The use of everolimus in the treatment of neurocognitive problems in tuberous sclerosis (TRON): study protocol for a randomised controlled trial

International consensus recommendations for the identification and treatment of tuberous sclerosis complex-associated neuropsychiatric disorders (TAND)

BACKGROUND

Tuberous sclerosis complex (TSC) is associated with a wide range of physical manifestations for which international clinical recommendations for diagnosis and management have been established. TSC is, however, also associated with a wide range of TSC-Associated Neuropsychiatric Disorders (TAND) that are typically under-identified and under-treated yet associated with a profound burden of disease. The contemporary evidence base for the identification and treatment of TAND is much more limited and, to date, consensus recommendations for the diagnosis and management of TAND have also been limited and non-specific.

METHODS

The TANDem project was launched with an international, interdisciplinary, and participatory consortium of 24 individuals, including TSC family representatives, from all World Health Organization (WHO) regions but one. One of the aims of the TANDem project was to generate consensus recommendations for the identification and treatment of TAND. At the time of this project, no internationally adopted standard methodology and methodological checklists existed for the generation of clinical practice recommendations. We therefore developed our own systematic procedure for evidence review and consensus-building to generate evidence-informed consensus recommendations of relevance to the global TSC community.

RESULTS

At the heart of the consensus recommendations are ten core principles surrounded by cluster-specific recommendations for each of the seven natural TAND clusters identified in the literature (autism-like, dysregulated behavior, eat/sleep, mood/anxiety, neuropsychological, overactive/impulsive, and scholastic) and a set of wraparound psychosocial cluster recommendations. The overarching recommendation is to "screen" for TAND at least annually, to "act" using appropriate next steps for evaluation and treatment, and to "repeat" the process to ensure early identification and early intervention with the most appropriate biological, psychological, and social evidence-informed approaches to support individuals with TSC and their families.

CONCLUSIONS

The consensus recommendations should provide a systematic framework to approach the identification and treatment of TAND for health, educational, social care teams and families who live with TSC. To ensure global dissemination and implementation of these recommendations, partnerships with the international TSC community will be important. One of these steps will include the generation of a "TAND toolkit" of "what to seek" and "what to do" when difficulties are identified in TAND clusters.

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.

A situational analysis of child and adolescent mental health services and systems in the Western Cape Province of South Africa

BACKGROUND

Even though child and adolescent mental health is a global health priority, services are very limited, particularly in low- and middle-income countries (LMIC), and therefore need comprehensive strengthening. This requires knowledge of the hardware elements of the system (human resources, financing, medicines, technology, organisational structure, service infrastructure, and information systems). This study sought to examine these elements of child and adolescent mental health (CAMH) services and systems in the Western Cape Province of South Africa.

METHODS

The World Health Organization Assessment Instrument of Mental Health Systems (WHO-AIMS) version 2.2 of 2005 was adapted to identify key variables of interest in CAMH. Data were collected for the calendar year 2016 and focused on the public health sector. We outlined findings based on best available data across the six domains of the WHO-AIMS.

RESULTS

In domain 1, we found no provincial CAMH policy or implementation plans to support the national CAMH policy and were unable to identify a CAMH-specific budget. In domain 2, there was no dedicated provincial leadership structure for CAMH, and no dedicated or 'child- and adolescent-friendly' mental health services at primary or secondary care levels. At tertiary level, there were only three specialist CAMH teams. The majority of CAMH resources were based in the City of Cape Town, with limited resources in the rural districts. Essential medicines were available in all facilities, and the majority of children and adolescents had access to free services. In domain 3, data were limited about the extent of training offered to primary healthcare staff, and little or no psychosocial interventions were available in primary care. Domain 4 identified a small and variable CAMH workforce across all levels of care. In domain 5, few public health campaigns focused on CAMH, and little evidence of formal intersectoral collaboration on CAMH was identified. Domain 6 identified significant limitations in health information systems for CAMH, including lack of child- and adolescent-specific and disaggregated data to establish baselines for policy development, monitoring, evaluation and CAMH research.

