Tuberous sclerosis complex: Diagnostic features, surveillance, and therapeutic strategies.

Tuberous sclerosis complex (TSC) is a rare neurocutaneous disorder of mTOR pathway dysregulation resulting from pathogenic variants in the TSC1 or TSC2 genes. Expression of this disorder may involve abnormal tissue growth and dysfunction within the brain, kidneys, heart, lungs, eyes, skin, bones, and teeth. Neurological manifestations can include subependymal giant cell astrocytomas (SEGAs), high rates of infantile spasms, drug-resistant epilepsy, developmental delay, cognitive impairment, autism spectrum disorder, and other neurobehavioral manifestations. Here we review the potential clinical manifestations of TSC by system, recommended diagnostic and surveillance testing, genetic testing, currently available therapeutic options, and considerations for education and social support resources given the unique challenges of this multi-system disorder.

The different sequences of CDK4/6 inhibitor and mTOR inhibitor in HR+/HER2-advanced breast cancer: A multicenter real-world study.

Background: Cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) and everolimus (EVE) are effective for patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer (MBC). However, the efficacy of different sequences of CDK4/6i and EVE are largely unknown. The study aimed to explore the efficacy of different sequences in China. Methods: 146 patients with HR+/HER2- MBC who received both CDK4/6i and EVE in salvage setting were collected. Objective response rate (ORR), clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS) were investigated. Results: 56 patients received CDK4/6i prior to EVE (Group A), 90 patients received CDK4/6i subsequent to EVE (Group B). The median PFS of CDK4/6i and EVE in Group A vs Group B were 8.4m and 2.5m vs 4.6m and 6.1m respectively. The total PFS of first-line and second-line endocrine therapy were not different between Group A and Group B [13.1m vs 17.7m (P = 0.330, HR = 0.738, 95%CI: 0.399-1.365)]. The 5y OS of patients in Group A or Group B were 62.0 % vs 57.4 %, P = 0.569. Conclusions: We found that no matter CDK4/6i or EVE was used first, the survival were not significantly different between Group A and Group B. Both can be clinical options.

Radioligand therapy in the therapeutic strategy for patients with gastro-entero-pancreatic neuroendocrine tumors: a consensus statement from the Italian Association for Neuroendocrine Tumors (Itanet), Italian Association of Nuclear Medicine (AIMN), Italian Society of Endocrinology (SIE), Italian Association of Medical Oncology (AIOM).

PURPOSE: This paper outlines the consensus of the Italian Association for Neuroendocrine Tumors(Itanet), the Italian Association of Nuclear Medicine (AIMN), the Italian Society of Endocrinology (SIE), and the Italian Association of Medical Oncology (AIOM) on treating neuroendocrine neoplasms (NENs)with radioligand therapy (RLT). METHODS: A list of 10 questions regarding using RLT ingastroenteropancreatic neuroendocrine tumors (GEP-NETs) was addressed after a careful review of theavailable literature. compiling information from the MEDLINE database, augmented with expert opinionsand recommendations, aligns with the latest scientific research and the author's extensive knowledge.The recommendations are evaluated using the GRADE system, showcasing the level of evidence andthe strength of the recommendations. RESULTS AND CONCLUSIONS: Specifically, this paper focuses on thesubcategories of well-differentiated gastroenteropancreatic neuroendocrine tumors (GEP-NETs) thatexpress somatostatin receptors and are considered suitable for RLT, according to internationalguidelines.

Neoadjuvant everolimus in renal angiomyolipoma with or without tuberous sclerosis complex: Results from a multicenter, retrospective study.

