Efficacy and safety of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis complex (EXIST-1): a multicentre, randomised, placebo-controlled phase 3 trial

mTOR inhibition in epilepsy: rationale and clinical perspectives

Despite a large number of available medical options, many individuals with epilepsy are refractory to existing therapies that mainly target neurotransmitter or ion channel activity. A growing body of preclinical data has uncovered a molecular pathway that appears crucial in many genetic and acquired epilepsy syndromes. The mammalian target of rapamycin (mTOR) pathway regulates a number of cellular processes required in the growth, metabolism, structure, and cell-cell interactions of neurons and glia. Rapamycin and similar compounds inhibit mTOR complex 1 and decrease seizures, delay seizure development, or prevent epileptogenesis in many animal models of mTOR hyperactivation. However, the exact mechanisms by which mTOR inhibition drives decreased seizure activity have not been completely determined. Nonetheless, these preclinical data have led to limited use in humans with epilepsy due to tuberous sclerosis complex and polyhydramnios, megalencephaly, and symptomatic epilepsy with promising results. Currently, larger controlled studies are underway using mTOR inhibitors in individuals with tuberous sclerosis complex and intractable epilepsy.

Persistent communicating hydrocephalus in adult tuberous sclerosis patients: a possible therapeutic role for everolimus

Subependymal giant cell tumor (SGCT) is a benign intraventricular tumor, usually located near the foramen of Monro. It is almost always associated with tuberous sclerosis complex (TSC). SGCTs may obstruct cerebrospinal fluid (CSF) pathways. Rarely, they may secrete a protein-rich exudate, causing communicating hydrocephalus. Surgery is indicated for symptomatic lesions or growing asymptomatic lesions. The operative approach to SGCT has shifted from simple shunt placement to a more aggressive approach, leading to early attempts at gross total resection. Recently, the mTOR inhibitor everolimus has been approved for treating SGCT. In this article, we present two cases of recurrent shunt malfunctions in adult TSC patients with protein-secreting SGCTs. We describe the complexity of treating such patients with an emphasis on the role mTOR inhibitors may have in their management. We also review the literature on surgical management of SGCT-related hydrocephalus.

Incidence and risk of high-grade stomatitis with mTOR inhibitors in cancer patients

BACKGROUND

Inhibitors of the mammalian target of rapamycin (mTOR) pathway including everolimus and temsirolimus have been used extensively in cancer patients. Their use is associated with stomatitis, an adverse event resulting in morbidity and treatment interruptions or discontinuation. This study was conducted to determine the overall incidence and risk of stomatitis in cancer patients treated with the mTOR inhibitors by a meta-analysis of randomized controlled clinical trials (RCTs).

PATIENTS AND METHODS

Databases from PubMed and abstracts presented at the American Society of Clinical Oncology annual meetings up to October 2013 were searched for relevant studies. Eligible studies included RCTs using everolimus and temsirolimus at approved doses in cancer patients. Summary incidences, relative risks (RR), and 95% confidence intervals (CI) were calculated using a random- or fixed-effects model depending on the heterogeneity of the included trials.

RESULTS

A total of 11 RCTs with 4,752 patients (mTORs: 2,725, controls: 2,027) with a variety of solid tumors were included in the analysis. The incidences of all-grade (grade 1-4) and high-grade stomatitis (grade 3-4) were 33.5% (95% CI: 21.9-47.6%) and 4.1% (95% CI: 2.6-6.3%), respectively. The incidence of high-grade stomatitis significantly varied with tumor types (p=.004), and mTOR inhibitors (temsirolimus vs. everolimus, p<.001). In comparison with controls, mTOR inhibitors significantly increased the risk for developing all-grade stomatitis (RR: 4.04, 95% CI: 3.13-5.22, p<.001) and high-grade stomatitis (RR: 8.84, 95% CI: 4.07-19.22, p<.001).

CONCLUSIONS

The mTOR inhibitors everolimus and temsirolimus significantly increased the risk of high-grade stomatitis in cancer patients. Efforts towards the prevention, treatment, and identification of individuals at risk may allow for improved quality of life and consistent dosing.

Advances in the management of low-grade gliomas

Low-grade gliomas (LGGs) represent the most common childhood brain tumors and are a histologically heterogenous group of tumors. Most LGGs are surgically resectable with excellent 10-year overall survival outcomes of more than 90 % with surgery alone. Tumors not amenable to surgical resection and those with an aggressive biology are more challenging to treat. Conventional radiotherapy is a more efficacious method of long-term tumor control than chemotherapy. However, radiation is associated with significant cognitive, endocrine, and cerebrovascular late effects, making chemotherapy an often-preferred modality over radiotherapy, especially in younger children. Multiple chemotherapy regimens have been evaluated over the past few decades with comparable survival outcomes and differing toxicity profiles. Newer regimens containing antiangiogenic agents also show promise. Recent molecular studies have implicated the BRAF oncogene, a key regulator of the MAPK pathway, and the AKT/mTOR pathway in pediatric LGG tumorigenesis. This has opened up promising new avenues for targeted therapy, with many agents currently under investigation.

Sustained effects of sirolimus on lung function and cystic lung lesions in lymphangioleiomyomatosis

RATIONALE

Sirolimus therapy stabilizes lung function and reduces the size of chylous effusions and lymphangioleiomyomas in patients with lymphangioleiomyomatosis.

OBJECTIVES

To determine whether sirolimus has beneficial effects on lung function, cystic areas, and adjacent lung parenchyma; whether these effects are sustained; and whether sirolimus is well tolerated by patients.

METHODS

Lung function decline over time, lung volume occupied by cysts (cyst score), and lung tissue texture in the vicinity of the cysts were quantified with a computer-aided diagnosis system in 38 patients. Then we compared cyst scores from the last study on sirolimus with studies done on sirolimus therapy. In 12 patients, we evaluated rates of change in lung function and cyst scores off and on sirolimus.

