Is mTOR inhibition a systemic treatment for tuberous sclerosis?

A Case Report of Pediatric Patient with Tuberous Sclerosis and Radiologically Isolated Syndrome

INTRODUCTION

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous disease with central nervous system (CNS) involvement. Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the CNS characterized by symptomatic episodes that occur months or years apart and affect different anatomic locations. In the absence of symptomatic episodes, radiologically isolated syndrome (RIS) could be diagnosed. Here, we report the case of a 10-year-old boy followed-up for TSC and diagnosed with RIS after a routine neuroimaging assessment.

CASE DESCRIPTION

The patient was diagnosed with TSC after seizure onset at the age of 4 years. The follow-up magnetic resonance imaging (MRI) showed multiple asymptomatic demyelinating lesions. Brain and spinal cord MRI was performed after 2 months and showed additional lesions in the right frontal white matter and left cerebral peduncle, the latter with contrast enhancement. Therefore, he received a diagnosis of RIS. Visual evoked potentials were normal. Cerebrospinal fluid examination showed oligoclonal bands. The search for AQP4-IgG and MOG-IgG antibodies was negative. He was treated with interferon beta-1a. Six months later, follow-up MRI revealed no new demyelinating lesions and resolution of contrast enhancement.

CONCLUSION

To the best of our knowledge, this is the third reported patient presenting a co-occurrence of TSC and demyelinating disease. Although we cannot state if the described comorbidity is casual or not, some clinical and preclinical data suggest that the mTOR complex might be the link between TSC and demyelinating disease.

Subependymal Giant Cell Astrocytomas in Tuberous Sclerosis Complex-Current Views on Their Pathogenesis and Management

Introduction, Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder caused by mutations inactivating TSC1 or TSC2 genes and characterized by the presence of tumors involving many organs, including the brain, heart, kidneys, and skin. Subependymal giant cell astrocytoma (SEGA) is a slow-growing brain tumor almost exclusively associated with TSC.

STATE OF THE ART

Despite the fact that SEGAs are benign, they require well-considered decisions regarding the timing and modality of pharmacological or surgical treatment. In TSC children and adolescents, SEGA is the major cause of mortality and morbidity.

CLINICAL IMPLICATIONS

Until recently, surgical resection has been the standard therapy for SEGAs but the discovery of the role of the mTOR pathway and the introduction of mTOR inhibitors to clinical practice changed the therapeutic landscape of these tumors. In the current paper, we discuss the pros and cons of mTOR inhibitors and surgical approaches in SEGA treatment.

FUTURE DIRECTIONS

In 2021, the International Tuberous Sclerosis Complex Consensus Group proposed a new integrative strategy for SEGA management. In the following review, we discuss the proposed recommendations and report the results of the literature search for the latest treatment directions.

Sirolimus relieves seizures and neuropsychiatric symptoms via changes of microglial polarity in tuberous sclerosis complex model mice

Tuberous sclerosis complex (TSC) is a genetic disorder involving a variety of physical manifestations, and is associated with epilepsy and multiple serious neuropsychiatric symptoms. These symptoms are collectively known as TSC-associated neuropsychiatric disorders (TAND), which is a severe burden for patients and their families. Overactivation of the mechanistic target of rapamycin complex 1 (mTORC1) by mutations in TSC1 or TSC2 is thought to cause TSC, and mTORC1 inhibitors such as sirolimus and everolimus are reported to be effective against various tumor types of TSC. However, there are various reports on the effect of mTORC1 inhibitor therapy on TAND in patients with TSC, which may or may not be effective. In our previous investigations, we generated TSC2 conditional knockout mice (Mitf-Cre, Tsc2 KO; Tsc2 cKO). These mice developed spontaneous epileptic activity. In the current study, we further analyzed the detailed behaviors of Tsc2 cKO mice and confirmed that they exhibited phenotypes of TAND as well as epileptic seizures, indicating that Tsc2 cKO mice are a useful model for TAND. Furthermore, the olfactory bulb and piriform cortex caused epilepsy and TAND in Tsc2 cKO mice, and neurodegeneration was observed. Immunohistology and immunophenotypic analysis of cells, and quantitative RT-PCR suggested that changes in microglial polarity were involved in the onset of TSC epilepsy and neuropsychiatric symptoms. Although the effect of mTORC1 inhibitors on TAND has not been established, the results of this study might help elucidate the mechanism of TAND pathogenesis and suggest that sirolimus may be a valuable therapeutic tool for TAND.

An Anomaly with Potential as a New Prognostic Marker in CLL with del(13q): Gain of 16p13.3

Deletion 13q [del(13q)] is a favorable prognostic marker if it is detected as a sole abnormality in chronic lymphocytic leukemia (CLL). However the clinical courses of cases with isolated del(13q) are quite heterogeneous. In our study, we investigated copy number variations (CNVs), loss of heterozygosity (LOH), and the size of del(13q) in 30 CLL patients with isolated del(13q). We used CGH+SNP microarrays in order to understand the cause of this clinical heterogeneity. We detected del(13q) in 28/30 CLL cases. The size of the deletion varied from 0.34 to 28.81 Mb, and there was no clinical effect of the deletion size. We found new prognostic markers, especially the gain of 16p13.3. These markers have statistically significant associations with short time to first treatment and advanced disease stage. Detecting both CNVs and LOH at the same time is an advantageous feature of aCGH+SNP. However, it is very challenging for the array analysis to detect mosaic anomalies. Therefore, it is very important to confirm the results by FISH. In our study, we detected approximately 9% mosaic del(13q) by microarray. In addition, the gain of 16p13.3 may affect the disease prognosis in CLL. However, additional studies with more patients are needed to confirm these results.

