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

Efficacy and safety of mTOR inhibitors (rapamycin and its analogues) for tuberous sclerosis complex: a meta-analysis

Background

The treatment of tuberous sclerosis complex (TSC) using mammalian target of rapamycin (mTOR) inhibitors is clinically promising. The aim of the present study was to evaluate the efficacy and safety of mTOR inhibitors for improving the clinical symptoms of TSC.

Methods

We performed a systematic search of major electronic databases (PubMed, EMBASE, Cochrane Library and WanFang, CNKI, and VIP databases) to identify randomized controlled trials (RCTs) and quasi-randomized studies from the date of database inception to November 2017; the Chinese Food and Drug Administration and clinicaltrials.gov were also searched for unpublished studies. The endpoints of the study were the tumor response rate and seizure frequency response rate (the proportion of patients achieving a ≥ 50% reduction relative to the baseline). Two researchers screened articles, assessed the risk of bias and extracted data independently. The included RCTs were analyzed using RevMan 5.3, which was provided by the Cochrane Collaboration.

Results

Compared with the placebo, mTOR inhibitors significantly reduced tumor volume in both angiomyolipoma (AML) (RR = 24.69, 95% CI = 3.51,173.41, P = 0.001) and subependymal giant cell astrocytoma (SEGA) (RR = 27.85, 95% CI = 1.74,444.82, P = 0.02). Compared with the placebo, mTOR inhibitors significantly reduced seizure frequency (RR = 2.12, 95% CI = 1.41,3.19, P = 0.0003). Regarding safety, compared with patients who did not receive mTOR inhibitors, those who did had a higher risk of suffering stomatitis (RR = 3.20, 95% CI = 1.49,6.86, P = 0.003). In contrast, patients who did and did not receive mTOR inhibitors experienced similar adverse events, such as upper respiratory tract infections (RR = 1.08, 95% CI = 0.81,1.45, P = 0.59) and nasopharyngitis (RR = 0.86, 95% CI = 0.60,1.21, P = 0.38).

Conclusion

In view of the efficacy and safety associated with tumor and seizure frequency in the TSC patients, mTOR inhibitors is a good therapeutic choice. Unlike the risks of upper respiratory tract infections and nasopharyngitis, mTOR inhibitors seem to increase the risk of stomatitis, mostly grade 1 and 2.

The role of mTOR inhibitors in preventing epileptogenesis in patients with TSC: Current evidence and future perspectives

Tuberous sclerosis complex (TSC) is one of the most common genetic causes of epilepsy. Mutations in the TSC1 or TSC2 genes lead to the dysregulation of the mechanistic target of rapamycin (mTOR) pathway. This mTOR pathway hyperactivation is associated with several processes resulting in epileptic conditions. The occurrence of seizures and their treatment outcomes seem to play a crucial role in cognitive and behavioral developments in patients with TSC. Mechanistic target of rapamycin inhibitors have been proven to be effective in epilepsy treatment in individuals with TSC. Specifically, because of their disease-modifying mechanism of action, they have the capability to prevent epileptogenesis in patients with TSC. This article will provide an overview of the current evidence of and delineate future perspectives for mTOR inhibitors and their role in preventing epileptogenesis.

The Roles of Common Variation and Somatic Mutation in Cancer Pharmacogenomics

Cancer pharmacogenomics is the science concerned with understanding genetic alterations and its effects on the pharmacokinetics and pharmacodynamics of anti-cancer drugs, with the aim to provide cancer patients with the precise medication that will achieve a good response and cause low/no incidence of adverse events. Advances in biotechnology and bioinformatics have enabled genomic research to evolve from the evaluation of alterations at the single-gene level to studies on the whole-genome scale using large-scale genotyping and next generation sequencing techniques. International collaborative efforts have resulted in the construction of databases to curate the identified genetic alterations that are clinically significant, and these are currently utilized in clinical sequencing and liquid biopsy screening/monitoring. Furthermore, countless clinical studies have accumulated sufficient evidence to match cancer patients to therapies by utilizing the information of clinical-relevant alterations. In this review we summarize the importance of germline alterations that act as predictive biomarkers for drug-induced toxicity and drug response as well as somatic mutations in cancer cells that function as drug targets. The integration of genomics into the medical field has transformed the era of cancer therapy from one-size-fits-all to cancer precision medicine.

Everolimus for epilepsy and autism spectrum disorder in tuberous sclerosis complex: EXIST-3 substudy in Japan

BACKGROUND

Epilepsy and autism spectrum disorder (ASD) are the common neurological manifestations of tuberous sclerosis complex (TSC). EXIST-3 study has recently demonstrated that everolimus reduces seizures in patients with TSC and refractory epilepsy. Here we report the efficacy and safety of everolimus for treatment-refractory seizures in Japanese patients of EXIST-3, along with the exploratory analysis evaluating the everolimus effect on comorbid ASD symptoms in these patients.

METHODS

Primary endpoint was change in seizure frequency from baseline defined as response rate (≥50% reduction) and median percentage reduction in the seizure frequency. Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS) scores were assessed at baseline and at week-18 for ASD symptoms.

RESULTS

Overall, 35 Japanese patients were randomized to everolimus low-exposure (LE; n = 10), everolimus high-exposure (HE; n = 14), or placebo (n = 11). The response rate was 30.0% and 28.6% versus 0% with the everolimus LE and HE versus placebo arm, respectively. Similarly, the median percentage reduction in seizure frequency was 6.88% and 38.06% versus -6.67%. Stomatitis was the most frequently reported adverse event (everolimus LE, 100%; HE, 78.6%; placebo, 9.1%). Four of 11 patients with ASD in the everolimus arms and 1 of 8 patients with ASD in the placebo arm showed ≥5 point decrease in PARS scores.

CONCLUSIONS

Adjunctive everolimus treatment improved seizure frequency with a tolerable safety relative to placebo among 35 Japanese patients with TSC-associated refractory seizures, consistent with the results of overall EXIST-3 study involving 366 patients. A favorable trend towards the improvement of ASD symptoms was observed.

Subependymal giant cell astrocytoma-like astrocytoma: a neoplasm with a distinct phenotype and frequent neurofibromatosis type-1-association

Neurofibromatosis type-1 is a familial genetic syndrome associated with a predisposition to develop peripheral and central nervous system neoplasms. We have previously reported on a subset of gliomas developing in these patients with morphologic features resembling subependymal giant cell astrocytoma, but the molecular features of these tumors remain undefined. A total of 14 tumors were studied and all available slides were reviewed. Immunohistochemical stains and telomere-specific FISH were performed on all cases. In addition, next-generation sequencing was performed on 11 cases using a platform targeting 644 cancer-related genes. The average age at diagnosis was 28 years (range: 4-60, 9F/5M). All tumors involved the supratentorial compartment. Tumors were predominantly low grade (n = 12), with two high-grade tumors, and displayed consistent expression of glial markers. Next-generation sequencing demonstrated inactivating NF1 mutations in 10 (of 11) cases. Concurrent TSC2 and RPTOR mutations were present in two cases (1 sporadic and 1 neurofibromatosis type-1-associated). Interestingly, alternative lengthening of telomeres was present in 4 (of 14) (29%) cases. However, an ATRX mutation associated with aberrant nuclear ATRX expression was identified in only one (of four) cases with alternative lenghtening of telomeres. Gene variants in the DNA helicase RECQL4 (n = 2) and components of the Fanconi anemia complementation group (FANCD2, FANCF, FANCG) (n = 1) were identified in two alternative lenghtening of telomere-positive/ATRX-intact cases. Other variants involved genes related to NOTCH signaling, DNA maintenance/repair pathways, and epigenetic modulators. There were no mutations identified in DAXX, PTEN, PIK3C genes, TP53, H3F3A, HIST1H3B, or in canonical hotspots of IDH1, IDH2, or BRAF. A subset of subependymal giant cell astrocytoma-like astrocytomas are alternative lenghtening of telomere-positive and occur in the absence of ATRX alterations, thereby suggesting mutations in other DNA repair/maintenance genes may also facilitate alternative lenghtening of telomeres. These findings suggest that subependymal giant cell astrocytoma-like astrocytoma represents a biologically distinct group that merits further investigation.

