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.

Inhibition of p70 Ribosomal S6 Kinase (S6K1) Reduces Cortical Blood Flow in a Rat Model of Autism-Tuberous Sclerosis

The manifestations of tuberous sclerosis complex (TSC) in humans include epilepsy, autism spectrum disorders (ASD) and intellectual disability. Previous studies suggested the linkage of TSC to altered cerebral blood flow and metabolic dysfunction. We previously reported a significant elevation in cerebral blood flow in an animal model of TSC and autism of young Eker rats. Inhibition of the mammalian target of rapamycin (mTOR) by rapamycin could restore normal oxygen consumption and cerebral blood flow. In this study, we investigated whether inhibiting a component of the mTOR signaling pathway, p70 ribosomal S6 kinase (S6K1), would yield comparable effects. Control Long Evans and Eker rats were divided into vehicle and PF-4708671 (S6K1 inhibitor, 75 mg/kg for 1 h) treated groups. Cerebral regional blood flow (14C-iodoantipyrine) was determined in isoflurane anesthetized rats. We found significantly increased basal cortical (+ 32%) and hippocampal (+ 15%) blood flow in the Eker rats. PF-4708671 significantly lowered regional blood flow in the cortex and hippocampus of the Eker rats. PF-4708671 did not significantly lower blood flow in these regions in the control Long Evans rats. Phosphorylation of S6-Ser240/244 and Akt-Ser473 was moderately decreased in Eker rats but only the latter reached statistical significance upon PF-4708671 treatment. Our findings suggest that moderate inhibition of S6K1 with PF-4708671 helps to restore normal cortical blood flow in Eker rats and that this information might have therapeutic potential in tuberous sclerosis complex and autism.

A Review of Topical Sirolimus for the Treatment of Facial Angiofibromas in Tuberous Sclerosis Complex

OBJECTIVE

This article assesses the efficacy, safety, pharmacology, and clinical applications of topical sirolimus 0.2% gel for the treatment of tuberous sclerosis complex (TSC)-associated facial angiofibromas.

DATA SOURCES

A review of the literature was conducted using the Medline (PubMed) and EMBASE databases using the keywords topical sirolimus, rapamycin, Hyftor, and tuberous sclerosis.

STUDY SELECTION AND DATA EXTRACTION

Articles written in English and relevant to the topic were included.

DATA SYNTHESIS

In the phase 2 trial, the mean improvement factor, a composite measure of improved tumor size and redness, was achieved in all patient groups (P < 0.001) with significant responses among the adult and pediatric subgroups at week 12. There were no serious adverse events recorded. In the phase 3 trial, 60% of participants responded to treatment in the sirolimus group compared with 0% in the placebo group with different response rates between the adult and pediatric subgroups at week 12. Sirolimus gel had no serious adverse events, and dry skin was the most common adverse reaction. Patients who had completed the 12-week trials were then enrolled in a long-term trial; angiofibromas had response rates of 78.2% to 0.2% sirolimus gel.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE IN COMPARISON TO EXISTING DRUGS

Topical sirolimus 0.2% is a first-in-class, newly Food and Drug Administration (FDA)-approved, mammalian target of rapamycin (mTOR) inhibitor that is a promising and safe, noninvasive alternative to surgical procedures for TSC-associated angiofibromas.

CONCLUSIONS

Topical sirolimus 0.2% gel is a moderately effective treatment for TSC-associated facial angiofibromas with an adequate safety profile.

Tuberous sclerosis complex in adulthood: focus on epilepsy prognosis

OBJECTIVE

Typically diagnosed in early childhood or adolescence, TSC is a chronic, multisystemic disorder with age-dependent manifestations posing a challenge for transition and for specific surveillance throughout the lifetime. Data on the clinical features and severity of TSC in adults and on the prognosis of epilepsy are scarce. We analyzed the clinical and genetic features of a cohort of adult patients with TSC, to identify the prognostic predictors of seizure remission after a long follow-up.

METHOD

We conducted a retrospective analysis of patients diagnosed with TSC according to the updated international diagnostic criteria. Pearson's chi-square or Fisher's exact test and Mann Whitney U test were used to compare variables among the Remission (R) and Non-Remission (NR) group. Univariate and multivariate logistic regression analyses were performed.

RESULTS

We selected 43 patients with TSC and neurological involvement in terms of epilepsy and/or brain lesions, attending the Epilepsy Center of our Institute: of them, 16 (37.2%) were transitioning from the pediatric care and 6 (13.9%) were referred by other specialists. Multiorgan involvement includes cutaneous (86.0%), nephrological (70.7%), hepatic (40.0%), ocular (34.3%), pneumological (28.6%) and cardiac (26.3%) manifestations. Thirty-nine patients (90.7 %) had epilepsy. The mean age at seizure onset was 4 ± 7.3 years: most patients (29, 76.3 %) presented with focal seizures or spasms by age 3 years; only 2 (5.3 %) had seizure onset in adulthood. Twenty-seven patients (69.2 %) experienced multiple seizure types overtime, 23 (59.0 %) had intellectual disability (ID). At last assessment, 14 (35.9 %) were seizure free (R group) and 25 (64.1 %) had drug-resistant seizures (NR group). At logistic regression univariate analysis, ID (OR 7.9, 95 % CI 1.8--34.7), multiple seizure types lifelong (OR 13.2, 95 % CI 2.6- 67.2), spasms/tonic seizures at presentation (OR 6.5, 95 % CI 1.2--35.2), a higher seizure frequency at onset (OR 5.4, 95 % CI 1.2--24.3), abnormal neurological examination (OR 9.8, 95 % CI 1.1--90.6) and pathogenic variants in TSC2 (OR 5.4, 95 % CI 1.2--24.5) were significantly associated with non-remission. In the multivariate analysis, both ID and multiple seizure types lifelong were confirmed as independent predictors of poor seizure outcome.

CONCLUSIONS

In our cohort of adult patients with TSC, epilepsy remains one of the main neurological challenges with only 5.3% of cases manifesting in adulthood. Approximately 64% of these patients failed to achieve seizure remission. ID and multiple seizure types were the main predictors of poor outcome. Nephrological manifestations require continuous specific follow-up in adults.

Treatment of tuberous sclerosis complex manifestations in children with mTOR inhibitors

PURPOSE

Tuberous sclerosis complex (TSC) is a rare autosomal dominant genetic disorder that affects multiple organ systems. Mutations in the TSC1 and TSC2 genes result in the constitutive hyperactivation of the mammalian target of rapamycin (mTOR) pathway, contributing to the growth of benign tumors or hamartomas in various organs. Due to the implication of mTOR pathway dysregulation in the disease pathology, increasing evidence supports the use of mTOR inhibitors for treating multiple manifestations of TSC.

METHODS

In this study, we conducted a retrospective analysis of clinical findings and treatment data from 38 patients diagnosed with tuberous sclerosis who were followed up in the Pediatric Oncology Clinic between 2010 and 2020. We collected information on patients' ages, genders, affected sites, familial history, imaging findings, presence of tumors, and treatments.

RESULTS

Among the patients, nine individuals with TSC manifestations were treated with mTOR inhibitors. Specifically, everolimus was successfully administered to five patients with inborn cardiac rhabdomyoma causing hemodynamic impairment. In addition, two patients with refractory seizures received everolimus in combination with anti-epileptic drugs. A patient with renal angiomyolipomas larger than 3 cm was treated with everolimus, while a patient with extensive facial angiofibroma received topical sirolimus. All patients tolerated the mTOR inhibitors well, and the side effects were deemed acceptable.

CONCLUSION

The utilization of mTOR inhibition in TSC is expected to become more prevalent in clinical practice, as current research is anticipated to provide a better understanding of the therapeutic roles of these treatments in TSC.

An updated meta-analysis of effectiveness and safety of mTOR inhibitors in the management of tuberous sclerosis complex patients

PURPOSE

Tuberculous sclerosis complex (TSC) is an autosomal dominant multi-system disease. In TSC patients, the inhibition of mTOR pathway is weakened, which leads to the uncontrolled proliferation of normal resting cells. Therefore, mTOR inhibitors have many therapeutic potentials in the treatment of TSC. However, there is no consensus on the safety and efficacy of mTOR inhibitors so far. This article aimed to present new evidence for the efficacy and safety of mTOR inhibitors in the treatment of TSC by evaluating published clinical trials.

METHODS

A systemic search of online databases, such as Cochrane Library, Embase, PubMed, and the US National Institutes of Health Clinical Trials Registry, was conducted. The researchers selected studies that met the following entry criteria: randomized, double-blinded or single-blinded, placebo-controlled, parallel-group studies with active and control arms receiving rapamycin or everolimus and matched placebo, respectively. The meta-analysis included seven studies. Tumor response or epilepsy seizure frequency response rates were considered efficacy outcomes.