Everolimus for severe arrhythmias in tuberous sclerosis complex related cardiac rhabdomyomas

Intracardiac rhabdomyoma is the most common primary cardiac tumor in children. Most cases are associated with tuberous sclerosis complex (TSC). Most of them are asymptomatic in the neonate and do not require treatment. However, some develop cardiovascular symptoms such as arrhythmias, heart failure, and ventricular inflow/outflow tract obstruction in the neonatal period with early death. Many of these tumors are not candidates for surgical resection and medical management is limited. Treatment with mammalian target of rapamycin (mTOR) inhibitor is currently approved for the management of central nervous tumors and angiomyolipoma in TSC. Two patients with malignant arrhythmias related to nonsurgical multiple rhabdomyomas associated with TSC who were successfully treated with an mTOR inhibitor were described. Everolimus therapy showed significant regression of rhabdomyomas with rapid improvement of arrhythmias and heart failure prior to tumor shrinkage.

The Efficacy of Everolimus for Facial Angiofibromas in Tuberous Sclerosis Complex Patients Treated for Renal Angiomyolipoma/Subependymal Giant Cell Astrocytoma

BACKGROUND

Facial angiofibromas may be present since early childhood in individuals with tuberous sclerosis complex (TSC), causing substantial cosmetic disfigurement. Current therapies are partially effective, but they are uncomfortable, produce scarring, and are especially expensive.

OBJECTIVE

The aim of the present study was to evaluate the efficacy of oral everolimus for TSC-associated angiofibromas.

METHODS

This retrospective study included TSC patients being treated with oral everolimus for subependymal giant cell astrocytomas (SEGAs) and angiomyolipomas (AMLs). We recorded the changes in facial angiofibromas. Changes in the Angiofibroma Grading Scale (AGS) indicators were recorded according to erythema, average lesion size, lesion density, and percent involvement on the forehead, nose, cheeks, and chin. The scores were recorded before and after the administration of oral everolimus.

RESULTS

Twenty-one patients being treated with oral everolimus were enrolled in this study. The mean age was 20.5 years (range 11-44 years, 4 males, and 17 females). The mean dose of oral everolimus was 3.6 mg/day. Clinically meaningful and statistically significant improvement was observed in erythema (p = 0.001), average lesion size (p < 0.001), lesion density (p < 0.001), and percent involvement (p < 0.001). Changes in the AGS findings were statistically significant on the forehead (p = 0.001), nose (p < 0.001) cheeks (p < 0.001), and chin (p = 0.004).

CONCLUSION

Everolimus shows evident improvement and is approved for TSC-associated SEGAs and AMLs. The current study demonstrated the efficacy of oral everolimus in reducing facial angiofibromas, showing the parallel benefits of the treatment protocol for TSC.

Trends in survival and treatment of SEGA: National Cancer Database Analysis

Background

SEGA is a rare, slow-growing CNS neoplasm that has historically been treated by surgical resection. However, the advent of a mammalian target of rapamycin complex-1 inhibitor, everolimus, has shown promising results in recent clinical trials. We sought to provide an analysis of epidemiological and survival risk factors in this rare tumor entity, while comparing trends in surgical management before and after introduction of everolimus in SEGAs.

Methods

Patients with SEGA were queried from the National Cancer Database between 2004 and 2015. Standard statistical analysis was conducted to assess variables associated with the odds of performing surgery and survival, while controlling for confounding variables.

Results

A total of 460 patients were diagnosed with SEGA. Multivariable analysis of survival demonstrated that increased age was associated with decreased survival (HR, 1.05; P < .0001). Multivariable analysis of surgery showed increased age (odds ratio [OR], 1.02, P = .04) and tumor size 20 mm or larger (OR, 9.52-16.75, P < .0001 for all) to be associated with higher odds of performing surgery. The use of radiotherapy (OR, 0.12, P = .008) or chemotherapy (OR, 0.21, P = .008) was associated with lower odds of surgery. A comparison of surgical rates between 2004 and 2010 and 2011 and 2015 was found to be significantly different, with a lower rate of surgery seen after 2011 (60.63% vs 48.06%, P = .007).

Conclusion

Our analysis of SEGAs demonstrated that age was the only variable affecting overall survival. Surgical resection was performed in older patients with larger tumors (> 20 mm) as a primary mode of treatment, without chemoradiotherapy. Expectedly, rates of surgical resection were found to have decreased since 2011, after FDA approval of everolimus for SEGA treatment.

Observational study of characteristics and clinical outcomes of Dutch patients with tuberous sclerosis complex and renal angiomyolipoma treated with everolimus

OBJECTIVE

To compare kidney size (used as proxy for total renal angiomyolipoma [rAML] size) and kidney function outcomes between patients with tuberous sclerosis complex (TSC) and rAML treated and not treated with everolimus.

METHODS

Medical charts of adults with TSC-associated rAML followed at a specialty medical center in the Netherlands (1990-2015). Included patients treated with everolimus (n = 33, of which 27 were included in the kidney size analyses and 27 in the kidney function analyses [21 patients in both]; index date = everolimus initiation) and non-treated patients (n = 39, of which 29 were included in the kidney size analyses and 33 in the kidney function analyses [23 patients in both]; index date = one date among all dates with outcome measurement).Percent change in kidney size and kidney function from the index date to the best measurement in the two years post-index date (best response) compared between patients treated and not treated with everolimus.