CONCLUSIONS

This study identified significant structural weaknesses in CAMH and presents a clear call for action to strengthen services and systems in the province and in South Africa. it would be important to expand research also to include provider and user perspectives for service strengthening.

Epilepsy in the mTORopathies: opportunities for precision medicine

The mechanistic target of rapamycin signalling pathway serves as a ubiquitous regulator of cell metabolism, growth, proliferation and survival. The main cellular activity of the mechanistic target of rapamycin cascade funnels through mechanistic target of rapamycin complex 1, which is inhibited by rapamycin, a macrolide compound produced by the bacterium Streptomyces hygroscopicus. Pathogenic variants in genes encoding upstream regulators of mechanistic target of rapamycin complex 1 cause epilepsies and neurodevelopmental disorders. Tuberous sclerosis complex is a multisystem disorder caused by mutations in mechanistic target of rapamycin regulators TSC1 or TSC2, with prominent neurological manifestations including epilepsy, focal cortical dysplasia and neuropsychiatric disorders. Focal cortical dysplasia type II results from somatic brain mutations in mechanistic target of rapamycin pathway activators MTOR, AKT3, PIK3CA and RHEB and is a major cause of drug-resistant epilepsy. DEPDC5, NPRL2 and NPRL3 code for subunits of the GTPase-activating protein (GAP) activity towards Rags 1 complex (GATOR1), the principal amino acid-sensing regulator of mechanistic target of rapamycin complex 1. Germline pathogenic variants in GATOR1 genes cause non-lesional focal epilepsies and epilepsies associated with malformations of cortical development. Collectively, the mTORopathies are characterized by excessive mechanistic target of rapamycin pathway activation and drug-resistant epilepsy. In the first large-scale precision medicine trial in a genetically mediated epilepsy, everolimus (a synthetic analogue of rapamycin) was effective at reducing seizure frequency in people with tuberous sclerosis complex. Rapamycin reduced seizures in rodent models of DEPDC5-related epilepsy and focal cortical dysplasia type II. This review outlines a personalized medicine approach to the management of epilepsies in the mTORopathies. We advocate for early diagnostic sequencing of mechanistic target of rapamycin pathway genes in drug-resistant epilepsy, as identification of a pathogenic variant may point to an occult dysplasia in apparently non-lesional epilepsy or may uncover important prognostic information including, an increased risk of sudden unexpected death in epilepsy in the GATORopathies or favourable epilepsy surgery outcomes in focal cortical dysplasia type II due to somatic brain mutations. Lastly, we discuss the potential therapeutic application of mechanistic target of rapamycin inhibitors for drug-resistant seizures in GATOR1-related epilepsies and focal cortical dysplasia type II.

Detection of endophenotypes associated with neuropsychiatric deficiencies in a mouse model of tuberous sclerosis complex using diffusion tensor imaging

Tuberous sclerosis complex (TSC) is a rare hereditary disease, which results from the mutation of either TSC1 or TSC2, and its clinical features include benign tumors and dysfunctions in numerous organs, including the brain. Many individuals with TSC manifest neuropsychiatric symptoms, such as learning impairments, cognitive deficits and anxiety. Current pharmacological treatment for TSC is the use of mTOR inhibitors. However, they are not effective in treating neuropsychiatric symptoms. We previously used curcumin, a diet-derived mTOR inhibitor, which possesses both anti-inflammatory and antiproliferative properties, to improve learning and memory deficits in Tsc2^+/- mice. Diffusion tensor imaging (DTI) provides microstructural information in brain tissue and has been used to study the neuropathological changes in TSC. In this study, we confirmed that the impaired recognition memory and increased anxiety-like behavior in Tsc2^+/- mice can be reversed by curcumin treatment. Second, we found altered fractional anisotropy and mean diffusivity in the anterior cingulate cortex and the hippocampus of the Tsc2^+/- mice, which may indicate altered circuitry. Finally, the mTOR complex 1 hyperactivity was found in the cortex and hippocampus, coinciding with abnormal cortical myelination and increased glial fibrillary acidic protein expression in the hippocampal CA1 of Tsc2^+/- mice, both of which can be rescued with curcumin treatment. Overall, DTI is sensitive to the subtle alterations that cannot be detected by conventional imaging, suggesting that noninvasive DTI may be suitable for longitudinally monitoring the in vivo neuropathology associated with the neuropsychiatric symptoms in TSC, thereby facilitating future clinical trials of pharmacological treatments.

