Everolimus: a challenging drug in the treatment of multifocal inoperable cardiac rhabdomyoma

Neonatal Cardiac Rhabdomyoma: A Single-Center Experience

AIM

Cardiac rhabdomyoma, known as the most common benign cardiac tumor in childhood, is strongly associated with tuberous sclerosis complex. This study aims to present our single-center experience regarding clinical observations, diagnostic approaches, and treatment modalities for cardiac rhabdomyoma identified during the neonatal period.

PATIENTS AND METHODS

In this clinical observational study, we retrospectively assessed the outcomes of 12 newborn patients diagnosed with cardiac rhabdomyoma who were followed up in our neonatal intensive care unit over the past 12 years.

RESULTS

The mean gestational age of the patients was 38.2±1.6 weeks, with an average birth weight of 3193±314 grams. The mean postnatal age at initial diagnosis was 12.42±15.75 days. Tuberous sclerosis complex was clinically identified in 50% of cases (six patients). Seven infants received everolimus treatment, while three infants underwent clinical monitoring without specific interventions. A significant reduction in cardiac mass size was observed in all surviving patients, leading to their subsequent discharge from the hospital.

CONCLUSION

Cardiac rhabdomyomas often undergo spontaneous regression in early childhood. However, in cases with obstructive lesions or arrhythmias, they may present life-threatening consequences. Timely diagnosis, appropriate clinical management, and monitoring are crucial in optimizing outcomes for neonates with cardiac rhabdomyoma.

A case of massive fetal cardiac rhabdomyoma: ultrasound features and management

We report the case of a massive fetal cardiac rhabdomyoma recently occurred at our clinic. A woman at 23 weeks of gestational age was referred to our center for a fetal cardiac echogenic mass of 26 mm detected at the second-trimester screening ultrasound. During pregnancy, though, the mass progressively increased its dimensions until reaching 48 mm in diameter at 37 weeks of gestation. Fetal echoencephalography and brain magnetic resonance did not show any further fetal anomalies, but molecular genetic testing at amniocentesis revealed a heterozygotic missense variant of gene TSC2 associated with Tuberous Sclerosis. The mass was therefore most likely preferable to a single large rhabdomyoma of gradually increasing dimensions. The baby was delivered at term with a cesarean section. Because of the rhabdomyoma remarkable size and newborn ECG electrical alterations, postnatal therapies with Flecainide and Everolimus were started. Everolimus treatment led to a significant and progressive reduction in the cardiac mass volume. This case, therefore, shows the efficacy of what seems to be a promising treatment in pediatric patients with large rhabdomyomas.Learning points:Rhabdomyomas may present with different features: most often they appear as multiple masses along the interventricular sept, but they may also appear as a single large thoracic mass.When a rhabdomyoma is suspected, genetic counseling is recommended.Both before and after birth, a multidisciplinary approach is useful to choose the appropriate therapy for the newborn.mTOR inhibitors therapies look like promising therapeutic approaches to stimulate the involution of rhabdomyomas.

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.

Perinatal outcome in prenatally diagnosed cardiac rhabdomyoma case series

OBJECTIVE

This study aims to determine the characteristics and outcome of prenatally diagnosed cardiac rhabdomyomas.

STUDY DESIGN

This retrospective descriptive study includes cases referred to our university hospital. We studied sonographic characteristics of rhabdomyoma along with the neonatal outcome.

RESULTS

Eight cases were included, with a mean gestational age at diagnosis at 31 weeks of gestation and five patients diagnosed after 32 weeks. We noted a male gender in 75%, multiple rhabdomyoma in 50%, mostly situated in the interventricular septum (41%) and valvular regurgitation in 25%. Most patients delivered at term, including five cesareans (62.5%). Six babies survived (75%); three of them were later diagnosed with tuberous sclerosis (50%).

CONCLUSION

Cardiac rhabdomyoma have variable ultrasound features. The usual favorable outcome can however be complicated by neonatal death (12%), valvular regurgitation and cerebral tuber.