RESULTS

Compared with non-treated patients, significantly more everolimus-treated patients experienced a reduction in the size of their largest kidney in the two years post-index date (85.2% vs. 37.9%, p < 0.01). Also, there was a tendency towards more improvement in the estimated glomerular filtration rate (eGFR) among the everolimus-treated patients (55.6% vs. 33.3%, p = 0.08).

CONCLUSIONS

The study results suggest that everolimus is effective in controlling and even reversing the growth of the kidneys, used as a proxy for rAML size, as well as preserving or improving kidney function in patients with TSC and rAML treated in a real-world, observational setting.

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.

Management of epilepsy associated with tuberous sclerosis complex: Updated clinical recommendations

Patients with tuberous sclerosis complex (TSC) are at very high risk for developing epilepsy, and the majority experience seizure onset during the first year of life. Early targeted interventions increase the probability of seizure-freedom and may protect neurodevelopment. In 2012, clinical recommendations for the management of epilepsy in patients with TSC were published by a panel of European experts. Since that time novel studies, reports, and expert opinions in preclinical and clinical TSC-related sciences prompted the need for updated recommendations, including epileptogenesis in TSC, the potential role of predictive biomarkers, the possible benefits of presymptomatic diagnosis and preventive treatment, and new treatment options including mTOR inhibitors. A reconvened panel reviewed the current literature to answer specific questions and five panelists discussed the findings, followed by a general discussion during which all issues were debated to achieve consensus regarding recommendations. A draft manuscript based on these discussions and recommendations was then circulated several times among the panelists, who added their own comments. All the panelists/authors agreed with the final manuscript, which was then submitted for publication. The panel concluded that the need for early diagnosis of TSC-associated seizures is now established, electroencephalographic monitoring has good predictive value for epilepsy before seizure onset in TSC, and, until conclusive data from the EPISTOP trial are available, administration of vigabatrin may be considered in children with subclinical epileptiform EEG discharges. The panel also supported the role of adjunctive everolimus for TSC-associated drug-refractory seizures and emphasized the necessity of early surgical evaluation.

mTOR-Dependent Cell Proliferation in the Brain

The mammalian Target of Rapamycin (mTOR) is a molecular complex equipped with kinase activity which controls cell viability being key in the PI3K/PTEN/Akt pathway. mTOR acts by integrating a number of environmental stimuli to regulate cell growth, proliferation, autophagy, and protein synthesis. These effects are based on the modulation of different metabolic pathways. Upregulation of mTOR associates with various pathological conditions, such as obesity, neurodegeneration, and brain tumors. This is the case of high-grade gliomas with a high propensity to proliferation and tissue invasion. Glioblastoma Multiforme (GBM) is a WHO grade IV malignant, aggressive, and lethal glioma. To date, a few treatments are available although the outcome of GBM patients remains poor. Experimental and pathological findings suggest that mTOR upregulation plays a major role in determining an aggressive phenotype, thus determining relapse and chemoresistance. Among several activities, mTOR-induced autophagy suppression is key in GBM malignancy. In this article, we discuss recent evidence about mTOR signaling and its role in normal brain development and pathological conditions, with a special emphasis on its role in GBM.

Innovative Strategies for the Management of a Massive Neonatal Rhabdomyoma

Rhabdomyomas are histologically benign tumors known to be associated with tuberous sclerosis. The natural history predicts the majority of tumors to be asymptomatic and regress within the first year of life. We describe a neonate presenting on day 1 of life with cardiovascular collapse secondary to a massive rhabdomyoma. Surgical resection was excluded due to the extensive nature of the lesion and oral sirolimus, a mammalian target of rapamycin inhibitor, was commenced to promote tumor regression. The patient developed intractable arrhythmias requiring extracorporeal life support during therapy.

Implementing a Multidisciplinary Approach to Treating Tuberous Sclerosis Complex: A Case Report

Objective:

Tuberous sclerosis complex is expressed throughout the body, resulting in a range of clinical manifestations that can be challenging to manage.

Results:

The authors report a patient who presented at age 3.5 years with several suspected seizures and was diagnosed with tuberous sclerosis complex following the discovery of numerous bilateral cortical tubers and subependymal nodules on magnetic resonance imaging. Interdisciplinary, comprehensive care was recommended; this included ongoing surveillance to monitor for the development of tuberous sclerosis complex–associated conditions. Approximately 2 years later, the patient began exhibiting aggressive and self-injurious behavior, and a subependymal giant cell astrocytoma was discovered. After everolimus was initiated, he demonstrated less aggression, had ceased self-injurious behavior, and subependymal giant cell astrocytoma growth stabilized.

Conclusions:

This case highlights the importance of a multidisciplinary approach to care in tuberous sclerosis complex, which ensures the early detection and appropriate treatment of clinical manifestations that may arise during the course of the patient’s life.