CD79B mutations in primary vitreoretinal lymphoma: Diagnostic and prognostic potential

OBJECTIVE

Primary vitreoretinal lymphoma (PVRL) is a rare type of lymphoma wherein the lesions are limited to the eyes. PVRL is difficult to diagnose because of the challenges related to obtaining sufficient samples for biopsy. Moreover, PVRL has poor outcomes and often leads to the development of central nervous system (CNS) lesions during its course. Two studies recently reported that approximately 70%-80% of patients with vitreoretinal lymphoma have MYD88^L265P , which is frequently mutated in primary CNS lymphoma (PCNSL). PCNSL is closely associated with PVRL. The mutation of CD79B^Y196 has been also frequently detected in PCNSL. Thus, we examined the mutation in PVRL to clarify its diagnostic and prognostic potential.

METHOD

By using direct sequencing and allele-specific polymerase chain reaction, we examined the mutation of CD79B^Y196 and MYD88^L265P in the DNA extracted from the vitreous fluid of 17 patients with PVRL upon diagnosis. We also retrospectively analyzed their prognostic potential for PVRL.

RESULTS

Among the included patients, six patients (35%) were found with CD79B^Y196 mutations. Twelve (71%) patients were positive for MYD88^L265P , and six samples from patients with benign uveitis were negative for both mutations. Interestingly, six patients with CD79B^Y196 mutations developed CNS diseases significantly earlier (16.5 months) than 11 patients with CD79B^WT (67 months; P = 0.0135).

CONCLUSION

Detecting CD79B^Y196 in vitreous DNA may contribute to the confirmation of the diagnosis and may have a prognostic potential for patients with PVRL.

Tuberous sclerosis complex: new insights into clinical and therapeutic approach

Tuberous sclerosis complex (TSC) is a complex disease with many different clinical manifestations. Despite the common opinion that TSC is a rare condition, with a mean incidence of 1/6000 live births and a prevalence of 1/20,000, it is increasingly evident that in reality this is not true. Its clinical sequelae span a range of multiple organ systems, in particular the central nervous system, kidneys, skin and lungs. The management of TSC patients is heavily burdensome in terms of time and healthcare costs both for the families and for the healthcare system. Management options include conservative approaches, surgery, pharmacotherapy with mammalian target of rapamycin inhibitors and recently proposed options such as therapy with anti-EGFR antibody and ultrasound-guided percutaneous microwaves. So far, however, no systematically accepted strategy has been found that is both clinically and economically efficient. Thus, decisions are tailored to patients' characteristics, resource availability and clinical and technical expertise of each single center. This paper reviews the pathophysiology and the clinical (diagnostic-therapeutic) management of TSC.

Short-term safety of mTOR inhibitors in infants and very young children with tuberous sclerosis complex (TSC): Multicentre clinical experience

OBJECTIVE

To evaluate the safety of mTOR inhibitors (sirolimus or everolimus) in infants and very young children with tuberous sclerosis complex (TSC) under two years of age.

METHODS

Study design was retrospective to capture medical record data from 52 international TSC Centres who initiated treatment with sirolimus or everolimus in TSC children before the age of two years. Data collection included demographic and clinical information including reason(s) for initiating treatment with mTOR inhibitors, treatment duration, dosing, and corresponding serum trough levels, response to treatment, and adverse events (AE).

RESULTS

19 of 52 (37%) TSC Centres reported treatment of at least one child with TSC under the age of two years with everolimus or sirolimus. Treatment-related data were provided for 45 patients meeting inclusion criteria. Everolimus was utilised 87% of the time, compared to 24% for sirolimus (5 subjects, 11%, were treated separately with both). Refractory epilepsy (45%) was the most common primary reason for initiating treatment and treatment was initiated on average at 11.6 ± 7.6 months of age. At least one AE, suspected or definitely treatment-related, occurred in 35 of 45 (78%) treated subjects. Most AEs were mild (Grade 1) or moderate (Grade 2) in severity and most commonly related to infections. Severe AE (Grade 3) was reported in 7 subjects (20%) and no life-threatening AE (Grade 4) or death/disability (Grade 5) was reported. Treatment was discontinued due to an AE in 9 of 45 (20%).

CONCLUSIONS

Everolimus, and to a lesser extent sirolimus, are increasingly being used to treat TSC infants and very young children for multiple TSC-associated clinical indications. While AEs were common, most were not severe and did not prevent continued treatment in the majority of this younger population.

The use of rapamycin in patients with tuberous sclerosis complex: Long-term results

PURPOSE

The purpose of this study was to evaluate the long-term results of eight cases diagnosed with tuberous sclerosis complex (TSC) and receiving rapamycin therapy because of epileptic seizures and/or accompanying TSC findings.

METHOD

Rapamycin therapy was initiated at a dose of 1.5 mg/m². Seizure frequency, electroencephalographic (EEG) findings, renal and cranial imaging findings, and cutaneous lesions over 3- to 6-month periods during follow-up and treatment were evaluated.

RESULTS

Four girls and four boys aged 4-16 years at the start of rapamycin therapy and now aged 9-24 years were evaluated. Duration of rapamycin therapy was 1-5 years, and the monitoring period after commencement of rapamycin therapy lasted 5-8 years. Positive effects were observed at 9-12 months in three out of six cases of renal angiomyolipoma (AML) and in the second year of treatment in one. An increase in AML dimensions was observed in three cases after treatment was stopped. Seizure control was established in the first year of rapamycin therapy in all cases. An increased frequency of seizures was observed in three cases after the second year of treatment. No seizure recurrence was determined in the second year of treatment with rapamycin in five out of eight cases. Recurrence of seizure was observed in 6-12 months after the discontinuation of rapamycin in three cases.

CONCLUSION

Rapamycin therapy exhibits positive effects on epileptic seizures in cases of TSC in 1-2 years but these positive effects on seizure control of rapamycin therapy decline after the second year. Larger case series are still needed to determine the duration and effectiveness of treatment in childhood.

Renal progression factors in young patients with tuberous sclerosis complex: a retrospective cohort study

BACKGROUND

Renal pathology in tuberous sclerosis complex (TSC) is characterized by the growth of angiomyolipoma and renal cysts, and in rare cases renal cell carcinoma. Other consequences of renal involvement in TSC, including hypertension, proteinuria, and hyperfiltration, are not well studied. We aimed to analyze the early manifestations of the renal TSC phenotype in a young TSC cohort and to explore common, modifiable risk factors.

METHODS

In this retrospective cohort study, TSC patients attending the TSC clinics of two tertiary hospitals were included. Data on demographics, history, genotype, kidney function, hematuria, proteinuria, blood pressure, and renal imaging were collected.

RESULTS

Eighty patients were included, with a median age of 0.8 years (0.0-63.0) at first presentation, and a median follow-up time of 10.2 (0.4-41.0) years. Mutation analysis was available in 64 patients (80%). Renal lesions (cysts or angiomyolipoma) were observed in 55/73 (75%). Thirty-two percent (19/60) were hypertensive, 8/51 (16%) had proteinuria, and 18/71 (25%) had hyperfiltration (median eGFR 154 ml/min/m²). Six (7.5%) patients had developed end stage renal disease at the last follow-up. No association was found between hyperfiltration, hypertension, or proteinuria and CKD ≥ 3. Cox regression showed a significant positive association between the presence of a renal intervention and CKD ≥ 3 (Hazard-Ratio 3.91, P < 0.05).

CONCLUSIONS

Besides renal cysts and angiomyolipoma, the modifiable progression factors hypertension, proteinuria, and hyperfiltration occur frequently and early in TSC patients. This represents a preventive treatment target.

The natural history of subependymal giant cell astrocytomas in tuberous sclerosis complex: a review

Tuberous sclerosis complex (TSC) is an auto-somal-dominant inherited condition with an incidence of approximately 1:6000 births, characterised by deregulated mTOR activity with multi-site hamartomas. Subependymal giant cell astrocytomas (SEGA) are one such hamartoma, affecting up to 24% of patients with TSC. Their intraventricular location may lead to life-threatening obstructive hydrocephalus. Current management is hampered by a lack of understanding regarding the natural history, behaviour and growth patterns of SEGA. We review the current literature to summarise what is known about SEGA in the following areas: (1) diagnostic criteria, (2) prevalence, (3) origin, (4) imaging characteristics, (5) growth rate, (6) genotype-phenotype correlation, (7) congenital SEGA and (8) SEGA as a marker of severity of other TSC manifestations.

mTOR inhibitor therapy as a disease modifying therapy for tuberous sclerosis complex

Between 1993 and 2003, through experiments involving Drosophila sp., cancer biologists identified the protein kinase known as the mammalian target of rapamycin, its pathway, and its relationship to the genes responsible for tuberous sclerosis. Thereafter, clinical research has resulted in regulatory approval of mTOR inhibitors for four distinct manifestations of the disease: giant cell astrocytoma, angiomyolipoma, lymphangioleiomyomatosis, and epilepsy. These developments are summarized and the practical use of mTOR inhibitors to improve the lives of patients with tuberous sclerosis reviewed.