RESULTS

In seven studies involving 877 patients, using of mTOR inhibitors therapy showed an improvement in both tumor response and seizure frequency outcomes in TSC. In combination of AML (angiomyolipomas), SEGA (subependymal giant cell astrocytoma), epilepsy, and facial angiofibroma subjects, the RR is 3.01 (95% CI 2.03 to 4.45, p = 0.000) with observed heterogeneity (I-squared = 55.4%). The main side effect of mTOR inhibitors was stomatitis.

CONCLUSION

The updated meta-analysis suggests that the use of mTOR inhibitors is an effective therapy for patients with TSC.

Treatment guidelines for rare, early-onset conditions associated with epileptic seizures: a literature review on Rett syndrome and tuberous sclerosis complex

BACKGROUND

Rett syndrome (RTT) and tuberous sclerosis complex (TSC) are two rare disorders presenting with a range of different epileptic seizures. Seizure management requires careful therapy selection, thereby necessitating development of high-quality treatment guidelines. This targeted literature review (TLR) aimed to characterise country-specific and international treatment guidelines available for pharmacological management of seizures in RTT and TSC.

METHODS

A TLR was performed between 25-Jan and 11-Mar 2021. Manual searches of online rare disease and guideline databases, and websites of national heath technology assessment bodies were conducted for the following countries: Australia, Canada, France, Germany, Israel, Italy, Japan, Spain, Switzerland, UK, and US as defined by pre-specified eligibility criteria. Search terms were developed for each condition and translated into local languages where appropriate. Eligible publications were defined as guidelines/guidance reporting pharmacological management of seizures in patients with RTT and TSC. Guideline development methodology, geographical focus, author information and treatment recommendations were extracted from guidelines. An author map was generated using R version 3.5.1 to visualise extent of collaboration between authors.

RESULTS

24 total guidelines were included, of which three and six contained only recommendations for RTT and TSC, respectively (some provided recommendations for ≥ 1 condition). Guideline development processes were poorly described (50% [12 guidelines] had unclear/absent literature review methodologies); reported methodologies were variable, including systematic literature reviews (SLRs)/TLRs and varying levels of expert consultation. Most (83% [20/24]) were country-specific, with guideline authors predominantly publishing in contained national groups; four guidelines were classified as 'International,' linking author groups in the US, UK, Italy and France. High levels of heterogeneity were observed in the availability of treatment recommendations across indications, with 13 and 67 recommendations found for RTT and TSC, respectively. For RTT, all treatment recommendations were positive and sodium valproate had the highest number of positive recommendations (Khwaja, Sahin (2011) Curr Opin Pediatr 23(6):633-9). All TSC treatments (21 medications) received either exclusively negative (National Organization for Rare Disorders (2019)) or positive (Chu-Shore et al. (2010) Epilepsia 51(7):1236-41) recommendations; vigabatrin received the highest number of positive recommendations (Kaur, Christodoulou (2019)).

CONCLUSIONS

This review highlights the need for the development of international high-quality and comprehensive consensus-based guidance for the management of seizures with pharmacological therapy in RTT and TSC.

TRIAL REGISTRATION

Not applicable.

The association between computed tomography attenuation value of renal angiomyolipoma associated with tuberous sclerosis complex and response to everolimus

BACKGROUND

The response to everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex (TSC-RAML) varies among individuals. This study aims to identify potential factors associated with the response to everolimus.

METHOD

We retrospectively examined data encompassing age, gender, tumor size, computed tomography attenuation value (CT value), CT enhancement, and tumor reduction rate in patients with TSC-RAML undergoing everolimus in two previously registered clinical trials.

RESULT

A total of 33 participants (29.33 ± 6.63 years old, 20 females) were included. The correlation analysis conducted separately for tumors located in the left and right kidneys revealed significant negative correlations (P < 0.05) between tumor reduction rate and age, as well as tumor size. While significant positive correlations (P < 0.05) were observed between tumor reduction rate and unenhanced CT value as well as CT enhancement. Nonetheless, based on multiple linear regression analysis, unenhanced CT value emerged as the sole-independent predictor of tumor reduction rate among age, gender, tumor size, unenhanced CT value and CT enhancement for both left (coefficient = 0.00319, P < 0.0001) and right kidneys (coefficient = 0.00315, P = 0.0104). Notable reductions were observed in unenhanced CT value (- 3.81 vs - 24.70HU, P < 0.0001) and CT enhancement (48.16 vs 33.56HU, P < 0.0001) following a 3-month administration of everolimus. The decline in both unenhanced CT value and tumor size predominantly occurred within the initial 3 months, subsequently maintaining a relatively stable level throughout the treatment.

CONCLUSION

The unenhanced CT value of TSC-RAML showed an independent correlation with the response to everolimus, suggesting its potential as a predictor of everolimus efficacy in patients with TSC-RAML.

Cannabidiol (Epidyolex®) for severe behavioral manifestations in patients with tuberous sclerosis complex, mucopolysaccharidosis type III and fragile X syndrome: protocol for a series of randomized, placebo-controlled N-of-1 trials

BACKGROUND

Many rare genetic neurodevelopmental disorders (RGNDs) are characterized by intellectual disability (ID), severe cognitive and behavioral impairments, potentially diagnosed as a comorbid autism spectrum disorder or attention-deficit hyperactivity disorder. Quality of life is often impaired due to irritability, aggression and self-injurious behavior, generally refractory to standard therapies. There are indications from previous (case) studies and patient reporting that cannabidiol (CBD) may be an effective treatment for severe behavioral manifestations in RGNDs. However, clear evidence is lacking and interventional research is challenging due to the rarity as well as the heterogeneity within and between disease groups and interindividual differences in treatment response. Our objective is to examine the effectiveness of CBD on severe behavioral manifestations in three RGNDs, including Tuberous Sclerosis Complex (TSC), mucopolysaccharidosis type III (MPS III), and Fragile X syndrome (FXS), using an innovative trial design.

METHODS

We aim to conduct placebo-controlled, double-blind, block-randomized, multiple crossover N-of-1 studies with oral CBD (twice daily) in 30 patients (aged ≥ 6 years) with confirmed TSC, MPS III or FXS and severe behavioral manifestations. The treatment is oral CBD up to a maximum of 25 mg/kg/day, twice daily. The primary outcome measure is the subscale irritability of the Aberrant Behavior Checklist. Secondary outcome measures include (personalized) patient-reported outcome measures with regard to behavioral and psychiatric outcomes, disease-specific outcome measures, parental stress, seizure frequency, and adverse effects of CBD. Questionnaires will be completed and study medication will be taken at the participants' natural setting. Individual treatment effects will be determined based on summary statistics. A mixed model analysis will be applied for analyzing the effectiveness of the intervention per disorder and across disorders combining data from the individual N-of-1 trials.

DISCUSSION

These N-of-1 trials address an unmet medical need and will provide information on the effectiveness of CBD for severe behavioral manifestations in RGNDs, potentially generating generalizable knowledge at an individual-, disorder- and RGND population level.

TRIAL REGISTRATION

EudraCT: 2021-003250-23, registered 25 August 2022, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-003250-23/NL .

Effectiveness and safety of everolimus treatment in patients with tuberous sclerosis complex in real-world clinical practice

BACKGROUND

The randomised double-blinded placebo-controlled EXIST-1-3 studies have showed everolimus effective with adverse effects reported as acceptable in treatment of symptoms in patients with tuberous sclerosis complex (TSC), although evidence of outcomes in clinical practice remains limited. This study aimed to investigate, in clinical practice, the effectiveness and safety of everolimus for epilepsy, renal angiomyolipoma (rAML), and subependymal giant cell astrocytoma (SEGA) in patients with TSC.

RESULTS

The study included 64 patients with TSC (median age: 19, range 0.9-54 years) receiving everolimus treatment (Norway: n = 35; Denmark: n = 29). Among 45 patients with epilepsy, 14 (31%) were responders experiencing ≥ 50% reduction in seizure frequency in the last 3 months of treatment compared with the last 3 months before treatment. Nineteen (42%) patients changed their anti-seizure medications (ASMs). Responders were more common among patients < 18 years (46%) than among patients ≥ 18 years (14%, p = 0.03). In 29 patients with rAML, everolimus reduced (≥ 30% decrease) and stabilized (< 20% increase, ≤ 30% decrease) longest diameter of rAML in 38% and 59%, respectively, after a mean treatment duration of 37 months. SEGA volume was reduced in three patients by 71%, 43%, and 48% after 39, 34, and 82 months. Adverse effects were reported in 61 of 64 patients (95%) after a median treatment duration of 31 months (range 0-106), with oral ulceration/stomatitis (63%) and upper respiratory tract infections (38%) being the most common. The most common laboratory abnormalities were increased cholesterol (41%), anaemia (30%), and leucopoenia (25%). Grade 3-4 adverse effects were reported in 36% of cases, and life-threatening conditions were reported in two patients. Nine patients discontinued everolimus treatment.