Treatment of Renal Angiomyolipoma and Other Hamartomas in Patients with Tuberous Sclerosis Complex

Tuberous sclerosis complex is an autosomal dominant genetic disease characterized by growth of benign tumors (hamartomas) in multiple organs, especially the kidneys, brain, heart, lungs, and skin. Tuberous sclerosis complex is usually caused by a mutation in either the tuberous sclerosis complex 1 or tuberous sclerosis complex 2 gene, resulting in constitutive activation of mammalian target of rapamycin signaling. Currently, mammalian target of rapamycin inhibitors are recommended in adult patients with tuberous sclerosis complex for the treatment of asymptomatic, growing renal angiomyolipoma that are >3 cm in diameter and pediatric or adult patients with brain lesions (subependymal giant cell astrocytoma) that either are growing or are not amenable to surgical resection. Clinical evidence suggests that systemic administration of a mammalian target of rapamycin inhibitor may provide concurrent improvements in multiple lesions and symptoms of tuberous sclerosis complex. With the major paradigm shift in consensus guidelines toward screening at diagnosis and ongoing monitoring and with the recent availability of an effective oral treatment, it is important that nephrologists have a thorough understanding of our role in the management of patients with tuberous sclerosis complex. Because the various manifestations of tuberous sclerosis complex typically emerge at different periods during patients' lifetimes, patients will need to be followed throughout their lives. Unlike brain and cardiac lesions, renal lesions are more likely to emerge as patients age and can grow at any time. Considerations regarding long-term medication administration for the potential control of multiple tuberous sclerosis complex manifestations will need to be addressed; these include the most appropriate starting dose, appropriate doses for tumor shrinkage versus prevention of regrowth, and management of adverse events. Best practices and potential obstacles for nephrologists treating patients with tuberous sclerosis complex who have multiple manifestations are considered.

Natural history of patients with tuberous sclerosis complex related renal angiomyolipoma

OBJECTIVE

To examine temporal relationships between tuberous sclerosis complex (TSC) and renal angiomyolipoma diagnosis and outcomes, treatment, and healthcare utilization.

METHODS

Administrative data from the MarketScan Commercial Database was used to select TSC-related renal angiomyolipoma patients during 1 January 2000-31 March 2013. Patients were followed until the earliest of inpatient death or end of enrollment or study. Occurrence of kidney-related outcomes, kidney-related procedures, and all-cause healthcare utilization and time to occurrence were reported. Kaplan-Meier curves were used to display the unadjusted distribution of time to outcome.

RESULTS

A total of 605 patients were selected (<18 years N = 225; ≥18 years N = 380). Mean time from TSC to renal angiomyolipoma diagnosis was 25.7 months in younger and 16.9 months in older patients. Patients ≥18 years had higher rates of chronic kidney disease (CKD), hematuria, kidney failure, embolization (EMB), and partial and complete nephrectomy compared to patients <18 years (all p < .05). Mean time from TSC-related renal angiomyolipoma diagnosis to CKD, hematuria, kidney failure, EMB, first emergency room and inpatient visits was shorter in older compared to younger patients (all p < .05). Probability of developing CKD was approximately 0.8 and 0.95 within 3 years in younger and older patients, respectively.

CONCLUSIONS

Patients with TSC-related renal angiomyolipoma had high rates of kidney-related outcomes and procedures. These events sometimes preceded the angiomyolipoma diagnosis. A key study limitation was that due to the small sample size, results may have been biased by outliers. Research is needed to determine whether earlier angiomyolipoma diagnosis can impact occurrence of events and reduce healthcare utilization.

Novel therapeutic approaches for disease-modification of epileptogenesis for curing epilepsy

This article describes the recent advances in epileptogenesis and novel therapeutic approaches for the prevention of epilepsy, with a special emphasis on the pharmacological basis of disease-modification of epileptogenesis for curing epilepsy. Here we assess animal studies and human clinical trials of epilepsy spanning 1982-2016. Epilepsy arises from a number of neuronal factors that trigger epileptogenesis, which is the process by which a brain shifts from a normal physiologic state to an epileptic condition. The events precipitating these changes can be of diverse origin, including traumatic brain injury, cerebrovascular damage, infections, chemical neurotoxicity, and emergency seizure conditions such as status epilepticus. Expectedly, the molecular and system mechanisms responsible for epileptogenesis are not well defined or understood. To date, there is no approved therapy for the prevention of epilepsy. Epigenetic dysregulation, neuroinflammation, and neurodegeneration appear to trigger epileptogenesis. Targeted drugs are being identified that can truly prevent the development of epilepsy in at-risk people. The promising agents include rapamycin, COX-2 inhibitors, TRK inhibitors, epigenetic modulators, JAK-STAT inhibitors, and neurosteroids. Recent evidence suggests that neurosteroids may play a role in modulating epileptogenesis. A number of promising drugs are under investigation for the prevention or modification of epileptogenesis to halt the development of epilepsy. Some drugs in development appear rational for preventing epilepsy because they target the initial trigger or related signaling pathways as the brain becomes progressively more prone to seizures. Additional research into the target validity and clinical investigation is essential to make new frontiers in curing epilepsy.

Insights into molecular therapy of glioma: current challenges and next generation blueprint

Glioma accounts for the majority of human brain tumors. With prevailing treatment regimens, the patients have poor survival rates. In spite of current development in mainstream glioma therapy, a cure for glioma appears to be out of reach. The infiltrative nature of glioma and acquired resistance substancially restrict the therapeutic options. Better elucidation of the complicated pathobiology of glioma and proteogenomic characterization might eventually open novel avenues for the design of more sophisticated and effective combination regimens. This could be accomplished by individually tailoring progressive neuroimaging techniques, terminating DNA synthesis with prodrug-activating genes, silencing gliomagenesis genes (gene therapy), targeting miRNA oncogenic activity (miRNA-mRNA interaction), combining Hedgehog-Gli/Akt inhibitors with stem cell therapy, employing tumor lysates as antigen sources for efficient depletion of tumor-specific cancer stem cells by cytotoxic T lymphocytes (dendritic cell vaccination), adoptive transfer of chimeric antigen receptor-modified T cells, and combining immune checkpoint inhibitors with conventional therapeutic modalities. Thus, the present review captures the latest trends associated with the molecular mechanisms involved in glial tumorigenesis as well as the limitations of surgery, radiation and chemotherapy. In this article we also critically discuss the next generation molecular therapeutic strategies and their mechanisms for the successful treatment of glioma.

