Tuberous Sclerosis Complex–Associated Angiomyolipomas: Focus on mTOR Inhibition

The impact of everolimus on hematologic parameters in patients with renal angiomyolipoma associated with tuberous sclerosis complex

BACKGROUND

Everolimus is an effective treatment for renal angiomyolipoma associated with TSC (TSC-RAML). However, its impact on hematologic parameters in TSC-RAML patients remains unclear.

METHODS

Hematologic data were collected from TSC-RAML patients undergoing everolimus treatment in two registered clinical trials. Dynamic changes in hematologic parameters during treatment were analyzed. Additionally, we also explored variations in hematologic impact based on gender and age within the patient population.

RESULT

A total of 55 patients from the two clinical trials are included in this analysis. Hemoglobin, white blood cells (WBC), lymphocytes, neutrophils, and platelet showed significant decreases during everolimus treatment (P < 0.05). However, the decline in hemoglobin, WBC, and neutrophils attenuated by the 12th month (P ≥ 0.05). Aspartate transaminase (AST), Alanine transferase (ALT), total cholesterol (TC), and triglyceride (TG) increased significantly during everolimus treatment (P < 0.05), and these increases persisted throughout the year-long treatment. Hemoglobin decreased significantly more in male patients (- 15 vs - 6, P = 0.010), and AST showed a more significant increase in males (7.0 vs 3.0, P = 0.041). Platelet counts decreased significantly more in younger patients (≤ 30 years old) compared to older patients (- 50 vs - 14, P = 0.020).

CONCLUSION

Everolimus administration in TSC-RAML patients may increase hematologic risks, with male and younger patients potentially exhibiting greater susceptibility to these effects.

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.

Surgical management of tuberous sclerosis complex with big fat-poor bilateral renal angiomyolipomas: A case report

INTRODUCTION

Tuberous sclerosis complex (TSC) is an autosomal dominant disease that affects multiple organs. Medical therapy with the mTOR inhibitor everolimus has become the first option in patients with angiomyolipomas. But mTOR inhibitor treatment shows no effect in some patients, in the case, surgery is a suitable method for treatment.

PRESENTATION OF CASE

A 30-year-old Chinese male patient received an ultrasound examination of the kidney, which showed bilateral hyperechogenic structures without stones or ureterohydronephrosis. A computed tomography (CT) scan of the kidneys showed multiple slightly high-density masses (largest size: left 6.5 cm, right 5.2 cm), and the masses lacking of lipids were obviously enhanced in the arterial phase. To clarify the components of the tumors, we performed retroperitoneal laparoscopic tumor enucleation to remove all visible masses in left kidney. The pathological results and genetic tests confirmed the diagnosis of TSC. For reducing the further spontaneously bleeding risk and the cost burden, the right renal tumors were also enucleated. Twelve months after the second operation, renal function remained normal, and no tumors were detected by CT.

DISCUSSION

Large angiomyolipomas (>4 cm in diameter) may develop life-threatening hemorrhage or compress normal kidney tissue. Fat-poor renal angiomyolipomas are difficult for making a differential diagnosis from renal cancer or renal sarcomatoid carcinoma. When medication treatment does not work, surgery is a good option to diagnose and treat big bilateral renal angiomyolipomas.

CONCLUSION

After 12 months of follow-up, retroperitoneal laparoscopic tumor enucleation may be a safe and effective method for treating big fat-poor renal angiomyolipomas in patients with TSC.

Association of multiple retinal nodular hamartomas and "confetti" skin lesions with end-stage renal disease in patients with tuberous sclerosis

PURPOSE

The main purpose of this study is to explore characteristics of patients with chronic kidney disease in tuberous sclerosis (TSC) and to underline differences in clinical characteristics between end-stage renal disease (ESRD) patients and patients in earlier stages of chronic kidney disease.

METHODS

This multicentric, retrospective study included data for 48 patients from seven South-Eastern European countries (Albania, Bosnia and Herzegovina, Croatia, Greece, Montenegro, Serbia, Slovenia) in the period from February to August 2020. Researchers collected data from local and national nephrological and neurological registries and offered clinical and laboratory results from medical histories in follow-up periods.

RESULTS

This study enrolled 48 patients with a median age of 32.3 years (range, 18-46 years), and predominant female gender (60.45%). The percentage of patients with chronic kidney disease (CKD) diagnosis of the total number of patients was 66.90%, with end-stage renal disease development in 39.6%. The most prevalent renal lesions leading to chronic kidney disease were angiomyolipomas (AMLs) in 76.6%, while multiple renal cysts were present in 42.6% of patients. Nephrectomy was performed in 43% of patients, while the mTOR inhibitors were used in 18 patients (37.5%). The majority of patients had cutaneous manifestations of tuberous sclerosis-83.30% had hypomelanotic cutaneous lesions, and 68.80% had angiofibromas. Multiple retinal nodular hamartomas and "confetti" skin lesions were more frequent in end-stage renal disease (ESRD) than in patients with earlier stages of chronic kidney disease (p-0.033 and 0.03, respectively).

