Accelerated Cardiac Rhabdomyoma Regression with Everolimus in Infants with Tuberous Sclerosis Complex

Everolimus and sirolimus in the treatment of cardiac rhabdomyomas in neonates

BACKGROUND AND OBJECTIVES

Cardiac rhabdomyoma (CR) is the principal cardiac tumor diagnosed in pediatric age and is commonly associated with tuberous sclerosis complex. In some patients, these masses can cause heart failure and difficult-to-control arrhythmias. There are multiple case reports on use of mammalian target of rapamycin (mTOR) inhibitors, everolimus or sirolimus, in treatment of CRs. We reviewed the current data regarding effectiveness of everolimus and sirolimus in treating of CRs in newborns with hemodynamic repercussions.

METHODS

This systematic review was reported according to the PRISMA guidelines. The EBSCO, PubMed, EMBASE, and Lilacs databases were searched for full-text articles reporting the use of everolimus or sirolimus in the treatment of CRs in neonates and infants.

RESULTS

Thirty-one articles met inclusion criteria, totaling 48 patients. Hemodynamic instability prompted treatment in 89.5% of cases. Everolimus was used in 83.3% of cases and sirolimus in 16.6%. The median treatment duration was 67 days, with a 57 ± 23% average CR size reduction. Common adverse events included hypertriglyceridemia, infections, and hematological abnormalities.

CONCLUSIONS

mTOR inhibitors appear effective and safe for treating CRs in neonates and infants. The average daily doses were 1.03 mg/m²/day for everolimus and 1.37 mg/m²/day for sirolimus. Randomized controlled clinical trials are necessary to confirm these findings and establish optimal treatment protocols.

IMPACT

Currently, there are no results from randomized clinical trials evaluating the efficacy of mammalian target of rapamycin inhibitors in patients with symptomatic cardiac rhabdomyomas. This is the first systematic review that evaluates the efficacy and safety of the use of everolimus and sirolimus in the non-surgical treatment of cardiac rhabdomyomas with hemodynamic repercussions in neonates. Everolimus and sirolimus may be particularly useful in the neonatal period when the hemodynamic complications caused by cardiac rhabdomyomas are more severe.

Cardiac Tumors: Review

Cardiac tumors are rare and encompass a variety of presentations. Clinica symptoms are usually nonspecific, but they can present as obstructive, embolic, or constitutional symptoms. Treatment options and prognosis vary highly depending on the subtype, tumor size, and location. Surgical resection is usually the first-line therapy, except for cardiac lymphomas, and provides favorable long-term prognosis in most benign tumors. Cardiac sarcomas, however, are usually diagnosed in advanced stages, and the treatment relies on a multimodal approach with chemotherapy and radiotherapy. Metastatic cardiac tumors are usually related to advanced disease and carry an overall poor prognosis.

Preventative treatment of tuberous sclerosis complex with sirolimus: Phase I safety and efficacy results

Objective

Tuberous sclerosis complex (TSC) results from overactivity of the mechanistic target of rapamycin (mTOR). Sirolimus and everolimus are mTOR inhibitors that treat most facets of TSC but are understudied in infants. We sought to understand the safety and potential efficacy of preventative sirolimus in infants with TSC.

Methods

We conducted a phase 1 clinical trial of sirolimus, treating five patients until 12 months of age. Enrolled infants had to be younger than 6 months of age with no history of seizures and no clinical indication for sirolimus treatment. Adverse events (AEs), tolerability, and blood concentrations of sirolimus measured by tandem mass spectrometry were tracked through 12 months of age, and clinical outcomes (seizure characteristics and developmental profiles) were tracked through 24 months of age.

Results

There were 92 AEs, with 34 possibly, probably, or definitely related to treatment. Of those, only two were grade 3 (both elevated lipids) and all AEs were resolved by the age of 24 months. During the trial, 94% of blood sirolimus trough levels were in the target range (5-15 ng/mL). Treatment was well tolerated, with less than 8% of doses held because of an AE (241 of 2941). Of the five patients, three developed seizures (but were well controlled on medications) at 24 months of age. Of the five patients, four had normal cognitive development for age. One was diagnosed with possible autism spectrum disorder.

Interpretation

These results suggest that sirolimus is both safe and well tolerated by infants with TSC in the first year of life. Additionally, the preliminary work suggests a favorable efficacy profile compared with previous TSC cohorts not exposed to early sirolimus treatment. Results support sirolimus being studied as preventive treatment in TSC, which is now underway in a prospective phase 2 clinical trial (TSC-STEPS).

Long-term use of everolimus for refractory arrhythmia in a child with tuberous sclerosis complex

Tuberous sclerosis complex is associated with the occurrence of cardiac rhabdomyomas that may result in life-threatening arrhythmia unresponsive to standard antiarrhythmic therapy. We report the case of an infant with multiple cardiac rhabdomyomas who developed severe refractory supraventricular tachycardia (SVT) that was successfully treated with everolimus. Pharmacological mTOR inhibition rapidly improved arrhythmia within few weeks after treatment initiation and correlated with a reduction in tumor size. Intermediate attempts to discontinue everolimus resulted in rhabdomyoma size rebound and recurrence of arrhythmic episodes, which resolved on resumption of therapy. While everolimus treatment led to successful control of arrhythmia in the first years of life, episodes of SVT reoccurred at the age of 6 years. Electrophysiologic testing confirmed an accessory pathway that was successfully ablated, resulting in freedom of arrhythmic events. In summary we present an in-depth evaluation of the long-term use of everolimus in a child with TSC-associated SVT, including the correlation between drug use and arrhythmia outcome. This case report provides important information on the safety and efficacy of an mTOR inhibitor for the treatment of a potentially life-threatening cardiac disease manifestation in TSC for which the optimal treatment strategy is still not well established.