CONCLUSIONS

Seizure reduction in this study sample was consistent with results from EXIST, but might be lower than expected, given that changes in concomitant ASMs are part of clinical practice. Seizure reduction was associated with younger age. As with EXIST, everolimus reduced or stabilised rAML size in most patients. SEGA volume was reduced in all three patients. Close follow-up is needed for this group, especially for children and patients who may not be able to report adverse effects.

Microscopic Kidney Disease in Tuberous Sclerosis Complex and Treatment With mTOR Inhibition

Declining kidney function in tuberous sclerosis complex (TSC) is often attributed to large lesions, including angiomyolipomas (AMLs) and cysts, that encroach on the normal parenchyma or that require intervention and loss of parenchyma from surgical debulking or embolization. Consequently, research on inhibitors of the mammalian target of rapamycin (mTOR), a protein complex implicated in TSC pathophysiology for its role in promoting cell growth and proliferation, has largely focused on their ability to reduce AML size. Clinical guidelines distilled from this research limit mTOR inhibition as a first-line treatment to patients with large AMLs. However, chronic kidney disease (CKD) occurs in patients without large AMLs or a history of renal intervention. Alternate mechanisms postulated for CKD in TSC may suggest a role for mTOR inhibition in this population. In this report, we present 2 cases of a microscopic variant of TSC kidney disease causing declining kidney function, as well as anecdotal evidence for the use of mTOR inhibition to improve kidney function in the absence of large AMLs. We highlight the importance of annual kidney function assessment in patients with TSC and suggest a low threshold for kidney biopsy in patients with declining glomerular filtration rate without a clear etiology clinically or radiographically.

Predicting Antiseizure Medication Treatment in Children with Rare Tuberous Sclerosis Complex-Related Epilepsy Using Deep Learning

BACKGROUND AND PURPOSE

Tuberous sclerosis complex disease is a rare, multisystem genetic disease, but appropriate drug treatment allows many pediatric patients to have positive outcomes. The purpose of this study was to predict the effectiveness of antiseizure medication treatment in children with tuberous sclerosis complex-related epilepsy.

MATERIALS AND METHODS

We conducted a retrospective study involving 300 children with tuberous sclerosis complex-related epilepsy. The study included the analysis of clinical data and T2WI and FLAIR images. The clinical data consisted of sex, age of onset, age at imaging, infantile spasms, and antiseizure medication numbers. To forecast antiseizure medication treatment, we developed a multitechnique deep learning method called WAE-Net. This method used multicontrast MR imaging and clinical data. The T2WI and FLAIR images were combined as FLAIR3 to enhance the contrast between tuberous sclerosis complex lesions and normal brain tissues. We trained a clinical data-based model using a fully connected network with the above-mentioned variables. After that, a weighted-average ensemble network built from the ResNet3D architecture was created as the final model.

RESULTS

The experiments had shown that age of onset, age at imaging, infantile spasms, and antiseizure medication numbers were significantly different between the 2 drug-treatment outcomes (P < .05). The hybrid technique of FLAIR3 could accurately localize tuberous sclerosis complex lesions, and the proposed method achieved the best performance (area under the curve = 0.908 and accuracy of 0.847) in the testing cohort among the compared methods.

CONCLUSIONS

The proposed method could predict antiseizure medication treatment of children with rare tuberous sclerosis complex-related epilepsy and could be a strong baseline for future studies.

Real-world evidence on the use of cannabidiol for the treatment of drug resistant epilepsy not related to Lennox-Gastaut syndrome, Dravet syndrome or Tuberous Sclerosis Complex

INTRODUCTION

Highly purified cannabidiol (CBD) has a broad spectrum of action and could be useful for the treatment of drug resistant epilepsy regardless of etiology or syndrome.

MATERIALS AND METHODS

Multicenter retrospective study that evaluated the efficacy and safety of CBD for the treatment of drug resistant epilepsy of different etiologies in patients >2 years of age.

RESULTS

Seventy-eight patients with a median age of 24 years and a wide spectrum of mainly structural and genetic etiologies were included. Patients were using a median of 3 antiseizure drugs (IQR=2-4) and had a median of 30 monthly seizures (IQR=12-100) before starting CBD. The median treatment time with CBD was 14 months (IQR=10-17). The efficacy analysis at the last available visit showed that mean percent reduction in seizures, ≥50% reduction in seizure frequency and seizure freedom was 67.8%, 68.8% and 11.5% respectively. We found no significant impact of concomitant clobazam use on the efficacy and safety of CBD. In the safety analysis, 28.2% (n = 22) of patients presented adverse events related to CBD and drug-retention rate was 78.2%.

CONCLUSIONS

In a real-world setting, highly purified CBD has been shown to be safe and effective for the treatment of drug resistant epilepsy not related to Lennox-Gastaut syndrome, Dravet syndrome or Tuberous Sclerosis Complex. Based on these findings, highly purified CBD should be considered as an adjuvant therapy for drug resistant epilepsy, regardless of its underlying cause or specific syndrome. Nevertheless, this assumption should be validated through further controlled trials.

A novel rapamycin cream formulation improves facial angiofibromas associated with tuberous sclerosis complex: a double-blind randomized placebo-controlled trial

BACKGROUND

Facial angiofibromas (FAs) are a major feature of tuberous sclerosis complex (TSC). Topical rapamycin can successfully treat FAs. A new stabilized cream formulation that protects rapamycin from oxidation has been developed in 0.5% and 1% concentrations.

OBJECTIVES

To assess the efficacy and safety of a novel, stabilized topical rapamycin cream formulation.

METHODS

This multicentre double-blind randomized placebo-controlled dose-response phase II/III study with a parallel design included participants aged 6-65 years with FAs of mild or moderate severity according to the Investigator's Global Assessment (IGA) scale. Participants were randomized to one of three treatment arms: topical rapamycin 0.5%, topical rapamycin 1% or placebo. Treatment was applied once daily for 26 weeks. Safety and efficacy measures were assessed at days 14, 56, 98, 140 and 182. The primary endpoint was the percentage of participants achieving IGA scores of 'clear' or 'almost clear' after 26 weeks of treatment. Secondary measures included Facial Angiofibroma Severity Index (FASI) and participant- and clinician-reported percentage-based improvement. Safety measures included the incidence of treatment-emergent adverse events and blood rapamycin concentration changes over time.

RESULTS

Participants (n = 107) were randomized to receive either rapamycin 1% (n = 33), rapamycin 0.5% (n = 36) or placebo (n = 38). All treated participants were included in the final analysis. The percentage of participants with a two-grade IGA improvement was greater in the rapamycin 0.5% treatment group (11%) and rapamycin 1% group (9%) than in the placebo group (5%). However, this was not statistically significant [rapamycin 0.5%: odds ratio (OR) 1.71, 95% confidence interval (CI) 0.36-8.18 (P = 0.50); rapamycin 1%: OR 1.68, 95% CI 0.33-8.40 (P = 0.53)]. There was a statistically significant difference in the proportion of participants treated with rapamycin cream that achieved at least a one-grade improvement in IGA [rapamycin 0.5%: 56% (OR 4.73, 95% CI 1.59-14.10; P = 0.005); rapamycin 1%: 61% (OR 5.14, 95% CI 1.70-15.57; P = 0.004); placebo: 24%]. Skin adverse reactions were more common in patients following rapamycin application (64%) vs. placebo (29%).

CONCLUSIONS

Both rapamycin cream formulations (0.5% and 1%) were well tolerated, and either strength could lead to clinical benefit in the treatment of FA.

Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma by the Japanese Urological Association: Summary of the update

New clinical issues have been raised through an interval of 7 years from the previous version (2016). In this study, we update the "Clinical Practice Guidelines for tuberous sclerosis complex-associated renal angiomyolipoma" as a 2023 version under guidance by the Japanese Urological Association. The present guidelines were cooperatively prepared by the Japanese Urological Association and Japanese Society of Tuberous Sclerosis Complex; committee members belonging to one of the two societies or specializing in the treatment of this disease were selected to prepare the guidelines in accordance with the "Guidance for preparing treatment guidelines" published by Minds (2020 version). The "Introduction" consisted of four sections, "Background Questions (BQ)" consisted of four sections, "Clinical Questions (CQ)" consisted of three sections, and "Future Questions (FQ)" consisted of three sections (total: 14 sections). Concerning CQ, an agreement was confirmed through voting by the committee members based on the direction and strength of recommendation, accuracy of evidence, and recommendation comments. The present guidelines were updated based on the current evidence. We hope that the guidelines will provide guiding principles for the treatment of tuberous sclerosis complex-associated renal angiomyolipoma to many urologists, becoming a foundation for subsequent updating.