OBJECTIVES: To assess the efficacy and safety of preoperative neoadjuvant everolimus in renal angiomyolipomas (AML) patients with or without Tuberous Sclerosis Complex (TSC). MATERIALS AND METHODS: This multi-institutional retrospective study enrolled renal AML patients who underwent partial nephrectomy (PN) or total nephrectomy after receiving at least 1 month of pre-operative everolimus. Imaging evaluations were collected before and after treatment, along with demographic, surgical, and follow-up information. The primary outcome was tumor volume reduction of ≥25%, with additional outcomes including recurrence, perioperative outcomes, renal function, and safety. RESULTS: From January 2015 to July 2022, 68 renal AML patients were studied-41 with TSC and 27 without. During everolimus treatment, 61.0% (25/41) of TSC patients and 44.4% (12/27) of non-TSC patients achieved tumor reduction of ≥25%. Additionally, 41.5% (17/41) of TSC patients and 18.5% (5/27) of non-TSC patients achieved a ≥ 50% reduction. Three TSC patients and 1 non-TSC patient discontinued treatment due to side-effects. Most patients (92.7% TSC, 85.2% non-TSC) underwent PN. After everolimus treatment, the necessary total nephrectomy decreased to 41.2% (7/17) from baseline. Postoperatively, 1 grade 3 and 3 grade 2 complications occurred, with no grade 4 or 5 complications. After a median follow-up of 24 months, only 1 TSC patient recurred with a diameter >3 cm. Retrospective nature is the major limitation of this study. CONCLUSION: Everolimus was effective and well-tolerated in neoadjuvant treatment for renal AML, especially in TSC patients. This neoadjuvant combination strategy of everolimus and PN could effectively controls recurrence and preserves renal function.

Therapeutic Approaches to Tuberous Sclerosis Complex: From Available Therapies to Promising Drug Targets.

Tuberous sclerosis complex (TSC) is a rare multisystem disorder caused by heterozygous loss-of-function pathogenic variants in the tumour suppressor genes TSC1 and TSC2 encoding the tuberin and hamartin proteins, respectively. Both TSC1 and TSC2 inhibit the mammalian target of rapamycin (mTOR) complexes pathway, which is crucial for cell proliferation, growth, and differentiation, and is stimulated by various energy sources and hormonal signaling pathways. Pathogenic variants in TSC1 and TSC2 lead to mTORC1 hyperactivation, producing benign tumours in multiple organs, including the brain and kidneys, and drug-resistant epilepsy, a typical sign of TSC. Brain tumours, sudden unexpected death from epilepsy, and respiratory conditions are the three leading causes of morbidity and mortality. Even though several therapeutic options are available for the treatment of TSC, there is further need for a better understanding of the pathophysiological basis of the neurologic and other manifestations seen in TSC, and for novel therapeutic approaches. This review provides an overview of the main current therapies for TSC and discusses recent studies highlighting the repurposing of approved drugs and the emerging role of novel targets for future drug design.

The impact of everolimus on hematologic parameters in patients with renal angiomyolipoma associated with tuberous sclerosis complex.

BACKGROUND: Everolimus is an effective treatment for renal angiomyolipoma associated with TSC (TSC-RAML). However, its impact on hematologic parameters in TSC-RAML patients remains unclear. METHODS: Hematologic data were collected from TSC-RAML patients undergoing everolimus treatment in two registered clinical trials. Dynamic changes in hematologic parameters during treatment were analyzed. Additionally, we also explored variations in hematologic impact based on gender and age within the patient population. RESULT: A total of 55 patients from the two clinical trials are included in this analysis. Hemoglobin, white blood cells (WBC), lymphocytes, neutrophils, and platelet showed significant decreases during everolimus treatment (P < 0.05). However, the decline in hemoglobin, WBC, and neutrophils attenuated by the 12th month (P ≥ 0.05). Aspartate transaminase (AST), Alanine transferase (ALT), total cholesterol (TC), and triglyceride (TG) increased significantly during everolimus treatment (P < 0.05), and these increases persisted throughout the year-long treatment. Hemoglobin decreased significantly more in male patients (- 15 vs - 6, P = 0.010), and AST showed a more significant increase in males (7.0 vs 3.0, P = 0.041). Platelet counts decreased significantly more in younger patients (≤ 30 years old) compared to older patients (- 50 vs - 14, P = 0.020). CONCLUSION: Everolimus administration in TSC-RAML patients may increase hematologic risks, with male and younger patients potentially exhibiting greater susceptibility to these effects.

Quality by Design-Steered Development of Stealth Liposomal Formulation of Everolimus: A Systematic Optimization and Evaluation.