CONCLUSION

Our study has also shown that retinal hamartomas and "confetti" skin lesions are more frequent in end-stage renal diseases (ESRD) patients than in other chronic kidney disease (CKD) patients. Usage of mTOR inhibitors can also reduce the number of complications and associated with tuberous sclerosis, such as dermatological manifestations and retinal hamartoma, which are more common in the terminal stage of chronic kidney disease.

Clinical features and outcomes of male patients with lymphangioleiomyomatosis: A review

BACKGROUND

Lymphangioleiomyomatosis (LAM) is a rare disease involving multiple systems, which is divided into sporadic LAM (S-LAM) and tuberous sclerosis complex-LAM, mostly affecting women who are in childbearing age stage. Data on male patients are limited and scattered. Therefore, it is necessary to conduct a systematic review to investigate the clinical features, diagnosis, treatment, and outcomes of LAM in male.

METHODS

We performed a literature review by searching for all the published reported cases of LAM in male during the past 35 years (April 1986-October 2021).

RESULTS

36 male patients described in 26 references were included in this article. The median age of onset was 34 years (interquartile range: 1-79). The most common initial manifestations were cough, dyspnea, respite, and hemoptysis, with pulmonary complications such as pneumothorax and chylothorax. Five patients (13.9%) were asymptomatic at admission. Nearly half of the 36 male patients had thin-walled air-filled cysts that were visible throughout both lungs. Considering the abovementioned atypical clinical features, misdiagnosis was committed in 8 patients (22.2%). In addition, patients with tuberous sclerosis complex lymphangioleiomyomatosis often have no pulmonary manifestations at onset but present multiple extrapulmonary manifestations and have higher rates of renal angiomyolipomas than patients with S-LAM (P < 0.01). Eventually, 4 patients with S-LAM eventually died.

CONCLUSION

Physicians should increase the awareness of LAM in male. Early monitoring of various systems should be recommended to ensure early management and active follow-up. Tuberous sclerosis complex patients should immediately be tracked for the onset of LAM disease to improve prognosis.

A Multi-Centric Study Assessing Safety and Efficacy of Everolimus in Adult Chinese Patients With Tuberous Sclerosis Complex Associated Renal Angiomyolipomas

Background

Everolimus has been approved in China for adult patients with TSC-AML (tuberous sclerosis associated renal angiomyolipomas) not requiring immediate surgery and has been previously shown to be an effective treatment option for TSC-AML in the Chinese population

Methods

This is an open label, single arm, multi-center Phase IV post-approval commitment study to further assess the safety and efficacy of everolimus in patients with TSC-AML who do not require immediate surgical intervention. The primary outcome was to evaluate the safety of everolimus while the secondary outcome was to evaluate AML response.

Results

Treatment with everolimus was associated with a clinically meaningful best overall AML response rate of 70% (95% CI: 53.5, 83.4). Of the 38 evaluable patients, 37 (97%) patients experienced a reduction in the sum of volumes of target angiomyolipoma lesions relative to baseline. At Week 12 (n=38), the median percentage change in sum of target AML volume was −56.60%, which further changed by -59.96% at Week 24 (n=38), and by −64.41% at Week 48 (n=22). Throughout the study, renal function remained relatively stable. Patients with TSC associated lymphangiomyomatosis (LAM) (N=13) demonstrated a lower than expected rate of decline in pulmonary function tests (PFTs). Everolimus was generally well tolerated with no significant safety findings in Chinese patients. Most of the adverse events were of grade 1-2, and manageable with appropriate dose adjustments and supportive therapies. There were no treatment discontinuation due to AE and no treatment death was reported.

Conclusions

Based on the efficacy and safety data presented in this study, the overall clinical benefit/risk assessment further supports the use of everolimus as a viable treatment option for Chinese patients with TSC-AML.

Long-Term Effects of Sirolimus on Human Skin TSC2-Null Fibroblast‒Like Cells

Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder characterized by hamartomatous tumors of the skin, kidneys, brain, and lungs. TSC is caused by mutations in the TSC1 and TSC2 genes, which result in hyperactivation of the mTOR, leading to dysregulated cell growth and autophagy. Rapamycin (sirolimus) shrinks TSC tumors, but the clinical benefits of sirolimus are not sustained after its withdrawal. In this study, we studied the cellular processes critical for tumor formation and growth, including cell proliferation and cell size. TSC2^-/- and TSC2^+/- cells were isolated from TSC skin tumors and normal-appearing skin, respectively. Cells were incubated with sirolimus for 72 hours. Withdrawal of sirolimus from TSC2^-/- cells resulted in a highly proliferative phenotype and caused cells to enter the S phase of the cell cycle, with persistent phosphorylation of mTOR, p70 S6 kinase, ribosomal protein S6, and 4EB-P1; decreased cyclin D kinase inhibitors; and transient hyperactivation of protein kinase B. Sirolimus modulated the estrogen- and autophagy-dependent volume of TSC2^-/- cells. These results suggest that sirolimus may decrease the size of TSC tumors by reducing TSC2^-/- cell volume, altering the cell cycle, and reprogramming TSC2-null cells.