MEASUREMENTS AND MAIN RESULTS

Sirolimus reduced yearly declines in FEV1 (-2.3 ± 0.1 vs. 1.0 ± 0.3% predicted; P < 0.001) and diffusing capacity of carbon monoxide (-2.6 ± 0.1 vs. 0.9 ± 0.2% predicted; P < 0.001). Cyst scores 1.2 ± 0.8 years (30.5 ± 11.9%) and 2.5 ± 2 years (29.7 ± 12.1%) after initiating sirolimus were not significantly different from pretreatment values (28.4 ± 12.5%). In 12 patients followed for 5 years, a significant reduction in rates of yearly decline in FEV1 (-1.4 ± 0.2 vs. 0.3 ± 0.4% predicted; P = 0.025) was observed. Analyses of 104 computed tomography scans showed a nonsignificant (P = 0.23) reduction in yearly rates of change of cyst scores (1.8 ± 0.2 vs. 0.3 ± 0.3%; P = 0.23) and lung texture features. Despite adverse events, most patients were able to continue sirolimus therapy.

CONCLUSIONS

Sirolimus therapy slowed down lung function decline and increase in cystic lesions. Most patients were able to tolerate sirolimus therapy.

Phase II study of mTORC1 inhibition by everolimus in neurofibromatosis type 2 patients with growing vestibular schwannomas

Neurofibromatosis type 2 (NF2) is a genetic disorder with bilateral vestibular schwannomas (VS) as the most frequent manifestation. Merlin, the NF2 tumor suppressor, was identified as a negative regulator of mammalian target of rapamycin complex 1. Pre-clinical data in mice showed that mTORC1 inhibition delayed growth of NF2-schwannomas. We conducted a prospective single-institution open-label phase II study to evaluate the effects of everolimus in ten NF2 patients with progressive VS. Drug activity was monitored every 3 months. Everolimus was administered orally for 12 months and, if the decrease in tumor volume was >20 % from baseline, treatment was continued for 12 additional months. Other patients stopped when completed 12 months of everolimus but were allowed to resume treatment when VS volume was >20 % during 1 year follow-up. Nine patients were evaluable. Safety was evaluated using CTCAE 3.0 criteria. After 12 months of everolimus, no reduction in volume ≥20 % was observed. Four patients had progressive disease, and five patients had stable disease with a median annual growth rate decreasing from 67 %/year before treatment to 0.5 %/year during treatment. In these patients, tumor growth resumed within 3-6 months after treatment discontinuation. Everolimus was then reintroduced and VS decreased by a median 6.8 % at 24 months. Time to tumor progression increased threefold from 4.2 months before treatment to > 12 months. Hearing was stable under treatment. The safety of everolimus was manageable. Although the primary endpoint was not reached, further studies are required to confirm the potential for stabilization of everolimus.

Incidence and risk of rash to mTOR inhibitors in cancer patients--a meta-analysis of randomized controlled trials

BACKGROUND

Inhibitors of the mammalian target of rapamycin (mTOR) are currently approved for the treatment of several cancers, and their use is associated with serious rash, which affects patient's quality of life and leads to undesirable dose reductions or interruptions. A meta-analysis of randomized controlled trials (RCTs) was performed to determine the overall risk of developing high-grade rash with mTOR inhibitors in cancer patients.

METHODS

We searched the PubMed database and abstracts presented at the American Society of Clinical Oncology (ASCO) meetings up to December 2013 for relevant studies. Eligible studies included RCTs in which everolimus or temsirolimus was compared to controls in cancer patients. The summary incidence, relative risk (RR), and 95% confidence intervals (CI) were calculated using a random- or fixed-effects model depending on the heterogeneity of the included trials.

RESULTS

A total of 11 RCTs with 4752 patients (mTORs: 2725, controls: 2027) with a variety of solid tumors were included in the analysis. The incidences of all-grade (grade 1-4) and high-grade rash (grade 3-4) were 27.3% (95% CI 21.0-34.7%) and 1.0% (95% CI 0.6-1.4%), respectively. In comparison with controls, mTOR inhibitors significantly increased the risk for developing all-grade rash (RR = 3.55, 95% CI 3.0-4.20, p < 0.001) and high-grade rash (RR = 4.25, 95% CI 1.63-11.10, p = 0.003). The increased risk of high-grade rash did not vary significantly among different tumors (p = 0.91). There was no significant difference between everolimus and temsirolimus (p = 0.60). There was also no significant difference between mTOR inhibitors alone and in combination with other agents (p = 0.57).

CONCLUSIONS

Everolimus and temsirolimus significantly increased the risk of high-grade rash in cancer patients. Early recognition and appropriate treatment is recommended.

A phase IB trial of the oral MEK inhibitor trametinib (GSK1120212) in combination with everolimus in patients with advanced solid tumors

BACKGROUND

This phase Ib trial investigated the safety, tolerability, and recommended phase II dose and schedule of the MEK inhibitor trametinib in combination with the mammalian target of rapamycin (mTOR) inhibitor everolimus. Secondary objectives included pharmacokinetic (PK) characterization and evaluation of clinical activity.

PATIENTS AND METHODS

A total of 67 patients with advanced solid tumors were enrolled in this open-label, single-arm, dose-escalation study. Dose escalation followed a 3 + 3 design. Patients were assigned to one of 10 different cohorts, involving either daily dosing with both agents or daily dosing with trametinib and intermittent everolimus dosing. This included an expansion cohort comprising patients with pancreatic tumors. PKs samples were collected predose, as well as 1, 2, 4, and 6 h post-dose on day 15 of the first treatment cycle.

RESULTS

Concurrent treatment with trametinib and everolimus resulted in frequent treatment-related adverse events, including mucosal inflammation (40%), stomatitis (25%), fatigue (54%), and diarrhea (42%). PK assessment did not suggest drug-drug interactions between these two agents. Of the 67 enrolled patients, 5 (7%) achieved partial response (PR) to treatment and 21 (31%) displayed stable disease (SD). Among the 21 patients with pancreatic cancer, PR was observed in 1 patient (5%) and SD in 6 patients (29%).

CONCLUSIONS

This study was unable to identify a recommended phase II dose and schedule of trametinib in combination with everolimus that provided an acceptable tolerability and adequate drug exposure.