Unique findings of subependymal giant cell astrocytoma within cortical tubers in patients with tuberous sclerosis complex: a histopathological evaluation

INTRODUCTION

Tuberous sclerosis is associated with three central nervous system pathologies: cortical/subcortical tubers, subependymal nodules (SENs), and subependymal giant cell astrocytomas (SEGAs). Tubers are associated with epilepsy, which is often medication-resistant and often leads to resective surgery. Recently, mammalian target of rapamycin inhibitors (mTORi) have been shown to be effective reducing seizure burden in some patients with tuberous sclerosis complex (TSC)-related refractory epilepsy. mTORi have also been shown to be an alternative for surgery treating SEGAs. We describe several cases of resected tubers that contained SEGA tissue without an intraventricular SEGA.

METHODS

After institutional review board (IRB) protocol approval, we retrospectively reviewed the surgical-pathological data for all TSC patients who underwent cortical resections for treatment of refractory epilepsy at NYU Langone Medical Center and Tel Aviv Medical Center between 2003 and 2013. Data included demographics, epilepsy type, MRI characteristics, epilepsy outcome, and histopathological staining.

RESULTS

We reviewed cortical resections from 75 patients with complete pathological studies. In three patients, cortical lesions demonstrated histopathological findings consistent with a SEGA within the resected tuber tissue, with no intraventricular SEGA. All lesions were cortically based and none had any intraventricular extension. No patient had been treated before surgery with an mTORi. Two of the three patients remain Engel grade I-II. All lesions stained positive for glial fibrillary acidic protein (GFAP), synaptophysin, and neuronal nuclear antigen (NeuN).

CONCLUSION

This is the first description of cortical tubers harboring SEGA tissue. This observation though preliminary may suggest a subgroup of patients with intractable epilepsy in whom mTORi may be considered before surgical intervention.

Healthcare utilization and costs in patients with tuberous sclerosiscomplex-related renal angiomyolipoma

OBJECTIVE

To quantify healthcare utilization and costs in patients with tuberous sclerosis complex (TSC) and renal angiomyolipoma (AML) in a matched cohort of patients without TSC or AML.

METHODS

Administrative data from the MarketScan Research Databases were used to select patients with TSC and renal AML during January 1, 2000-March 31, 2013 from the Commercial database and January 1, 2000-June 30, 2012 from the Medicaid database. Patients were required to have at least 30 days of follow-up from initiation into the study, and were followed until inpatient death, end of insurance coverage, or the end of study. Age, calendar year, and payer-matched controls that had no TSC and no AML were selected. All-cause annualized healthcare utilization and costs were calculated by service category.

RESULTS

A total of 218 patients under 18 years and 377 patients 18 years and older with TSC-renal AML were selected from the Commercial database, and matched to 654 and 1,131 controls, respectively. Thirty-eight patients under 18 years and 110 patients 18 years or older with TSC-renal AML were selected from the Medicaid database, and matched to 54 and 212 controls, respectively. Within the Commercial cohort, and across both age groups, TSC-renal AML patients utilized more healthcare services than their matched controls. Within the Medicaid cohort, in both age groups, utilization was higher in TSC-renal AML patients vs control patients for inpatient admissions, emergency room visits, physician office visits, and hospital-based outpatient visits. Across age groups and in both the Commercial and Medicaid cohorts, the annual average total costs were significantly higher in TSC-renal AML patients compared to control patients (p < 0.05 for all). Healthcare costs ranged from $29,240-$48,499 for TSC-renal AML patients and from $2,082-$10,864 for control patients.

CONCLUSIONS

Compared to controls, TSC-renal AML patients incurred substantially higher annual healthcare utilization and costs.

Successful use of sirolimus for refractory atrial ectopic tachycardia in a child with cardiac rhabdomyoma

Cardiac rhabdomyomas are common in tuberous sclerosis. We report a child who developed rhabdomyoma related arrhythmia refractory to antiarrhythmic drug therapy. Reversion of the atrial ectopic tachycardia was achieved with mammalian target of rapamycin pathway (mTOR) inhibitor sirolimus. As per our knowledge, this is the first time that sirolimus has been successfully used in this setting.

The Role of mTOR Inhibitors in the Treatment of Patients with Tuberous Sclerosis Complex: Evidence-based and Expert Opinions

Tuberous sclerosis complex (TSC) is a genetic disorder arising from mutations in the TSC1 or TSC2 genes. The resulting over-activation of the mammalian target of rapamycin (mTOR) signalling pathway leaves patients with TSC susceptible to the growth of non-malignant tumours in multiple organs. Previously, surgery was the main therapeutic option for TSC. However, pharmacological therapy with mTOR inhibitors such as everolimus and sirolimus is now emerging as an alternate approach. Everolimus and sirolimus have already been shown to be effective in treating subependymal giant cell astrocytoma (SEGA) and renal angiomyolipoma (AML), and everolimus is currently being evaluated in treating TSC-related epilepsy. In November 2013 a group of European experts convened to discuss the current options and practical considerations for treating various manifestations of TSC. This article provides evidence-based recommendations for the treatment of SEGA, TSC-related epilepsy and renal AML, with a focus on where mTOR inhibitor therapy may be considered alongside other treatment options. Safety considerations regarding mTOR inhibitor therapy are also reviewed. With evidence of beneficial effects in neurological and non-neurological TSC manifestations, mTOR inhibitors may represent a systemic treatment for TSC.