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.

Bilateral Renal Angiomyolipomas and Subependymal Giant Cell Astrocytoma Associated with Tuberous Sclerosis Complex: a Case Report and Review of The Literature

Tuberous sclerosis complex (TSC) is an autosomal-dominant multi system disorder. The genetic basis of the disorder is mutations in the TSC1 or TSC2 gene, which leads to over activation of the mammalian target of rapamycin (mTOR) protein complex and results in development of benign tumors in different body systems such as brain, skin, lungs and kidney. The mTOR inhibitors are presently the main treatment option for patients with TSC. We here report a 21-year female patient with large bilateral angiomyolipoma (AML) in both kidneys with longest diameter more than 12.3 cm and subependymal giant cell astrocytoma (SEGA). Treatment with everolimus (EVE) was initiated at a dose of 10.0 mg/day and continued during the following 3 years. Magnetic resonance imaging (MRI) was performed before treatment with everolimus was initiated, and consequently at 12 and 36 months for follow-up of the efficacy of the treatment. After 3 years, the total size of largest AML decreased by ~24.0% in the longest diameter. A reduction of the total size of SEGA was also observed. The most common adverse effect of treatment was stomatitis grades 3 to 4 and one febrile episode associated with skin rash that required a reduced dose of EVE. In conclusion, the everolimus treatment improved even such a large renal AML and the effect persisted during the long-term administration with a small number of adverse effects. A positive effect was observed on the brain tumor as well.

Enhancing disease awareness for tuberous sclerosis complex in patients with radiologic diagnosis of renal angiomyolipoma: an observational study

Background

Tuberous Sclerosis Complex (TSC) is a genetic disorder, with renal manifestations like angiomyolipoma (AML) occurring in 70–80% of patients. AML usually cause more complications in TCS patients than in non-TSC patients. However, AML patients are not routinely investigated for TSC. Our aim was to retrospectively assess the correlation between radiologically diagnosed AML and TSC.

Methods

All patients were stratified into AML related vs. unrelated to TSC. Correlations were calculated to determine the association between age, AML, and TSC.

Results

Complete data were available for 521 patients with renal AML, in 7 of which the concurrent diagnosis of TSC was found. Younger age significantly positively correlated with the prevalence of TSC in AML patients (p <  0.01). 37 (7%) of the 521 patients were within the age-range of 18–40 years, in which TSC occurred in 6 cases, 4 (66.7%) of which presented with multiple, bilateral renal AML (p <  0.05), and 2 (33.3%) of which with a single, unilateral AML (p <  0.05). In patients with AML but without TSC, unilateral AML was found in 83.9% and bilateral AML in 16.1% (p <  0.05). Simple binary logistic regression analysis revealed bilateral AML (OR 33.0; 95% CI 3.2–344.0; p = 0.003) (but not unilateral AML (OR 0.09; 95% CI 0.01–0.88; p = 0.04)) to be a risk factor for TSC.

Conclusions

The presence of bilateral AML in patients within the age-range of 18–40 years should raise suspicion for TSC as the underlying cause. Therefore, our advice is to refer patients with multiple bilateral renal AML for further investigations regarding TSC.

Renal Manifestations of Tuberous Sclerosis Complex: Key Findings From the Final Analysis of the TOSCA Study Focussing Mainly on Renal Angiomyolipomas

Renal angiomyolipomas are one of the most common renal manifestations in patients with tuberous sclerosis complex (TSC), with potentially life-threatening complications and a poor prognosis. Despite the considerable progress in understanding TSC-associated renal angiomyolipomas, there are no large scale real-world data. The aim of our present study was to describe in detail the prevalence and outcome of renal angiomyolipomas in patients with TSC, enrolled into the TuberOus SClerosis registry to increase disease Awareness (TOSCA) from 170 sites across 31 countries worldwide. We also sought to evaluate the relationship of TSC-associated renal angiomyolipomas with age, gender and genotype. The potential risk factors for renal angiomyolipoma-related bleeding and chronic kidney disease (CKD) were studied in patients who participated in the TOSCA renal angiomyolipoma substudy. Of the 2,211 eligible patients, 1,062 (48%) reported a history of renal angiomyolipomas. The median age of TSC diagnosis for the all subjects (n = 2,211) was 1 year. The median age of diagnosis of renal angiomyolipoma in the 1,062 patients was 13 years. Renal angiomyolipomas were significantly more prevalent in female patients (p < 0.0001). Rates of angiomyolipomas >3 cm (p = 0.0119), growing lesions (p = 0.0439), and interventions for angiomyolipomas (p = 0.0058) were also higher in females than males. Pre-emptive intervention for renal angiomyolipomas with embolisation, surgery, or mammalian target of rapamycin (mTOR) inhibitor may have abolished the gender difference in impaired renal function, hypertension, and other complications. The rate of interventions for angiomyolipomas was less common in children than in adults, but interventions were reported in all age groups. In the substudy of 76 patients the complication rate was too low to be useful in predicting risk for more severe CKD. In addition, in this substudy no patient had a renal hemorrhage after commencing on an mTOR inhibitor. Our findings confirmed that renal angiomyolipomas in subjects with TSC1 mutations develop on average at the later age, are relatively smaller in size and less likely to be growing; however, by age 40 years, no difference was observed in the percentage of patients with TSC1 and TSC2 mutations needing intervention. The peak of appearance of new renal angiomyolipomas was observed in patients aged between 18 and 40 years, but, given that angiomyolipomas can occur later, lifelong surveillance is necessary. We found that pre-emptive intervention was dramatically successful in altering the outcome compared to historical controls; with high pre-emptive intervention rates but low rates of bleeding and other complications. This validates the policy of surveillance and pre-emptive intervention recommended by clinical guidelines.