Effect of different dose regimens of everolimus in a series of neonates with giant cardiac rhabdomyomas

Everolimus is a mTOR inhibitor that has been increasingly used in high-risk cardiac rhabdomyomas in recent years. There are questions regarding the optimal dose and duration of therapy with everolimus for cardiac rhabdomyomas. The purpose of this study was to examine retrospectively the dosage-efficacy relationship in seven babies diagnosed with rhabdomyoma treated with different everolimus dose regimens retrospectively. Cardiac rhabdomyoma diagnosis was made in six of seven babies during the prenatal period. Indication of everolimus was an obstruction in six patients and supraventricular tachycardia which is resistant to antiarrhythmic drugs in the remaining one patient. The median age was 8 days (range; 2-105 days) at the time of starting everolimus. It was administered at a dose of 0.25 mg twice a day for two days a week in four patients; 0.1 mg/day in two and 0.4 mg/day in one patient. Serum everolimus level was kept between 5 and 15 ng/ml. All seven cases showed significant regression of cardiac rhabdomyoma within four weeks, and supraventricular tachycardia was controlled in two weeks after everolimus administration.This study demonstrates that everolimus was effective in accelerating regression of the cardiac rhabdomyoma. Dose with 2 × 0,25 mg/day, 2 days a week, seems appropriate. However, lower doses such as 0.1 mg/day are also effective. But dose adjustment should be made according to serum level monitoring.

Paradigm shift in the treatment of tuberous sclerosis: Effectiveness of everolimus

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterised by abnormal cell proliferation and differentiation that affects multiple organs and can lead to the growth of hamartomas. Tuberous sclerosis complex is caused by the disinhibition of the protein mTOR (mammalian target of rapamycin). In the past, various therapeutic approaches, even if only symptomatic, have been attempted to improve the clinical effects of this disease. While all of these therapeutic strategies are useful and are still used and indicated, they are symptomatic therapies based on the individual symptoms of the disease and therefore not fully effective in modifying long-term outcomes. A new therapeutic approach is the introduction of allosteric inhibitors of mTORC1, which allow restoration of metabolic homeostasis in mutant cells, potentially eliminating most of the clinical manifestations associated with Tuberous sclerosis complex. Everolimus, a mammalian target of the rapamycin inhibitor, is able to reduce hamartomas, correcting the specific molecular defect that causes Tuberous sclerosis complex. In this review, we report the findings from the literature on the use of everolimus as an effective and safe drug in the treatment of TSC manifestations affecting various organs, from the central nervous system to the heart.

Case report: Accelerated regression of giant cardiac rhabdomyomas in neonates with low dose everolimus

Cardiac rhabdomyoma (CRHM) is the principal cardiac tumor in children and is most often associated with tuberous sclerosis complex (TSC). Mutations in the TSC1 and TSC2 genes cause the overactivation of the mammalian Target of Rapamycin (mTOR). This protein family is responsible for abnormal cell proliferation leading to the formation of CRHMs and hamartomas in other organs. Despite the tendency for spontaneous regression, some CRHMs can cause heart failure and intractable arrhythmias, requiring surgical resection. In recent years, the use of everolimus and sirolimus (mTOR inhibitors) in the treatment of CRHMs has been reported. We report two cases of neonates with giant rhabdomyomas, with hemodynamic repercussions treated with low-dose everolimus (4.5 mg/m²/week). In both cases, we obtained an approximate decrease of 50% in the total area of the mass after three weeks of treatment. Despite rebound growth after stopping the drug, we were able to evidence that the use of low doses of everolimus immediately after birth is effective and safe in the treatment of giant CRHMs, avoiding surgical resection of the tumor and associated morbidity and mortality.

Health-related quality of life in children and adolescents with tuberous sclerosis complex and their caregivers: A multicentre cohort study from Germany

OBJECTIVE

This study aimed to measure health-related quality of life (HRQOL) in children and adolescents with tuberous sclerosis complex (TSC) and quality of life (QOL) and depressive symptoms among caregivers.

METHODS

Adequate metrics were used to assess HRQOL in children and adolescents with TSC (4-18 years, KINDL^R) as well as QOL (EQ-5D) and symptoms of depression (BDI-II) among caregivers. Predictors for reduced HRQOL and depressive symptoms were identified by variance analysis, ordinal regression, and bivariate correlation.

RESULTS

The mean HRQOL score was 67.9 ± 12.7, and significantly lower values were associated with increasing age, attending special needs education, TSC-associated psychiatric symptoms, and drug-related adverse events. The mean QOL of caregivers was 85.4 ± 15.7, and caregiver's sex, TSC mutation locus, familial TSC clustering, special needs education, degree of disability, care dependency, presence of TSC-associated psychiatric symptoms, and TSC severity were significant predictors of lower QOL. Depressive symptoms were identified in 45.7% of caregivers, associated with female sex of the caregiver, familial TSC clustering, special needs education, and presence of TSC-associated psychiatric symptoms of the child. Multivariate regression analysis revealed adolescence and drug-related adverse events as significant predictors for lower HRQOL in TSC children, and TSC2 variants predicted lower QOL and depressive symptoms in caregivers.

CONCLUSION

Compared with other chronic diseases, such as headache, diabetes or obesity, children with TSC have significantly lower HRQOL, which further decreases during adolescence. A decreased HRQOL of patients correlates with a lower QOL and increased symptoms of depression of their caregivers. These results may improve the comprehensive therapy and care of children and adolescents with TSC and their families and caregivers.

TRIAL REGISTRATION

DRKS, DRKS00016045. Registered 01 March 2019, http://www.drks.de/DRKS00016045.