Kidney involvement in tuberous sclerosis complex: the impact on healthcare resource use and costs

OBJECTIVE

Tuberous sclerosis complex (TSC) is associated with non-malignant kidney lesions-angiomyolipomata-that may be associated with chronic kidney disease (CKD). This study investigated the relationship between renal angiomyolipomata and CKD in TSC, including the impact on healthcare resource utilization (HCRU) and costs.

METHODS

This was a retrospective, longitudinal cohort study based on medical record data spanning January 1990-April 2012 for 369 TSC patients treated at a specialty center in the Netherlands. Cohorts were established based on CKD stage and angiomyolipoma size. Rates of HCRU (physician visits, monitoring, and interventions) were compared across cohorts using rate ratios. Healthcare costs were compared across cohorts using cost differences. Regression models were used to identify predictive factors for HCRU and healthcare costs.

RESULTS

Sixteen per cent of patients reached CKD stage 3 or higher during follow-up. Patients at more advanced stages of CKD more frequently had either large or multiple small angiomyolipomata and higher HCRU rates and healthcare costs. In the multivariate analyses, male gender, CKD stage >1, angiomyolipoma size ≥3.5 cm, embolization, and the presence of moderate or severe lymphangioleiomyomatosis (LAM) were associated with greater HCRU (p ≤ 0.002 for all comparisons). Definite (vs suspected) TSC diagnosis, CKD stage 5 (vs CKD stage 1), angiomyolipoma size ≥3.5 cm, and moderate or severe LAM were associated with higher costs (p = 0.050 for TSC diagnosis, p ≤ 0.002 for other comparisons). Costs in CKD stage 5 were driven primarily by dialysis.

CONCLUSIONS

A substantial proportion of patients with TSC developed moderate-to-severe CKD, which was associated with renal angiomyolipomata and increased HCRU and costs.

The effects of everolimus on tuberous sclerosis-associated lesions can be dramatic but may be impermanent

BACKGROUND

Tuberous sclerosis complex (TSC) predisposes to the development of benign lesions within multiple organ systems, including the brain, kidneys, heart, lungs, and skin. Disease mortality is due to space-occupying subependymal giant cell astrocytomas and hemorrhage-prone renal angiomyolipomas. The recent use of mTORC1 inhibitors, such as everolimus, has allowed for direct targeting of TSC-associated mass lesions without apparent effect on surrounding tissues. Because of the mechanism of these drugs, there is reason to believe that these effects are not durable and that there may be need for continued long-term maintenance therapy.

CASE-DIAGNOSIS/TREATMENT

We present a case of TSC-associated mass lesions that were ill-suited for definitive surgical therapy. The patient was started on everolimus, however due to a complex social situation treatment was discontinued and ultimately resumed many months later. Radiologic studies acquired before and after each period of therapeutic onset/cessation reveal the dramatic but impermanent effects of mTORC1 inhibition.

CONCLUSIONS

While everolimus provides a non-invasive way to treat TSC-associated lesions, patients may require lifelong therapy. When termination of therapy is considered, the patient should be made aware of the expectation of potentially dramatic increases in lesion size. If consideration is to be given to definitive surgical therapy, it should be pursued while the patient is still on the medication, or at least soon after treatment is halted.

Risk of fatigue and hepatic and metabolic toxicities in patients with solid tumors treated with everolimus: a meta-analysis

ABSTRACT 

Background: We performed a systematic review and meta-analysis of fatigue, hepatic and metabolic toxicities associated with everolimus intake in patients with solid tumors. Methods: Eligible studies included randomized trials of patients with solid tumors on everolimus describing events of fatigue, hyperlipidemia, hyperglycemia and elevated alanine aminotransferase (ALT). Results: After the exclusion of ineligible studies, a total of ten clinical trials were considered eligible for the meta-analysis. The relative risks of all-grade fatigue, hyperglycemia, hyperlipidemia and elevated ALT were 1.31 (p < 0.002), 3.06 (p < 0.0001), 2.54 (p = 0.0001) and 2.96 (p < 0.003), respectively. Conclusion: Our meta-analysis demonstrates that everolimus is associated with a significantly increased risk of all-grade fatigue, hyperglycemia, hyperlipidemia and elevated ALT.

Tuberous sclerosis associated neuropsychiatric disorders (TAND) and the TAND Checklist

BACKGROUND

Tuberous sclerosis complex is a multisystem genetic disorder with a range of physical manifestations that require evaluation, surveillance, and management. Individuals with tuberous sclerosis complex also have a range of behavioral, psychiatric, intellectual, academic, neuropsychologic, and psychosocial difficulties. These may represent the greatest burden of the disease. Around 90% of individuals with tuberous sclerosis complex will have some of these difficulties during their lifetime, yet only about 20% ever receive evaluation and treatment. The Neuropsychiatry Panel at the 2012 Tuberous Sclerosis Complex International Consensus Conference expressed concern about the significant "treatment gap" and about confusion regarding terminology relating to the biopsychosocial difficulties associated with tuberous sclerosis complex.

METHODS

The Tuberous Sclerosis Complex Neuropsychiatry Panel coined the term TAND-tuberous sclerosis complex-associated neuropsychiatric disorders-to bring together these multidimensional manifestations of the disorder, and recommended annual screening for TAND. In addition, the Panel agreed to develop a TAND Checklist as a guide for screening.

RESULTS

Here, we present an outline of the conceptualization of TAND, rationale for the structure of the TAND Checklist, and include the full US English version of the TAND Checklist.

CONCLUSION

We hope that the unified term TAND and the TAND Checklist will raise awareness of the importance of tuberous sclerosis complex-associated neuropsychiatric disorders and of the major burden of disease associated with it, provide a shared language and a simple tool to describe and evaluate the different levels of TAND, alert clinical teams and families or individuals of the importance of screening, assessment, and treatment of TAND, and provide a shared framework for future studies of tuberous sclerosis complex-associated neuropsychiatric disorders.