Effect of everolimus on renal function in patients with tuberous sclerosis complex: evidence from EXIST-1 and EXIST-2

Background

A reduction in renal angiomyolipoma volume observed with everolimus (EVE) treatment in patients with tuberous sclerosis complex (TSC) has been postulated to translate to clinical benefit by reducing the risk of renal hemorrhage and chronic renal failure.

Methods

The long-term effects of EVE on renal function (∼4 years of treatment) were examined in patients treated with EVE in the Phase 3 EXIST-1 and EXIST-2 studies. Patients in EXIST-1 had TSC and subependymal giant cell astrocytoma (SEGA), and patients in EXIST-2 had renal angiomyolipoma and a definite diagnosis of TSC or sporadic lymphangioleiomyomatosis. EVE was administered at 4.5 mg/m²/day, with adjustment to achieve target trough levels of 5–15 ng/mL in EXIST-1 and at 10 mg/day in EXIST-2. Estimated glomerular filtration rate (eGFR) and creatinine levels were assessed at baseline, at Weeks 2, 4, 6, 8, 12 and 18, then every 3 months thereafter. Proteinuria was graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0.

Results

A total of 111 patients from EXIST-1 and 112 patients from EXIST-2 were included in this analysis. Respective mean ages at EVE initiation were 10.5 [standard deviation (SD) 6.45] and 33.2 (SD 10.29) years, and 3.6% and 37.5% of patients had undergone prior renal intervention. Mean baseline eGFR was 115 and 88 mL/min/1.73 m² in EXIST-1 and EXIST-2, respectively. Overall, mean eGFR remained stable over time in both studies, with an decline in renal function mostly confined to some patients with severely compromised renal function before treatment. Patients with prior renal intervention exhibited low eGFR values throughout the study. The incidence of proteinuria increased after initiating treatment with EVE and was mostly Grade 1/2 in severity, with Grade 3 proteinuria reported in only two patients. Measurements of proteinuria were limited by the use of urine dipstick tests.

Conclusions

The use of EVE does not appear to be nephrotoxic in patients with SEGA or renal angiomyolipoma associated with TSC and may preserve renal function in most patients.

ClinicalTrials.gov identifiers NCT00789828 and NCT00790400

From tuberous sclerosis complex to end stage renal disease: who are these patients?

In patients with tuberous sclerosis complex (TSC), renal complications are not limited to bleeding angiomyolipoma (AML); although rare, end-stage renal disease (ESRD) may occur. New treatments (e.g., mammalian target of rapamycin (m-Tor) inhibitors) for AML might influence the epidemiology of ESRD in patients with TSC. In France, 99 patients with TSC from the Renal Epidemiology and Information Network (REIN) registry and having undergone renal replacement therapy (RRT) between 2002 and 2016 were included in the present study. Additional data were collected from the patients' medical charts. The mean ± standard deviation age at RRT initiation was 48.4 ± 16.4 and 73.8% had a neurologic impairment. Fifty-four patients underwent kidney transplantation after an average of 23 ± 12.3 months on dialysis. Among the 61 patients with additional data the most common renal lesion was AML: 26.2% of the patients had isolated AML, and 26.2% had AML and renal cysts, 65.6% of patients had undergone nephrectomy, and 16.4% had undergone at least one embolization. None of the patients had been treated with an m-Tor inhibitor before dialysis. The graft survival rate was 92.5% at 5 years and 70.2% at 10 years. The present cohort study is the first to have assessed TSC patients on RRT from a national registry. Nephrectomy or embolization due to AML was the leading cause of ESRD in our cohort. By reducing the size of the AML, m-tor inhibitors might lower the risk of complications and thus reduce the number of patients with TSC requiring RRT.