Clinical, cellular, and molecular characterisation of cardiac rhabdomyoma in tuberous sclerosis

BACKGROUND

Rhabdomyoma is the most common cardiac tumour in children. It is usually associated with tuberous sclerosis complex caused by mutations in TSC-1 or TSC-2 genes. This tumour typically regresses by unknown mechanisms; however, it may cause inflow or outflow obstruction that necessitates urgent surgery. Here we investigate the clinical features and the genetic analysis of patients with tuberous sclerosis complex presenting with large rhabdomyoma tumours. We also investigate the potential role of autophagy and apoptosis in the pathogenesis of this tumour.

METHODS

All the patients with cardiac rhabdomyoma referred to Aswan Heart Centre from 2010 to 2018 were included in this study. Sanger sequencing was performed for coding exons and the flanking intronic regions of TSC1 and TSC2 genes. Histopathological evaluation, immunohistochemistry, and western blotting were performed with P62, LC3b, caspase3, and caspase7, to evaluate autophagic and apoptotic signaling.

RESULTS

Five patients were included and had the clinical features of tuberous sclerosis complex. Three patients, who were having obstructive tumours, were found to have pathogenic mutations in TSC-2. The expression of two autophagic markers, P62 and LC3b, and two apoptotic markers, caspase3 and caspase7, were increased in the tumour cells compared to normal surrounding myocardial tissue.

CONCLUSION

All the patients with rhabdomyoma were diagnosed to have tuberous sclerosis complex. The patients who had pathogenic mutations in the TSC-2 gene had a severe disease form necessitating urgent intervention. We also demonstrate the potential role of autophagy and apoptosis as a possible mechanism for tumourigenesis and regression. Future studies will help in designing personalised treatment for cardiac rhabdomyoma.

Everolimus treatment in a 3-month-old infant with tuberous sclerosis complex cardiac rhabdomyoma, severe left ventricular outflow tract obstruction, and hearing loss

Tuberous sclerosis complex is a rare multisystem genetic disorder characterised by the growth of numerous tumour-like malformations in many parts of the body including skin, kidneys, brain, lung, eyes, liver, and heart. Mutations in the TSC1 or TSC2 genes have been reported to cause disruption in the TSC1-TSC2 intracellular protein complex, causing over-activation of the mammalian target of rapamycin protein complex. In this study, we present a 3-month-old male infant diagnosed with tuberous sclerosis, bilateral neurosensorial hearing loss, Wolff-Parkinson-White syndrome on electrocardiography, multiple cardiac rhabdomyomas with severe stenosis in the left ventricular outflow tract, who responded well to the Everolimus therapy.

Brain Symptoms of Tuberous Sclerosis Complex: Pathogenesis and Treatment

The mammalian target of the rapamycin (mTOR) system plays multiple, important roles in the brain, regulating both morphology, such as cellular size, shape, and position, and function, such as learning, memory, and social interaction. Tuberous sclerosis complex (TSC) is a congenital disorder caused by a defective suppressor of the mTOR system, the TSC1/TSC2 complex. Almost all brain symptoms of TSC are manifestations of an excessive activity of the mTOR system. Many children with TSC are afflicted by intractable epilepsy, intellectual disability, and/or autism. In the brains of infants with TSC, a vicious cycle of epileptic encephalopathy is formed by mTOR hyperactivity, abnormal synaptic structure/function, and excessive epileptic discharges, further worsening epilepsy and intellectual/behavioral disorders. Molecular target therapy with mTOR inhibitors has recently been proved to be efficacious for epilepsy in human TSC patients, and for autism in TSC model mice, indicating the possibility for pharmacological treatment of developmental synaptic disorders.

Sirolimus Can Increase the Disappearance Rate of Cardiac Rhabdomyomas Associated with Tuberous Sclerosis: A Prospective Cohort and Self-Controlled Case Series Study

OBJECTIVES

To investigate the efficacy and safety of sirolimus in the treatment of cardiac rhabdomyomas associated with tuberous sclerosis complex and the specific benefits in different subgroups.

STUDY DESIGN

The study was a prospective cohort and self-controlled case series study. Based on the prevalence of cardiac rhabdomyoma at different ages, we estimated the natural tumor disappearance rate. The subgroup analysis was done by Cox regression. Self-controlled case series method was used to assess the magnitude and duration of the drug effect. Adverse events were described.

RESULTS

A total of 217 patients were included in the cohort study. Tumor disappearance rate was higher in younger age groups (hazard ratio = 0.99, P = .027) and female patients (hazard ratio = 2.08, P = .015). The age-adjusted incidence ratio showed that the disappearance of rhabdomyomas between 3 and 6 months was more related to sirolimus. Adverse events were observed 60 times in 42 of 217 children, mainly stomatitis.

CONCLUSIONS

Sirolimus can increase the disappearance rate of cardiac rhabdomyoma in the tuberous sclerosis complex population. Efficacy varies by sex and age: female and younger patients have higher tumor disappearance rate. Sirolimus is well-tolerated.

Treatment of Cardiac Rhabdomyomas with mTOR Inhibitors in Children with Tuberous Sclerosis Complex-A Systematic Review

BACKGROUND

Cardiac rhabdomyomas (CRs) are the earliest sign of tuberous sclerosis complex (TSC). Most of them spontaneously regress after birth. However, multiple and/or large tumors may result in heart failure or cardiac arrhythmia. Recently, the attempts to treat CRs with mTOR inhibitors (mTORi) have been undertaken. We reviewed the current data regarding the effectiveness and safety of mTORi in the treatment of CRs in children with TSC.

METHODS

The review was conducted according to the PRISMA guidelines. Medline, Embase, Cochrane library, and ClinicalTrial.gov databases were searched for original, full-text articles reporting the use of mTORi (everolimus or sirolimus) in the treatment of CRs in children with TSC.