Seizure reduction in TSC2-mutant mouse model by an mTOR catalytic inhibitor

OBJECTIVE

Tuberous sclerosis complex (TSC) is a neurodevelopmental disorder caused by autosomal-dominant pathogenic variants in either the TSC1 or TSC2 gene, and it is characterized by hamartomas in multiple organs, such as skin, kidney, lung, and brain. These changes can result in epilepsy, learning disabilities, and behavioral complications, among others. The mechanistic link between TSC and the mechanistic target of the rapamycin (mTOR) pathway is well established, thus mTOR inhibitors can potentially be used to treat the clinical manifestations of the disorder, including epilepsy.

METHODS

In this study, we tested the efficacy of a novel mTOR catalytic inhibitor (here named Tool Compound 1 or TC1) previously reported to be more brain-penetrant compared with other mTOR inhibitors. Using a well-characterized hypomorphic Tsc2 mouse model, which displays a translationally relevant seizure phenotype, we tested the efficacy of TC1.

RESULTS

Our results show that chronic treatment with this novel mTOR catalytic inhibitor (TC1), which affects both the mTORC1 and mTORC2 signaling complexes, reduces seizure burden, and extends the survival of Tsc2 hypomorphic mice, restoring species typical weight gain over development.

INTERPRETATION

Novel mTOR catalytic inhibitor TC1 exhibits a promising therapeutic option in the treatment of TSC.

Retrospective pharmacogenetic study in a cohort of pediatric tuberous sclerosis complex patients using everolimus

Aim: Tuberous sclerosis complex (TSC) is a rare disease that produces multisystemic disorders. Everolimus (EVR) is the only immunosuppressive drug approved to control the symptoms and progression of the disease. The aim was to evaluate the genotype-phenotype association to improve the pediatric TSC pharmacotherapeutic outcome. Patients & methods: Ten pediatric TSC patients were recruited. Concomitant treatment and main metabolic enzymes and transporter coding gene variants of EVR were analyzed. Results: Significant associations were found between CYP3A4*22 allele and concomitant treatment with valproic acid (CYP3A4-inhibitor) with a poor metabolizer phenotype and the presence of pneumonia. Conclusion: This is the first pharmacogenetic study of EVR in pediatric TSC patients. The authors propose to consider concomitant treatment and pharmacogenetics due to their multifactorial status.

Adverse Events of Everolimus in Patients with Tuberous Sclerosis Complex Treated for Renal Angiomyolipoma/Subependymal Giant Cell Astrocytoma

Background: Although regarded as a potentially efficient approach to address tuberous sclerosis complex (TSC)-associated complications, the adverse event profile of everolimus has not yet been fully elucidated. The present study aimed to clarify the adverse event spectrum in patients with TSC who are using everolimus for common indications, in comparison to those who do not use everolimus. Materials and Methods: We recruited patients with TSC who were followed up annually at TSC integrated clinics or referred for medical assistance. Medical reviews and laboratory investigations were performed at baseline and annually by clinical physicians. The adverse events were assessed as per the National Cancer Institute Common Terminology Criteria for Adverse Events. Results: Common adverse events in everolimus users included hypercholesterolemia (55%), gingivostomatitis (50%), proteinuria (50%), and hyperglycemia (40%). Compared with everolimus nonusers, the occurrence of gingivostomatitis and proteinuria was significantly higher in everolimus users (gingivostomatitis, p=0.02; proteinuria, p=0.02). Among the everolimus users, 12 patients had level I CTCAE, and five had level II CTCAE. None of the everolimus users presented with CTCAE level III or higher. Conclusion: Patients with TSC who are everolimus users had a higher tendency to develop gingivostomatitis and proteinuria compared to nonusers. However, no differences were observed in the occurrence of other adverse events between everolimus users and nonusers.

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.

Complete Remission of a Diffuse Large B-Cell Lymphoma in a Young Patient, with Severe Tuberous Sclerosis, Treated with Metronomic Chemotherapy and Ibrutinib: A Case Report

Tuberous sclerosis (TS) is a rare autosomal dominant genetic multisystem disease caused by mutations in either the TSC1 or TSC2 gene and results in the growth of non-cancerous masses in several organs. Diffuse large B-cell lymphoma (DLBCL) is the predominant non-Hodgkin lymphoma in adolescents and young adults. Metronomic chemotherapy (mCHEMO) can be defined as the frequent, regular administration of drug doses able to maintain a low, but active, range of concentrations of chemotherapeutic drugs during prolonged periods of time. We present the case of a young woman with severe TS who developed DLBCL. She was treated consecutively with the mCHEMO schedule R-DEVEC (prednisone, vinorelbine, etoposide, cyclophosphamide, plus rituximab) and then ibrutinib, achieving an impressive long-lasting complete remission. In conclusion, alternative treatments could be necessary when comorbidities are present in patients, and mCHEMO can be a potential successful therapeutic approach in frail subjects.

Rapamycin and rapalogs for tuberous sclerosis complex

BACKGROUND

Potential benefits of rapamycin or rapalogs for treating people with tuberous sclerosis complex (TSC) have been shown. Currently everolimus (a rapalog) is only approved for TSC-associated renal angiomyolipoma and subependymal giant cell astrocytoma (SEGA), but not other manifestations of TSC. A systematic review needs to establish evidence for rapamycin or rapalogs for various manifestations in TSC. This is an updated review.

OBJECTIVES

To determine the effectiveness of rapamycin or rapalogs in people with TSC for decreasing tumour size and other manifestations and to assess the safety of rapamycin or rapalogs in relation to their adverse effects.

SEARCH METHODS

We identified relevant studies from the Cochrane-Central-Register-of-Controlled-Trials (CENTRAL), Ovid MEDLINE and ongoing trials registries with no language restrictions. We searched conference proceedings and abstract books of conferences. Date of the last searches: 15 July 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of rapamycin or rapalogs in people with TSC.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of each study; a third review author verified the extracted data and risk of bias decisions. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The current update added seven RCTs, bringing the total number to 10 RCTs (with 1008 participants aged 3 months to 65 years; 484 males). All TSC diagnoses were by consensus criteria as a minimum. In parallel studies, 645 participants received active interventions and 340 placebo. Evidence is low-to-high certainty and study quality is mixed; mostly a low risk of bias across domains, but one study had a high risk of performance bias (lack of blinding) and three studies had a high risk of attrition bias. Manufacturers of the investigational products supported eight studies. Systemic administration Six studies (703 participants) administered everolimus (rapalog) orally. More participants in the intervention arm reduced renal angiomyolipoma size by 50% (risk ratio (RR) 24.69, 95% confidence interval (CI) 3.51 to 173.41; P = 0.001; 2 studies, 162 participants, high-certainty evidence). In the intervention arm, more participants in the intervention arm reduced SEGA tumour size by 50% (RR 27.85, 95% CI 1.74 to 444.82; P = 0.02; 1 study; 117 participants; moderate-certainty evidence) ,and reported more skin responses (RR 5.78, 95% CI 2.30 to 14.52; P = 0.0002; 2 studies; 224 participants; high-certainty evidence). In one 18-week study (366 participants), the intervention led to 25% fewer seizures (RR 1.63, 95% CI 1.27 to 2.09; P = 0.0001) or 50% fewer seizures (RR 2.28, 95% CI 1.44 to 3.60; P = 0.0004); but there was no difference in numbers being seizure-free (RR 5.30, 95% CI 0.69 to 40.57; P = 0.11) (moderate-certainty evidence). One study (42 participants) showed no difference in neurocognitive, neuropsychiatry, behavioural, sensory and motor development (low-certainty evidence). Total adverse events (AEs) did not differ between groups (RR 1.09, 95% CI 0.97 to 1.22; P = 0.16; 5 studies; 680 participants; high-certainty evidence). However, the intervention group experienced more AEs resulting in withdrawal, interruption of treatment, or reduced dose (RR 2.61, 95% CI 1.58 to 4.33; P = 0.0002; 4 studies; 633 participants; high-certainty evidence and also reported more severe AEs (RR 2.35, 95% CI 0.99 to 5.58; P = 0.05; 2 studies; 413 participants; high-certainty evidence). Topical (skin) administration Four studies (305 participants) administered rapamycin topically. More participants in the intervention arm showed a response to skin lesions (RR 2.72, 95% CI 1.76 to 4.18; P < 0.00001; 2 studies; 187 participants; high-certainty evidence) and more participants in the placebo arm reported a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; 1 study; 164 participants; high-certainty evidence). More participants in the intervention arm responded to facial angiofibroma at one to three months (RR 28.74, 95% CI 1.78 to 463.19; P = 0.02) and three to six months (RR 39.39, 95% CI 2.48 to 626.00; P = 0.009; low-certainty evidence). Similar results were noted for cephalic plaques at one to three months (RR 10.93, 95% CI 0.64 to 186.08; P = 0.10) and three to six months (RR 7.38, 95% CI 1.01 to 53.83; P = 0.05; low-certainty evidence). More participants on placebo showed a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; P < 0.0001; 1 study; 164 participants; moderate-certainty evidence). The intervention arm reported a higher general improvement score (MD -1.01, 95% CI -1.68 to -0.34; P < 0.0001), but no difference specifically in the adult subgroup (MD -0.75, 95% CI -1.58 to 0.08; P = 0.08; 1 study; 36 participants; moderate-certainty evidence). Participants in the intervention arm reported higher satisfaction than with placebo (MD -0.92, 95% CI -1.79 to -0.05; P = 0.04; 1 study; 36 participants; low-certainty evidence), although again with no difference among adults (MD -0.25, 95% CI -1.52 to 1.02; P = 0.70; 1 study; 18 participants; low-certainty evidence). Groups did not differ in change in quality of life at six months (MD 0.30, 95% CI -1.01 to 1.61; P = 0.65; 1 study; 62 participants; low-certainty evidence). Treatment led to a higher risk of any AE compared to placebo (RR 1.72, 95% CI 1.10, 2.67; P = 0.02; 3 studies; 277 participants; moderate-certainty evidence); but no difference between groups in severe AEs (RR 0.78, 95% CI 0.19 to 3.15; P = 0.73; 1 study; 179 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Oral everolimus reduces the size of SEGA and renal angiomyolipoma by 50%, reduces seizure frequency by 25% and 50% and implements beneficial effects on skin lesions with no difference in the total number of AEs compared to placebo; however, more participants in the treatment group required a dose reduction, interruption or withdrawal and marginally more experienced serious AEs compared to placebo. Topical rapamycin increases the response to skin lesions and facial angiofibroma, an improvement score, satisfaction and the risk of any AE, but not severe adverse events. With caution regarding the risk of severe AEs, this review supports oral everolimus for renal angiomyolipoma, SEGA, seizure, and skin lesions, and topical rapamycin for facial angiofibroma.