How many surgically-treated angiomyolipomas are related to tuberous sclerosis complex? Insights from a retrospective multicenter study

BACKGROUND

Patients with TSC - related renal angiomyolipoma (AML) are eligible for targeted therapy with mTOR inhibitors, avoiding the morbidity of interventional management. Despite clinical criteria for TSC diagnosis have been defined, their use in routine clinical practice is likely suboptimal, leading to potential misclassification of TSC-related AML. The study aims to assess the proportion and characteristics of surgically-treated patients with putative sporadic AML that would have been re-classified as TSC-related.

METHODS

We retrospectively reviewed a prospectively collected multi-institutional database to select patients with suspected TSC-related AML among those undergoing surgery at three referral Centers over 11-years (2005-2015). Possible diagnosis of TSC was defined according to the 2012 International Tuberous Sclerosis Complex Consensus (ITSCC) criteria. The proportion and characteristics of patients with possible TSC-related AML (as compared to those of patients with sporadic AML) were considered the main study endpoints.

RESULTS

Overall, 132 patients were included. Of these, 10 (7.6%) were considered TSC-related. Most patients (84%) were female. Patients with TSC-related AML were likely to be younger (median age 53 vs. 56 years, P=0.29), symptomatic at diagnosis (70% vs. 21%, P=0.002), with slightly worse preoperative physical status (median ASA score 2 vs. 1, P=0.001) and bilateral disease (30% vs. 7.4%, P=0.04) as compared to patients with sporadic AML. Anatomic complexity and tumor size were also higher among TSC-related AMLs.

CONCLUSIONS

A non-negligible proportion of surgically-treated, putative sporadic AMLs were reclassified as potentially hereditary (TSC-related). As TSC patients may be treated with targeted therapies, our findings may increase urologists' awareness of TSC-related AML and prompt the design of future studies evaluating targeted diagnostic pathways for these patients.

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.

Characterization of the Basal Ganglia Using Diffusion Tensor Imaging in Children with Self-Injurious Behavior and Tuberous Sclerosis Complex

BACKGROUND AND PURPOSE

Tuberous sclerosis complex (TSC) is a rare, genetic disease that is associated with multiple manifestations including epilepsy and autism. Self‐injurious behaviors (SIBs) also occur in a subset of patients. This study used diffusion tensor imaging (DTI) in children with TSC for quantitative and volumetric analysis of brain regions that have been associated with SIB in other genetic conditions.

METHODS

We used DTI to compare 6 children with TSC‐associated SIB and 10 children with TSC without SIB. Atlas‐based analysis of DTI data and calculation of number of voxels; fractional anisotropy (FA); and mean, axial, and radial diffusivity were performed for multiple regions; DTI measures were summarized using medians and interquartile ranges and were compared using Wilcoxon rank sum tests and false discovery rates (FDRs).

RESULTS

Analysis showed that children with TSC and SIB had reduced numbers of voxels (median) in the bilateral globus pallidus (right: 218 vs. 260, P = .008, FDR = .18; left: 222 vs. 274, P = .002, FDR = .12) and caudate nucleus (right: 712 vs. 896, P = .01, FDR = .26; left: 702 vs. 921, P = .03, FDR = .44) and reduced FA in the bilateral globus pallidus (right: .233 vs. .272, P = .003, FDR = .12; left: .223 vs. .247, P = .004, FDR = .12) and left caudate nucleus (.162 vs. .186, P = .03, FDR = .39) versus children without SIB. No other statistically significant differences were found.

CONCLUSIONS

These data support a correlation between lower volumes of the globus pallidus and caudate with SIB in children with TSC.

Conditional Knockout of Raptor/mTORC1 Results in Dentin Malformation

mTORC1 signaling plays an important role in extracellular and intracellular signals, including growth factors, nutrients, energy metabolism, and stress. However, the functional role of mTORC1 in dentinogenesis is unknown. To study the role of Raptor/mTORC1 in dentinogenesis, an Raptor^fl/fl; Osx-Cre (Rap-Osx) mouse, in which Raptor was conditionally deleted in odontoblasts and dental mesenchymal cells, was generated, and postnatal tooth development was compared between Rap-Osx mice and control littermates. Rap-Osx mice presented a phenotype known as dentinogenesis imperfecta and had smaller tooth volume, a thinner dentin layer and a larger pulp chamber. The proliferation and differentiation of odontoblasts/preodontoblasts were attenuated in mutant mice, which was likely responsible for the defects in dentinogenesis. Raptor/mTORC1-pS6K1 signaling was inactivated during tooth development in Rap-Osx mice, whereas it was activated in control mice. These results indicate that Raptor/mTORC1 plays a critical role in dentinogenesis via promoting odontoblasts/preodontoblasts proliferation and differentiation. Raptor/mTORC1 might regulate tooth development through the pS6K1 signaling pathway.

CT characteristics predict the response to everolimus or sirolimus of renal angiomyolipomas in patients with tuberous sclerosis complex

OBJECTIVE

To investigate factors influencing the volume response of everolimus and sirolimus in tuberous sclerosis complex (TSC) associated-angiomyolipomas (AML).