BACKGROUND: Everolimus is a drug approved for the treatment of breast cancer with HR+ and advanced breast cancer reoccurring in postmenopausal women. The oral administration of EVE has been observed to have low oral bioavailability and severe epithelial cutaneous events that include rashes and lip ulceration followed by mouth ulceration after oral administration. AIM: The present research aimed to enhance the bioavailability by loading the EVE into a stealth liposomal formulation (S-EVE-LIPO) intended for intravenous administration. METHODS: The surface of the liposomes was modified with vitamin E TPGS, which prolongs the systemic circulation of the drug and provides additional benefits like inhibition of the P-gp efflux pump and acting synergistically with EVE. RESULTS: The formulation was prepared using the thin film hydration method and optimized using a D-optimal mixture design. ANOVA suggested the significance of the proposed mathematic model, and the optimized formulation was generated by design expert software. The optimized formulation (S-EVE-LIPO) was observed with nanometric size (99.5 ± 3.70 nm) with higher encapsulation efficacy (81.5 ± 2.86 %). The S-EVELIPO formulation indicated a sustained release profile as 90.22% drug release was observed in 48 h, whereas the formulation without vitamin E TPGS (EVE-LIPO) released only 74.15 drugs in 24 hours. In vitro cytotoxicity study suggested that the presence of vitamin E TPGS lowers the IC50 value (54.2 ± 1.69), increases the cellular uptake of the formulation, also increases the generation of ROS, and shows better hemocompatibility. CONCLUSION: Vitamin E TPGS could be set as a vital additive to improve therapeutic efficacy and reduce offsite toxicity and dosing frequency.

Effect of Everolimus on Prognosis of Neurofibromatosis Type 1 Lesions: A Systematic Review and Meta Analysis.

PURPOSE: This study addresses the effectiveness of oral everolimus in treating various malignancies associated with Neurofibromatosis Type 1 (NF1). The purpose is to determine whether everolimus reduces lesion size in NF1 patients, considering the controversial findings from previous clinical trials. The scientific hypotheses and questions involve evaluating the impact of everolimus on NF1-associated lesions and understanding the variability in treatment outcomes. METHODS: A systematic review and meta-analysis were conducted following PRISMA and Cochrane Collaboration guidelines. The study included four-phase II, single-arm, nonrandomized trials investigating the effect of oral everolimus on NF1-associated lesion size. The search covered multiple databases, and data extraction involved evaluating studies for inclusion criteria and assessing quality using the Cochrane Collaboration's Risk of Bias in Nonrandomized Studies tool. Statistical analysis utilized Open Meta(Analyst). FINDINGS: The search yielded 388 studies, with 10 selected for full-text review and four included in the final analysis. The quality of the studies ranged from low to moderate. The meta-analysis indicated no observed heterogeneity (I^2 = 0%), and the overall estimate suggested no significant reduction in NF1-associated lesion size with everolimus (P = 0.069). IMPLICATIONS: The findings reveal a varied and inconsistent picture of everolimus efficacy in NF1 treatment. The study highlights the need for personalized approaches, considering individual genetic and clinical differences. The limitations, including small sample sizes and nonrandomized trials, call for larger, more standardized research efforts. The study emphasizes ongoing trials and the importance of future research in understanding predictors of everolimus response and optimizing treatment strategies for NF1 patients. CONCLUSION: While everolimus shows promise in reducing lesion size in a subset of NF1 patients, the study cannot draw conclusive results due to limitations in the included studies. Ongoing, adequately powered trials are crucial for advancing the evidence base and informing the potential role of everolimus in NF1 treatment. OTHERS: There was no funding for this review and no conflicts of interest.

SnoRNA U50A mediates everolimus resistance in breast cancer through mTOR downregulation.

Breast cancer remains the most prevalent cancer in women globally, posing significant challenges in treatment due to the inevitable development of resistance to targeted therapies like everolimus, an mTOR inhibitor. While several mechanisms of resistance have been proposed, the role of snoRNAs in this context remains inadequately explored. Our study unveils a novel connection between snoRNAs and everolimus resistance, focusing on the snoRNA U50A. We discovered that U50A negatively regulates mTOR signaling by transcriptionally downregulating mTOR gene expression, which consequently leads to decreased sensitivity to everolimus treatment. Through RNA sequencing, gene set enrichment analyses, and experimental validations, we established that U50A overexpression in breast cancer cells results in mTOR downregulation and subsequently, everolimus desensitization. Clinical results further supported our findings, showing a higher prevalence of everolimus resistance in tumors with elevated U50A expression. Moreover, our results suggest that U50A's effect on mTOR is mediated through the suppression of the transcription factors c-Myc, with a notable impact on cancer cell viability under everolimus treatment. This study not only highlights the complex role of snoRNAs in cancer drug resistance but also proposes U50A as a potential biomarker for predicting everolimus efficacy in breast cancer treatment.