Complementary genomic approaches highlight the PI3K/mTOR pathway as a common vulnerability in osteosarcoma

Osteosarcoma is the most common primary bone tumor, yet there have been no substantial advances in treatment or survival in three decades. We examined 59 tumor/normal pairs by whole-exome, whole-genome, and RNA-sequencing. Only the TP53 gene was mutated at significant frequency across all samples. The mean nonsilent somatic mutation rate was 1.2 mutations per megabase, and there was a median of 230 somatic rearrangements per tumor. Complex chains of rearrangements and localized hypermutation were detected in almost all cases. Given the intertumor heterogeneity, the extent of genomic instability, and the difficulty in acquiring a large sample size in a rare tumor, we used several methods to identify genomic events contributing to osteosarcoma survival. Pathway analysis, a heuristic analytic algorithm, a comparative oncology approach, and an shRNA screen converged on the phosphatidylinositol 3-kinase/mammalian target of rapamycin (PI3K/mTOR) pathway as a central vulnerability for therapeutic exploitation in osteosarcoma. Osteosarcoma cell lines are responsive to pharmacologic and genetic inhibition of the PI3K/mTOR pathway both in vitro and in vivo.

Recent advances in pathophysiology studies and treatment of epilepsy in neurocutaneous disorders

Introduction.Epilepsy that is associated with neurocutaneous disorders seriously deteriorates quality of life and cognitive outcome of affected children. Recent advances in epilepsy pathophysiology raise hopes for better treatment results in this difficult group of patients.

Aim.The aim of this review is to present recent treatment recommendations as well as current research progress in the most frequent neurocutaneous disorders.

Material and methods.We analyzed PubMed database to select the most prominent and recent (up to 2014 year) publications on the treatment and mechanisms of epilepsy in selected neurocutaneous disorders. We aimed to emphasize evidence-based medicine recommendations as well as basic experimental studies dealing with molecular mechanisms of epileptogenesis.

Discussion and conclusions.Recent advances in disease-modifying treatment options such as mTOR inhibitors in patients with tuberous sclerosis complex open up new perspectives for neurologists. Traditional resective surgery has still a major role as a treatment of choice in carefully selected cases.

Efficacy and safety of a mammalian target of rapamycin inhibitor in pediatric patients with tuberous sclerosis complex: A systematic review and meta-analysis

Inhibitors of mammalian target of rapamycin (mTOR) are increasingly used as therapy for pediatric patients with tuberous sclerosis complex (TSC). The uncertainty over the efficacy and safety of mTOR inhibitor therapy for the treatment of pediatric patients with TSC emphasizes the necessity for a synthesis of existing evidence. The aim of this study was to assess the efficacy and safety of mTOR inhibitor therapy for the treatment of pediatric patients with TSC. The PubMed, EmBase and Cochrane Library electronic databases were searched, and studies of mTOR inhibitor therapy and non-mTOR inhibitor therapy in pediatric patients with TSC (<18 years old) were selected. Eleven studies met the inclusion criteria. There was evidence of a significantly increased response rate in pediatric patients with TSC treated with mTOR inhibitor therapy compared with those treated with non-mTOR inhibitor therapy (odds ratio, 24.71; 95% confidence interval, 7.46–81.72; P<0.001). The majority of studies reported few adverse events. There was an increased incidence of mouth ulceration, stomatitis, convulsion and pyrexia in pediatric patients with TSC treated with mTOR inhibitor therapy. In conclusion, mTOR inhibitor therapy is an efficacious and safe treatment for pediatric patients with TSC.

TOSCA - first international registry to address knowledge gaps in the natural history and management of tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex (TSC) is a rare, multisystem, genetic disorder with an estimated prevalence between 1/6800 and 1/15000. Although recent years have seen huge progress in understanding the pathophysiology and in the management of TSC, several questions remain unanswered. A disease registry could be an effective tool to gain more insights into TSC and thus help in the development of improved management strategies.

METHODS

TuberOus SClerosis registry to increase disease Awareness (TOSCA) is a multicentre, international disease registry to assess manifestations, interventions, and outcomes in patients with TSC. Patients of any age diagnosed with TSC, having a documented visit for TSC within the preceding 12 months, or newly diagnosed individuals are eligible. Objectives include mapping the course of TSC manifestations and their effects on prognosis, identifying patients with rare symptoms and co-morbidities, recording interventions and their outcomes, contributing to creation of an evidence-base for disease assessment and therapy, informing further research on TSC, and evaluating the quality of life of patients with TSC. The registry includes a 'core' section and subsections or 'petals'. The 'core' section is designed to record general information on patients' background collected at baseline and updated annually. Subsections will be developed over time to record additional data related to specific disease manifestations and will be updated annually. The registry aimed to enrol approximately 2000 patients from about 250 sites in 31 countries. The initial enrolment period was of 24 months. A follow-up observation period of up to 5 years is planned.

RESULTS

A pre-planned administrative analysis of 'core' data from the first 100 patients was performed to evaluate the feasibility of the registry. Results showed a high degree of accuracy of the data collection procedure. Annual interim analyses are scheduled. Results of first interim analysis will be presented subsequent to data availability in 2014.

IMPLICATIONS

The results of TOSCA will assist in filling the gaps in understanding the natural history of TSC and help in planning better management and surveillance strategies. This large-scale international registry to study TSC could serve as a model to encourage planning of similar registries for other rare diseases.

Oral everolimus treatment in a preterm infant with multifocal inoperable cardiac rhabdomyoma associated with tuberous sclerosis complex and a structural heart defect

Rhabdomyoma (RHM) is a benign cardiac tumour usually associated with tuberous sclerosis complex (TSC). Most RHMs are asymptomatic and regress spontaneously during the first years of life. Haemodynamically significant RHMs are classically treated with surgical excision. We present a case of a premature infant, born to a mother having TSC, with a prenatal diagnosis of pulmonary valve atresia and a large ventricular septal defect. Multiple cardiac RHMs were also present, including a large tumour affecting the right ventricular filling. Owing to the prematurity and low birth weight, the infant was inoperable. In this report, we describe our approach to pharmacologically reduce the RHM size using oral everolimus in preparation for a two-ventricle surgical repair of the structural cardiac defect. We also specifically describe the dose of everolimus that was used in this case to achieve therapeutic serum levels, which was seven times lower than the conventional dose applicable for older infants.