Central nervous system manifestations of tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a neurocutaneous autosomal-dominant genetic syndrome marked by development of hamartomatous lesions arising from dysfunction of the mammalian target of rapamycin (mTOR) pathway. Although TSC remains a heterogeneous clinical entity, the recent inclusion of genetic diagnostic criteria reflects advancement in our understanding of its underlying etiopathogenesis. Abnormal cellular growth, differentiation, and migration result in multisystem sequelae, with neurologic manifestations of TSC representing the primary cause of morbidity and mortality for the majority of individuals. Modern imaging techniques aid in the diagnosis of TSC and guide treatment strategies by revealing central nervous system findings. Cortical tubers are the namesake lesion of the disorder and occur in up to 90% of cases, often exerting significant epileptogenic potential. Subependymal nodules are found in 80% of patients as calcified tumors lining the ependyma of the lateral ventricles. In some cases, these nodules are thought to progress to subependymal giant cell astrocytomas and may present with obstructive hydrocephalus. Retinal astrocytic hamartomas are also common, present in 50% of patients. Surgery remains the treatment of choice for large or symptomatic lesions, though clinical trials have highlighted a potential role for mTOR pathway antagonism. A multidisciplinary approach is necessary for achieving optimal patient outcomes.

Oral stomatitis and mTOR inhibitors: A review of current evidence in 20,915 patients

BACKGROUND

Traditional treatment of malignancies with chemotherapeutic agents is often affected by the damage inflicted on non-cancerous cells. Toxicities of the oral cavity, such as mucositis and stomatitis, are some of the most significant and unavoidable toxicities associated with anti-cancer therapies. For such reason, in the last decades, newer targeted agents have been developed aiming to decrease the rates of side effects on healthy cells. Unfortunately, targeted anti-cancer therapies also showed significant rate of toxicity on healthy tissues. mTOR inhibitors showed some adverse events, such as hyperglycemia, hyperlipidemia, hypophosphatemia, hematologic toxicities, and mucocutaneous eruption, but the most important are still stomatitis and skin rash, often reported as dose-limiting side effects.

PATIENTS AND METHODS

A search of the literature was performed by authors on the PubMed online database using the following key words: "sirolimus" OR "everolimus" OR "temsirolimus" OR "deforolimus" OR "ridaforolimus" combined with the Boolean operator AND with the terms: "stomatitis" OR "mucositis" OR "oral pain." Titles and abstracts of 382 potentially relevant studies were screened; of these, 114 studies were excluded because they did not report the inclusion criteria. In the second round, 268 studies were read full-text, but only 135 reported the inclusion criteria and were included for data extraction. Of the included studies, 95 referred to everolimus use, 16 to ridaforolimus, and 26 to temsirolimus (two studies referred to both everolimus and temsirolimus).

RESULTS

The incidence rate of stomatitis according to the agent used was 25.07% (3,959/15,787) for everolimus, 27.02% (724/2,679) for temsirolimus, and 54.76% (598/1,092) for ridaforolimus. All the three agents analyzed showed high rates of low-grade stomatitis (G1-G2), while the onset of severe stomatitis (G3-G4) was rare.

CONCLUSIONS

Analysis of the reports with patients treated with everolimus, temsirolimus, and ridaforolimus showed a clear prevalence of stomatitis grade 1 or 2. These data differ from that of patients treated with conventional chemotherapy in which mucositis is predominantly of grade 3 or 4.

Cellular antiseizure mechanisms of everolimus in pediatric tuberous sclerosis complex, cortical dysplasia, and non-mTOR-mediated etiologies

The present study was designed to examine the potential cellular antiseizure mechanisms of everolimus, a mechanistic target of rapamycin (mTOR) pathway blocker, in pediatric epilepsy cases. Cortical tissue samples obtained from pediatric patients (n = 11, ages 0.67–6.75 years) undergoing surgical resections for the treatment of their pharmacoresistant epilepsy were examined electrophysiologically in ex vivo slices. The cohort included mTOR‐mediated pathologies (tuberous sclerosis complex [TSC] and severe cortical dysplasia [CD]) as well as non–mTOR‐mediated pathologies (tumor and perinatal infarct). Bath application of everolimus (2 μm) had practically no effect on spontaneous inhibitory postsynaptic activity. In contrast, long‐term application of everolimus reduced spontaneous excitatory postsynaptic activity, burst discharges induced by blockade of γ‐aminobutyric acid A (GABA_A) receptors, and epileptiform activity generated by 4‐aminopyridine, a K⁺ channel blocker. The antiseizure effects were more pronounced in TSC and CD cases, whereas in non–mTOR‐mediated pathologies, the effects were subtle at best. These results support further clinical trials of everolimus in mTOR pathway–mediated pathologies and emphasize that the effects require sustained exposure over time.

Expert opinion on the metabolic complications of mTOR inhibitors

Using mTOR inhibitors (mTORi) as anticancer drugs led to hyperglycemia (12-50%) and hyperlipidemia (7-73%) in phase-III trials. These high rates require adapted treatment in cancer patients. Before initiating mTORi treatment, lipid profile screening should be systematic, with fasting glucose assay in non-diabetic patients and HbA_1C in diabetic patients. After initiation, lipid profile monitoring should be systematic, with fasting glucose assay in non-diabetic patients, every 2 weeks for the first month and then monthly. The HbA_1C target is≤8%, before and after treatment initiation in known diabetic patients and in case of onset of diabetes under mTORi. LDL-cholesterol targets should be adapted to general health status and cardiovascular and oncologic prognosis. If treatment is indicated, pravastatin should be prescribed in first line; atorvastatin and simvastatin are contraindicated. Fenofibrate should be prescribed for hypertriglyceridemia>5g/l resisting dietary measures adapted to oncologic status. In non-controllable hypertriglyceridemia exceeding 10g/l, mTORi treatment should be interrupted and specialist opinion should be sought.

A clinical update on tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

Tuberous sclerosis complex (TSC) is associated with a wide range of behavioral, psychiatric, intellectual, academic, neuropsychological, and psychosocial difficulties, which are often underdiagnosed and undertreated. Here, we present a clinical update on TSC-associated neuropsychiatric disorders, abbreviated as "TAND," to guide screening, diagnosis, and treatment in practice. The review is aimed at clinical geneticists, genetic counselors, pediatricians, and all generalists involved in the assessment and treatment of children, adolescents and adults with TSC, and related disorders. The review starts with a summary of the construct and levels of TAND, before presenting up-to-date information about each level of investigation. The review concludes with a synopsis of current and future TAND research.

[Neuropsychiatric manifestations in Tuberous Sclerosis Complex (TSC): diagnostic guidelines, TAND concept and therapy with mTOR inhibitors]

Neuropsychiatric manifestations in Tuberous Sclerosis Complex (TSC): diagnostic guidelines, TAND concept and therapy with mTOR inhibitors Abstract. Tuberous sclerosis complex (TSC), albeit a rare autosomal-dominant multisystem disease with an incidence of 1:6,000, is one of the most important monogenetic disorders in child and adolescent psychiatry. In up to 90 % of patients, neurological disorders such as epilepsy and psychiatric disorders such as autism spectrum disorder, ADHD, affective disorders, and intellectual disability are observed. In recent years, significant progress has been made in understanding the molecular mechanism as well as in the clinical diagnosis and treatment of the disease. Here, we review these recent developments. In the first part, we describe the need for psychiatric assessment and treatment of patients and analyse challenges in interdisciplinary work between child and adolescent psychiatry, child neurology, and other professional groups. In the second part, we introduce the concept of TSC-associated neuropsychiatric disorders (TAND), developed by the TSC Neuropsychiatry Panel as a guide to help clinical teams, families, and individuals with TSC via screening, assessment, and treatment of neuropsychiatric symptoms and disorders as well as with a novel screening instrument, the TAND Checklist. Finally, we report findings from recent clinical trials of mTOR-inhibitors to treat TAND. The paper includes the German translation of the TAND Checklist as an electronic supplement.