Rhabdomyoma and Hypoplastic Left Heart Syndrome - Case Report of a Very Rare Combination

The most benign cardiac tumor in the pediatric population is cardiac rhabdomyoma. They are known to be associated with tuberous sclerosis complex. Here we report a case with multiple cardiac rhabdomyomas and another rare anomaly of the heart known as hypoplastic left heart syndrome. The fetus was antenatally diagnosed with echocardiography which showed both rhabdomyoma and hypoplastic left heart. The patient was started on prostaglandin immediately after birth. He was confirmed postnatally to have inoperable congenital hypoplastic left heart syndrome. On the third day, the baby started to have progressive bradycardia and then died.

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.

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.

Combination percutaneous and medical management of cardiac rhabdomyomas obstructing tricuspid valve inflow: Case report

BACKGROUND

Cardiac rhabdomyomas can be prenatally diagnosed in patients with tuberous sclerosis complex. Many neonates require no intervention in early life other than close monitoring for regression of tumor over the period of months to years. In rare instances, cardiac rhabdomyomas can result in obstruction to blood flow or decreased ventricular function.

CASE REPORT

We describe the case of a neonate who was prenatally diagnosed with multiple large cardiac rhabdomyomas, one of which caused clinically significant obstruction to prograde blood flow across the tricuspid valve in the newborn period. To address the disturbance to prograde pulmonary blood flow, the patient underwent successful ductal stent placement in the neonatal period. A troponin elevation was noted shortly after birth, but no evidence of coronary compression or involvement was demonstrated by coronary angiography. The patient has subsequently been treated with sirolimus over a period of three months, with noted regression in tumors and improvement in tricuspid valve inflow.

CONCLUSIONS

A brief review of the literature regarding the diagnosis, treatment, and management of neonatal patients with cardiac rhabdomyomas is presented. A combined percutaneous and medical management approach may be of benefit in future cases of rhabdomyomas causing obstruction to pulmonary blood flow.

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.

Literature review of international mammalian target of rapamycin inhibitor use in the non-surgical management of haemodynamically significant cardiac rhabdomyomas

Cardiac rhabdomyomas represent the most common primary paediatric cardiac tumour and typically regresses over time in the majority of patients. Among those who are symptomatic, surgical resection or catheterisation procedures have traditionally proven effective. More recently, those invasive or challenging tumours have been successfully treated with mammalian target of rapamycin inhibitors, typically everolimus and sirolimus. This review outlines the current medical literature of the state-of-the-art medical treatment of these tumours. We specifically focus on dosing regimens, duration of therapy, and side-effect profiles of mammalian target of rapamycin inhibitors among this population. Although the majority of cases responded to mammalian target of rapamycin inhibition, standardised guidelines for dosing and duration of treatment remain to be defined.

Cardiac tumors in both twins - A case report of a rare occurrence

Cardiac tumors in neonates and infancy are one among the many known congenital cardiac diseases. Although fetal cardiac tumors are rare, there is increased detection because of expertise in echocadiographic examination. Rhabdomyomas are the most common cardiac tumors among infants and children. Here, we describe twin neonates who had multiple cardiac tumors. This kind of presentation appears to be a very rare situation.

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.

Cardiac rhabdomyomas with atrial septal defect and tricuspid insufficiency: A case report

Primary cardiac tumors are very rare and generally benign. The most common type, cardiac rhabdomyoma, comprises 45% to 75% of primary cardiac tumors. Cardiac rhabdomyoma is a rare benign tumor that commonly presents with tuberous sclerosis. We present a case of an infant with multifocal cardiac rhabdomyomas with an atrial septal defect and tricuspid insufficiency and no sign of tuberous sclerosis. She was successfully treated with an operation, the treatment plan included mass resection, tricuspid annuloplasty, and closure of the patent foramen ovale. The right atrial lesion was resected entirely, while the lobulated lesion in the right ventricle was resected as two pieces. There was no evidence of recurrence 1 year after the surgery.

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.

Sirolimus therapy for fetal cardiac rhabdomyoma in a pregnant woman with tuberous sclerosis

Rhabdomyoma is the most common fetal cardiac tumor, and its development is related to tuberous sclerosis. Fetal cardiac rhabdomyomas often spontaneously regress in utero or after birth, but large tumors can cause hemodynamic obstruction. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been used as an immunosuppressant after organ transplantation. The mTOR inhibitors are well-known to have anti-tumor activity, and they have been used for the treatment of patients with tuberous sclerosis. In the current case, fetal cardiac rhabdomyoma was completely resolved in utero during oral sirolimus treatment in the mother with tuberous sclerosis. This case shows that oral sirolimus therapy in pregnancy may be a treatment for multiple or large fetal cardiac rhabdomyomas.