Methuosis Inducer SGI-1027 Cooperates with Everolimus to Promote Apoptosis and Pyroptosis by Triggering Lysosomal Membrane Permeability in Renal Cancer.

The mTOR inhibitor everolimus has been approved as a sequential or second-line therapy for renal cell carcinoma (RCC). However, the development of drug resistance limits its clinical applications. This study aims to address the challenge of everolimus resistance and provide new insights into the treatment of advanced RCC. Here, the cytotoxicity of the DNA methyltransferase 1 (DNMT1) inhibitor SGI-1027 in inducing cell vacuolation and methuosis is discovered and demonstrated for the first time. Additionally, SGI-1027 exerts synergistic effects with everolimus, as their combination suppresses the growth, migration, and invasion of renal cancer cells. Mechanistically, apoptosis and GSDME-dependent pyroptosis triggered by lysosomal membrane permeability (LMP) are observed. The upregulation of GSDME expression and increased lysosomal activity in renal cancer cells provide a therapeutic window for the combination of these two drugs to treat renal cancer. The combination treatment exhibits effective anti-tumor activity and is well tolerated in a subcutaneous tumor model. Overall, this study validates and reveals the specific cytotoxicity property of SGI-1027 and its potent synergistic effect with everolimus, offering new insights into advanced RCC therapy and everolimus-resistance overcoming.

The role of everolimus in metastatic breast cancer and possibilities of moving forward-a narrative review.

Background and Objective: In hormone-receptor-positive (HR+) and human epidermal growth factor receptor 2-negative (HER2-) metastatic breast cancer endocrine-based therapies are preferred over chemotherapy. One of the treatment options is the combination of everolimus with exemestane or other endocrine drug in later lines mainly based on progression-free survival (PFS) results of the phase 3 BOLERO-2 trial. Altogether, clinical trials did not prove an overall survival (OS) benefit and considerable side effects hampered its application in the day-by-day practice. In recent years CDK4/6-inhibitors became a first-choice combination partner to the endocrine treatment, everolimus still has a place within the treatment armamentarium. Although everolimus is a targeted drug, there is no accepted predictive biomarker and further patient selection is not possible. However, several directions can be defined how to optimally use everolimus. For update information on everolimus treatment in breast cancer I have performed a literature search. Methods: I used the keywords "breast cancer" and "everolimus" and extended the search in PubMed from 01/01/2014 to 10/02/2023. I considered all phase 3 trials, the phase 1-2 trials with not repetitive information, studies with biomarker results and I also checked review articles to identify potential relevant other clinical trial reports. I also have made a search in clinicaltrials.gov for recently completed and ongoing trials. Key Content and Findings: I summarized the search results in this concise and brief report focusing on main trial results and ongoing research with everolimus. Conclusions: The most promising research directions seem to be further investigations for useable predictive biomarkers, for combinations with other targeted drugs (even in a triple combination) and for the feasibility of pharmacologically guided dosing method.

Peptide Receptor Radionuclide Therapy or Everolimus in Metastatic Neuroendocrine Tumors: The SeqEveRIV Study, a National Study from the French Group of Endocrine Tumors and Endocan-RENATEN Network.