Surgery for subependymal giant cell astrocytomas in children with tuberous sclerosis complex

OBJECTIVE

Subependymal giant cell astrocytomas (SEGAs) are low-grade intraventricular glial tumors that develop in 10-15% of patients with tuberous sclerosis complex; they often cause hydrocephalus and are potentially accessible to a surgical treatment. Our aim is to evaluate morbidity and results after surgery in symptomatic and asymptomatic patients.

METHOD

We present a retrospective series of 18 pediatric patients operated on for SEGA between 2006 and 2016 at our institution. We reviewed surgical indications, preoperative clinical and radiologic data, surgical management, and clinical and radiological follow-up.

RESULTS

Mean age at surgery was 10.7 years. The surgical decision was based on clinical signs of raised intracranial pressure due to hydrocephalus in 8 and on radiological findings without any clinical signs in the other 10 patients (increased in SEGA volume with or without ventricular enlargement). Surgical treatment consisted in a frontal trans-ventricular microsurgical approach in 17 patients and an endoscopic approach in 1. External ventricular drainage was placed in all the patients but 1. Ventriculoperitoneal shunting (VPS) became necessary in 6 patients, all of them presenting with a preoperative active hydrocephalus. Morbidity appeared very low with meningitis occurring in 1 patient. Resection was complete in 15 children with no recurrence during a mean follow-up of 5.25 years and incomplete in 3 requiring a second surgery.

CONCLUSION

Surgery of SEGA represents a very effective treatment with low morbidity and no mortality in the present series. In patients operated before the onset of clinical signs of hydrocephalus, internal VPS could be avoided whereas in others, an additional shunt surgery became necessary. This gives arguments in favor of a regular MRI surveillance in tuberous sclerosis complex patients with SEGA in order to best propose resective surgery once a growth of tumor and/or ventricular size have been confirmed but before raised intracranial pressure occurs.

Thoracoabdominal imaging of tuberous sclerosis

Imaging of tuberous sclerosis complex has rapidly evolved over the last decade in association with increased understanding of the disease process and new treatment modalities. Tuberous sclerosis complex is best known for the neurological symptoms and the associated neuroimaging findings, and children with tuberous sclerosis complex require active surveillance of associated abnormalities in the chest, abdomen and pelvis. Common findings that require regular imaging surveillance are angiomyolipomas in the kidneys and lymphangioleiomyomatosis in the chest. However multiple rarer associations have been attributed to tuberous sclerosis complex and should be considered by radiologists reviewing any imaging in these children. In this review the authors discuss the spectrum of imaging findings in people with tuberous sclerosis complex, focusing on MR imaging findings in the chest, abdomen and pelvis.

Effect of everolimus on skin lesions in patients treated for subependymal giant cell astrocytoma and renal angiomyolipoma: final 4-year results from the randomized EXIST-1 and EXIST-2 studies

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder associated with tumour growth in various organs, including the brain, kidneys, heart and skin. Cutaneous lesions are prevalent manifestations of TSC, occurring in up to 90% of patients. Oral mammalian target of rapamycin inhibitors, such as everolimus, is believed to be effective for treatment of TSC-associated lesions because they act on the underlying disease pathophysiology.

OBJECTIVE

We evaluated the long-term effect of oral everolimus on TSC-associated skin lesions as a secondary objective in the phase III studies EXIST-1 (NCT00789828) and EXIST-2 (NCT00790400) after approximately 4 years of treatment.

MATERIALS AND METHODS

Everolimus was dosed 4.5 mg/m² /day (titrated to trough 5-15 ng/mL) in patients with TSC-associated subependymal giant cell astrocytoma in EXIST-1, and 10 mg/day initially in adult patients with TSC- or sporadic lymphangioleiomyomatosis-associated renal angiomyolipoma in EXIST-2. Following positive results from the core phase, remaining patients were offered open-label everolimus in an extension. Skin lesion response rate was the proportion of patients achieving complete or partial clinical response.

RESULTS

A total of 105 patients in EXIST-1 and 107 in EXIST-2 received everolimus and had ≥1 skin lesion at baseline. Skin lesion response rate (95% confidence interval) was 58.1% (48.1-67.7%) in EXIST-1 and 68.2% (58.5-76.9%) in EXIST-2; most were partial responses. At week 192 (EXIST-1: n = 55; EXIST-2: n = 56), 69% and 66% had a response. Most common drug-related adverse event was stomatitis (41-45%).

CONCLUSION

Oral everolimus improved TSC-related skin lesions, with responses sustained over 4 years of treatment in EXIST-1 and EXIST-2.

Everolimus shows synergistic antimyeloma effects with bortezomib via the AKT/mTOR pathway

Multiple myeloma (MM) is characterized by the proliferation of malignant plasma cells and a subsequent overabundance of monoclonal paraproteins (M proteins). Everolimus works similarly to sirolimus as a mammalian target of rapamycin (mTOR) inhibitor. Bortezomib was the first therapeutic proteasome inhibitor to be tested in humans with MM. However, the combination of these two drugs for the treatment of MM has been rarely reported. In this study, we compared the therapeutic effects of everolimus and bortezomib, as well as those of a combination of everolimus and bortezomib, using an in vitro MM cell line model and in vivo xenograft mouse model. Our results showed that the synergistic antitumor effects of everolimus and bortezomib have significant inhibitory effect through inhibition of the AKT/mTOR pathway in both the MM cell lines and MM-bearing mice model. Our results provided evidence that the mTOR inhibitor, everolimus, will be a potential drug in MM therapy.

Population pharmacokinetics-pharmacodynamics of oral everolimus in patients with seizures associated with tuberous sclerosis complex

Everolimus is approved in Europe and in the USA for the adjunctive treatment of patients aged 2 years and older whose refractory partial-onset seizures, with or without secondary generalization, are associated with tuberous sclerosis complex. The objective of this analysis was to establish a population pharmacokinetic (PK)/pharmacodynamic model describing the relationship between seizure frequency and everolimus exposure to confirm the recommended target concentration range of 5-15 ng/mL. The PK model was a two-compartment model with first order absorption and clearance. CYP3A and P-gp inducers and body-surface area were shown to impact everolimus exposure, justifying dose adjustments. A Poisson distribution was found to adequately describe the random nature of daily seizure counts during the screening phase. A placebo effect on the Poisson seizure mean was implemented as an asymptotic exponential function of time leading to a new steady-state seizure mean. The everolimus effect was implemented as an inhibitory E_max function of C_min on the seizure mean, where E_max exhibited an asymptotic exponential increase over time to a higher steady-state value. Increasing age was found to decrease the baseline seizure mean and to prolong the half-life of the increase in E_max. The dependence of seizure frequencies on C_min was explored by simulation. The responder rate increased with increasing C_min. As C_min decreased below 5 ng/mL, variability in response became larger and responder rates decreased more rapidly. The results supported the recommended target concentration range for everolimus of 5-15 ng/mL to ensure treatment efficacy.

LCCC 1025: a phase II study of everolimus, trastuzumab, and vinorelbine to treat progressive HER2-positive breast cancer brain metastases

PURPOSE

HER2 + breast cancer (BC) is an aggressive subtype with high rates of brain metastases (BCBM). Two-thirds of HER2 + BCBM demonstrate activation of the PI3K/mTOR pathway driving resistance to anti-HER2 therapy. This phase II study evaluated everolimus (E), a brain-permeable mTOR inhibitor, trastuzumab (T), and vinorelbine (V) in patients with HER2 + BCBM.

PATIENTS AND METHODS

Eligible patients had progressive HER2 + BCBM. The primary endpoint was intracranial response rate (RR); secondary objectives were CNS clinical benefit rate (CBR), extracranial RR, time to progression (TTP), overall survival (OS), and targeted sequencing of tumors from enrolled patients. A two-stage design distinguished intracranial RR of 5% versus 20%.