METHODS

A retrospective analysis of 30 cases of TSC-AML treated by mTOR inhibitors (everolimus 18 cases, and sirolimus 12 cases) between April 2014 and November 2017 at our center was carried out. Epidemiological data, therapeutic response and influence factors were reviewed and analyzed. Age, sex, associated with SEGA and/or LAM or not, plasma rapamycin concentration, AML volume at baseline, and mean CT value of AML in the maximum cross-section at baseline were analyzed as potential influencing factors.

RESULTS

Eighteen patients with 32 lesions in everolimus group and 12 patients with 15 lesions in sirolimus group were included. There was no statistically significant difference of baseline characteristics except for involved side (P = 0.008) between two groups. The mean volume of AML was 1000 ± 1276 cm³ at baseline and 633 ± 1121 cm³ at 6 months after treatment (P < 0.001) in everolimus group, and 1984 ± 2861 cm³ at baseline and 1733 ± 2533 cm³ at 6 months after treatment (P = 0.001) in sirolimus group, respectively. The mean volume reduction of the AML in everolimus and sirolimus groups were 55.56% ± 23.79% and 30.5% ± 22.8% (P = 0.001). Stepwise multiple linear regression analysis revealed that factors influencing the short-term volume response of everolimus and sirolimus for TSC-associated AML were AML volume at baseline (P < 0.001 and 0.038, respectively) and mean CT value at baseline (P < 0.001 and 0.020, respectively). The rates of ≥ 50% volume reduction in high CT value group was much higher than that in low CT value group (90.5% vs. 18.2%, P < 0.001).

CONCLUSIONS

Everolimus at 10 mg daily might be more effective than sirolimus at 2 mg daily in treatment of patients with TSC-AML. AML volume and mean CT value at baseline were factors influencing the short-term volume response of everolimus or sirolimus for TSC-AML.

Angiomyolipoma rebound tumor growth after discontinuation of everolimus in patients with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis

Introduction

The EXIST-2 (NCT00790400) study demonstrated the superiority of everolimus over placebo for the treatment of renal angiomyolipomas associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (LAM). This post hoc analysis of EXIST-2 study aimed to assess angiomyolipoma tumor behavior among patients who submitted to continued radiographic examination following discontinuation of everolimus in the noninterventional follow-up phase.

Methods

For patients who discontinued everolimus at the completion of extension phase for reasons other than angiomyolipoma progression, a single CT/MRI scan of the kidney was collected after 1 year of treatment discontinuation. Changes from baseline and from the time of everolimus discontinuation in the sum of volumes of target angiomyolipoma lesions were assessed in the non-interventional follow-up phase (data cutoff date, November 6, 2015).

Results

Of the 112 patients who received ≥1 dose of everolimus and discontinued treatment by the end of extension phase, 34 (30.4%) were eligible for participation in the non-interventional follow-up phase. Sixteen of 34 patients were evaluable for angiomyolipoma tumor behavior as they had at least one valid efficacy assessment (i.e. kidney CT/MRI scan) after everolimus discontinuation. During the non-interventional follow-up phase, compared with baseline, two patients (12.5%) experienced angiomyolipoma progression (angiomyolipoma-related bleeding [n = 1], increased kidney volume [n = 1]). Five patients out of 16 (31.3%) experienced angiomyolipoma progression when compared with the angiomyolipoma tumor assessment at everolimus discontinuation. The median (range) percentage change in angiomyolipoma tumor volume (cm³) from baseline was −70.56 (−88.30; −49.64) at time of everolimus discontinuation (n = 11), and −50.55 (−79.40; −23.16) at week 48 (n = 7) after discontinuation of everolimus. One patient death was reported due to angiomyolipoma hemorrhage.

Conclusions

Angiomyolipoma lesions displayed an increase in volume following discontinuation of everolimus in patients with renal angiomyolipoma or sporadic LAM associated with TSC, but there was no evidence of rapid regrowth.

Trial registration

ClinicalTrials.gov NCT00790400

Effect of everolimus on skin lesions in patients treated for subependymal giant cell astrocytoma and renal angiomyolipoma: final 4-year results from the randomized EXIST-1 and EXIST-2 studies

BACKGROUND

Tuberous sclerosis complex (TSC) is a genetic disorder associated with tumour growth in various organs, including the brain, kidneys, heart and skin. Cutaneous lesions are prevalent manifestations of TSC, occurring in up to 90% of patients. Oral mammalian target of rapamycin inhibitors, such as everolimus, is believed to be effective for treatment of TSC-associated lesions because they act on the underlying disease pathophysiology.

OBJECTIVE

We evaluated the long-term effect of oral everolimus on TSC-associated skin lesions as a secondary objective in the phase III studies EXIST-1 (NCT00789828) and EXIST-2 (NCT00790400) after approximately 4 years of treatment.