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.

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.

The UK guidelines for management and surveillance of Tuberous Sclerosis Complex

BACKGROUND

The severity of Tuberous Sclerosis Complex (TSC) can vary among affected individuals. Complications of TSC can be life threatening, with significant impact on patients' quality of life. Management may vary dependent on treating physician, local and national policies, and funding. There are no current UK guidelines. We conducted a Delphi consensus process to reach agreed guidance for the management of patients with TSC in the UK.

METHODS

We performed a literature search and reviewed the 2012/13 international guideline for TSC management. Based on these, a Delphi questionnaire was formed. We invited 86 clinicians and medical researchers to complete an online survey in two rounds. All the people surveyed were based in the UK. Clinicians were identified through the regional TSC clinics, and researchers were identified through publications. In round one, 55 questions were asked. In round two, 18 questions were asked in order to obtain consensus on the outstanding points that had been contentious in round one. The data was analysed by a core committee and subcommittees, which consisted of UK experts in different aspects of TSC. The Tuberous Sclerosis Association was consulted.

RESULTS

About 51 TSC experts took part in this survey. Two rounds were required to achieve consensus. The responders were neurologists, nephrologists, psychiatrist, psychologists, oncologists, general paediatricians, dermatologist, urologists, radiologists, clinical geneticists, neurosurgeons, respiratory and neurodisability clinicians.

CONCLUSIONS

These new UK guidelines for the management and surveillance of TSC patients provide consensus guidance for delivery of best clinical care to individuals with TSC in the UK.

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.

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.

Rapid regression of large cardiac rhabdomyomas in neonates after sirolimus therapy

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

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.

Fetal Primary Cardiac Tumors During Perinatal Period

Fetal primary cardiac tumors are rare, but they may cause complications, which are sometimes life threatening, including arrhythmias, hydrops fetalis, ventricular outflow/inflow obstruction, cardiac failure, and even sudden death. Among fetal primary cardiac tumors, rhabdomyomas are most common, followed by teratomas, fibromas, hemangiomas, and myxomas. Everolimus, a mammalian target of rapamycin inhibitor, has been reported to be an effective drug to cause tumor remission in three neonates with multiple cardiac rhabdomyomas. Neonatal cardiac surgery for the resection of primary cardiac tumors found by fetal echocardiography has been reported sporadically. However, open fetal surgery for pericardial teratoma resection, which was performed successfully via a fetal median sternotomy in one case report, could be a promising intervention to rescue these patients with large pericardial effusions. These recent achievements undoubtedly encourage further development in early management of fetal cardiac tumors. Owing to the rarity of fetal primary cardiac tumors, relevant information in terms of prenatal diagnosis, treatment, and prognosis remains to be clarified.

Rapid Regression of Obstructive Cardiac Rhabdomyoma in a Preterm Neonate after Sirolimus Therapy

Cardiac rhabdomyoma can be subclinical or fatal depending on the onset age, involving site, and the size and degree of invasion. Although most rhabdomyomas become smaller with time, emergency intervention is indicated when severe obstruction induces hemodynamic instability. Mammalian target of rapamycin (mTOR) inhibitors have been used to treat neonates and children with hemodynamically obstructive cardiac rhabdomyoma. Herein, we report a premature neonate at the gestational age of 30 + 4 weeks with severe left ventricular outflow tract obstructive cardiac rhabdomyoma who was successfully treated with the mTOR inhibitor sirolimus. To the best of our knowledge, this is the first recorded case of a premature neonate with obstructive cardiac rhabdomyoma who was successfully treated with an mTOR inhibitor. Therefore, sirolimus could be considered as an alternative medical option for managing premature neonates with obstructive cardiac rhabdomyoma.