RESULTS

Thirty articles describing 41 patients were identified (mostly case reports, no randomized or large cohort studies). Thirty-three children (80.5%) had symptomatic CRs and mTORi therapy resulted in clinical improvement in 30 of them (90.9%). CRs size reduction was reported in 95.1%. Some CRs regrew after mTORi withdrawal but usually without clinical symptoms recurrence. The observed side effects were mostly mild.

CONCLUSIONS

mTORi may be considered as a temporary and safe treatment for symptomatic CRs in children with TSC, especially in high-risk or inoperable tumors. However, high-quality, randomized trials are still lacking.

Efficacy of Everolimus Low-Dose Treatment for Cardiac Rhabdomyomas in Neonatal Tuberous Sclerosis: Case Report and Literature Review

Background: Cardiac rhabdomyomas (CRs) are the most common cardiac tumors in newborns. Approximately 80-90% of cases are associated with tuberous sclerosis complex (TSC). In selective cases, Everolimus has resulted in a remarkable tumoral regression effect in children with TS. The optimal dosage for neonates is still unknown. Case presentation: We describe the use of Everolimus in a neonate with multiple biventricular CRs, causing subaortic obstruction, in which a low-dose treatment (0.1 mg/die), in an effort to maintain serum trough levels of 3-7 ng/mL, was successfully used off-label, without adverse effects. Conclusions: We showed that a low-dose Everolimus regimen may be an effective and safe treatment for CR regression in TS neonates, when the minimum therapeutic range was maintained.

Efficacy, Retention and Tolerability of Everolimus in Patients with Tuberous Sclerosis Complex: A Survey-Based Study on Patients' Perspectives

BACKGROUND

The approval of everolimus (EVE) for the treatment of angiomyolipoma (2013), subependymal giant cell astrocytoma (2013) and drug-refractory epilepsy (2017) in patients with tuberous sclerosis complex (TSC) represents the first disease-modifying treatment option available for this rare and complex genetic disorder.

OBJECTIVE

The objective of this study was to analyse the use, efficacy, tolerability and treatment retention of EVE in patients with TSC in Germany from the patient's perspective.

METHODS

A structured cross-age survey was conducted at 26 specialised TSC centres in Germany and by the German TSC patient advocacy group between February and July 2019, enrolling children, adolescents and adult patients with TSC.

RESULTS

Of 365 participants, 36.7% (n = 134) reported the current or past intake of EVE, including 31.5% (n = 115) who were taking EVE at study entry. The mean EVE dosage was 6.1 ± 2.9 mg/m² (median: 5.6 mg/m², range 2.0-15.1 mg/m²) in children and adolescents and 4 ± 2.1 mg/m² (median: 3.7 mg/m², range 0.8-10.1 mg/m²) in adult patients. An early diagnosis of TSC, the presence of angiomyolipoma, drug-refractory epilepsy, neuropsychiatric manifestations, subependymal giant cell astrocytoma, cardiac rhabdomyoma and overall multi-organ involvement were associated with the use of EVE as a disease-modifying treatment. The reported efficacy was 64.0% for angiomyolipoma (75% in adult patients), 66.2% for drug-refractory epilepsy, and 54.4% for subependymal giant cell astrocytoma. The overall retention rate for EVE was 85.8%. The retention rates after 12 months of EVE therapy were higher among adults (93.7%) than among children and adolescents (88.7%; 90.5% vs 77.4% after 24 months; 87.3% vs 77.4% after 36 months). Tolerability was acceptable, with 70.9% of patients overall reporting adverse events, including stomatitis (47.0%), acne-like rash (7.7%), increased susceptibility to common infections and lymphoedema (each 6.0%), which were the most frequently reported symptoms. With a total score of 41.7 compared with 36.8 among patients not taking EVE, patients currently being treated with EVE showed an increased Liverpool Adverse Event Profile. Noticeable deviations in the sub-items 'tiredness', 'skin problems' and 'mouth/gum problems', which are likely related to EVE-typical adverse effects, were more frequently reported among patients taking EVE.

CONCLUSIONS

From the patients' perspective, EVE is an effective and relatively well-tolerated disease-modifying treatment option for children, adolescents and adults with TSC, associated with a high long-term retention rate that can be individually considered for each patient. Everolimus therapy should ideally be supervised by a centre experienced in the use of mechanistic target of rapamycin inhibitors, and adverse effects should be monitored on a regular basis.

A Bama miniature pig model of monoallelic TSC1 mutation for human tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a dominant genetic neurocutaneous syndrome characterized by multiple organ hamartomas. Although rodent models bearing a germline mutation in either TSC1 or TSC2 gene have been generated, they do not develop pathogenic lesions matching those seen in patients with TSC because of the significant differences between mice and humans, highlighting the need for an improved large animal model of TSC. Here, we successfully generate monoallelic TSC1-modified Bama miniature pigs using the CRISPR/Cas9 system along with somatic cell nuclear transfer (SCNT) technology. The expression of phosphorylated target ribosomal protein S6 is significantly enhanced in the piglets, indicating that disruption of a TSC1 allele activate the mechanistic target of rapamycin (mTOR) signaling pathway. Notably, differing from the mouse TSC models reported previously, the TSC1^+/- Bama miniature pig developed cardiac rhabdomyoma and subependymal nodules, resembling the major clinical features that occur in patients with TSC. These TSC1^+/- Bama miniature pigs could serve as valuable large animal models for further elucidation of the pathogenesis of TSC and the development of therapeutic strategies for TSC disease.