RESULTS

32 patients were evaluable for toxicity, 26 for efficacy. Intracranial RR was 4% (1 PR). CNS CBR at 6 mos was 27%; at 3 mos 65%. Median intracranial TTP was 3.9 mos (95% CI 2.2-5). OS was 12.2 mos (95% CI 0.6-20.2). Grade 3-4 toxicities included neutropenia (41%), anemia (16%), and stomatitis (16%). Mutations in TP53 and PIK3CA were common in BCBM. Mutations in the PI3K/mTOR pathway were not associated with response. ERBB2 amplification was higher in BCBM compared to primary BC; ERBB2 amplification in the primary BC trended toward worse OS.

CONCLUSION

While intracranial RR to ETV was low in HER2 + BCBM patients, one-third achieved CNS CBR; TTP/OS was similar to historical control. No new toxicity signals were observed. Further analysis of the genomic underpinnings of BCBM to identify tractable prognostic and/or predictive biomarkers is warranted.

CLINICAL TRIAL

(NCT01305941).

Tuberous sclerosis complex: review based on new diagnostic criteria

Tuberous sclerosis complex is a multisystemic, autosomal dominant genetic disorder with complete penetrance, that can evolve with hamartomas in multiple organs, such as skin, central nervous system, kidney and lung. Due to the wide phenotypic variability, the disease is often not recognized. Tuberous sclerosis complex affects one in 10,000 newborns and most patients are diagnosed during the first 15 months of life. The diagnostic criteria for tuberous sclerosis were reviewed in 2012, at the second International Tuberous Sclerosis Complex Consensus Conference. The diagnosis is based on genetic criteria, by the identification of inactivating pathogenic mutation of tumor suppressor genes TSC1 and TSC2, and clinical criteria, including cutaneous, renal, pulmonary, cardiac and neurological manifestations. The treatment of tuberous sclerosis complex consists, mainly, in management of the symptoms caused by hamartomas and in prevention of organ failure. Multidisciplinary approach is recommended, in order to obtain better clinical outcomes.

Tuberous sclerosis complex: Concerns and needs of patients and parents from the transitional period to adulthood

INTRODUCTION

Transitioning into adulthood and from pediatric services to adult healthcare are both challenging processes for young adults with rare chronic disorders such as tuberous sclerosis complex (TSC) and their parents. Adult healthcare systems are often less family-oriented and lack multidisciplinary care and experience with TSC, which can result in increased health risks and morbidity. Patient-driven data on care needs are necessary to optimize support for this vulnerable patient group.

AIM

The aim of this study was to explore the concerns and care needs of young adult patients with TSC in medical, psychological, and socioeconomical domains.

METHOD

A qualitative study was performed using semistructured interviews with 16 patients (median age: 21years; range: 17 to 30) and 12 parents. Concerns and care needs were organized using the International Classification of Functioning, Disability, and Health (ICF).

RESULTS

Main concerns involved mental and physical health, participation, self-management skills, family planning, and side effects of medications. Patients expressed the need for multidisciplinary care that is well-informed, easily accessible, and focused on the patient as a whole, including his/her family. Parents reported high stress levels.

CONCLUSION

The current study provides patient-driven information, allowing recommendations to facilitate the (transition of) care for young adults with TSC. In addition to seizures, tumor growth, and TSC-associated neuropsychiatric disorders (TAND), more attention is needed for concerns and care needs specific to the transitional period, participation, and environmental factors. Adult healthcare providers should offer expert multidisciplinary care for adult patients with TSC, including attention for parental stress.

The mTOR pathway in treatment of epilepsy: a clinical update

Nearly a third of patients with epilepsy have seizures refractory to current medical therapies. In the search for novel drug targets, the mTOR pathway has emerged as key in the regulation of neuronal function, growth and survival, and other cellular processes related to epileptogenesis. Hyperactivation of the mTOR pathway has been implicated in tuberous sclerosis complex and other 'mTORopathies', clinical syndromes associated with cortical developmental malformations and drug-resistant epilepsy. Recently published clinical trials of mTOR inhibitors in tuberous sclerosis complex have shown that these drugs are effective at decreasing seizure frequency. Future studies may establish whether mTOR inhibitors can provide effective treatment for patients with diverse genetic and acquired epilepsies, including preventative, disease-modifying therapies.

Adjunctive everolimus for children and adolescents with treatment-refractory seizures associated with tuberous sclerosis complex: post-hoc analysis of the phase 3 EXIST-3 trial

BACKGROUND

Epilepsy occurs in 70-90% of patients with tuberous sclerosis complex. We aimed to assess the efficacy and safety of adjunctive everolimus for treatment-refractory seizures associated with tuberous sclerosis complex in paediatric patients enrolled in the EXIST-3 trial, a double-blind, placebo-controlled, randomised, phase 3 study.

METHODS

This post-hoc analysis focused on paediatric patients (age <18 years) in the EXIST-3 trial, which consisted of baseline (8 weeks), core (18 weeks), and extension phases (≥48 weeks) and was done at 99 centres in 25 countries worldwide. Briefly, patients with tuberous sclerosis complex-associated treatment-refractory seizures, who were receiving a stable dose of one to three antiepileptic drugs, were randomly assigned (1:1:1) to receive placebo, low-exposure everolimus (3-7 ng/mL), or high-exposure everolimus (9-15 ng/mL). Following the core phase, patients could enter the extension phase to receive everolimus at a targeted exposure range of 3-15 ng/mL up to 48 weeks after the last patient had completed the core phase. Efficacy endpoints were response rate (≥50% of reduction from baseline in average weekly seizure frequency) and median percentage reduction in seizure frequency during the 12-week maintenance period of the core phase, and at 12-week intervals throughout the extension phase. This study is registered with ClinicalTrials.gov, number NCT01713946.

FINDINGS

Between July 3, 2013, and May 29, 2015, 299 paediatric patients enrolled in the trial. In the younger subgroup (<6 years; n=104), 34 received placebo, 33 low-exposure everolimus, and 37 high-exposure everolimus; in the older subgroup (≥6 years to <18 years; n=195), 62 received placebo, 63 low-exposure everolimus, and 70 high-exposure everolimus. At the end of the core phase, response rate was higher in the treatment groups than placebo in both the younger subgroup (17·6% [6·8-34·5] for placebo vs 30·3% [95% CI 15·6-48·7; p=0·2245] for low-exposure everolimus vs 59·5% [42·1-75·2; p=0·0003] for high-exposure everolimus) and the older subgroup (12·9% [5·7-23·9] vs 27·0% [16·6-39·7; p=0·0491] vs 30·0% [19·6-42·1; p=0·0179]), as were median reduction in seizure frequency (12·3% [95% CI -10·1 to 24·8] vs 29·3% [95% CI 13·4 to 46·3; p=0·0474] vs 54·7% [43·5 to 73·1; p<0·0001] in younger patients; 13·5% [-3·0 to 26·8] vs 31·0% [16·1 to 42·9; p=0·0128] vs 34·8% [26·7 to 41·3; p=0·0006] in older patients). The efficacy persisted, with sustained seizure reduction after 1 year of treatment across both paediatric subgroups (response rate 48·9% [95% CI 38·1-59·8] for the younger subgroup vs 47·2% [39·3-55·2] for the older subgroup; median percentage reduction in seizure frequency 48·4% [95% CI 34·3-73·6] vs 48·0% [38·2-57·5]). At the cutoff date for the extension phase, grade 3 or 4 adverse events were reported in 45 (45%) younger patients (commonly pneumonia [n=16]) and 74 (38%) older patients (commonly pneumonia [n=8] and stomatitis [n=6]). Two deaths (pneumonia, which was suspected to be treatment-related, and sudden unexplained death due to epilepsy) were reported.

INTERPRETATION

Adjunctive everolimus resulted in sustained reductions in seizure frequency after 1 year and was well tolerated in paediatric patients with treatment-refractory seizures associated with tuberous sclerosis complex.

FUNDING

Novartis Pharmaceuticals Corporation.