Assessment of tumors in children with tuberous sclerosis: a single centre's experience

AIM

As a result of mutations in TSC1 (9q34) and TSC2 (16p13.3) tumor supressor genes, the mammalian target of the rapamycin (mTor) signaling pathway is overactivated in patients with tuberous sclerosis. Abnormal cell proliferation and differentiation is responsible for the growth several different tumors. The aim of this study was to review tumors in our patients with tuberous sclerosis.

MATERIAL AND METHODS

Thirty-six patients with tuberous sclerosis were reviewed retrospectively in terms of age, sex, family history, clinical findings, presence of tumors, and treatments.

RESULTS

Our study included 36 patients (18/18:M/F) aged between two days and 17 years with a median age of 6 years. There were hypopigmented spots in 30 patients, seizures in 28 patients, and a family history in 11 patients. Tumors related to tuberous sclerosis were renal angiomyolipomas in 21 patients, cardiac rhabdomyomas in 11, subependymal giant cell astrocytomas in seven, and non renal hamartoma in one patient. Everolimus treatment was used in only two patients because of hemodynamic instability.

CONCLUSIONS

Tuberous sclerosis is a multisystemic disease characterized by the presence of various benign tumors and neurologic disorders. Renal angiomyolipomas, cardiac rhabdomyomas, and subependymal giant cell astrocytomas are commonly observed in patients with tuberous sclerosis. mTOR inhibitors such as everolimus and sirolimus have been increasingly used in the treatment of these tumors. However, the duration and optimal dose of mTOR inhibitors is still controversial and should be used in selected cases.

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.

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

Tuberous sclerosis complex is associated with benign tumors such as cardiac rhabdomyomas (RHM) caused by the disinhibition of the mammalian target of rapamycin (mTOR) protein. Recent reports on everolimus, an mTOR inhibitor, have shown size reduction of RHM. We compared cases recently treated with everolimus to historic controls whose first echocardiography was within first month of life. The largest dimension of the largest RHM was reported as a percentage compared to the earliest echocardiography study. Treatment of the four cases was started at a median age of 6.5 days (range 2-20) with an initial enteral dose of 0.1 mg daily, aiming at a therapeutic serum trough level of 5-15 ng/mL. Median duration of everolimus treatment was 73 days (range 34-138). Compared to 10 historic controls, everolimus-treated patients had 11.8 times faster RHM size regression rate (slope -0.0285 vs. -0.0024; p < 0.001). The average time to 50% size reduction was 1.13 ± 0.33 month (range 0.66-1.4 months) with everolimus versus 72.9 ± 53.03 months in controls (p = 0.026). Following treatment with everolimus, one case was operated for congenital heart disease, without requirement of RHM resection, two others had the massive left ventricle RHM shrink to non-consequential size. The latter had a disappearance of RHM, but everolimus therapy was maintained to prevent the regrowth of a significant cerebral tumor. Everolimus is efficacious for size reduction of RHM during the neonatal period. With limited safety data, this approach should be used with caution in selective cases.

Regression of Neonatal Cardiac Rhabdomyoma in Two Months Through Low-Dose Everolimus Therapy: A Report of Three Cases

Cardiac rhabdomyoma (CR) is the most common cardiac tumor in newborns. Approximately 75% of cases are associated with tuberous sclerosis complex. Although these tumors usually spontaneously regress after 2 years of age, they can be life-threatening when they obstruct major cardiac inflow or outflow pathways. Everolimus is an inhibitor of the mammalian target of rapamycin, reducing its production of the proteins harmartin and tuberin. Everolimus has demonstrated a remarkable suppression effect in children with tuberous sclerosis complex at doses of 4.7-5.6 mg/M²/day and serum trough levels of 5-15 ng/mL. Since 2012, five case reports of neonates with CR have also reported the tumor-regressing effect of everolimus. However, the optimal dosage for neonates is still unknown. Over the past 2 years, we have deliberately used a low dose everolimus regimen (0.3-0.67 mg/M²/day) in three neonates with large CRs, in an effort to maintain serum trough levels at 3-7 ng/mL. In all three cases, the tumors regressed smoothly within 2 months. Regarding the drug's side effect of predisposing patients to infection, we observed that adenovirus pneumonia occurred in one case at 3 months of age, and chicken pox occurred in another case at 9 months of age; both recovered smoothly. Our three cases of neonatal CR demonstrate that a low-dose everolimus regimen is an effective treatment for tumor regression.