[Importance of heart rabdomioma in pediatric population. A 39 year experience. Case series]

Introducción: Los rabdomiomas son los tumores cardiacos benignos más prevalentes en la etapa fetal y durante la infancia. Objetivo: Nuestro objetivo es dar a conocer nuestra experiencia durante 39 años en pacientes pediátricos con rabdomioma en nuestra institución, así como enfatizar la importancia de su detección, estudio y control por la asociación que tiene con esclerosis tuberosa (ET). Material y métodos: Realizamos un estudio retrospectivo y descriptivo, de enero de 1980 a marzo del 2018. Veinticuatro cumplieron con nuestros criterios, recogimos información respecto a la clínica y estudios de gabinete, así como su evolución y el tratamiento dado. Se les llamó vía telefónica para conocer su evolución y estado actual. Resultados: Encontramos 51 pacientes con diagnóstico de tumor cardiaco, de los cuales 24 eran rabdomiomas. El diagnóstico se hizo prenatal en 8 pacientes, 5 al nacimiento y en 11 durante el primer año de vida. Las manifestaciones clínicas más frecuentes fueron la presencia de soplo, arritmias, cianosis, disnea y diaforesis. En 17 de ellos se hizo diagnóstico de ET. La mitad tuvo seguimiento por neurología, 10 por dermatología, 8 por oftalmología y 4 con genética. La mitad se dejó en vigilancia, a 7 se les dio tratamiento médico y 5 requirieron cirugía. En cuanto a la evolución, 17 pacientes se mantuvieron estables, 5 presentaron regresión espontánea y 2 fallecieron. Conclusiones: El rabdomioma es un tumor benigno poco frecuente, su evolución puede ser maligna y asociado a ET ensombrece el pronóstico.

Clinical Treatment of Pediatric Primary Cardiac Tumors: A Single-Institute 12-Year Experience

BACKGROUND

Primary cardiac tumors in children are extremely rare. This study aimed to analyze clinical treatment and follow-up of pediatric primary cardiac tumors.

PATIENTS AND METHODS

We performed a retrospective analysis by searching the medical records of 75 patients diagnosed with pediatric primary cardiac tumors from June 2005 to August 2017 in our institution. We followed operative patients every half year in the first postoperative year and then at least every year. If the patients had no serious symptoms or hemodynamic changes, they received nonoperative management and were followed regularly every year.

RESULTS

Nineteen patients underwent surgery at our department for serious symptoms and critical hemodynamic changes. Four patients had postoperative complications. Two died of low cardiac output syndrome and arrhythmia after surgery. One patient with myxomas had tumor recurrence and one had been found of another rhabdomyoma after surgery. The other 14 patients recovered well. Fifty-six patients had nonoperative management. Four were lost in follow-up. Two patients with malignant tumors died of unknown causes after discharge. The remaining patients had no severe symptoms or tumor growth during follow-up.

CONCLUSIONS

Clinical treatment of pediatric primary cardiac tumors should be performed individually. Most pediatric primary cardiac tumors are benign, and spontaneous regression is possible, especially for rhabdomyomas. The principle purpose of surgical treatment is to restore normal hemodynamics and protect important structures and cardiac tissue.

Rhabdomyoma association with atrioventricular septal defect in an infant: a rare coincidence

Cardiac rhabdomyoma is the most common primary heart tumor in childhood. This tumor, which is frequently associated with tuberous sclerosis complex, mostly disappears in childhood with spontaneous regression. Surgical resection is required in case of outflow obstruction and arrhythmia and when protruding to disrupt the filling of the heart cavities. There are very few case series in the literature about rhabdomyoma, whose relationship with other congenital heart defects has not been clearly verified. In this study, we report our approach to the tumor during the corrective surgery of the infant, who was diagnosed with an atrioventricular septal defect and patent ductus arteriosus, and rhabdomyoma accompanying these malformations. We treated this asymptomatic rhabdomyoma with everolimus in line with the current literature, without excision.

Medical treatment of tuberous sclerosis-related epilepsy

Epilepsy is one of the most frequent CNS manifestations of tuberous sclerosis, and for most patients, it is the major debilitating factor. In up to 70% of the cases, the epilepsy is refractory and usually associated with significant behavioral as well as developmental consequences. Therefore, controlling seizures is one of the biggest medical and surgical challenges. Understanding the cellular mechanism involved in the disease empowered targeted research aimed toward early intervention in the epileptogenicity process. In this review, we present an update on the pharmacological treatments in tuberous sclerosis-related epilepsy.

A case report of severe tuberous sclerosis complex detected in utero and linked to a novel duplication in the TSC2 gene

BACKGROUND

Disease severity is tremendously variable in tuberous sclerosis complex (TSC). In contrast with the detailed guidelines available for TSC diagnosis and management, clinical practice lacks adequate tools to evaluate the prognosis, especially in the case of in utero diagnosis. In addition, the correlation between genotypes and phenotypes remains a challenge, in part due to the large number of mutations linked to TSC. In this report, we describe a case of severe TSC diagnosed in utero and associated with a specific mutation in the gene tuberous sclerosis complex 2 (TSC2).

CASE PRESENTATION

A mother was referred for a thorough investigation following the observation by ultrasound of cardiac abnormalities in her fetus. The mother was healthy and reported frequent, intense and long-lasting hiccups/spasms in the fetus. The fetus of gestational age 33 weeks and 4 days was found to have multiple cardiac tumors with cardiac ultrasound. Brain magnetic resonance imaging (MRI) performed in utero revealed the presence of sub-ependymal nodules and of abnormal signals disseminated in the white matter, in the cerebral cortex and in the cerebellum. Following diagnosis of definite TSC, pregnancy interruption was chosen by the parents. Genetic testing of the fetus exposed a duplication in exon 41 of TSC2 (c.5169dupA), which was absent in the parents. The autopsy ascertained the high severity of brain damage characterized by an extensive disorganisation of white and grey matter in most cerebral lobes.

CONCLUSIONS

This case presentation is the first to depict the association between a de novo TSC2 c.5169dupA and multi-organ manifestation together with indications of a particularly high disease severity. This report can help physicians to perform early clinical diagnosis of TSC and to evaluate the prognosis.