Targeted therapy in pediatric low-grade glioma

Collectively, pediatric low-grade gliomas account for most brain tumors reported in children. Surgery is typically curable for operable lesions. However, more effective therapies are required for inaccessible tumors, both to overcome refractory disease and to minimize the toxicity associated with conventional adjuvant chemotherapy and radiotherapy regimens. Recent years have witnessed rapid improvements in our understanding of the molecular pathogenesis of several childhood tumors, including low-grade gliomas. As a result, several novel compounds targeting and inhibiting critical components of molecular signaling pathways purported to be overactive in the disease have been developed. This article summarizes the most recent literature evaluating such novel targeted agents in childhood low-grade gliomas.

Amenorrhea as a rare drug-related adverse event associated with everolimus for pancreatic neuroendocrine tumors

The patient was an asymptomatic 43-year-old woman. Abdominal ultrasonography and enhanced computed tomography showed a tumor lesion accompanied by multiple cystic changes in the liver and the pancreatic tail. Endoscopic ultrasound-fine needle aspiration was performed on the pancreatic tumor lesion and revealed pancreatic neuroendocrine tumor (PNET). As it was unresectable due to multiple liver metastases, the decision was made to initiate treatment with everolimus and transcatheter arterial chemoembolization. The patient ceased menstruating after the start of everolimus administration. When the administration was discontinued due to interstitial lung disease, menstruation resumed, but then again stopped with everolimus resumption. An association between everolimus and amenorrhea was highly suspected. Amenorrhea occurred as a rare adverse event of everolimus. As the younger women might be included in PNETs patients, we should put this adverse event into consideration.

mTOR controls kidney epithelia in health and disease

Renal epithelial function is the cornerstone of key excretory processes performed by our kidneys. Most of these tasks need to be tightly controlled to keep our internal environment in balance. Recently, the mTOR signalling network emerged as a key pathway controlling renal epithelial cells from the glomerular tuft along the entire nephron. Both mTOR complexes, mTORC1 and mTORC2, regulate such diverse processes as glomerular filtration and the fine tuning of tubular electrolyte balance. Most importantly, dysregulation of mTOR signalling contributes to prevalent kidney diseases like diabetic nephropathy and cystic kidney disease. The following review shall summarize our current knowledge of the renal epithelial mTOR signalling system under physiological and pathophysiological conditions.

Subependymal giant cell astrocytomas in patients with tuberous sclerosis complex: considerations for surgical or pharmacotherapeutic intervention

Tuberous sclerosis complex is a genetic disorder caused by mutations in either the TSC1 or TSC2 gene that can result in the growth of hamartomas in multiple organ systems. Subependymal giant cell astrocytomas are slow-growing brain tumors associated primarily with tuberous sclerosis complex. They are usually located in the ventricles, often near the foramen of Monro, where they can cause an obstruction if they grow too large, leading to increased intracranial pressure. Surgery to remove a tumor has been the mainstay of treatment but can be associated with postoperative morbidity and mortality. Not all tumors and/or patients are suitable for surgery. The recent development of mammalian target of rapamycin inhibitors that target the pathway affected by TSC1/TSC2 mutations offers a novel pharmacotherapeutic option for these patients. We review the timing and use of surgery versus pharmacotherapy for the treatment of subependymal giant cell astrocytoma in patients with tuberous sclerosis complex.

Regulation of YAP by mTOR and autophagy reveals a therapeutic target of tuberous sclerosis complex

Liang et al. find that the tumor suppressors TSC1 and TSC2, defects in which underlie the genetic disease Tuberous Sclerosis Complex (TSC), drive the mTOR-dependent autophagosomal destruction of the transcriptional activator YAP. Blocking YAP inhibited the abnormal proliferation of TSC1/2-deficient human cells and reversed TSC-like disease symptoms in mosaic Tsc1 mutant mice.

Genetic studies have shown that the tuberous sclerosis complex (TSC) 1–TSC2–mammalian target of Rapamycin (mTOR) and the Hippo–Yes-associated protein 1 (YAP) pathways are master regulators of organ size, which are often involved in tumorigenesis. The crosstalk between these signal transduction pathways in coordinating environmental cues, such as nutritional status and mechanical constraints, is crucial for tissue growth. Whether and how mTOR regulates YAP remains elusive. Here we describe a novel mouse model of TSC which develops renal mesenchymal lesions recapitulating human perivascular epithelioid cell tumors (PEComas) from patients with TSC. We identify that YAP is up-regulated by mTOR in mouse and human PEComas. YAP inhibition blunts abnormal proliferation and induces apoptosis of TSC1–TSC2-deficient cells, both in culture and in mosaic Tsc1 mutant mice. We further delineate that YAP accumulation in TSC1/TSC2-deficient cells is due to impaired degradation of the protein by the autophagosome/lysosome system. Thus, the regulation of YAP by mTOR and autophagy is a novel mechanism of growth control, matching YAP activity with nutrient availability under growth-permissive conditions. YAP may serve as a potential therapeutic target for TSC and other diseases with dysregulated mTOR activity.

Response of subependymal giant cell astrocytoma with spinal cord metastasis to everolimus

BACKGROUND

Brain subependymal giant cell astrocytomas (SEGAs) in patients with tuberous sclerosis have been reported to respond to everolimus.

METHODS

A 15-year-old male patient with intractable seizures and multiple SEGAs of the brain developed leptomeningeal enhancement and multiple metastatic, histologically confirmed SEGAs of the spinal cord. He received daily everolimus at a dose of 3 mg/m for 6 weeks, which was then increased to 6 mg/m.

RESULTS

Magnetic resonance image of the brain and spine showed significant reduction in the size of SEGAs after 6 weeks of treatment. The patient has remained free of progression for 24 months. Additional benefits included: excellent seizure control, decrease in the size of cardiac rhabdomyomas, and improved quality of life.