Mechanisms and Therapy for Cancer Metastasis to the Brain

Advances in chemotherapy and targeted therapies have improved survival in cancer patients with an increase of the incidence of newly diagnosed brain metastases (BMs). Intracranial metastases are symptomatic in 60–70% of patients. Magnetic resonance imaging (MRI) with gadolinium is more sensitive than computed tomography and advanced neuroimaging techniques have been increasingly used in the detection, treatment planning, and follow-up of BM. Apart from the morphological analysis, the most effective tool for characterizing BM is immunohistochemistry. Molecular alterations not always reflect those of the primary tumor. More sophisticated methods of tumor analysis detecting circulating biomarkers in fluids (liquid biopsy), including circulating DNA, circulating tumor cells, and extracellular vesicles, containing tumor DNA and macromolecules (microRNA), have shown promise regarding tumor treatment response and progression. The choice of therapeutic approaches is guided by prognostic scores (Recursive Partitioning Analysis and diagnostic-specific Graded Prognostic Assessment-DS-GPA). The survival benefit of surgical resection seems limited to the subgroup of patients with controlled systemic disease and good performance status. Leptomeningeal disease (LMD) can be a complication, especially in posterior fossa metastases undergoing a “piecemeal” resection. Radiosurgery of the resection cavity may offer comparable survival and local control as postoperative whole-brain radiotherapy (WBRT). WBRT alone is now the treatment of choice only for patients with single or multiple BMs not amenable to surgery or radiosurgery, or with poor prognostic factors. To reduce the neurocognitive sequelae of WBRT intensity modulated radiotherapy with hippocampal sparing, and pharmacological approaches (memantine and donepezil) have been investigated. In the last decade, a multitude of molecular abnormalities have been discovered. Approximately 33% of patients with non-small cell lung cancer (NSCLC) tumors and epidermal growth factor receptor mutations develop BMs, which are targetable with different generations of tyrosine kinase inhibitors (TKIs: gefitinib, erlotinib, afatinib, icotinib, and osimertinib). Other “druggable” alterations seen in up to 5% of NSCLC patients are the rearrangements of the “anaplastic lymphoma kinase” gene TKI (crizotinib, ceritinib, alectinib, brigatinib, and lorlatinib). In human epidermal growth factor receptor 2-positive, breast cancer targeted therapies have been widely used (trastuzumab, trastuzumab-emtansine, lapatinib-capecitabine, and neratinib). Novel targeted and immunotherapeutic agents have also revolutionized the systemic management of melanoma (ipilimumab, nivolumab, pembrolizumab, and BRAF inhibitors dabrafenib and vemurafenib).

mTOR Signaling and Neural Stem Cells: The Tuberous Sclerosis Complex Model

The mechanistic target of rapamycin (mTOR), a serine-threonine kinase, plays a pivotal role in regulating cell growth and proliferation. Notably, a great deal of evidence indicates that mTOR signaling is also crucial in controlling proliferation and differentiation of several stem cell compartments. Consequently, dysregulation of the mTOR pathway is often associated with a variety of disease, such as cancer and metabolic and genetic disorders. For instance, hyperactivation of mTORC1 in neural stem cells (NSCs) is associated with the insurgence of neurological manifestation characterizing tuberous sclerosis complex (TSC). In this review, we survey the recent contributions of TSC physiopathology studies to understand the role of mTOR signaling in both neurogenesis and tumorigenesis and discuss how these new insights can contribute to developing new therapeutic strategies for neurological diseases and cancer.

Everolimus dosing recommendations for tuberous sclerosis complex-associated refractory seizures

Objective

The present analysis examined the exposure‐response relationship by means of the predose everolimus concentration (C_min) and the seizure response in patients with tuberous sclerosis complex–associated seizures in the EXIST‐3 study. Recommendations have been made for the target C_min range of everolimus for therapeutic drug monitoring (TDM) and the doses necessary to achieve this target C_min.

Methods

A model‐based approach was used to predict patients' daily C_min. Time‐normalized C_min (TN‐C_min) was calculated as the average predicted C_min in a time interval. TN‐C_min was used to link exposure to efficacy and safety end points via model‐based approaches. A conditional logistic regression stratified by age subgroup was used to estimate the probability of response in relation to exposure. A multiplicative linear regression model was used to estimate the exposure‐response relationship for seizure frequency (SF). An extended Cox regression model was used to link exposure to the time to first adverse event.

Results

There was a strong, consistent, and highly significant relationship between everolimus exposure and efficacy, measured by TN‐C_min and SF, regardless of patient's age and concomitant use of cytochrome P450 3A4 (CYP3A4) inhibitors/inducers. Results of an extended Cox regression analyses indicated that twofold increases in TN‐C_min were not associated with statistically significant increases in the risk of stomatitis or infections.

Significance

The recommended TDM is to target everolimus C_min within a range of 5‐7 ng/mL initially and 5‐15 ng/mL in the event of an inadequate clinical response, and safety is consistent with previous reports. Starting doses depend on age and the concomitant use of CYP3A4/P‐glycoprotein inducers/inhibitors.

Efficacy and safety of everolimus in patients younger than 12 months with congenital subependymal giant cell astrocytoma

Tuberous sclerosis complex (TSC) is a multisystem genetic disorder that activates mammalian target of rapamycin and produces tumor growth in several organs. We present five patients younger than 12 months who were diagnosed with TSC and treated with everolimus (EVL), after which congenital subependymal giant astrocytoma (cSEGA) promptly regressed in all patients. All patients achieved at least 50% reduction in the volume of cSEGA within 6 months. The most rapid reduction of cSEGA volume (79.1%) was found during the initial 3 months of EVL treatment. Patients underwent EVL treatment for an average of 27 months (range: 4-55 months). Mean EVL maintenance dose was 1.35 mg per day. EVL blood trough concentrations ranged from 2.0 to 11.7 ng/ml. The cSEGA became larger after discontinuing EVL in two patients. In all four patients who had multiple cardiac rhabdomyomas (CRMs), the CRMs showed accelerated regression after receiving EVL. Adverse events were noted in four patients: infection, stomatitis, and increased triglycerides. Four patients had febrile status epilepticus, which occurred during acute encephalopathy in a patient, and after discontinuing EVL in another. Three patients were still receiving EVL at their latest evaluations. Maintenance therapy with EVL is an effective therapeutic option for patients with cSEGA, and moreover may have additional favorable effects on other complications, even in early infancy; however, adverse effects should be carefully monitored.

TSC2-deficient tumors have evidence of T cell exhaustion and respond to anti-PD-1/anti-CTLA-4 immunotherapy

Tuberous sclerosis complex (TSC) is an incurable multisystem disease characterized by mTORC1-hyperactive tumors. TSC1/2 mutations also occur in other neoplastic disorders, including lymphangioleiomyomatosis (LAM) and bladder cancer. Whether TSC-associated tumors will respond to immunotherapy is unknown. We report here that the programmed death 1 coinhibitory receptor (PD-1) is upregulated on T cells in renal angiomyolipomas (AML) and pulmonary lymphangioleiomyomatosis (LAM). In C57BL/6J mice injected with syngeneic TSC2-deficient cells, anti-PD-1 alone decreased 105K tumor growth by 67% (P < 0.0001); the combination of PD-1 and CTLA-4 blockade was even more effective in suppressing tumor growth. Anti-PD-1 induced complete rejection of TSC2-deficient 105K tumors in 37% of mice (P < 0.05). Double blockade of PD-1 and CTLA-4 induced rejection in 62% of mice (P < 0.01). TSC2 reexpression in TSC2-deficient TMKOC cells enhanced antitumor immunity by increasing T cell infiltration and production of IFN-γ/TNF-α by T cells, suggesting that TSC2 and mTORC1 play specific roles in the induction of antitumor immunity. Finally, 1 month of anti-PD-1 blockade reduced renal tumor burden by 53% (P < 0.01) in genetically engineered Tsc2+/- mice. Taken together, these data demonstrate for the first time to our knowledge that checkpoint blockade may have clinical efficacy for TSC and LAM, and possibly other benign tumor syndromes, potentially yielding complete and durable clinical responses.

Exceptional response to everolimus in a novel tuberous sclerosis complex-2 mutation-associated metastatic renal-cell carcinoma

Everolimus, an oral inhibitor of the mammalian target of rapamycin (mTOR) pathway, is currently approved for treatment of advanced renal-cell carcinoma (RCC) after failure of initial treatment with the tyrosine kinase inhibitors. Patients with tuberous sclerosis complex (TSC) syndrome can also develop RCC primarily mediated through mTOR signaling. However, the efficacy and duration of response of mTOR inhibition in patients with TSC-associated RCC is not well known. Herein, we describe a case of a patient with TSC2-associated metastatic RCC with mutations H1620R and Y1650C who has had an exceptional response to everolimus in the frontline setting and continues to derive benefit from mTOR inhibition 2 yr into therapy. Furthermore, the alteration H1620R in exon 37 resulting in a missense mutation is likely deleterious given our findings and previous analyses of the TSC2 gene. Further studies of somatic mutations in extended responders to mTOR inhibitors will help personalize therapy for these patients. It also emphasizes the value of targeted therapies based on genomic analyses.