Everolimus and peptide receptor radionuclide therapy (PRRT, 177Lu-DOTATATE) are 2 treatments recommended in guidelines for gastroenteropancreatic metastatic neuroendocrine tumors. However, the best treatment sequence remains unknown. Methods: We designed a retrospective multicenter study that included patients from the national prospective database of the Groupe d'Étude des Tumeurs Endocrines who had been treated using everolimus and PRRT between April 2004 and October 2022. The primary aim was to compare the 2 treatments (everolimus and PRRT) in terms of efficacy and safety, and the secondary aim was to evaluate the sequences (PRRT followed by everolimus or everolimus followed by PRRT) based on overall progression-free survival (PFS) (PFS during first treatment + PFS during second treatment) in patients with metastatic neuroendocrine tumors. Results: Both treatments were used for 84 patients. The objective response rate and median PFS were 5 (6.0%) and 16.1 mo (95% CI, 11.5-20.7 mo), respectively, under everolimus and 19 (22.6%) and 24.5 mo (95% CI, 17.7-31.3 mo), respectively, for PRRT. The safety profile was also better for PRRT. Median overall PFS was 43.2 mo (95% CI, 33.7-52.7 mo) for the everolimus-PRRT sequence and 30.6 mo (95% CI, 17.8-43.4 mo) for the PRRT-everolimus sequence (hazard ratio, 0.69; 95% CI, 0.39-1.24; P = 0.22). Conclusion: PRRT was more effective and less toxic than everolimus. Overall PFS was similar between the 2 sequences, suggesting case-by-case discussion if the patient is eligible for both treatments, but PRRT should be used first when an objective response is needed or in frail populations.

Efficacy of everolimus plus hormonal treatment after cyclin-dependent kinase inhibitor; real-life experience, A TOG study.

PURPOSE: In advanced breast cancer, endocrine therapy is preferred in the absence of visceral crisis. Cyclin-dependent kinase inhibitors (CDKi) are the gold standards. The selection of subsequent treatments after CDKi treatment is still controversial, and the efficacy of everolimus (EVE) combinations is unknown. In this study, we aimed to investigate the efficacy of EVE after CDKi administration in real-life experiences. METHOD: The study received data from 208 patients from 26 cancer centers. Demographic and histologic features, diagnosis, progression, last visit dates, and toxicities were recorded. This study was a retrospective case series. RESULTS: One hundred and seven patients received palbociclib, while 101 patients received ribociclib as a CDKi. The overall response and disease control rates of EVE combinations were 60% and 88%, respectively. In univariate analysis, the absence of liver metastasis, age > 40 years, better type of response, and immediate treatment after CDKi were related to increased progression-free survival. Liver metastasis and response type were significantly associated with overall survival. In the multivariate analysis, response remained significant in terms of progression-free survival, while response type, liver metastatic disease, and hematologic toxicity were prognostic in terms of overall survival. CONCLUSION: This study provides evidence of the benefits of EVE combinations after CDKi treatment. EVE combinations may be more appropriate for patients with non-liver metastasis, and the first treatment response shows the benefit of treatment. In addition, immediate treatment after CDKi treatment is more beneficial than later lines of treatment.

Proteomic Changes Induced by the Immunosuppressant Everolimus in Human Podocytes.

mTOR inhibitors (mTOR-Is) may induce proteinuria in kidney transplant recipients through podocyte damage. However, the mechanism has only been partially defined. Total cell lysates and supernatants of immortalized human podocytes treated with different doses of everolimus (EVE) (10, 100, 200, and 500 nM) for 24 h were subjected to mass spectrometry-based proteomics. Support vector machine and partial least squares discriminant analysis were used for data analysis. The results were validated in urine samples from 28 kidney transplant recipients receiving EVE as part of their immunosuppressive therapy. We identified more than 7000 differentially expressed proteins involved in several pathways, including kinases, cell cycle regulation, epithelial-mesenchymal transition, and protein synthesis, according to gene ontology. Among these, after statistical analysis, 65 showed an expression level significantly and directly correlated with EVE dosage. Polo-Like Kinase 1 (PLK1) content was increased, whereas osteopontin (SPP1) content was reduced in podocytes and supernatants in a dose-dependent manner and significantly correlated with EVE dose (p < 0.0001, FDR < 5%). Similar results were obtained in the urine of kidney transplant patients. This study analyzed the impact of different doses of mTOR-Is on podocytes, helping to understand not only the biological basis of their therapeutic effects but also the possible mechanisms underlying proteinuria.

Recurrent rejections after liver transplantation for hepatocellular carcinoma with stem cell features in an adult patient.