MATERIALS AND METHODS

Everolimus was dosed 4.5 mg/m² /day (titrated to trough 5-15 ng/mL) in patients with TSC-associated subependymal giant cell astrocytoma in EXIST-1, and 10 mg/day initially in adult patients with TSC- or sporadic lymphangioleiomyomatosis-associated renal angiomyolipoma in EXIST-2. Following positive results from the core phase, remaining patients were offered open-label everolimus in an extension. Skin lesion response rate was the proportion of patients achieving complete or partial clinical response.

RESULTS

A total of 105 patients in EXIST-1 and 107 in EXIST-2 received everolimus and had ≥1 skin lesion at baseline. Skin lesion response rate (95% confidence interval) was 58.1% (48.1-67.7%) in EXIST-1 and 68.2% (58.5-76.9%) in EXIST-2; most were partial responses. At week 192 (EXIST-1: n = 55; EXIST-2: n = 56), 69% and 66% had a response. Most common drug-related adverse event was stomatitis (41-45%).

CONCLUSION

Oral everolimus improved TSC-related skin lesions, with responses sustained over 4 years of treatment in EXIST-1 and EXIST-2.

Consequences of delay in screening, monitoring, and treatment of angiomyolipoma and tuberous sclerosis: A case report

BACKGROUND

Tuberous sclerosis complex (TSC) is a multisystem disorder that results in tumor growth in various organs. TSC can affect the kidneys in the form of renal angiomyolipomas and cysts that can lead to chronic kidney disease.

CASE PRESENTATION

A 38-year-old woman was referred to Kennedy Krieger Institute for comprehensive TSC management. Before referral, the patient had gone most of her life without a definite diagnosis of TSC despite visually-prominent signs such as forehead plaques, facial angiofibromas, and ungual fibromas. Eventually, complications of the disease led to the patient requiring hemodialysis at age 34 and a complete bilateral nephrectomy at age 36. However, the patient was not diagnosed with TSC until an evaluation at the National Institutes of Health at age 37. After becoming a patient at our clinic, a multidisciplinary approach was taken to provide comprehensive care by including various disciplines such as nephrology, neurology, pulmonology, ophthalmology, dentistry, dermatology, and cardiology.

DISCUSSION AND CONCLUSION

TSC consensus recommendations aid in diagnosis, monitoring, and treatment of TSC and its associated manifestations, including those involving the kidneys. Our case underscores the importance of early identification of TSC to prevent future complications and promotes use of a multidisciplinary team to provide comprehensive care.
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Benign Neoplasm of Kidney: Angiomyolipoma

Angiomyolipoma is one of the renal benign neoplasms. The most of the angiomyolipomas are asymptomatic and found incidentally with ultrasound. They are more prevalent in patients with tuberous sclerosis. It is very important to make differential diagnosis from other renal neoplasm such as renal cell carcinoma. Growth rate is higher among pregnant women suggest that the hormones may play a role in the stimulation of angiomyolipoma. The most common serious presentation is rupture and hemorrhage, and sometimes it can lead to shock. Adequate diagnosis, treatment, and follow-up are very important in the face of renal angiomyolipoma.

Everolimus Reduces the Size of Tuberous Sclerosis Complex-Related Huge Renal Angiomyolipomas Exceeding 20 cm in the Longest Diameter

We evaluated the efficacy of everolimus in 3 patients who had huge renal angiomyolipomas associated with tuberous sclerosis complex. Two patients with large lipid-rich angiomyolipomas had a history of renal transarterial embolization for renal bleeding, but the effect had only been temporary and the embolized kidneys had continued to enlarge. In case 1, case 2, and case 3, total renal volume was respectively 3,891, 4,035, and 1,179 cm³ before administration of everolimus, decreasing to 3,016 (77%), 3,043 (75%), and 1,051 (89%) cm³ after 1 year of everolimus therapy and to 2,832 (73%), 3,209 (80%), and 1,102 (93%) cm³ after 3 years. New renal bleeding did not occur, but elevation of serum creatinine and urinary protein were noted in 2 patients. While previous reports have largely assessed the effect of everolimus for angiomyolipomas of < 10 cm in the longest diameter, our findings suggest that this drug might also be effective for huge lesions of > 20 cm in diameter. However, total renal volume still exceeds 2,000 cm³ in 2 of our patients, suggesting limited size reduction of lipid-rich angiomyolipomas. In addition, occurrence of everolimus-related nephropathy needs to be monitored carefully.

An update on recent developments in rupture of renal angiomyolipoma

BACKGROUND

Renal angiomyolipoma (AML) is a common benign tumor of the kidney. The main complication of AML is retroperitoneal hemorrhage caused by AML rupture, which can be severe and life threatening. The risk of AML rupture used to be determined by tumor size. However, these criteria have been challenged by series of clinical studies and case reports, suggesting prediction AML rupture based on tumor size is not always reliable.

METHODS

The authors searched PubMed using "angiomyolipoma," "AML," and "rupture" and reviewed relevant studies. The authors investigated the risk factors of AML rupture using the retrieved literature. The authors also summarized current modalities to evaluate and manage AML.