Long-term treatment of epilepsy with everolimus in tuberous sclerosis

OBJECTIVE

To evaluate the long-term benefit and safety of everolimus for the treatment of medically refractory epilepsy in patients with tuberous sclerosis complex (TSC).

METHODS

Everolimus was titrated over 4 weeks and continued an additional 8 weeks in a prospective, open-label, phase I/II clinical trial design. Participants demonstrating initial benefit continued treatment until study completion (48 months). The primary endpoint was percentage of patients with a ≥50% reduction in seizure frequency compared to baseline. Secondary endpoints assessed absolute seizure frequency, adverse events (AEs), behavior, and quality of life.

RESULTS

Of the 20 participants who completed the initial study phase, 18 continued extended treatment. Fourteen of 18 (78%) participants completed the study, all but 1 of whom reported ≥50% reduction in seizure frequency at 48 months. All participants reported at least 1 AE, the vast majority (94%) of which were graded mild or moderate severity. Improvements in behavior and quality of life were also observed, but failed to achieve statistical significance at 48 months.

CONCLUSIONS

Improved seizure control was maintained for 4 years in the majority of patients with TSC with medically refractory epilepsy treated with everolimus. Long-term treatment with everolimus is safe and well-tolerated in this population. Everolimus may be a therapeutic option for refractory epilepsy in TSC.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for patients with TSC with medically refractory epilepsy everolimus improves seizure control.

Regression of Cardiac Rhabdomyomas in a Neonate after Everolimus Treatment

Cardiac rhabdomyoma often shows spontaneous regression and usually requires only close follow-up. However, patients with symptomatic inoperable rhabdomyomas may be candidates for everolimus treatment. Our patient had multiple inoperable cardiac rhabdomyomas causing serious left ventricle outflow-tract obstruction that showed a dramatic reduction in the size after everolimus therapy, a mammalian target of rapamycin (mTOR) inhibitor. After discontinuation of therapy, an increase in the diameter of masses occurred and everolimus was restarted. After 6 months of treatment, rhabdomyomas decreased in size and therapy was stopped. In conclusion, everolimus could be a possible novel therapy for neonates with clinically significant rhabdomyomas.

Everolimus-induced near-resolution of giant cardiac rhabdomyomas and large renal angiomyolipoma in a newborn with tuberous sclerosis complex

We report a case of a newborn, affected by tuberous sclerosis complex, with a prenatally diagnosed giant cardiac rhabdomyoma associated with a large renal angiomyolipoma presenting as a duct-depending lesion not treatable by surgery. After receiving everolimus, a mammalian target of rapamycin inhibitor, we observed a rapid, significant, and durable reduction of both lesions without remarkable side effects.

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.

Rapid resolution of cardiac rhabdomyomas following everolimus therapy

Cardiac rhabdomyoma is the most common primary cardiac tumour during childhood and is usually associated with tuberous sclerosis complex (TSC). These tumours are generally considered benign, and spontaneous regression occurs commonly. However, when the tumours cause significant symptoms, the current standard treatment is surgical resection. Everolimus is an mammalian target of rapamycin (mTOR) complex 1 inhibitor that has been successfully used to treat subependymal giant cell astrocytomas and renal angiomyolipomas associated with TSC. A few case reports have described the effectiveness of everolimus therapy in treating cardiac rhabdomyomas as well. We report a case of a newborn who had near complete resolution of multiple rhabdomyomas within a month of receiving everolimus therapy for non-cardiac masses. To the best of our knowledge, this is the fastest resolution of cardiac rhabdomyomas associated with everolimus therapy to date. Everolimus may be a promising alternative for high-risk surgical candidates with haemodynamically significant cardiac rhabdomyomas.