CONCLUSIONS

We describe a rare case of metastatic SEGA, which was successfully treated with everolimus.

Phenotypes associated with inherited and developmental somatic mutations in genes encoding mTOR pathway components

Mutations affecting the genes that encode upstream components in the mammalian (or mechanistic) target of rapamycin signalling pathway are associated with a group of rare inherited and developmental disorders that show overlapping clinical features. These include predisposition to a variety of benign or malignant tumours, localized overgrowth, developmental abnormalities of the brain, neurodevelopmental disorders and epilepsy. Many of these features have been linked to hyperactivation of signalling via mammalian target of rapamycin complex 1, suggesting that inhibitors of this complex such as rapamycin and its derivatives may offer new opportunities for therapy. In this review we describe this group of inherited and developmental disorders and discuss recent progress in their treatment via mTORC1 inhibition.

Targeting PI3 kinase in cancer

The PI3K/Akt/mTOR pathway is the most frequently known activated aberrant pathway in human cancers. Pathologic activation can occur at multiple levels along the signaling pathway by a variety of mechanisms, including point mutations, amplifications, and inactivation of tumor suppressor genes. This pathway is also a known resistance pathway, as it can be activated by both receptor tyrosine kinases and other oncogenes. mTOR inhibitors were the first targeted molecules in this pathway, and have already been FDA-approved in multiple indications. Because of the broad potential applications of inhibiting this pathway upstream of mTOR, multiple compounds targeting PI3K are in development. In this review, we discuss the clinical development of these inhibitors, including dual PI3K/mTOR inhibitors, pan-PI3K inhibitors, and isoform-selective PI3K inhibitors. Common adverse events, including rash, nausea, vomiting, diarrhea, and hyperglycemia, have created a narrow therapeutic window for all classes of PI3K inhibitors. Furthermore, single agent clinical activity has also been limited, with the exception of isoform-selective inhibitors, particularly the PI3Kδ and PI3Kγ inhibitors in hematologic malignancies. The future role of inhibitors of the PI3K/Akt/mTOR pathway in the clinical practice of oncology likely depends on the development of patient selection strategies and the results of combination trials that are currently ongoing.

High-throughput drug screen identifies chelerythrine as a selective inducer of death in a TSC2-null setting

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome associated with tumors of the brain, heart, kidney, and lung. The TSC protein complex inhibits the mammalian or mechanistic target of rapamycin complex 1 (mTORC1). Inhibitors of mTORC1, including rapamycin, induce a cytostatic response in TSC tumors, resulting in temporary disease stabilization and prompt regrowth when treatment is stopped. The lack of TSC-specific cytotoxic therapies represents an important unmet clinical need. Using a high-throughput chemical screen in TSC2-deficient, patient-derived cells, we identified a series of molecules antagonized by rapamycin and therefore selective for cells with mTORC1 hyperactivity. In particular, the cell-permeable alkaloid chelerythrine induced reactive oxygen species (ROS) and depleted glutathione (GSH) selectively in TSC2-null cells based on metabolic profiling. N-acetylcysteine or GSH cotreatment protected TSC2-null cells from chelerythrine's effects, indicating that chelerythrine-induced cell death is ROS dependent. Induction of heme-oxygenase-1 (HMOX1/HO-1) with hemin also blocked chelerythrine-induced cell death. In vivo, chelerythrine inhibited the growth of TSC2-null xenograft tumors with no evidence of systemic toxicity with daily treatment over an extended period of time. This study reports the results of a bioactive compound screen and the identification of a potential lead candidate that acts via a novel oxidative stress-dependent mechanism to selectively induce necroptosis in TSC2-deficient tumors.

IMPLICATIONS

This study demonstrates that TSC2-deficient tumor cells are hypersensitive to oxidative stress-dependent cell death, and provide critical proof of concept that TSC2-deficient cells can be therapeutically targeted without the use of a rapalog to induce a cell death response.

The mTOR signaling pathway as a treatment target for intracranial neoplasms

Inhibition of the mammalian target of rapamycin (mTOR) signaling pathway has become an attractive target for human cancer therapy. Hyperactivation of mTOR has been reported in both sporadic and syndromic (hereditary) brain tumors. In contrast to the large number of successful clinical trials employing mTOR inhibitors in different types of epithelial neoplasms, their use to treat intracranial neoplasms is more limited. In this review, we summarize the role of mTOR activation in brain tumor pathogenesis and growth relevant to new human brain tumor trials currently under way using mTOR inhibitors.

Risk of mucocutaneous toxicities in patients with solid tumors treated with everolimus; a systematic review and meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis of mucocutaneous toxicities associated with the use of everolimus in solid tumors.

PATIENTS AND METHODS

Eligible studies included randomized Phase II and III trials of patients with solid tumors on everolimus; describing events of stomatitis, skin rash, pruritus and mouth ulceration.

RESULTS

Our search strategy yielded 380 potentially relevant citations on everolimus from Pubmed/Medline, CENTRAL Cochrane registry and American Society of Clinical Oncology meeting library. After exclusion of ineligible studies, a total of 10 clinical trials were considered eligible for the meta-analysis, including eight Phase III trials and two Phase II trials. The relative risk of all-grade stomatitis, skin rash, pruritus and mouth ulceration were 3.86(95% CI: 2.23-6.68; p < 0.001); 3.49(95% CI: 2.39-5.08; p < 0.0001); 2.85(95% CI: 2.04-3.97; p = 0.0001); 3.31 (95% CI: 1.46-7.50; p = 0.004); respectively. Exploratory subgroup analysis showed no effect of tumor types or treatment regimen on the relative risk of the relevant adverse events.

CONCLUSION

Our meta-analysis has demonstrated that everolimus is associated with a significantly increased risk of all-grade stomatitis, skin rash, and pruritus and mouth ulceration. Clinicians should be aware of these risks and perform early clinical assessment and intervene accordingly.