Efficacy and safety of Everolimus in children with TSC - associated epilepsy - Pilot data from an open single-center prospective study

BACKGROUND

Epilepsy occurs in up to 90 % of all individuals with tuberous sclerosis complex (TSC). In 67 % disease onset is during childhood. In ≥ 50 % seizures are refractory to currently available treatment options. The mTOR-Inhibitor Everolimus (Votubia®) was approved for the treatment of subependymal giant cell astrocytoma (SEGA) and renal angiomyolipoma (AML) in Europe in 2011. It's anticonvulsive/antiepileptic properties are promising, but evidence is still limited. Study aim was to evaluate the efficacy and safety of Everolimus in children and adolescents with TSC-associated epilepsies.

METHODS

Inclusion-criteria of this investigator-initiated, single-center, open, prospective study were: 1) the ascertained diagnosis of TSC; 2) age ≤ 18 years; 3) treatment indication for Votubia® according to the European Commission guidelines; 4) drug-resistant TSC-associated epilepsy, 5) prospective continuous follow-up for at least 6 months after treatment initiation and 6) informed consent to participate. Votubia® was orally administered once/day, starting with 4.5 mg/m2 and titrated to achieve blood trough concentrations between 5 and 15 ng/ml. Primary endpoint was the reduction in seizure frequency of ≥ 50 % compared to baseline.

RESULTS

Fifteen patients (nine male) with a median age of six (range; 1-18) years fulfilled the inclusion criteria. 26 % (4/15) had TSC1, 66 % (10/15) had TSC2 mutations. In one patient no mutation was found. Time of observation after treatment initiation was median 22 (range; 6-50) months. At last observation, 80 % (12/15) of the patients were responders, 58 % of them (7/12) were seizure free. The overall reduction in seizure frequency was 60 % in focal seizures, 80 % in generalized tonic clonic seizures and 87 % in drop attacks. The effect of Everolimus was seen already at low doses, early after treatment initiation. Loss of efficacy over time was not observed. Transient side effects were seen in 93 % (14/15) of the patients. In no case the drug had to be withdrawn.

CONCLUSION

Everolimus seems to be an effective treatment option not only for SEGA and AML, but also for TSC-related epilepsies. Although there are potential serious side effects, treatment was tolerated well by the majority of patients, provided that patients are under close surveillance of epileptologists who are familiar with immunosuppressive agents.

Adjunctive everolimus therapy for treatment-resistant focal-onset seizures associated with tuberous sclerosis (EXIST-3): a phase 3, randomised, double-blind, placebo-controlled study

BACKGROUND

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been used for various benign tumours associated with tuberous sclerosis complex. We assessed the efficacy and safety of two trough exposure concentrations of everolimus, 3-7 ng/mL (low exposure) and 9-15 ng/mL (high exposure), compared with placebo as adjunctive therapy for treatment-resistant focal-onset seizures in tuberous sclerosis complex.

METHODS

In this phase 3, randomised, double-blind, placebo-controlled study, eligible patients aged 2-65 years with tuberous sclerosis complex and treatment-resistant seizures (≥16 in an 8-week baseline phase) receiving one to three concomitant antiepileptic drugs were recruited from 99 centres across 25 countries. Participants were randomly assigned (1:1:1), via permuted-block randomisation (block size of six) implemented by Interactive Response Technology software, to receive placebo, low-exposure everolimus, or high-exposure everolimus. Randomisation was stratified by age subgroup (<6 years, 6 to <12 years, 12 to <18 years, and ≥18 years). Patients, investigators, site personnel, and the sponsor's study team were masked to treatment allocation. The starting dose of everolimus depended on age, body-surface area, and concomitant use of cytochrome 3A4/P-glycoprotein inducers. Dose adjustments were done to attain target trough ranges during a 6-week titration period, and as needed during a 12-week maintenance period of core phase. Patients or their caregivers recorded events in a seizure diary throughout the study. The primary endpoint was change from baseline in the frequency of seizures during the maintenance period, defined as response rate (the proportion of patients achieving ≥50% reduction in seizure frequency) and median percentage reduction in seizure frequency, in all randomised patients. This study is registered with ClinicalTrials.gov, number NCT01713946.

FINDINGS

Between July 3, 2013, and May 29, 2015, 366 patients were enrolled and randomly assigned to placebo (n=119), low-exposure everolimus, (n=117), or high-exposure everolimus (n=130). The response rate was 15·1% with placebo (95% CI 9·2-22·8; 18 patients) compared with 28·2% for low-exposure everolimus (95% CI 20·3-37·3; 33 patients; p=0·0077) and 40·0% for high-exposure everolimus (95% CI 31·5-49·0; 52 patients; p<0·0001). The median percentage reduction in seizure frequency was 14·9% (95% CI 0·1-21·7) with placebo versus 29·3% with low-exposure everolimus (95% CI 18·8-41·9; p=0·0028) and 39·6% with high-exposure everolimus (95% CI 35·0-48·7; p<0·0001). Grade 3 or 4 adverse events occurred in 13 (11%) patients in the placebo group, 21 (18%) in the low-exposure group, and 31 (24%) in the high-exposure group. Serious adverse events were reported in three (3%) patients who received placebo, 16 (14%) who received low-exposure everolimus, and 18 (14%) who received high-exposure everolimus. Adverse events led to treatment discontinuation in two (2%) patients in the placebo group versus six (5%) in the low-exposure group and four (3%) in the high-exposure group.