Everolimus as cancer therapy: Cardiotoxic or an unexpected antiatherogenic agent? A narrative review

Everolimus (EVE) is now approved by many agencies for the treatment of variable neoplasms. The risk for adverse events with this agent is not adequately defined. The purpose of this review is to summarize the EVE-induced cardiotoxic effect as an antineoplastic factor on patients who received the specific drug and to evaluate any possible antiatherogenic effects due to systemic use of the drug. Articles were searched on PubMed until August 2017. Articles included an expanded-access clinical trial, as well as phase 2 or 3 clinical trials (most of them were randomized). Three experimental studies that provided evidence for the possible antiatherogenic action of EVE were also included. In addition, only studies that evaluated the systemic use of the drug were included. To be eligible for inclusion, trials should have evaluated patients with malignancy, treated by EVE, or assessed the antiatherogenic effect of the systemic use of EVE through clinical or experimental studies. Only articles written in English language were included. No direct cardiotoxic adverse effects (arrhythmia, acute coronary event, heart failure, and echocardiography pathologic findings) were reported. Patients appeared to have a risk of developing adverse events that could be associated with the risk factors of cardiovascular disease. In all clinical studies, patients suffered hyperglycemia, and in most of them, hyperlipidemia was observed. Fewer studies have reported the incidence of hypertension. Finally, there is evidence claiming that EVE has an antiatherogenic action. Three experimental studies have shown that the systemic use of EVE in mice or rabbits with atherosclerotic lesions led to the reduction in atheromatous plaque growth. However, we could not find any clinical study that showed similar results in patients with cancer. To sum up, the only reported cardiac adverse event of EVE treatment in patients with cancer is indirect. They are associated with the risk factors of cardiovascular disease (hyperglycemia, hyperlipidemia, and hypertension), which are mainly mild and easily manageable. Further research and data that support the antiatherogenic action of EVE are needed.

Assessing the outcomes of everolimus on renal angiomyolipoma associated with tuberous sclerosis complex in China: a two years trial

Background

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder characterized by the development of numerous benign tumors. Renal angiomyolipoma (RAML) occur in up to 80% of TSC patients, which is a leading cause of TSC-related death in adult patients. The aim of the study was to evaluate the efficacy and safety profiles of everolimus in Chinese patients of TSC associated with RAML(TSC-RAML).

Methods

In this 2-years, nonrandomized, open-label trial, 18 patients of TSC-RAML, with at least one RAML 3 cm or larger in its longest diameter, were enrolled to assess the efficacy and safety of everolimus therapy in Chinese patients. Everolimus was administered for the first 12 months only. The primary endpoint was a reduction of 50% or more relative in RAML volume to the baseline in the absence of new RAML ≥1 cm and no RAML-related bleeding of grade ≥ 2. The secondary endpoints included: safety, lung function and skin lesions response rate. Serial computed tomography of RAML, magnetic resonance imaging of brain lesions and pulmonary-function tests were performed. Adverse events were investigated using CTCAE v4.0. All analyses used a significance level of 0.05 and were generated in SPSS19.0 software.

Results

The proportion of patients who achieved ≥50% reduction from baseline in the sum of volumes of target lesions increased from 52.94% at 3 months, to 58.82% and 66.67% at months 6 and 12, respectively. During the period of everolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 s (FEV1) increased by 276 ± 78 ml (P < 0.001), the forced vital capacity (FVC) increased by 433 ± 170 ml (P < 0.001), and the residual volume decreased by 408 ± 243 ml (P = 0.009), as compared with baseline values. The angiomyolipoma volume and the lung function approached, but did not completely return to, the baseline values. The skin lesions response rate was 37.5% after 12 months of therapy falling to 21.4% at 12 months after stopping everolimus. The most common adverse events were mucositis oral, irregular menstruation, abdominal pain, hypertriglyceridemia and headache. The most common grade 3 adverse events were irregular menstruation and mucositis oral. In addition, one patient died from RAML spontaneous haemorrhage during treatment with everolimus, even with reduction in RAML volume of 60.68% at 3 months. A second death was due to epithelioid RAML progression, with metastasis to multiple retroperitoneal lymph node, who died from severe infection one month after surgery.

Conclusions

Angiomyolipomas regressed somewhat during everolimus therapy but tended to increase in volume after the therapy was stopped. Everolimus was well tolerated and showed promising activity in Chinese patients with TSC-RAML, however, we should alert the life-threatening hemorrhage of large RAML in the early period and the lymph node metastasis of epithelioid RAML.

Trial registration

ChiCTR-OPC-14005488. Registered November 17, 2014.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0781-y) contains supplementary material, which is available to authorized users.

Efficacy and Safety of Mammalian Target of Rapamycin Inhibitor Use-Long-term Follow-up of First Tuberous Sclerosis Complex Patient Treated De Novo With Sirolimus After Kidney Transplantation: A Case Report

Mammalian target of rapamycin inhibitors (mTORI) are increasingly used in the treatment of tuberous sclerosis complex (TSC) and as immunosuppressants after organ transplantation. In TSC patients, mTORI are the treatment of choice after kidney transplantation. It is still under debate if benefits from long-term mTORI use will not be limited by side effects.

MATERIALS AND METHODS

We report long-term follow-up data of the first TSC patient after kidney transplantation treated with sirolimus de novo. In 2005, a female patient was transplanted with a kidney graft after bilateral nephrectomy due to angiomyolipoma. Initial immunosuppressive treatment consisted of antithymocyte globulin, methylprednisolone, tacrolimus, and, due to TSC diagnosis, sirolimus. Creatinine level at discharge was 1.2 mg/dL.

RESULTS

Long-term mTORI use resulted in skin lesion regression (angiofibromas, "confetti" skin lesions, shagreen patch) and disease stabilization in brain, abdominal, and chest magnetic resonance imaging/computed tomography scans. Pulmonary function tests showed improvement in restriction and slow deterioration in obstruction and diffusion parameters. Sirolimus related adverse reactions were hyperlipidemia and hypertriglyceridemia and respiratory and urinary tract infections. No gastrointestinal or hematologic symptoms occurred. Sirolimus concentrations ranged between 1.7 and 8.2 ng/mL (mean 4.01 ± 2.09 ng/mL). Since 2009 proteinuria and slow increase in creatinine level have been observed. No biopsy was performed to establish etiology and potential association with mTORI. In 2017 creatinine level was 2.2 mg/dL.

CONCLUSION

The case of the patient confirms clinical effectiveness and acceptable safety of long-term mTORI treatment. Long-term mTORI use requires meticulous patient observation to optimize dosage, achieve immunosuppressive effect, and improve TSC manifestations with minimal side effects.

Drug discovery targeting the mTOR pathway

Mechanistic target of rapamycin (mTOR) is the kinase subunit of two structurally and functionally distinct large multiprotein complexes, referred to as mTOR complex 1 (mTORC1) and mTORC2. mTORC1 and mTORC2 play key physiological roles as they control anabolic and catabolic processes in response to external cues in a variety of tissues and organs. However, mTORC1 and mTORC2 activities are deregulated in widespread human diseases, including cancer. Cancer cells take advantage of mTOR oncogenic signaling to drive their proliferation, survival, metabolic transformation, and metastatic potential. Therefore, mTOR lends itself very well as a therapeutic target for innovative cancer treatment. mTOR was initially identified as the target of the antibiotic rapamycin that displayed remarkable antitumor activity in vitro Promising preclinical studies using rapamycin and its derivatives (rapalogs) demonstrated efficacy in many human cancer types, hence supporting the launch of numerous clinical trials aimed to evaluate the real effectiveness of mTOR-targeted therapies. However, rapamycin and rapalogs have shown very limited activity in most clinical contexts, also when combined with other drugs. Thus, novel classes of mTOR inhibitors with a stronger antineoplastic potency have been developed. Nevertheless, emerging clinical data suggest that also these novel mTOR-targeting drugs may have a weak antitumor activity. Here, we summarize the current status of available mTOR inhibitors and highlight the most relevant results from both preclinical and clinical studies that have provided valuable insights into both their efficacy and failure.