Lymphangioleiomyomatosis: differential diagnosis and optimal management

Lymphangioleiomyomatosis (LAM) is an uncommon disease presented as diffuse thin-walled cystic changes in the lung. The main differential diagnoses include pulmonary Langerhans’ histiocytosis (PLCH), Birt-Hogg-Dubé syndrome (BHD), lymphoid interstitial pneumonia (LIP), and amyloidosis. A combination of clinical, radiological, and pathological approaches as well as genetic testing will clarify the diagnosis in most cases. LAM is a disease almost exclusively in women. Dyspnea, pneumothorax, and hemoptysis are common presentations in LAM patients. LAM is also a lymphatic disorder affecting lymphatic vessels and lymph nodes. Chylothorax, chylous ascites, and lymphangiomyomas are frequently seen. LAM can present sporadically as a single entity or as part of tuberous sclerosis complex (TSC). Angiomyolipoma (AML) is a characteristic extra-pulmonary lesion, either found in association with sporadic or TSC-related LAM. High-risk populations should be screened for LAM, including adult women with TSC and female patients with spontaneous pneumothorax, AMLs in the kidney, and diffuse cystic lung diseases. Definitive diagnosis of LAM is based on a high level of clinical suspicion on presentation supported by pathological findings or by a distinct feature, such as a history of TSC, AMLs in the kidney, chylothorax, or chylous ascites. Vascular endothelial growth factor-D (VEGF-D) in serum is a noninvasive and reliable diagnostic biomarker. In experienced centers, trans-bronchial lung biopsy (TBLB) provides a convenient and safe way to obtain lung specimens for diagnostic purposes. An effective treatment for LAM is now available, namely using a mechanistic target of rapamycin (mTOR) inhibitor such as sirolimus. Efficacy of sirolimus has been confirmed in clinical trials. Research in other molecular-targeted therapies is under investigation. A previously little-known rare disease with no cure is now better understood with regards to its pathogenesis, diagnosis, and management. In this review, current knowledge in diagnosis and differential diagnosis of LAM will be discussed, followed by the discussion of therapy with mTOR inhibitors.

[New aspects in the field of epilepsy]

Regarding epilepsy several new developments can be reported. The International League Against Epilepsy (ILAE) has suggested a new definition of epilepsy, for the first time including a definition of epilepsy resolution. Progress in the diagnosis relates to new genetic findings, improvements in magnetic resonance imaging (MRI) and the increasing use of stereo electroencephalograms (sEEG). Regarding treatment there are new clinically relevant data on the pathophysiology and prevention of sudden unexpected death in epilepsy (SUDEP). Zonisamide has been approved by the European Medicines Agency (EMA) for monotherapy in adults with focal seizures and combination therapy in children aged ≥ 6 years. Retigabin and perampanel have been approved but are currently taken off the market in Germany (only) because the Gemeinsamer Bundesausschuss (GBA, Joint Federal Committee) did not find any additional therapeutic value as compared to lamotrigine due to a lack of data. A decision regarding a new application for perampanel is pending. Regarding surgical treatment novel ablation techniques (e.g. stereotactic radiofrequency and laser ablation as well as focussed ultrasound ablation) and brain stimulation paradigms are under investigation. Experimental studies, generously supported by the European Union (EU) and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) are focusing on (opto-)genetic (e.g. using lentoviral transfection), epigenetic (e.g. micro-RNA-related) approaches and on the investigation of neuronal micronetworks.

mTOR regulate EMT through RhoA and Rac1 pathway in prostate cancer

Recently, an increasing number of studies have suggested that mTOR plays a critical role in the regulation of tumor cell motility, invasion and cancer metastasis. However, little is known about the signaling mechanisms in regulating epithelial-mesenchymal transition (EMT) of prostate cancer. In this study, we found that the expression levels of Raptor and Rictor in prostate cancer tissues were elevated, which may suggest that Raptor and Rictor signaling pathways are associated with prostate cancer progression and metastasis. Inhibition of mTORC1 or mTORC2 by knock down of Raptor or Rictor, respectively, migration and invasion of prostate cancer were attenuated. Furthermore, EMT, a characterized by the changed expression levels of various markers like E-cadherin, β-catenin, N-cadherin, and vimentin emergend following inhibition of Raptor or Rictor. Finally, the small GTPases (RhoA and Rac1) which were crucial regulatory proteins in cell migration and invasion were inactivited after downregulating Raptor and Rictor. These results suggest that mTOR regulate EMT at least in part by down regulation of RhoA and Rac1 signaling pathways. Our findings provide novel very attractive target strategies that the inhibition of mTOR signaling pathways may retard prostate cancer migration and invasion at early stages.

Phase II multicentered study of low-dose everolimus plus cisplatin and weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin as first-line treatment for patients with advanced gastric cancer

OBJECTIVE

This phase II trial investigates the efficacy and safety of low-dose everolimus in combination with cisplatin-fluorouracil chemotherapy in patients with advanced gastric cancer.

METHODS

Eligible patients with chemotherapy-naïve advanced gastric cancer received low-dose everolimus (10 mg p.o. on days 1, 8 and 15) plus cisplatin and a weekly 24-hour infusion of high-dose 5-fluorouracil and leucovorin (HDFL) chemotherapy (cisplatin 35 mg/m(2) intravenous infusion for 24 h on days 1 and 8, 5-fluorouracil 2,000 mg/m(2) and leucovorin 300 mg/m(2) intravenous infusion for 24 h on days 1, 8 and 15) every 28 days. The primary endpoint was objective response rate (ORR) according to the Response Evaluation Criteria in Solid Tumors version 1.0.

RESULTS

Forty patients (19 men; 21 women; median age, 54.1 years; range, 33.7-73.3 years) received a median of 6 (range, 1-30; 95% CI, 4.9-8.0) cycles of study treatment. The ORR was 52.5% (21 confirmed partial response). The median progression-free survival and overall survival were 6.9 (95% CI, 4.9-8.4) and 10.5 (95% CI, 8.6-12.3) months, respectively. Most adverse events were mild.

CONCLUSION

Adding low-dose everolimus to cisplatin-HDFL chemotherapy failed to increase the ORR as in a preplanned statistical assumption but may prolong progression-free survival in treatment-naïve advanced gastric cancer patients.