Everolimus for cardiac rhabdomyomas in children with tuberous sclerosis. The ORACLE study protocol (everOlimus for caRdiac rhAbdomyomas in tuberous sCLErosis): a randomised, multicentre, placebo-controlled, double-blind phase II trial

INTRODUCTION

Tuberous sclerosis complex is a rare genetic disorder leading to the growth of hamartomas in multiple organs, including cardiac rhabdomyomas. Children with symptomatic cardiac rhabdomyoma require frequent admissions to intensive care units, have major complications, namely, arrhythmias, cardiac outflow tract obstruction and heart failure, affecting the quality of life and taking on high healthcare cost. Currently, there is no standard pharmacological treatment for this condition, and the management includes a conservative approach and supportive care. Everolimus has shown positive effects on subependymal giant cell astrocytomas, renal angiomyolipoma and refractory seizures associated with tuberous sclerosis complex. However, evidence supporting efficacy in symptomatic cardiac rhabdomyoma is limited to case reports. The ORACLE trial is the first randomised clinical trial assessing the efficacy of everolimus as a specific therapy for symptomatic cardiac rhabdomyoma.

METHODS

ORACLE is a phase II, prospective, randomised, placebo-controlled, double-blind, multicentre protocol trial. A total of 40 children with symptomatic cardiac rhabdomyoma secondary to tuberous sclerosis complex will be randomised to receive oral everolimus or placebo for 3 months. The primary outcome is 50% or more reduction in the tumour size related to baseline. As secondary outcomes we include the presence of arrhythmias, pericardial effusion, intracardiac obstruction, adverse events, progression of tumour reduction and effect on heart failure.

CONCLUSIONS

ORACLE protocol addresses a relevant unmet need in children with tuberous sclerosis complex and cardiac rhabdomyoma. The results of the trial will potentially support the first evidence-based therapy for this condition.

Multiple cardiac rhabdomyomas in tuberous sclerosis complex: case report and review of the literature

Cardiac rhabdomyoma is a benign tumor which constitutes the most common cardiovascular feature of the tuberous sclerosis complex, a multisystem genetically determined neurocutaneous disorder. Cardiac rhabdomyomas can be detected in the prenatal ultrasound, are usually asymptomatic and spontaneously regress within the first three years of life. Less often, the tumors' size, number, and location can produce a mass effect that may lead to blood flow abnormalities or organ dysfunction (heart failure and arrhythmia). In this setting, severe morbidity, and eventually, a lethal outcome despite clinical and surgical treatment may ensue. We describe a fatal case of multiple cardiac rhabdomyomas in a newborn girl. One of the rhabdomyomas was large and unfavorably located, causing significant obstruction of the left ventricular outflow tract. The autopsy identified, in addition to cardiac rhabdomyomas, brain glioneuronal hamartomas (cortical tubers), subependymal nodules and subependymal giant cell tumors, characteristic of the tuberous sclerosis complex. The newborn's family was investigated for the presence of typical clinical symptoms of the complex and image findings showed significant phenotypical variations and a broad symptom spectrum among the family members. This interesting case underscores the variability of tuberous sclerosis complex and the importance of performing a comprehensive postmortem examination in the identification of the cause of death, especially in the setting of familial disease.

Everolimus for the treatment of refractory seizures associated with tuberous sclerosis complex (TSC): current perspectives

Up to 90% of patients with tuberous sclerosis complex (TSC) have epilepsy, and in over half of patients seizure control cannot be achieved by regular antiepileptic drugs. The underlying problem is mTOR hyperactivation due to loss of function of the TSC proteins. Treatment with everolimus, an mTOR inhibitor, has been shown to be of great benefit to TSC patients, both in reducing tumor growth and as a treatment for intractable epilepsy. Up to 40% of TSC patients with intractable epilepsy show a clinically relevant seizure response to everolimus. It has not yet fully lived up to its promise as a disease-modifying drug, however, as half of TSC patients with intractable epilepsy do not show a clinically relevant seizure frequency reduction. There is no evidence yet of a positive effect on the cognitive and neuropsychiatric deficits in TSC patients. In preclinical studies, mTOR inhibition can rescue abnormal neuronal migration and synapse formation that is caused by mTOR hyperactivation. These studies show a critical time window that suggests that mTOR inhibition may be most beneficial in young children. The trials done so far have not studied treatment in children under 2 years of age, although case series suggest that the safety profile is similar to that in older children. Further studies into the optimal time window, dosing schedules and possibly combination with other drugs may further improve the benefit of everolimus for TSC patients.

Clinical and genetic description of patients with prenatally identified cardiac tumors

OBJECTIVE

Rhabdomyomas are the most common type of prenatal cardiac tumors. When isolated, 50% to 70% are related to the tuberous sclerosis complex (TSC). The aim of this study was to reinforce the importance of additional clinical data in patients with prenatal heart tumors.

METHODS

From 2010 to 2017, 10 prenatally detected cardiac tumors were referred to the Genetics Department, and a complete family history was taken. Postnatal echocardiographic and full clinical evaluation were completed. Next generation sequencing (NGS) of the TSC1 and TSC2 genes was performed.

RESULTS

The 10 cases were postnatally confirmed as rhabdomyomas. Four de novo and four family cases were detected, and only one patient was previously aware of the TSC diagnosis. Molecular analysis by NGS was performed in four patients with three TSC2 mutations, two of which were previously reported and one not.

DISCUSSION

Prenatal cardiac tumors are associated with TSC in 60% of cases. Prenatal diagnosis of cardiac tumors permits a further analysis of family members using the fetus as a clue for familial disease diagnosis.