Targeting the PI3K pathway in cancer: are we making headway?

The PI3K-AKT-mTOR pathway is one of the most frequently dysregulated pathways in cancer and, consequently, more than 40 compounds that target key components of this signalling network have been tested in clinical trials involving patients with a range of different cancers. The clinical development of many of these agents, however, has not advanced to late-phase randomized trials, and the antitumour activity of those that have been evaluated in comparative prospective studies has typically been limited, or toxicities were found to be prohibitive. Nevertheless, the mTOR inhibitors temsirolimus and everolimus and the PI3K inhibitors idelalisib and copanlisib have been approved by the FDA for clinical use in the treatment of a number of different cancers. Novel compounds with greater potency and selectivity, as well as improved therapeutic indices owing to reduced risks of toxicity, are clearly required. In addition, biomarkers that are predictive of a response, such as PIK3CA mutations for inhibitors of the PI3K catalytic subunit α isoform, must be identified and analytically and clinically validated. Finally, considering that oncogenic activation of the PI3K-AKT-mTOR pathway often occurs alongside pro-tumorigenic aberrations in other signalling networks, rational combinations are also needed to optimize the effectiveness of treatment. Herein, we review the current experience with anticancer therapies that target the PI3K-AKT-mTOR pathway.

Rapid regression of large cardiac rhabdomyomas in neonates after sirolimus therapy

Cardiac rhabdomyomas are the most common tumours in children and are typically seen in association with the tuberous sclerosis complex. Although benign and often associated with spontaneous regression, in rare circumstances surgical resection is indicated to relieve obstruction or other mass-related effects. Recent clinical trials have demonstrated the benefits of mammalian target of rapamycin inhibitors for the treatment of other tumour sub-types associated with tuberous sclerosis. Here we report rapid regression of several massive cardiac rhadomyomas in two neonates with the use of the mammalian target of rapamycin inhibitor sirolimus.

Safety and efficacy of temsirolimus as second line treatment for patients with recurrent bladder cancer

BACKGROUND

Bladder cancer is the 7th cause of death from cancer in men and 10th in women. Metastatic patients have a poor prognosis with a median overall survival of 14 months. Until recently, vinflunine was the only second-line chemotherapy available for patients who relapse. Deregulation of the PI3K/AKT/mTOR pathway was observed in more than 40% of bladder tumors and suggested the use of mTOR as a target for the treatment of urothelial cancers.

METHODS

This trial assessed the efficacy of temsirolimus in a homogenous cohort of patients with recurrent or metastatic bladder cancer following first-line chemotherapy. Efficacy was measured in terms of non-progression at two months according to the RECIST v1.1 criteria. Based on a two-stage optimal Simon's design, 15 non-progressions out of 51 evaluable patients were required to claim efficacy. Patients were treated at a weekly dose of 25 mg IV until progression, unacceptable toxicities or withdrawal.

RESULTS

Among the 54 patients enrolled in the study between November 2009 and July 2014, 45 were assessable for the primary efficacy endpoint. A total of 22 (48.9%) non-progressions were observed at 2 months with 3 partial responses and 19 stable diseases. Remarkably, 4 patients were treated for more than 30 weeks. Fifty patients experienced at least a related grade1/2 (94%) and twenty-eight patients (52.8%) a related grade 3/4 adverse event. Eleven patients had to stop treatment for toxicity. This led to recruitment being halted by an independent data monitoring committee with regard to the risk-benefit balance and the fact that the primary objective was already met.

CONCLUSIONS

While the positivity of this trial indicates a potential benefit of temsirolimus for a subset of bladder cancer patients who are refractory to first line platinum-based chemotherapy, the risk of adverse events associated with the use of this mTOR inhibitor would need to be considered when such an option is envisaged in this frail population of patients. It also remains to identify patients who will benefit the most from this targeted therapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01827943 (trial registration date: October 29, 2012); Retrospectively registered.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Intracellular signaling pathways: tyrosine kinase and mTOR inhibitors)

BACKGROUND

The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biologic therapies.

AIMS

To review, from an infectious diseases perspective, the safety profile of therapies targeting different intracellular signaling pathways and to suggest preventive recommendations.

SOURCES

Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family.

CONTENT

Although BCR-ABL tyrosine kinase inhibitors modestly increase the overall risk of infection, dasatinib has been associated with cytomegalovirus and hepatitis B virus reactivation. BRAF/MEK kinase inhibitors do not significantly affect infection susceptibility. The effect of Bruton tyrosine kinase inhibitors (ibrutinib) among patients with B-cell malignancies is difficult to distinguish from that of previous immunosuppression. However, cases of Pneumocystis jirovecii pneumonia (PCP), invasive fungal infection and progressive multifocal leukoencephalopathy have been occasionally reported. Because phosphatidylinositol-3-kinase inhibitors (idelalisib) may predispose to opportunistic infections, anti-Pneumocystis prophylaxis and prevention strategies for cytomegalovirus are recommended. No increased rates of infection have been observed with venetoclax (antiapoptotic protein Bcl-2 inhibitor). Therapy with Janus kinase inhibitors markedly increases the incidence of infection. Pretreatment screening for chronic hepatitis B virus and latent tuberculosis infection must be performed, and anti-Pneumocystis prophylaxis should be considered for patients with additional risk factors. Cancer patients receiving mTOR inhibitors face an increased incidence of overall infection, especially those with additional risk factors (prior therapies or delayed wound healing).

IMPLICATIONS

Specific preventive approaches are warranted in view of the increased risk of infection associated with some of the reviewed agents.

Retinal astrocytoma regression in tuberous sclerosis patients treated with everolimus

Everolimus is an inhibitor of the mammalian target of rapamycin (mTOR) that has been approved by the US Food and Drug Administration for the treatment of subependymal giant cell astrocytoma (SEGA) in patients with tuberous sclerosis complex (TSC). Retinal hamartomas, which are one of the major diagnostic features of TSC, tend to remain stable or gradually progress in the natural history of the disease. We report 2 patients with TSC treated with everolimus for SEGA in whom fundus photographs and spectral domain optical coherence tomography demonstrated regression of previously documented multiple retinal hamartomas in all 4 eyes.

Precision Medicine in Pediatric Neurooncology: A Review

Central nervous system tumors are the leading cause of cancer related death in children. Despite much progress in the field of pediatric neurooncology, modern combination treatment regimens often result in significant late effects, such as neurocognitive deficits, endocrine dysfunction, secondary malignancies, and a host of other chronic health problems. Precision medicine strategies applied to pediatric neurooncology target specific characteristics of individual patients' tumors to achieve maximal killing of neoplastic cells while minimizing unwanted adverse effects. Here, we review emerging trends and the current literature that have guided the development of new molecularly based classification schemas, promising diagnostic techniques, targeted therapies, and delivery platforms for the treatment of pediatric central nervous system tumors.

TFEB activation restores migration ability to Tsc1-deficient adult neural stem/progenitor cells

Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by mutations in either of two genes, TSC1 or TSC2, resulting in the constitutive activation of the mammalian target of rapamycin complex 1 (mTORC1). mTOR inhibitors are now considered the treatment of choice for TSC disease. A major pathological feature of TSC is the development of subependymal giant cell astrocytomas (SEGAs) in the brain. Nowadays, it is thought that SEGAs could be a consequence of aberrant aggregation and migration of neural stem/progenitor cells (NSPCs). Therefore, reactivation of cell migration of NSPCs might be the crucial step for the treatment of patients. In order to identify potential in vitro targets activating migration, we generated Tsc1-deficient NSPCs. These cells summarize most of the biochemical and morphological characteristics of TSC neural cells, such as the mTORC1 activation, the formation of abnormally enlarged astrocytes-like cells, the reduction of autophagy flux and the impairment of cell migration. Moreover, nuclear translocation, namely activation of the transcription factor EB (TFEB) was markedly impaired. Herein, we show that compounds such as everolimus, ionomycin and curcumin, which directly or indirectly stimulate TFEB nuclear translocation, restore Tsc1-deficient NSPC migration. Our data suggest that reduction of TFEB activation, caused by mTORC1 hyperactivation, contributes to the migration deficit characterizing Tsc1-deficient NSPCs. The present work highlights TFEB as a druggable protein target for SEGAs therapy, which can be additionally or alternatively exploited for the mTORC1-directed inhibitory approach.