Early Everolimus When Calcineurin Inhibitors Are Not Recommended in Orthotopic Liver Transplantation

Our aim was to study the safety and efficacy of immunosuppression with everolimus (EVL) within the 1st month after orthotopic liver transplantation (LT) when calcineurin inhibitors are not recommended. For this purpose, 28 recipients who had been treated with EVL within the 1st month after adult LT were eligible to enter in a retrospective multicenter study. Patients were followed up for 12 months after LT. EVL therapy was initiated at a median of 14 days (range, 4-24) after LT. The reason for early EVL was neurotoxicity in 14 cases, renal dysfunction in 12, and acute cellular rejection combined with renal impairment in 2. In 23 patients, immunosuppression was EVL + mycophenolate mofetil/mycophenolate sodium + steroids, and EVL + tacrolimus + steroids/mycophenolate sodium was used in 4 cases. Neurotoxicity disappeared in all patients. Renal function in patients with renal impairment improved from a median of 32 mL/min/1.73 m² at the moment of implementation of EVL to 62 mL/min/1.73 m² at 1 year. Four patients (14.3%) developed acute cellular rejection. We observed incisional hernia in 4 patients (14.3%), hematologic complications in 6 (21.4%), proteinuria in 2 (7.1%), edema and/or effusions in 8 (28.6%), and dyslipidemia in 12 (42.8%). No arterial complications were observed. EVL was withdrawn in 5 patients during the 1st year after LT. One-year patient survival was 92.7%. In conclusion, use of EVL within the 1st month after LT when calcineurin inhibitors are not recommended seems to be an effective therapeutic option with an acceptable safety profile.

Everolimus-associated stomatitis in a patient who had renal transplant

Everolimus is used as an immunosuppressant in renal allograft transplant rejection and in metastatic breast cancer treatment. One side effect of everolimus is stomatitis, referred to as mammalian target of rapamycin inhibitor-associated stomatitis. This side effect can affect treatment course and contribute to discontinuation of therapy or dose reduction, previously reported in the treatment of metastatic breast cancer. Here, we present a case of everolimus-associated stomatitis with a novel management method with intralesional triamcinolone that allows for continuous course of everolimus.

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.

Natural products as probes in pharmaceutical research

From the start of the pharmaceutical research natural products played a key role in drug discovery and development. Over time many discoveries of fundamental new biology were triggered by the unique biological activity of natural products. Unprecedented chemical structures, novel chemotypes, often pave the way to investigate new biology and to explore new pathways and targets. This review summarizes the recent results in the area with a focus on research done in the laboratories of Novartis Institutes for BioMedical Research. We aim to put the technological advances in target identification techniques in the context to the current revival of phenotypic screening and the increasingly complex biological questions related to drug discovery.

Incidence and Risk Factors for Tuberculosis After Liver Transplantation in an Endemic Area: A Nationwide Population-Based Matched Cohort Study

Morbidity and mortality from tuberculosis (TB) are high in Taiwan. We conducted a nationwide population-based matched cohort study using data retrieved from the Taiwan's National Health Insurance Research Database to determine the impact of TB after liver transplantation (LT). During 2000-2011, we identified 3202 liver transplant recipients and selected subjects from the general population matched for age, sex, and comorbidities on the same index date of recognition of LT with a 1:10 ratio. The data were analyzed using Cox proportional hazards models. Compared to the matched cohort, liver transplant patients had a higher risk for TB (adjusted HR 2.25, 95% CI 1.65-3.05, p < 0.001), and those with TB showed higher mortality (HR 2.27, 95% CI 1.30-3.97, p = 0.004). Old age (HR 2.64, 95% CI 1.25-5.54, p = 0.011) and mammalian target of rapamycin inhibitors (mTORis) (HR 3.09, 95% CI 1.68-5.69, p < 0.001) were significant risk factors for TB in LT; mTORis were also associated with mortality after adjusting for confounders (HR 2.13, 95% CI 1.73-2.62, p < 0.001). Therefore, regular surveillance of TB and treatment of latent TB infection in high-risk patients after LT are important, especially in TB-endemic areas.