Efficacy and safety of vigabatrin in patients with tuberous sclerosis complex and infantile epileptic spasm syndrome: a systematic review

INTRODUCTION

Tuberous sclerosis complex (TSC) is a common genetic cause of epilepsy. Infantile epileptic spasm syndrome (IESS) is often the presenting neurologic feature, progressively evolving into refractory epilepsy. Vigabatrin (VGB) is often used in clinical practice as a first-line therapy in TSC with IESS. This systematic review aims to collect and analyze the efficacy data about VGB in TSC cases with IESS, in order to evaluate the strength of evidence in the literature.

METHODS

A systematic search of trials, observational studies, and case series involving patients with TSC and IESS treated with VGB was performed using MEDLINE, CENTRAL, and the US NIH Clinical Trials Registry. Single case studies, animal and non-English language studies were excluded. Seventeen studies were selected, of which 3 were RCTs and 14 were observational studies.

RESULTS

An overall response rate of 67% (231/343 responders) resulted from the analysis, with a spasm-free rate restricted to RCTs of 88% (29/33 subjects).

CONCLUSIONS

Although all the studies analyzed reported beneficial effects of VGB in TSC patients with IESS, with higher response rates in comparison to non-TSC subjects with IESS, a low level of evidence and high heterogeneity do not guarantee sufficient strength for therapeutic recommendations.

Epilepsy Severity Is Associated With Head Circumference and Growth Rate in Infants With Tuberous Sclerosis Complex

BACKGROUND

Abnormal brain growth in tuberous sclerosis complex (TSC) reflects abnormalities in cellular proliferation and differentiation and results in epilepsy and other neurological manifestations. Head circumference (HC) as a proxy for brain volume may provide an easily tracked clinical measure of brain overgrowth and neurological disease burden. This study investigated the relationship between HC and epilepsy severity in infants with TSC.

METHODS

Prospective multicenter observational study of children from birth to three years with TSC. Epilepsy data were collected from clinical history, and HC was collected at study visits at age three, six, nine, 12, 18, 24, and 36 months. Epilepsy severity was classified as no epilepsy, low epilepsy severity (one seizure type and one or two antiepileptic drugs [AEDs]), moderate epilepsy severity (either two to three seizure types and one to two AEDs or one seizure type and more than three AEDs), or high epilepsy severity (two to three seizure types and more than three AEDs).

RESULTS

As a group, children with TSC had HCs approximately 1 S.D. above the mean World Health Organization (WHO) reference by age one year and demonstrated more rapid growth than the normal population reference. Males with epilepsy had larger HCs than those without. Compared with the WHO reference population, infants with TSC and no epilepsy or low or moderate epilepsy had an increased early HC growth rate, whereas those with severe epilepsy had an early larger HC but did not have a faster growth rate.

CONCLUSIONS

Infants and young children with TSC have larger HCs than typical growth norms and have differing rates of head growth depending on the severity of epilepsy.

Prdx5 in the Regulation of Tuberous Sclerosis Complex Mutation-Induced Signaling Mechanisms

(1) Background: Tuberous sclerosis complex (TSC) mutations directly affect mTORC activity and, as a result, protein synthesis. In several cancer types, TSC mutation is part of the driver mutation panel. TSC mutations have been associated with mitochondrial dysfunction, tolerance to reactive oxygen species due to increased thioredoxin reductase (TrxR) enzyme activity, tolerance to endoplasmic reticulum (ER) stress, and apoptosis. The FDA-approved drug rapamycin is frequently used in clinical applications to inhibit protein synthesis in cancers. Recently, TrxR inhibitor auranofin has also been involved in clinical trials to investigate the anticancer efficacy of the combination treatment with rapamycin. We aimed to investigate the molecular background of the efficacy of such drug combinations in treating neoplasia modulated by TSC mutations. (2) Methods: TSC2 mutant and TSC2 wild-type (WT) cell lines were exposed to rapamycin and auranofin in either mono- or combination treatment. Mitochondrial membrane potential, TrxR enzyme activity, stress protein array, mRNA and protein levels were investigated via cell proliferation assay, electron microscopy, etc. (3) Results: Auranofin and rapamycin normalized mitochondrial membrane potential and reduced proliferation capacity of TSC2 mutant cells. Database analysis identified peroxiredoxin 5 (Prdx5) as the joint target of auranofin and rapamycin. The auranofin and the combination of the two drugs reduced Prdx5 levels. The combination treatment increased the expression of heat shock protein 70, a cellular ER stress marker. (4) Conclusions: After extensive analyses, Prdx5 was identified as a shared target of the two drugs. The decreased Prdx5 protein level and the inhibition of both TrxR and mTOR by rapamycin and auranofin in the combination treatment made ER stress-induced cell death possible in TSC2 mutant cells.

Upregulation of acid ceramidase contributes to tumor progression in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is characterized by multisystem, low-grade neoplasia involving the lung, kidneys, brain, and heart. Lymphangioleiomyomatosis (LAM) is a progressive pulmonary disease affecting almost exclusively women. TSC and LAM are both caused by mutations in TSC1 and TSC2 that result in mTORC1 hyperactivation. Here, we report that single-cell RNA sequencing of LAM lungs identified activation of genes in the sphingolipid biosynthesis pathway. Accordingly, the expression of acid ceramidase (ASAH1) and dihydroceramide desaturase (DEGS1), key enzymes controlling sphingolipid and ceramide metabolism, was significantly increased in TSC2-null cells. TSC2 negatively regulated the biosynthesis of tumorigenic sphingolipids, and suppression of ASAH1 by shRNA or the inhibitor ARN14976 (17a) resulted in markedly decreased TSC2-null cell viability. In vivo, 17a significantly decreased the growth of TSC2-null cell-derived mouse xenografts and short-term lung colonization by TSC2-null cells. Combined rapamycin and 17a treatment synergistically inhibited renal cystadenoma growth in Tsc2+/- mice, consistent with increased ASAH1 expression and activity being rapamycin insensitive. Collectively, the present study identifies rapamycin-insensitive ASAH1 upregulation in TSC2-null cells and tumors and provides evidence that targeting aberrant sphingolipid biosynthesis pathways has potential therapeutic value in mechanistic target of rapamycin complex 1-hyperactive neoplasms, including TSC and LAM.