Effects of bumetanide on neurodevelopmental impairments in patients with tuberous sclerosis complex: an open-label pilot study

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant disease that affects multiple organs including the brain. TSC is strongly associated with broad neurodevelopmental disorders, including autism spectrum disorder symptomatology. Preclinical TSC studies have indicated altered neuronal chloride homeostasis affecting the polarity of γ-aminobutyric acid (GABA) ergic transmission as a potential treatment target. Bumetanide, a selective NKCC1 chloride importer antagonist, may attenuate depolarizing GABA action, and in that way reduce disease burden. In this open-label pilot study, we tested the effect of bumetanide on a variety of neurophysiological, cognitive, and behavioral measures in children with TSC.

METHODS

Participants were treated with bumetanide (2dd 0.5-1.0 mg) for 13 weeks in an open-label trial. The Aberrant Behavior Checklist-Irritability (ABC-I) subscale was chosen as the primary endpoint. Secondary endpoints included other behavioral questionnaires in addition to event-related potentials (ERP) and neuropsychological tests if tolerated. Additionally, the treatment effect on seizure frequency and quality of life was assessed. Endpoint data were collected at baseline, after 91 days of treatment and after a 28-day wash-out period.

RESULTS

Fifteen patients (8-21-years old) with TSC were included of which 13 patients completed the study. Treatment was well-tolerated with only expected adverse events due to the diuretic effects of bumetanide. Irritable behavior (ABC-I) showed significant improvement after treatment in 11 out of 13 patients (t(12) = 4.41, p = .001, d = .773). A favorable effect was also found for social behavior (Social Responsiveness Scale) (t(11) = 4.01, p = .002, d = .549) and hyperactive behavior (ABC-hyperactivity subscale) (t(12) = 3.65, p = .003, d = .686). Moreover, patients rated their own health-related quality of life higher after treatment. At baseline, TSC patients showed several atypical ERPs versus typically developing peers of which prepulse inhibition was significantly decreased in the TSC group. Neuropsychological measurements showed no change and bumetanide had no effect on seizure frequency.

LIMITATIONS

The sample size and open-label design of this pilot study warrant caution when interpreting outcome measures.

CONCLUSIONS

Bumetanide treatment is a potential treatment to alleviate the behavioral burden and quality of life associated with TSC. More elaborate trials are needed to determine the application and effect size of bumetanide for the TSC population. Trial registration EU Clinical Trial Register, EudraCT 2016-002408-13 (www.clinicaltrialsregister.eu/ctr-search/trial/2016-002408-13/NL). Registered 25 July 2016.

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

Background

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

Methods

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

Results

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

Conclusion

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

Diagnosis of tuberous sclerosis complex in the fetus

Tuberous sclerosis complex is a dominantly inherited genetic disorder of striking clinical variability. It is caused by mutations in either TSC1 or TSC2 gene, which regulate cell growth and proliferation by inhibition of mTORC1 signaling. TS is characterized by the development of benign tumors in many tissues and organs and its neurological manifestations include epilepsy, autism, cognitive and behavioral dysfunction, and giant cell tumors. With mechanism-based mTOR inhibitors therapy now available for many of its manifestations, early diagnosis of TSC is very important in order to offer appropriate care, long-term surveillance and parental counseling. Fetal ultrasound and MRI imaging techniques have evolved and may capture even earlier the following TSC-associated lesions: cardiac rhabdomyomas, subependymal nodules, cortical tubers and renal cysts. Often these represent an incidental finding during a routine ultrasound. Furthermore, in the past decades prenatal molecular diagnosis of TSC has emerged as an important option for families with a known affected member; however, the existing evidence with regards to the clinical characteristics and long-term outcome of babies diagnosed prenatally with TSC is yet limited and the path that follows early TSC detection merits further research.

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

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