Patients with hepatoblastoma featuring carcinoma characteristics have better outcomes after liver transplantation, than after chemotherapy and resection. Possibly this should be extrapolated to aggressive subtypes of hepatocellular carcinomas in non-cirrhotic livers, where early liver transplantation might also be indicated. However, the risks associated with liver transplantation and immunosuppressive treatment after liver transplantation are once again demonstrated by this case of a 32-year-old women with a negative personal and familial history of liver diseases. She underwent transplantation (DBD) for a hepatocellular carcinoma with stem cell features (HCC-HS; an aggressive 'hepatoblast subtype' of hepatocellular carcinoma) after chemotherapeutical downstaging techniques failed to sufficiently downstage the tumor. Despite being on conventional immunosuppressive regimens (tacrolimus and mycophenolate mofetil with initial corticosteroids tapered), this patient still developed two severe rejection episodes, one of which necessitated retransplantation (DCD). Both episodes were preceded by alterations in tacrolimus trough levels, either intentionally, when tacrolimus was reduced within a nephroprotective regimen, or unintentionally, when rifampicin, a CYP3A4 inducer, significantly lowered the trough levels. Together, these episodes stress the importance of therapeutic drug monitoring of tacrolimus. Furthermore, the patient experienced an everolimus-linked drug-induced thrombotic microangiopathy, underwent multiple ERCPs for an anastomotic stricture and only one and a half year after the first liver transplantation she already suffers from long-term immunosuppressive-related side effects such as impaired glucose tolerance, hypertension and a potential cardiomyopathy. At present, she is still alive and experienced no recurrence of her primary tumor. Her case underscores the significant challenges in post-liver transplantation care.

Long-term follow-up of the randomized, prospective Scandinavian heart transplant everolimus de novo study with early calcineurin inhibitors avoidance (SCHEDULE) trial.

BACKGROUND: Early substitution of calcineurin inhibitor (CNI) with mammalian target of rapamycin inhibitors has been shown to improve kidney function and reduce intimal hyperplasia in heart transplant (HTx) recipients but data on long-term outcome of such a regime are still sparse. METHODS: In the SCHEDULE trial, 115 de novo HTx recipients were randomized to (1) everolimus with reduced exposure of CNI followed by CNI withdrawal at week 7-11 post-transplant or (2) standard-exposure with CNI. Both groups received mycophenolate mofetil and corticosteroids. Herein we report on the 10-12-year long-term follow-up of the study. RESULTS: A total of 78 patients attended the follow-up visit at a median time of 11 years post-transplant. In the everolimus intention to treat (ITT) group 87.5% (35/40 patients) still received everolimus and in the CNI ITT group 86.8% (33/38) still received CNI. Estimated glomerular filtration rate (eGFR) (least square mean (95% CI)) at the 10-12 years visit was 82.7 (74.2-91.1) ml/min/1.73 m2 and 61.0 (52.3-69.7) ml/min/1.73 m2 in the everolimus and CNI group, respectively (p < 0.001). Graft function measured by ejection fraction, ECG, NT-proBNP and drug safety were comparable between groups. During the study period there was a total of 28 deaths, but there was no difference in survival between the everolimus and the CNI group (aHR 0.61 (95% CI 0.29-1.30) p = 0.20). For the composite endpoint of death, re-transplantation, myocardial infarction, PCI, dialysis, kidney transplantation or cancer no between group differences were found (aHR 1.0 (95% CI 0.57-1.77) p = 0.99). CONCLUSIONS: De novo HTx patients randomized to everolimus and low dose CNI followed by CNI free therapy sustained significantly better long-term kidney function than patients randomized to standard therapy. The graft function at 10-12 years was similar in both groups and there was no difference in survival.

Early Conversion to Everolimus Within 180 Days of Living Donor Liver Transplantation.