INTERPRETATION

Adjunctive everolimus treatment significantly reduced seizure frequency with a tolerable safety profile compared with placebo in patients with tuberous sclerosis complex and treatment-resistant seizures.

FUNDING

Novartis Pharmaceuticals Corporation.

Long-Term Use of Everolimus in Patients with Tuberous Sclerosis Complex: Final Results from the EXIST-1 Study

Background

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, has demonstrated efficacy in treating subependymal giant cell astrocytomas (SEGAs) and other manifestations of tuberous sclerosis complex (TSC). However, long-term use of mTOR inhibitors might be necessary. This analysis explored long-term efficacy and safety of everolimus from the conclusion of the EXIST-1 study (NCT00789828).

Methods and Findings

EXIST-1 was an international, prospective, double-blind, placebo-controlled phase 3 trial examining everolimus in patients with new or growing TSC-related SEGA. After a double-blind core phase, all remaining patients could receive everolimus in a long-term, open-label extension. Everolimus was initiated at a dose (4.5 mg/m²/day) titrated to a target blood trough of 5–15 ng/mL. SEGA response rate (primary end point) was defined as the proportion of patients achieving confirmed ≥50% reduction in the sum volume of target SEGA lesions from baseline in the absence of worsening nontarget SEGA lesions, new target SEGA lesions, and new or worsening hydrocephalus. Of 111 patients (median age, 9.5 years) who received ≥1 dose of everolimus (median duration, 47.1 months), 57.7% (95% confidence interval [CI], 47.9–67.0) achieved SEGA response. Of 41 patients with target renal angiomyolipomas at baseline, 30 (73.2%) achieved renal angiomyolipoma response. In 105 patients with ≥1 skin lesion at baseline, skin lesion response rate was 58.1%. Incidence of adverse events (AEs) was comparable with that of previous reports, and occurrence of emergent AEs generally decreased over time. The most common AEs (≥30% incidence) suspected to be treatment-related were stomatitis (43.2%) and mouth ulceration (32.4%).

Conclusions

Everolimus use led to sustained reduction in tumor volume, and new responses were observed for SEGA and renal angiomyolipoma from the blinded core phase of the study. These findings support the hypothesis that everolimus can safely reverse multisystem manifestations of TSC in a significant proportion of patients.

Trial Registration

ClinicalTrials.gov NCT00789828

Regression of massive cardiac rhabdomyoma on everolimus therapy

Cardiac rhabdomyoma is the primary feature of the genetic disease, tuberous sclerosis complex, the most common cardiac tumor diagnosed in neonates and infants. Spontaneous regression is observed in most cases, but these tumors may cause hemodynamic instability, arrhythmias or other complications. We describe the case of a critically ill neonate, resuscitated after cardiac arrest secondary to massive locally invasive cardiac rhabdomyoma, who was successfully treated with everolimus (mammalian target of rapamycin [mTOR] inhibitor). Rapid tumor regression was observed on echocardiography, but it was unlikely that it was confounded by the natural disease course of regression. The presented case suggests that mTOR inhibitors may play a significant role in the treatment of large cardiac rhabdomyomas in critically ill neonates.

Everolimus treatment of a newborn with rhabdomyoma causing severe arrhythmia

Rhabdomyoma is the most common cardiac tumour in children often associated with tuberous sclerosis. Arrhythmia caused by cardiac rhabdomyomas may be the initial sign of tuberous sclerosis. Rhabdomyomas unresponsive to other treatments could be successfully managed with everolimus, which has demonstrated benefit in tuberous sclerosis. We report a case of rhabdomyoma causing severe arrhythmia in a newborn managed successfully with everolimus.

Neurological and neuropsychiatric aspects of tuberous sclerosis complex

Tuberous sclerosis (also known as tuberous sclerosis complex [TSC]) is a multisystem genetic disorder that affects almost every organ in the body. Mutations in the TSC1 or TSC2 genes lead to disruption of the TSC1-TSC2 intracellular protein complex, causing overactivation of the mammalian target of rapamycin (mTOR) protein complex. The surveillance and management guidelines and clinical criteria for tuberous sclerosis were revised in 2012, and mTOR inhibitors are now recommended as treatment options for subependymal giant cell astrocytomas and renal angiomyolipomas-two common features of the disease. However, most morbidity and mortality caused by tuberous sclerosis is associated with neurological and neuropsychiatric manifestations. Treatment of epilepsy associated with tuberous sclerosis remains a major challenge, with more than 60% of patients having ongoing seizures. Tuberous-sclerosis-associated neuropsychiatric disorders (TAND) are multilevel and occur in most individuals with the disorder, but are rarely assessed and treated. Clinical trials of mTOR inhibitors to treat seizures and TAND are underway. Management of the neurological and neuropsychiatric manifestations of the disorder should be coordinated with treatment of other organ systems. In view of the age-related expression of manifestations from infancy to adulthood, continuity of clinical care and ongoing monitoring is paramount, and particular attention is needed to plan transition of patient care from childhood to adult services.