Topical everolimus for facial angiofibromas in the tuberous sclerosis complex. A first case report

BACKGROUND

Facial angiofibromas are present in most of the patients with the tuberous sclerosis complex and may cause severe disfiguration of the face. The tumor growth in tuberous sclerosis complex is promoted by the disinhibition of the mammalian target of rapamycin pathway. Thus, the systemic treatment with mammalian target of rapamycin inhibitors such as sirolimus and everolimus has recently been established to treat specific tuberous sclerosis complex-associated lesions. For patients who suffer from disfiguring facial angiofibromas only, there is a need for a topical use of mammalian target of rapamycin inhibitors. Sirolimus has been shown to be beneficial in treating facial angiofibromas. But the topical use of everolimus, which has the approval to treat tuberous sclerosis complex-associated tumors, namely giant cell astrocytomas and renal angiofibromas, has not been reported.

PATIENTS AND RESULTS

We present a 10-year-old girl whose facial angiofibromas were successfully treated with an everolimus ointment without relevant side effects. In addition, we provide a short pharmacological overview of sirolimus and everolimus with focus on the topical use.

CONCLUSIONS

Topical everolimus seems to be a favorable and safe option for patients with facial angiofibromas who do not require systemic treatment.

Targeting the mammalian target of rapamycin pathway with everolimus: implications for the management of metastatic breast cancer

The inhibitors of mammalian target of rapamycin (mTOR) have documented antitumor activity via disruption of various signaling pathways leading to impaired cellular growth, proliferation, and survival. In preclinical studies, mTOR inhibitors use in combination with hormonal therapy has shown promising results in overcoming endocrine resistance in breast cancer cells. The role of everolimus in breast cancer was established in the Breast Cancer Trial of Oral Everolimus-2 (BOLERO-2) trial in combination with exemestane for patients with advanced metastatic hormone receptor-positive (HR+) breast cancer, who relapsed after initial hormonal manipulation. The study met its primary endpoint of significant improvement in progression free survival (PFS) with a median time to progression of 6.9 months in the combination group versus 2.8 months in exemestane group. Favorable improvements in PFS were reported across all patient subgroups regardless of age, Eastern Cooperative Oncology Group performance status, number of prior therapies, and presence of visceral metastases. Adverse events were mostly mild to moderate in severity and consistent with the known safety profile of everolimus. Major toxicities reported include stomatitis, non-infectious pneumonitis, and hyperglycemia. The purpose of this review is to discuss the role of everolimus as a valuable component in advanced metastatic breast cancer and delineate current strategies to prevent and manage the most common toxicities associated with this combination regimen.

Clinical neurogenetics: autism spectrum disorders

Autism spectrum disorders are neurodevelopmental disorders characterized by deficits in social interactions, communication, and repetitive or restricted interests. There is strong evidence that de novo or inherited genetic alterations play a critical role in causing Autism Spectrum Disorders, but non-genetic causes, such as in utero infections, may also play a role. Magnetic resonance imaging based and autopsy studies indicate that early rapid increase in brain size during infancy could underlie the deficits in a large subset of subjects. Clinical studies show benefits for both behavioral and pharmacological treatment strategies. Genotype-specific treatments have the potential for improving outcome in the future.

Defining key signaling nodes and therapeutic biomarkers in NF1-mutant cancers

NF1 encodes a RAS GTPase-activating protein. Accordingly, aberrant RAS activation underlies the pathogenesis of NF1-mutant cancers. Nevertheless, it is unclear which RAS pathway components represent optimal therapeutic targets. Here, we identify mTORC1 as the key PI3K effector in NF1-mutant nervous system malignancies and conversely show that mTORC2 and AKT are dispensable. However, we find that tumor regression requires sustained inhibition of both mTORC1 and MEK. Transcriptional profiling studies were therefore used to establish a signature of effective mTORC1-MEK inhibition in vivo. We unexpectedly found that the glucose transporter GLUT1 was potently suppressed, but only when both pathways were inhibited. Moreover, unlike VHL- and LKB1-mutant cancers, reduction of (18)F-FDG uptake required the suppression of both mTORC1 and MEK. Together, these studies identify optimal and suboptimal therapeutic targets in NF1-mutant malignancies and define a noninvasive means of measuring combined mTORC1-MEK inhibition in vivo, which can be readily incorporated into clinical trials.

SIGNIFICANCE

This work demonstrates that mTORC1 and MEK are key therapeutic targets in NF1-mutant cancers and establishes a noninvasive biomarker of effective, combined target inhibition that can be evaluated in clinical trials.

Treatment-related mortality with everolimus in cancer patients

INTRODUCTION

The overall incidence and odds of fatal adverse events (FAEs) after exposure to everolimus are not well defined. We performed a comprehensive meta-analysis of published randomized controlled trials (RCTs) to determine the role of everolimus in treatment-related mortality in patients with cancer.

METHODS

PubMed databases and abstracts from the proceedings of the American Society of Clinical Oncology and the San Antonio Breast Cancer Symposium were searched for RCTs of everolimus either alone or in combination with another agent compared with the control arm without everolimus and that reported deaths from an adverse event from January 1966 to July 2013. The primary objective was to determine the difference of FAEs between everolimus-treated patients and control group patients.

RESULTS

In total, 2,997 patients with multiple solid tumors from nine RCTs were included. The overall incidence of FAEs in cancer patients treated with everolimus was 0.7% (95% CI 0.3%-1.1%) compared with 0.4% (95% CI 0.0%-0.7%) in cancer patients who did not receive everolimus. The odds ratio of FAEs was greater in everolimus-treated patients (Peto odds ratio = 3.80, 95% CI 1.59-9.07, p = .003). In subgroup analyses, no significant difference was found in the incidence or odds of FAEs by everolimus administration (alone or in combination) or tumor type (breast cancer vs. nonbreast cancer; p = .63).

CONCLUSION

In patients with cancer, everolimus is associated with a small but significant increase in the odds of a treatment-related fatal events.