Mammalian Target of Rapamycin Inhibitors and Life-Threatening Conditions in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a multisystem disease associated with an overall reduction in life expectancy due to the possible occurrence of different life-threatening conditions. Subjects affected by TSC are, in fact, at risk of hydrocephalus secondary to the growth of subependymal giant cell astrocytomas, or of sudden unexpected death in epilepsy. Other nonneurological life-threatening conditions include abdominal bleeding owing to renal angiomyolipomas rupture, renal insufficiency due to progressive parenchymal destruction by multiple cysts, pulmonary complications due to lymphangioleiomyomatosis, and cardiac failure or arrhythmias secondary to rhabdomyomas. In the last decades, there has been a great progress in understanding the pathophysiology of TSC-related manifestations, which are mainly linked to the hyperactivation of the so-called mammalian target of rapamycin (mTOR) pathway, as a consequence of the mutation in 1 of the 2 genes TSC1 or TSC2. This led to the development of new treatment strategies for this disease. In fact, it is now available as a biologically targeted therapy with everolimus, a selective mTOR inhibitor, which has been licensed in Europe and USA for the treatment of subependymal giant cell astrocytomas and angiomyolipomas in subjects with TSC. This drug also proved to benefit other TSC-related manifestations, including pulmonary lymphangioleiomyomatosis, cardiac rhabdomyomas, and presumably epileptic seizures. mTOR inhibitors are thus proving to be a systemic therapy able to simultaneously address different and potentially life-threatening complications, giving the hope of improving life expectation in individuals with TSC.

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.

Everolimus Treatment for an Early Infantile Subependymal Giant Cell Astrocytoma With Tuberous Sclerosis Complex

Subependymal giant cell astrocytomas are benign tumors often observed with tuberous sclerosis complex. These tumors are rarely diagnosed during fetal life or early infancy. Until recently, the only available treatment has been surgical resection. Current clinical research has demonstrated that everolimus can induce these tumors' regression. We report a 19-month-old boy with tuberous sclerosis complex. At 2 months of age, he presented with congenital subependymal giant cell astrocytoma that was complicated by refractory epilepsy and severe mental retardation. Treatment with everolimus was started when he was 10 months old. Three months after initiating everolimus, the tumor was significantly reduced in size, and the reduction was subsequently maintained. His seizures decreased and he showed cognitive and developmental improvement. No severe adverse events have been observed to date. Everolimus has promise as an effective alternative to surgery for subependymal giant cell astrocytomas during early infancy.

Oral Everolimus for Treatment of a Giant Left Ventricular Rhabdomyoma in a Neonate-Rapid Tumor Regression Documented by Real Time 3D Echocardiography

The presented case reports on successful treatment with everolimus in a neonate with left ventricular giant rhabdomyoma. The authors used a different dosage regime compared to literature and documented rapid tumor regression by 3D echocardiography.

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.

Regression of symptomatic multiple cardiac rhabdomyomas associated with tuberous sclerosis complex in a newborn receiving everolimus

Cardiac rhabdomyoma is the most common primary cardiac tumor, is considered to be a hamartoma of developing cardiac myocytes. Cardiac rhabdomyoma is associated with tuberous sclerosis complex (TSC) in 50-86% of cases. Mutations in TSC-1/TSC-2 genes result in increased mammalian target of rapamycin (mTOR) pathway activation responsible for the hamartomatous lesions of tuberous sclerosis complex. Therapy with mTOR inhibitors is currently under investigation as a treatment option for tumors associated with TSC. In this report we present a case with multiple symptomatic rhabdomyomas associated with tuberous sclerosis complex, deemed to be ineligible for surgical removal, treated with everolimus (mTOR inhibitor).

CONCLUSION

As we observed in our patient, in cases with inoperable symptomatic rhabdomyomas associated with TSC, everolimus, an mTOR inhibitor, may be the treatment of choice, which should be confirmed with additional studies.

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

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

Rapid regression of left ventricular outflow tract rhabdomyoma after sirolimus therapy

The neonatal presentation of cardiac rhabdomyomas varies in severity from severe outflow tract obstruction to minimal cardiac dysfunction. The natural history for these lesions is spontaneous regression in the majority of cases. We describe a newborn boy with severe left ventricular outflow tract obstruction secondary to a large rhabdomyoma. The tumor infiltrated the paraaortic area and extended around the origin of the right coronary artery, making surgical resection challenging. Oral sirolimus therapy resulted in a rapid regression of the tumor and alleviation of outflow tract obstruction within 1 month of treatment. This is the first report of sirolimus therapy in alleviating critical left ventricular outflow tract obstruction in this condition.