Kinase Inhibitors in Genetic Diseases

Over the years, several studies have shown that kinase-regulated signaling pathways are involved in the development of rare genetic diseases. The study of the mechanisms underlying the onset of these diseases has opened a possible way for the development of targeted therapies using particular kinase inhibitors. Some of these are currently used to treat other diseases, such as cancer. This review aims to describe the possibilities of using kinase inhibitors in genetic pathologies such as tuberous sclerosis, RASopathies, and ciliopathies, describing the various pathways involved and the possible targets already identified or currently under study.

Population Pharmacokinetic Analysis and Dosing Optimization of Sirolimus in Children With Tuberous Sclerosis Complex

Sirolimus is confirmed to be effective in the treatment of tuberous sclerosis complex (TSC) and related disorders. The study aims to establish a population pharmacokinetic model of oral sirolimus for children with TSC and provide an evidence-based approach for individualization of sirolimus dosing in the pediatric population. A total of 64 children were recruited in this multicenter, retrospective pharmacokinetic study. Whole-blood concentrations of sirolimus, demographic, and clinical information were collected and analyzed using a nonlinear mixed-effects population modeling method. The final model was internally and externally validated. Then Monte Carlo simulations were performed to evaluate and optimize the dosing regimens. In addition, the efficacy and safety of sirolimus therapy was assessed retrospectively in patients with epilepsy or cardiac rhabdomyomas associated with TSC. Finally, the sirolimus pharmacokinetic profile was described by a 1-compartment model with first-order absorption and elimination along with body weight and total daily dose as significant covariates. The typical population parameter estimates of apparent volume of distribution and apparent clearance were 69.48 L and 2.79 L/h, respectively. Simulations demonstrated that dosage regimens stratified by body surface area may be more appropriate for children with TSC. These findings could be used to inform individualized dosing strategies of sirolimus for pediatric patients with TSC.

Safety of inactivated COVID-19 vaccine in tuberous sclerosis complex patients with epilepsy treated with rapamycin

Purpose

Methods

Results

Conclusion

Long-term administration of sirolimus does not affect the physical development of children with tuberous sclerosis complex

PURPOSE

There was no evidence whether the mammalian/mechanistic target of rapamycin pathway hyperactivation and long-term use of mTOR inhibitors have any effects on the physical development of children. The aim was to evaluate these effects by comparing the physical development of children with TSC and normal children.

METHODS

A total of 120 eligible children were enrolled. They were administered sirolimus and followed for at least 12 months. Height, weight, BMI and lipid metabolism index were collected during treatment. Pearson's chi-square and Fisher's exact test were used for comparison of proportions of patients exhibiting normal and abnormal physical growth before and after 1 year of treatment. Logistic regression was used to evaluate the influence of age, sex and abnormal lipid metabolism on the increased BMIs of TSC patients after treatment.

RESULTS

Most of the enrolled TSC children were in the normal height, weight and BMI ranges at baseline (91.7%, 95.8% and 78.3%, respectively). Most remained in the normal height, weight and BMI ranges after 1 year of sirolimus treatment (94.2%, 95% and 76.7%, respectively). There was no significant difference in the proportion of physical development before and after treatment (p > 0.05). Thirty-eight (38/106, 35.8%) patients had increased BMIs after 1 year of treatment, but there was no significant correlation between age, sex and lipid metabolism and increased BMI.

CONCLUSIONS

Overactivation of the mTOR pathway and long-term administration of sirolimus does not affect the physical development of children with TSC.

Focal Epilepsy in Children With Tuberous Sclerosis Complex: Does Vigabatrin Control Focal Seizures?

We evaluated the efficacy and safety of vigabatrin in focal epilepsy associated with tuberous sclerosis complex by retrospectively reviewing patients with focal epilepsy and tuberous sclerosis complex treated with vigabatrin at a pediatric epilepsy center over an 8-year period. Of 85 patients, 20 (23.5%) were seizure-free for >12 months, 45 (52.9%) were responders (≥50% seizure reduction), and 20 (23.5%) were nonresponders. The median age (in months) at seizure onset in the seizure-free group (median, 15; interquartile range [IQR], 6-23.3) was higher than that of responders (median, 5; IQR, 3-14) and nonresponders (median, 6; IQR, 2-12). Fewer patients in the seizure-free group had calcification in their largest tubers, but the presence of tuber calcification did not differ among groups. Vigabatrin is more likely to result in seizure freedom in children with tuberous sclerosis complex who have later infantile onset of focal seizures and no calcification in their largest tuber.

Neonatal rhabdomyoma with cardiac dysfunction: favourable response to sirolimus

Cardiac rhabdomyoma is the most common cardiac tumour in childhood, with a strong genetic association to tuberous sclerosis complex. Although most of the patients remain asymptomatic, a small proportion present with cardiac complications in the early neonatal period. Timely initiation of treatment can potentially reduce disease morbidity, and mammalian target of rapamycin (M-TOR) inhibitors play an effective role in promoting regression of these tumours. A healthy term newborn was diagnosed with a giant congenital cardiac rhabdomyoma at birth. He developed clinical signs of compromised cardiac function and progressive myocardial ischaemia, with echocardiography showing significant dyskinesia. He was treated with M-TOR inhibitors and clinical response was monitored via serial echocardiography. Remarkable regression of the tumour was visibly demonstrated within 4 months of sirolimus treatment. The infant continues to be reviewed by a multidisciplinary team of physicians and monitored for features of tuberous sclerosis complex.

Loss of TSC1/TSC2 sensitizes immune checkpoint blockade in non-small cell lung cancer

Tuberous sclerosis complex subunit 1 (TSC1) and 2 (TSC2) are frequently mutated in non-small cell lung cancer (NSCLC), however, their effects on antitumor immunity remained unexplored. A CRISPR screening in murine Kras^G12D/Trp53^-/- (KP) model identified Tsc1 and Tsc2 as potent regulators of programmed cell death ligand 1 (Pd-l1) expression in vitro and sensitivity to anti-programmed cell death receptor 1 (PD-1) treatment in vivo. TSC1 or TSC2 knockout (KO) promoted the transcriptional and membrane expression of PD-L1 in cell lines. TSC2-deficient tumors manifested an inflamed microenvironment in patient samples and The Cancer Genome Atlas dataset. In syngeneic murine models, KP-Tsc2-KO tumors showed notable response to anti-PD-1 antibody treatment, but Tsc2-wild-type tumors did not. Patients with TSC1/TSC2-mutant NSCLC receiving immune checkpoint blockade (ICB) had increased durable clinical benefit and survival. Collectively, TSC1/TSC2 loss defines a distinct subtype of NSCLC characterized as inflamed tumor microenvironment and superior sensitivity to ICB.

Mechanistic Target of Rapamycin (mTOR) Inhibitors

Mechanistic target of rapamycin (mTOR) inhibitors are macrocyclic lactone antibiotics derived from Streptomyces hygroscopicus that prevent T lymphocyte activation and B cell differentiation. Unlike calcineurin inhibitors (CNIs) that inhibit cytokine production, mTOR inhibitors block the cytokine signal transduction to arrest cells in the G1 to S phase. This class of drugs is commonly used for post-transplantation and cancer management because of its immunosuppressive and antiproliferative properties, respectively. The potential uses of mTOR inhibitors are heavily explored because of their impact on cell growth and proliferation. However, mTOR inhibitors have a broad range of effects that can result in adverse reactions, but side effects can occur with other immunosuppressive agents as well. Thus, the performance of mTOR inhibitors is compared to the outcomes and adverse effects of other immunosuppressive drugs or the combination of other immunosuppressants and mTOR inhibitors. Because mTOR regulates many downstream pathways, mTOR inhibitors can affect these pathways to manage various diseases. Sirolimus (rapamycin) is approved by the Food and Drug Administration (FDA) to treat post-renal transplantation and lymphangioleiomyomatosis (LAM). Everolimus is approved by the FDA to treat postmenopausal advanced hormone receptor-positive, HER2-negative breast cancer in women, progressive neuroendocrine tumors of pancreatic origin (PNET), advanced renal cell carcinoma (RCC), renal angiomyolipoma (AML) and tuberous sclerosis complex (TSC), and subependymal giant cell astrocytoma (SEGA) associated with TSC as well as renal and liver transplantation. Temsirolimus is approved by the FDA to treat advanced RCC. Opportunities to use mTOR inhibitors as therapy for other transplantation, metabolic disease, and cancer management are being researched. mTOR inhibitors are often called proliferation signal inhibitors (PSIs) because of their effects on proliferation pathways.

Prenatal Sirolimus Treatment for Rhabdomyomas in Tuberous Sclerosis

BACKGROUND

In tuberous sclerosis, most cardiac rhabdomyomas regress spontaneously. In some cases, the tumors can cause life-threatening hemodynamic compromise requiring subsequent surgical resection. The mechanistic target of rapamycin inhibitors everolimus and sirolimus have shown to be effective treatments for multiple conditions. There are four reports of off-label treatment with transplacental sirolimus for fetal rhabdomyomas due to tuberous sclerosis complex. The optimal dosing regimen is unknown.