BACKGROUND: Early conversion to Everolimus (EVR) post deceased donor liver transplant has been associated with improved renal function but increased rejection. Early EVR conversion has not been evaluated after living donor liver transplant (LDLT). A retrospective cohort study was conducted to compare the rate of rejection and renal function in patients converted to EVR early post-LDLT to patients on calcineurin inhibitors (CNIs). METHODS: This was a single center retrospective cohort study of adult LDLT recipients between January 2012 and July 2019. Patients converted to EVR within 180 days of transplant were compared to patients on CNIs. The primary endpoint was biopsy proven acute rejection (BPAR) at 24 months posttransplant. Key secondary endpoints included eGFR at 24 months, change in eGFR, adverse events, and all-cause mortality. RESULTS: From a total of 173 patients involved in the study: 58 were included in the EVR group and 115 in the CNI group. Median conversion to EVR was 26 days post-LDLT. At 24 months, there was no difference in BPAR (22.7% EVR vs. 19.1% CNI, p = 0.63). Median eGFR at 24 months posttransplant was not significantly different (68.6 [24.8 to 112.4] mL/min EVR vs. 75.9 [35.6-116.2] mL/min CNI, p = 0.103). Change in eGFR from baseline was worse in the EVR group (-13.0 [-39.9 to 13.9] mL/min EVR vs. -5.0 [-31.2 to 21.2] mL/min CNI, p = 0.047). Median change from conversion to 24 months posttransplant (EVR group only) was -3.43 mL/min/1.73 m2 (-21.0 to 9.6). CONCLUSIONS: Early EVR conversion was not associated with increased risk of rejection among LDLT recipients. Renal function was not impacted. EVR may be considered as an alternative after LDLT in patients intolerant of CNIs.

mTOR inhibitors after lung transplantation: a real-life experience.

Background: The mammalian target of rapamycin (mTOR) inhibitors in combination with calcineurin inhibitors (CNIs), antimetabolites and corticosteroids for immunosuppression after lung transplantation (TPL) have gained importance in patients with chronic kidney disease (CKD). The goal of this study was to characterize lung transplant recipients (LTR) treated with mTOR inhibitors, with a special focus on kidney function. Methods: LTR transplanted at the University Hospital Zurich between December 1992 and April 2022 were analyzed. Demographics, estimated glomerular filtration rate (eGFR) before and after mTOR initiation, TPL circumstances, immunosuppressive regimens, and allograft function were recorded. We used linear regression to calculate the Mitch curves and a linear mixed-effects model to compare the eGFR. Results: Of all LTR, 70/593 (12%) received mTOR inhibitors. Intolerance or adverse events of antimetabolites were the most common indications for mTOR inhibitor introduction. Discontinuation in 34/70 (49%) was often related to planned or urgent surgery to prevent impaired wound healing. The majority of patients had a preserved baseline eGFR at mTOR inhibitor introduction with CKD Kidney Disease Improving Global Outcomes (KDIGO) stage G1 or 2. The mean annual eGFR decline changed significantly from -16.19 mL/min/1.73 m2/year [95% confidence interval (CI): -22.27 to -10.11] 12 months before to -6.16 mL/min/1.73 m2/year (95% CI: -13.37 to 1.05) 12 months after mTOR initiation (P=0.009) showing better outcomes with earlier mTOR inhibitor initiation after lung TPL. Conclusions: This retrospective study suggests stabilization of kidney function after mTOR inhibitor initiation in LTR documented by a slower eGFR decline after mTOR inhibitor introduction with better outcomes early after lung TPL. Intolerance or adverse events of antimetabolites are important indications for the introduction of mTOR inhibitors. A relatively high discontinuation rate (49%) can be explained by planned discontinuation of mTOR inhibitors prior to surgery to avoid impaired wound healing.

Unconventional mechanism of action and resistance to rapalogs in renal cancer.

mTORC1 is aberrantly activated in renal cell carcinoma (RCC) and is targeted by rapalogs. As for other targeted therapies, rapalogs clinical utility is limited by the development of resistance. Resistance often results from target mutation, but mTOR mutations are rarely found in RCC. As in humans, prolonged rapalog treatment of RCC tumorgrafts (TGs) led to resistance. Unexpectedly, explants from resistant tumors became sensitive both in culture and in subsequent transplants in mice. Notably, resistance developed despite persistent mTORC1 inhibition in tumor cells. In contrast, mTORC1 became reactivated in the tumor microenvironment (TME). To test the role of the TME, we engineered immunocompromised recipient mice with a resistance mTOR mutation (S2035T). Interestingly, TGs became resistant to rapalogs in mTORS2035T mice. Resistance occurred despite mTORC1 inhibition in tumor cells and could be induced by coculturing tumor cells with mutant fibroblasts. Thus, enforced mTORC1 activation in the TME is sufficient to confer resistance to rapalogs. These studies highlight the importance of mTORC1 inhibition in nontumor cells for rapalog antitumor activity and provide an explanation for the lack of mTOR resistance mutations in RCC patients.