Effect and Complications of Everolimus Use for Giant Cardiac Rhabdomyomas with Neonatal Tuberous Sclerosis

Most cardiac rhabdomyomas with tuberous sclerosis (TS) are asymptomatic and spontaneously regress. However, some cases require surgical intervention due to arrhythmia and severe obstruction of cardiac inflow or outflow. We report herein a neonatal case of giant cardiac rhabdomyomas with TS and insufficient pulmonary blood flow from the right ventricle. Lipoprostaglandin E1 was necessary to maintain patency of the ductus arteriosus. We used everolimus, a mammalian target of rapamycin inhibitor, to diminish the cardiac rhabdomyomas. After treatment, the rhabdomyomas shrank rapidly, but the serum concentration of everolimus increased sharply (maximum serum trough level: 76.1 ng/mL) and induced complications including pulmonary hemorrhage, liver dysfunction, and acne. After the everolimus level decreased, the complications resolved. Everolimus may be a viable treatment option for rhabdomyomas, but its concentration requires close monitoring to circumvent complications associated with its use.

Use of Cardiac MRI to Assess Antitumor Efficacy of Everolimus in Sporadic Cardiac Rhabdomyoma

Cardiac rhabdomyoma is the most common neonatal cardiac tumor and is typically associated with tuberous sclerosis complex (TSC). Although these tumors may naturally regress, some patients require surgical resection because of cardiac instability. If not fully resected, patients may also require medical therapy to improve their hemodynamics. Everolimus, a mammalian target of rapamycin inhibitor, has shown promise in reducing rhabdomyoma in patients with TSC, but the drug's impact in patients without TSC has not been reported. Monitoring of tumor response has typically been limited to echocardiograms, which is not ideal given inherent difficulties in three-dimensional measurements. We report a case of sporadic cardiac rhabdomyoma in a neonate treated with everolimus resulting in tumor regression as documented by cardiac MRI. While on everolimus, our patient had an increased incidence of a preexisting arrhythmia, which resolved with planned cessation of therapy, suggesting that close monitoring is imperative in patients with arrhythmia.

Fetal Echocardiographic Detection of Cardiac Tumors: A Case Report of Multiple Fetal Cardiac Rhabdomyomas

Cardiac rhabdomyomas are the most common fetal cardiac tumor. They can be detected in the second and third trimesters. Rhabdomyomas are most commonly associated with the genetic disorder tuberous sclerosis complex. When associated with tuberous sclerosis complex, cardiac rhabdomyomas usually regress within the first few years of life, without complications. Symptoms depend on the size, number, and location of the rhabdomyomas. A case report of multiple cardiac rhabdomyomas that was found at 35 weeks’ gestation and is discussed.

Safety and efficacy of mTOR inhibitor treatment in patients with tuberous sclerosis complex under 2 years of age - a multicenter retrospective study

Background

Tuberous sclerosis complex (TSC) is a multisystem disease with prominent neurologic manifestations such as epilepsy, cognitive impairment and autism spectrum disorder. mTOR inhibitors have successfully been used to treat TSC-related manifestations in older children and adults. However, data on their safety and efficacy in infants and young children are scarce. The objective of this study is to assess the utility and safety of mTOR inhibitor treatment in TSC patients under the age of 2 years.

Results

A total of 17 children (median age at study inclusion 2.4 years, range 0–6; 12 males, 5 females) with TSC who received early mTOR inhibitor therapy were studied. mTOR inhibitor treatment was started at a median age of 5 months (range 0–19 months). Reasons for initiation of treatment were cardiac rhabdomyomas (6 cases), subependymal giant cell astrocytomas (SEGA, 5 cases), combination of cardiac rhabdomyomas and SEGA (1 case), refractory epilepsy (4 cases) and disabling congenital focal lymphedema (1 case). In all cases everolimus was used. Everolimus therapy was overall well tolerated. Adverse events were classified according to the Common Terminology Criteria of Adverse Events (CTCAE, Version 5.0). Grade 1–2 adverse events occurred in 12 patients and included mild transient stomatitis (2 cases), worsening of infantile acne (1 case), increases of serum cholesterol and triglycerides (4 cases), changes in serum phosphate levels (2 cases), increase of cholinesterase (2 cases), transient neutropenia (2 cases), transient anemia (1 case), transient lymphopenia (1 case) and recurrent infections (7 cases). No grade 3–4 adverse events were reported. Treatment is currently continued in 13/17 patients. Benefits were reported in 14/17 patients and included decrease of cardiac rhabdomyoma size and improvement of arrhythmia, decrease of SEGA size, reduction of seizure frequency and regression of congenital focal lymphedema. Despite everolimus therapy, two patients treated for intractable epilepsy are still experiencing seizures and another one treated for SEGA showed no volume reduction.

Conclusion

This retrospective multicenter study demonstrates that mTOR inhibitor treatment with everolimus is safe in TSC patients under the age of 2 years and shows beneficial effects on cardiac manifestations, SEGA size and early epilepsy.

mTOR Inhibitors as a New Therapeutic Strategy in Treatment Resistant Epilepsy in Hemimegalencephaly: A Case Report

Hemimegalencephaly is a hamartomatous malformation of one hemisphere. Functional hemispherectomy, the definitive treatment, is associated with significant morbidity and mortality in early infancy. Dysregulation of the mTOR pathway can result in malformations of cortical development, and mTOR inhibitors can effectively reduce seizures in tuberous sclerosis complex. We report a 6-day-old female with hemimegalencephaly and frequent seizures despite 9 antiseizure medications. At 3 months of age, while awaiting hemispherectomy, an mTOR inhibitor, rapamycin, was initiated by the neurologist. After 1 week of treatment, there was >50% reduction in seizures and total seizure burden, and after 2 weeks, development improved, resulting in deferral of surgery by 2.5 months with an increased body weight. Pathology demonstrated cortical dysplasia with upregulation of the mTOR pathway. Deep-sequencing of brain tissue demonstrated 16% mosaicism for a pathogenic de novo MTOR gene mutation. This case exemplifies how mTOR inhibitors could be considered for seizure reduction in patients with hemimegalencephaly while awaiting surgery.