METHODS

We reviewed the medical records of all patients treated prenatally with sirolimus for rhabdomyomas. All fetuses had a clinical and molecular diagnosis of tuberous sclerosis complex (2012 Consensus Diagnostic Criteria, including a positive genetic test). Clinical history, mechanistic target of rapamycin inhibitor dosing and levels, outcome, and adverse events were reviewed after initiation of sirolimus treatment.

RESULTS

Three fetuses were treated with maternal sirolimus. Dosing regimens and subsequent trough levels differed from 1 mg/day to 6 mg/day and <1.0 ng/mL to 12.2 ng/mL. Cardiac rhabdomyomas gradually shrank in all patients. Growth restriction was noted in one patient. No severe adverse events occurred during the treatment period.

CONCLUSIONS

Maternal sirolimus appears to be a safe treatment option in prenatally detected rhabdomyomas with possible need for intervention. Follow-up visits with fetal ultrasound, echocardiography, and laboratory work should be performed weekly during the treatment period. The optimal dosing and trough level timepoints remain unclear. Based on our results, we recommend a sirolimus starting dose of at least 2 mg/m²/day, preferably 3-3.5 mg/m²/day to achieve a target trough level of 10-12 ng/mL.

Pharmacotherapy for Seizures in Tuberous Sclerosis Complex

Epilepsy is one of the main symptoms affecting the lives of individuals with tuberous sclerosis complex (TSC), causing a high rate of morbidity. Individuals with TSC can present with various types of seizures, epilepsies, and epilepsy syndromes that can coexist or appear in relation to age. Focal epilepsy is the most frequent epilepsy type with two developmental and epileptic encephalopathies: infantile spasms syndrome and Lennox-Gastaut syndrome. Active screening and early management of epilepsy is recommended in individuals with TSC to limit its consequences and its impact on quality of life, cognitive outcome and the economic burden of the disease. The progress in the knowledge of the mechanisms underlying epilepsy in TSC has paved the way for new concepts in the management of epilepsy related to TSC. In addition, we are moving from traditional "reactive" and therapeutic choices with current antiseizure medications used after the onset of seizures, to a proactive approach, aimed at predicting and preventing epileptogenesis and the onset of epilepsy with vigabatrin, and to personalized treatments with mechanistic therapies, namely mechanistic/mammalian target of rapamycin inhibitors. Indeed, epilepsy linked to TSC is one of the only epilepsies for which a predictive and preventive approach can delay seizure onset and improve seizure response. However, the efficacy of such interventions on long-term cognitive and psychiatric outcomes is still under investigation.

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.

Renal angiomyolipoma and tuberous sclerosis complex: long-term safety and efficacy outcomes of Everolimus therapy

INTRODUCTION

Renal angiomyolipoma is a frequent manifestation of Tuberous Sclerosis Complex (TSC), for which everolimus therapy has been recently established as a novel non-invasive therapeutic option. As there are limited real life and long-term data, the analysis of our experience provides added value in terms of safety and efficacy.

MATERIAL AND METHODS

Descriptive analysis of our experience in patients with giant bilateral renal angiomyolipomas, in the context of TSC, treated with 10 mg oral everolimus daily, during a median of 71.5 months. We evaluated the following parameters: response rate and duration, reduction of kidney size and lesions, prevention of complications and presentation of toxicity and its cause.

RESULTS

We confirm the effectiveness of treatment in 4 young patients, with multiple, bilateral angiomyolipomas of a median of 12 (5-19) cm maximum diameter, from June 2013 to date, after continuous reduction in lesion size, a decrease of 30% of the volume in 75% at six months and 50% in half of the subjects at two years, still showing drug response. Absence of complications such as bleeding or glomerular filtration rate decline in the long term, with a favorable safety profile, without interruptions and with mild-moderate, non-cumulative adverse effects, mostly within the first year of treatment.

CONCLUSION

Everolimus is a safe and effective therapeutic option for renal angiomyolipoma and various manifestations of TSC, which has been reproduced in real life with six years of follow-up.

Vigabatrin-associated Reversible MRI Abnormalities in an Infant with Tuberous Sclerosis

Vigabatrin therapy is commonly used in infants diagnosed with tuberous sclerosis complex, particularly in the setting of epilepsy. Utilization of vigabatrin can result in bilateral and symmetric abnormal sequence changes within the deep brain matter and brainstem on magnetic resonance imaging. These abnormalities occur predominantly in infancy, are reversible, and can be asymptomatic or result in symptomatic clinical manifestations. We present a case with classic neuroimaging findings. Familiarity with these findings can prevent unnecessary follow up tests or studies and the cost of continuing or discontinuing vigabatrin therapy should be weighed heavily against the potential manifestation of extrapyramidal symptoms.

Study on the Treatment of Tuberous Sclerosis with Rapamycin Nanomicelles Based on Abdominal Ultrasound

In recent years, mTOR signaling pathway has been found to be the main bridge between TSC1/TSC2 gene mutation and tuberous sclerosis phenotype. Although mTOR inhibitors have been reported to treat tuberous sclerosis in foreign countries, there is still a lack of long-term follow-up results and clinical treatment experience in children. Therefore, research at home and abroad is actively focusing on the mTOR signaling pathway to further clarify the pathogenesis of the disease, and from a clinical point of view, to summarize the clinical data of more patients treated with mTOR inhibitors, to conduct a long-term follow-up and exploration of rapamycin treatment, and to summarize mature treatment experience. This is also the research hotspot of tuberous sclerosis. Based on the study of the treatment of tuberous sclerosis patients with rapamycin nanomicelles by abdominal ultrasound, the therapeutic effect and safety were compared and evaluated through the observation and description of the clinical seizure control and the recovery of EEG peak out of rhythm in children with tuberous sclerosis and infantile spasm.

Efficacy and safety of low-dose everolimus treatment for renal angiomyolipoma associated with tuberous sclerosis complex

BACKGROUND

The aim of this study was to evaluate the safety and efficacy of low-dose everolimus treatment in patients with tuberous sclerosis complex (TSC)-associated angiomyolipoma (AML) with renal dysfunction or low body weight.

METHODS

We investigated a total of 50 adult patients underwent everolimus treatment for AML associated with TSC. For patients with renal dysfunction (serum creatinine level ≥ 1.5 mg/dl) or low body weight (body weight < 35 kg), 5 mg of everolimus was administered daily (low-dose group). For patients without renal dysfunction or low body weight, 10 mg of everolimus was administered daily (conventional-dose group). The treatment effects and adverse events were compared between the two groups.

RESULTS

There were 20 patients in the low-dose group, and 30 in the conventional-dose group. The average reduction rate of the AML volume in the low-dose group was 52%, whereas it was 60% in the conventional-dose group. No significant differences were found in the average reduction rate between the groups (P = 0.24). The average blood everolimus trough levels were 7.7 ± 3.1 ng/mL in the low-dose group and 12.2 ± 5.7 ng/mL in the conventional-dose group. The level was significantly higher in the conventional-dose group than in the low-dose group (P = 0.004). The incidences of stomatitis and irregular menstruation were significantly lower in the low-dose group than in the conventional-dose group (P = 0.009, P = 0.045, respectively).

CONCLUSIONS

The present study demonstrates that low-dose everolimus treatment is safe and effective for TSC-associated AML. This treatment was well tolerated and adverse events were mild in all cases.

Therapeutic Targeting of the Secreted Lysophospholipase D Autotaxin Suppresses Tuberous Sclerosis Complex-Associated Tumorigenesis

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by multiorgan hamartomas, including renal angiomyolipomas and pulmonary lymphangioleiomyomatosis (LAM). TSC2 deficiency leads to hyperactivation of mTOR Complex 1 (mTORC1), a master regulator of cell growth and metabolism. Phospholipid metabolism is dysregulated upon TSC2 loss, causing enhanced production of lysophosphatidylcholine (LPC) species by TSC2-deficient tumor cells. LPC is the major substrate of the secreted lysophospholipase D autotaxin (ATX), which generates two bioactive lipids, lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P). We report here that ATX expression is upregulated in human renal angiomyolipoma-derived TSC2-deficient cells compared with TSC2 add-back cells. Inhibition of ATX via the clinically developed compound GLPG1690 suppressed TSC2-loss associated oncogenicity in vitro and in vivo and induced apoptosis in TSC2-deficient cells. GLPG1690 suppressed AKT and ERK1/2 signaling and profoundly impacted the transcriptome of these cells while inducing minor gene expression changes in TSC2 add-back cells. RNA-sequencing studies revealed transcriptomic signatures of LPA and S1P, suggesting an LPA/S1P-mediated reprogramming of the TSC lipidome. In addition, supplementation of LPA or S1P rescued proliferation and viability, neutral lipid content, and AKT or ERK1/2 signaling in human TSC2-deficient cells treated with GLPG1690. Importantly, TSC-associated renal angiomyolipomas have higher expression of LPA receptor 1 and S1P receptor 3 compared with normal kidney. These studies increase our understanding of TSC2-deficient cell metabolism, leading to novel potential therapeutic opportunities for TSC and LAM. SIGNIFICANCE: This study identifies activation of the ATX-LPA/S1P pathway as a novel mode of metabolic dysregulation upon TSC2 loss, highlighting critical roles for ATX in TSC2-deficient cell fitness and in TSC tumorigenesis.