12-Deoxyphorbol 13-palmitate inhibits the expression of VEGF and HIF-1α in MCF-7 cells by blocking the PI3K/Akt/mTOR signaling pathway

Vascular endothelial growth factor (VEGF) is an essential component for angiogenesis, and hypoxia-inducible factor-1α (HIF-1α), which controls the switch of glycolytic and oxidative metabolism, activates the transcription of VEGF. 12-Deoxyphorbol 13-palmitate (DP) is a compound isolated from the roots of Euphorbia fischeriana, and has been revealed to possess anticancer activity. In the present study, we found that DP is an effective inhibitor of VEGF and HIF-1α in MCF-7 cells. DP markedly reduced cell viability as determined by MTT assay. ELISA, western blotting and RT-qPCR assays indicated that DP significantly decreased the protein and mRNA expression of VEGF and the protein expression of HIF-1α, while HIF-1α mRNA remained unchanged. In addition, the entrance of HIF-1α into the nucleus was blocked after DP treatment as detected by immunofluorescence analysis. In a further study, we proved that the effects mentioned above were associated with constitutive interference of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway. DP effectively inhibited the phosphorylation of PI3K and its downstream factors p-Akt and p-mTOR, oppositely enhanced the expression of TSC1 (hamartin) and TSC2 (tuberin), which could be reversed by the co-treatment with the PI3K inhibitor wortmannin. Moreover, the addition of wortmanin further downregulated the protein levels of VEGF and HIF-1α. The results revealed that DP inhibited the expression of VEGF and HIF-1α through the PI3K/Akt/mTOR signaling pathway, confirming that DP may be a potential therapeutic candidate for breast cancer.

Recent treatment advances and novel therapeutic approaches in epilepsy

The purpose of this article is to review recent advances in the treatment of epilepsy. It includes five antiepileptic drugs that have been recently added to the pharmacologic armamentarium and surgical techniques that have been developed in the last few years. Finally, we review ongoing research that may have a potential role in future treatments of epilepsy.

Use of mTOR inhibitor everolimus in three neonates for treatment of tumors associated with tuberous sclerosis complex

BACKGROUND

Tuberous sclerosis complex is characterized by the growth of benign tumors in multiple organs, caused by the disinhibition of the mammalian target of rapamycin (mTOR) protein. mTOR inhibitors, such as everolimus, are used in patients with tuberous sclerosis complex, mainly to reduce the size of renal angiomyolipomas and subependymal giant cell astrocytomas. There are minimal data available regarding its use during the neonatal period.

METHODS

We report clinical and pharmacological data of three neonates treated with the mTOR inhibitor everolimus (two hemodynamically significant cardiac rhabdomyomas and one voluminous subependymal giant cell astrocytoma).

RESULTS

Beneficial clinical responses were observed in all three patients and the medication was generally well-tolerated. Optimal dose was 0.1 mg orally once daily and was confirmed with therapeutic drug monitoring.

CONCLUSION

Everolimus is a promising pharmacological approach to treat clinically significant inoperable cardiac rhabdomyomas or subependymal giant cell astrocytoma associated with tuberous sclerosis complex during the neonatal period.

Mechanistic target of rapamycin (mTOR) in tuberous sclerosis complex-associated epilepsy

BACKGROUND

Tuberous sclerosis complex is a multiorgan disease resulting from a mutation of one of two TSC genes. The two gene products form a functional complex that regulates the mTOR signaling pathway (mTOR initially represented mammalian target of rapamycin, but increasingly the term mechanistic target of rapamycin is used to reflect the ubiquitous occurrence of mTOR). Epilepsy is the most common neurological symptom of tuberous sclerosis complex, occurring in 80% to 90% of affected individuals over the course of their lifetimes and causing significant morbidity and mortality. The mechanistic target of rapamycin (mTOR) signaling pathway is intricately involved in multiple cellular functions--including protein synthesis, cell growth and proliferation, and synaptic plasticity--which may influence neuronal excitability and precipitate epileptogenesis. Recent preclinical and clinical studies have increased interest in the potential role of mTOR inhibitors for the treatment of tuberous sclerosis complex-related epilepsy.

METHODS

Medline and PubMed database searches were used to identify relevant studies and other information on tuberous sclerosis complex-related epilepsies, the mTOR pathway, and current advances in treatment approaches.

RESULTS

Although current management strategies that provide symptomatic relief are effective at reducing the frequency of seizures in individuals with tuberous sclerosis complex, there is further room for the exploration of therapies that directly address hyperactive mTOR signaling--the underlying etiology of the disease. The role of the antiepileptic effect of mTOR inhibition was first demonstrated in knockout TSC1 mouse models. Additionally, several case studies demonstrated a positive effect on seizure frequency and severity in patients with pharmacoresistant epilepsy. In a phase 1/2 clinical trial with 28 patients, clinically relevant reduction in overall seizure frequency was documented in individuals treated with the mTOR inhibitor everolimus. In a phase 3 trial evaluating the role of everolimus in subependymal giant cell astrocytoma, seizures were a secondary end point. Because the median seizure frequency was zero in this study, the analysis was inconclusive.

CONCLUSION

Various preclinical models provide substantial evidence for the role of mTOR inhibition in the treatment of epilepsy in individuals with tuberous sclerosis complex. Preliminary clinical studies provide supportive evidence for a role of mTOR inhibition in the management of tuberous sclerosis complex-associated epilepsy and pave the way for new randomized placebo-controlled studies. This article reviews current treatment recommendations for the management of tuberous sclerosis complex-associated epilepsy as well as the rationale and evidence to support the use of mTOR inhibitors.