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.

Symptomatic improvement using everolimus in infants with cardiac rhabdomyoma

Background:

Cardiac rhabdomyoma (CR) often shows spontaneous regression and needs close follow-up. These tumors may be associated with tuberous sclerosis complex (TSC), caused by the disinhibition of m-TOR protein.

Objective:

The aim of the study is to observe the efficacy of everolimus in infants with significant CR.

Materials and Methods:

This is a single-center prospective observational study including infants with significant CR causing either clinical symptoms or obstruction to the blood flow. Everolimus was administered at a dose of 4.5 mg/M2/wk till the symptomatic improvement. Liver and renal function tests were monitored during treatment.

Results:

There were six cases of suspected CR included in the study. Median age and weight of patients were 5 days (range: 1–90 days) and 3.2 kg (range: 2.2–4.5 kg), respectively. One patient was excluded after surgical excision biopsy during concomitant closure of associated large perimembranous ventricular septal defect confirmed it as a fibroma. The remaining all five cases showed regression of tumor during mean follow-up of 6.1 ± 5.1 months. One child developed varicella infection necessitating temporary discontinuation of medicine during follow-up. One case had sudden death at 4 months of age.

Conclusion:

Everolimus appears to be useful in selected cases of symptomatic CR. Multicentric studies are needed to determine its safety and efficacy in larger population.

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.

Autopsy case of right ventricular rhabdomyoma in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a genetic multisystem disorder characterized by widespread hamartomas in several organs, including the brain, heart, skin, eyes, kidney, lung, and liver. Rhabdomyoma is the most common cardiac tumor diagnosed in fetuses, neonates and infants, and is closely linked to TSC. Here we describe an autopsy case of right ventricular rhabdomyoma in TSC. The deceased was a 3-month-old male infant, and TSC with a cardiac tumor had been diagnosed before his death. Since the cardiac tumor had not been physically blocking the blood flow, he had not undergone surgical intervention. At autopsy, the patient's height was 62 cm and his body weight was 6 kg. The heart weighed 37.3 g and the right ventricle was filled with the tumor. The tumor measured 2.1 cm × 1.6 cm, being a fusion of multiple tumors with several attachment sites to the myocardium. Histologically, the tumor was diagnosed as a rhabdomyoma, and was positive for mammalian target of rapamycin (mTOR). The brain weighed 795.0 g, without hydrocephalus. The cut surface of the brain revealed multiple cortical tubers and subependymal nodules. Through screening for the TSC1 (hamartin) and TSC2 (tuberin) genes, a nonsense mutation, c.1108C>T:p.Gln370^∗, was detected in the TSC2 gene. Immediate cause of death was determined to be ventricular obstruction by a cardiac rhabdomyoma with insidious growth. This case highlights the need for forensic pathologists to perform a complete autopsy to determine the cause of sudden death with cardiac tumor, including genetic examination.

Giant left ventricular rhabdomyoma treated successfully with everolimus: case report and review of literature

IntroductionIntracardiac rhabdomyomas can cause severe ventricular dysfunction and outflow tract obstruction.Case reportA term newborn infant with antenatal diagnosis of giant left ventricle rhabdomyoma presented with cardiac failure and duct-dependent systemic circulation after birth. She was treated successfully with everolimus, showing decrease in tumour size and improvement in left ventricular ejection fraction.DiscussionTumour regression rate was 0.32 cm2/day and improved to 0.80 cm2/day with the use of everolimus. Herein we report a newborn with inoperable giant left ventricular cardiac rhabdomyoma and significant regression of the tumour. To our knowledge, this is the largest left ventricular rhabdomyoma reported. A review of the literature was undertaken for comparison.

CONCLUSION

Everolimus has proven to be efficacious in size reduction of cardiac rhabdomyomas in cases when surgical resection is not possible.

Evolution of a rare ECG pattern in an aggressive case of neonatal tuberous sclerosis complex

INTRODUCTION

Rhabdomyomas are the most frequent cardiac tumors in children. Furthermore, they are often associated to tuberous sclerosis complex, an autosomal dominant neurocutaneous disorder characterized by tumor-like malformations that involve many organ systems.

PRESENTATION OF THE CASE

We describe a rare ECG pattern in a severe case of neonatal tuberous sclerosis complex.

DISCUSSION

In the presence of significant rhabdomyomatosis related to tuberous sclerosis, multiple clusters of rhabdomyoma-like cells can infiltrate the myocardium, with increased fibrosis areas.

CONCLUSION

Considering the fact that rhabdomyomas often show spontaneous regression, close follow-up is sufficient in hemodynamically stable cases. Destruction of the conduction system, with arrhythmias as consequence, can be the presenting feature of diffuse rhabdomyomatosis.

Primary cardiac tumors associated with genetic syndromes: a comprehensive review

Various cardiac tumors occur in the setting of a genetic syndrome such as myxomas in Carney complex and rhabdomyomas in tuberous sclerosis. Tumor biology can be different in syndromic forms, and on imaging children sometimes demonstrate additional manifestations of the underlying syndrome. We discuss the imaging appearance of cardiac tumors occurring in the framework of a genetic syndrome, the findings that suggest an underlying syndrome, and the impact on management.

Punch-out lesion following regression of a large left ventricular outflow rhabdomyoma

Abstracts We report the case of a patient with rhabdomyoma of the left ventricular outflow tract, causing severe obstruction at birth. The tumour regressed completely by 6 years of age, leaving a punch-out lesion. The potential for spontaneous regression of these tumours and the formation of a myocardial lesion following rhabdomyoma regression are discussed.