IMPDH inhibitors for antitumor therapy in tuberous sclerosis complex

Recent studies in distinct preclinical tumor models have established the nucleotide synthesis enzyme inosine-5'-monophosphate dehydrogenase (IMPDH) as a viable target for antitumor therapy. IMPDH inhibitors have been used clinically for decades as safe and effective immunosuppressants. However, the potential to repurpose these pharmacological agents for antitumor therapy requires further investigation, including direct comparisons of available compounds. Therefore, we tested structurally distinct IMPDH inhibitors in multiple cell and mouse tumor models of the genetic tumor syndrome tuberous sclerosis complex (TSC). TSC-associated tumors are driven by uncontrolled activation of the growth-promoting protein kinase complex mechanistic target of rapamycin (mTOR) complex 1 (mTORC1), which is also aberrantly activated in the majority of sporadic cancers. Despite eliciting similar immunosuppressive effects, the IMPDH inhibitor mizoribine, used clinically throughout Asia, demonstrated far superior antitumor activity compared with the FDA-approved IMPDH inhibitor mycophenolate mofetil (or CellCept, a prodrug of mycophenolic acid). When compared directly to the mTOR inhibitor rapamycin, mizoribine treatment provided a more durable antitumor response associated with tumor cell death. These results provide preclinical support for repurposing mizoribine, over other IMPDH inhibitors, as an alternative to mTOR inhibitors for the treatment of TSC-associated tumors and possibly other tumors featuring uncontrolled mTORC1 activity.

[Clinical case of delayed diagnosis of tuberous sclerosis]

A clinical case of successful drug treatment of multiple renal angiomyolipomas in patient with tuberous sclerosis is presented, which suggests potential role of medical treatment of benign kidney tumors.

Everolimus as adjunctive treatment in tuberous sclerosis complex-associated epilepsy in children

INTRODUCTION

Tuberous sclerosis complex (TSC) is a rare autosomal dominant multi-organ disease. In TSC, epilepsy is frequent and often treatment refractory. Dysfunction of the tumour-suppressing hamartin/tuberin complex leads to an over-activated mammalian target of rapamycin (mTOR) signalling pathway and uncontrolled cell growth. Protocolled treatment of TSC-associated epilepsy with the mTOR inhibitor everolimus has recently been approved by The Danish Medicines Council in Denmark.

METHODS

Clinical data on the first Danish paediatric patients treated with everolimus for epilepsy and a review of the literature are presented.

RESULTS

Four patients met the inclusion criteria and had been treated for more than 12 months. Onset of epilepsy was at a median age of 1.1 years (range: 0.3-3.3 years) and current age was 3.4 years (range: 2.2-7.4 years). The previous median number of antiepileptic drugs was 5.0 (range: 2-10) and the concomitant median number of antiepileptic drugs was 2.5 (range: 1-4). Several other treatment modalities had been or were still being applied, including ketogenic diet (n = 3), vagus nerve stimulation (n = 1) and epilepsy surgery (n = 2). The number of focal seizures was in the 20-160 range per week before everolimus. All patients had a > 50% seizure reduction after 12 months of everolimus treatment. One patient became seizure free. Side effects were mild and self-limiting.

CONCLUSIONS

Early data on everolimus as an adjunctive treatment in TSC-associated epilepsy are promising with regards to both effect and tolerability.

FUNDING

none.

TRIAL REGISTRATION

not relevant.

Everolimus compliance and persistence among tuberous sclerosis complex patients with renal angiomyolipoma or subependymal giant cell astrocytoma

OBJECTIVE

Everolimus is the only FDA approved drug to treat renal angiomyolipoma or subependymal giant-cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC). Potential differences exist between patients with commercial and Medicaid insurance on everolimus use; however, there is limited information from the real world. This study compared compliance and persistence of everolimus between commercial and Medicaid patients using US claims data.

METHODS

Patients with ≥1 claim of TSC with renal angiomyolipoma or SEGA were selected from the MarketScan commercial (1 January 2009-31 August 2016) and Medicaid (1 January 2009-30 June 2015) databases. Patients were followed from index date (the earliest date of TSC, renal angiomyolipoma or SEGA diagnosis) to death or end of data. Non-persistence, defined as ≥60 day gap without everolimus, and medication possession ratio (MPR) were assessed among the subset of patients with ≥1 year of follow-up from the first everolimus claim.

RESULTS

A total of 1497 TSC patients met the study criteria (896 renal angiomyolipoma only, 411 SEGA only and 190 both). Compared to Medicaid patients (N = 513), commercial patients (N = 984) had the same ages (22 years) but a shorter length of follow-up (38 vs. 48 months, p < .001). Medicaid and commercial patients had similar rates of being treated with everolimus (14.4% vs. 13.6%, p = .668), but it took Medicaid patients a longer time to start everolimus (871 vs. 704 days, p < .001). Although the non-persistence rate was not significantly different between commercial and Medicaid patients (42.5% vs. 35.1%, p = .561), the number of days from everolimus initiation to non-persistence was significantly lower for commercial patients (945 vs. 1132, p < .001). During the 1 year post everolimus initiation, commercial patients had a significantly higher MPR (0.81 vs. 0.74, p < .001) and higher percentage of patients with MPR ≥0.80 (67.8% vs. 58.1%, p < .001).

CONCLUSIONS

Among TSC patients with renal angiomyolipoma or SEGA and treated with everolimus, everolimus MPR was between 0.74 and 0.81. Medicaid patients had lower MPR than commercial patients but better persistence.

Hypervascularization in mTOR-dependent focal and global cortical malformations displays differential rapamycin sensitivity

OBJECTIVES

Patients with mammalian target of rapamycin (mTOR)-dependent malformations of cortical development (MCDs) associated with seizures display hyperperfusion and increased vessel density of the dysmorphic cortical tissue. Some studies have suggested that the vascular defect occurred independently of seizures. Here, we further examined whether hypervascularization occurs in animal models of global and focal MCD with and without seizures, and whether it is sensitive to the mTOR blocker, rapamycin, that is approved for epilepsy treatment in tuberous sclerosis complex.

METHODS

We used two experimental models of mTOR-dependent MCD consisting of conditional transgenic mice containing Tsc1^null cells in the forebrain generating a global malformation associated with seizures and of wild-type mice containing a focal malformation in the somatosensory cortex generated by in utero electroporation (IUE) that does not lead to seizures. Alterations in blood vessels and the effects of a 2-week-long rapamycin treatment on these phenotypes were assessed in juvenile mice.

RESULTS

Blood vessels in both the focal and global MCDs of postnatal day 14 mice displayed significant increase in vessel density, branching index, total vessel length, and decreased tissue lacunarity. In addition, rapamycin treatment (0.5 mg/kg, every 2 days) partially rescued vessel abnormalities in the focal MCD model, but it did not ameliorate the vessel abnormalities in the global MCD model that required higher rapamycin dosage for a partial rescue.

SIGNIFICANCE

Here, we identified hypervascularization in mTOR-dependent MCD in the absence of seizures in young mice, suggesting that increased angiogenesis occurs during development in parallel to alterations in corticogenesis. In addition, a predictive functional outcome is that dysplastic neurons forming MCD will have better access to oxygen and metabolic supplies via their closer proximity to blood vessels. Finally, the difference in rapamycin sensitivity between a focal and global MCD suggest that rapamycin treatment will need to be titrated to match the type of MCD.

Rapid Involution of Large Cardiac Rhabdomyomas With Everolimus Therapy

Rhabdomyoma of the fetal heart is a rare disease accounting for about 1% of all fetal cardiac structural anomalies. They are often found in association with tuberous sclerosis complex. Large cardiac rhabdomyomas can compromise the cardiac function. We report a case of multiple large rhabdomyomas of the right and left ventricles, affecting the cardiac function, which was successfully treated with the chemotherapeutic and immunosuppressive medication everolimus, in a neonate with genetically confirmed tuberous sclerosis complex with multisystem manifestations. There was rapid involution of the tumors in response to everolimus therapy in this infant.