RESULTS

It is established that risk of AML rupture is associated with lesion size. However, genetic abnormality, aneurysm formation, and pregnancy are also risk factors for tumor rupture. Thus, the prediction of AML rupture should be based on a more comprehensive risk assessment system. The management of renal AML and tumor rupture was also discussed in the present paper.

CONCLUSION

The risk of AML rupture is associated with but not exclusive to lesion size. Any decision to intervene AML must be based on multiple factors including risk, symptoms, and auxiliary findings.

Angiomyolipoma of the Kidneys: Current Perspectives and Challenges in Diagnostic Imaging and Image-Guided Therapy

Angiomyolipomas (AML) are benign tumors of the kidneys frequently encountered in radiologic practice in large tertiary centers. In comparison to renal cell carcinomas (RCC), AML are seldom treated unless they are large, undergo malignant transformation or develop complications like acute hemorrhage. The common garden triphasic (classic) AML is an easy diagnosis, however, some variants lack macroscopic fat in which case the radiologic differentiation from RCC becomes challenging. Several imaging features, both qualitative and quantitative, have been described in differentiating the 2 entities. Although minimal fat AML is not entirely a radiologic diagnosis, the suspicion raised on imaging necessitates sampling and potentially avoids an unwanted surgery. Recently a new variant, epitheloid AML has been described which often has atypical imaging features and is at a higher risk for malignant transformation. Apart from the diagnosis, the radiologist also needs to convey information regarding nephrometric scores which help in surgical decision-making. Recently, more and more AMLs are managed with selective arterial embolization and percutaneous ablation, both of which are associated with less morbidity when compared to surgery. The purpose of this article is to review the imaging and pathologic features of classic AML as well as the differentiation of minimal fat AML from RCC. In addition, an overview of nephrometric scoring and image-guided interventions is also provided.

Sclerotic bone lesions as a potential imaging biomarker for the diagnosis of tuberous sclerosis complex

Tuberous-sclerosis-complex (TSC) is associated with a high lifetime risk of severe complications. Clinical manifestations are largely variable and diagnosis is often missed. Sclerotic-bone-lesions (SBL) could represent a potential imaging biomarker for the diagnosis of TSC. In this study, computed tomography (CT) data sets of 49 TSC patients (31 females) were included and compared to an age/sex matched control group. Imaging features of SBLs included frequency, size and location pattern. Sensitivities, specificities and cutoff values for the diagnosis of TSC were established for the skull, thorax, and abdomen/pelvis. In TSC patients, 3439 SBLs were detected, including 665 skull SBLs, 1426 thoracal SBLs and 1348 abdominal/pelvic SBLs. In the matched control-collective, 157 SBLs could be found. The frequency of SBLs enabled a reliable differentiation between TSC patients and the control collective with the following sensitivities and specificities. Skull: ≥5 SBLs, 0.783, 1; thorax: ≥4 SBLs, 0.967, 0.967; abdomen/pelvis: ≥5 SBLs: 0.938, 0.906. SBL size was significantly larger compared to controls (p < 0.05). Based on the frequency, size and location pattern of SBLs TSC can be suspected. SBLs may serve as a potential imaging biomarker in the workup of TSC patients.

The effect of everolimus on renal angiomyolipoma in pediatric patients with tuberous sclerosis being treated for subependymal giant cell astrocytoma

BACKGROUND

Patients with tuberous sclerosis complex (TSC) often have multiple TSC-associated hamartomas, particularly in the brain and kidney.

METHODS

This was a post hoc analysis of pediatric patients being treated for subependymal giant cell astrocytomas (SEGAs) during the phase 3, randomized, double-blind, placebo-controlled EXIST-1 trial. Patients were initially randomly assigned to receive everolimus 4.5 mg/m²/day (target blood trough 5-15 mg/dl) or placebo and could continue in an open-label extension phase. Angiomyolipoma response rates were analyzed in patients aged <18 years with ≥1 target angiomyolipoma lesion at baseline. Response was defined as the proportion of patients with a ≥50% reduction in the sum volume of target renal angiomyolipomata from baseline, in the absence of new target angiomyolipomata, a >20% increase in kidney volume from nadir, and angiomyolipoma-related bleeding ≥ grade 2. Tolerability was also assessed.

RESULTS

Overall, this analysis included 33 patients. Renal angiomyolipoma response was achieved by 75.8% of patients (95% confidence interval, 57.7-88.9%), with sustained mean reductions in renal angiomyolipoma volume over nearly 4 years of treatment. In addition, most (≥80%) achieved clinically relevant reductions in angiomyolipoma volume (≥50%), beginning at week 24 and continuing for the remainder of the study. Everolimus was generally well tolerated in this subgroup, with most adverse events being grade 1 or 2 in severity.

CONCLUSIONS

Although everolimus is currently not indicated for this use, this analysis from EXIST-1 demonstrates its long-term efficacy and safety for the treatment of renal angiomyolipoma in pediatric patients undergoing treatment for TSC-associated SEGA.

Treatment effect of mTOR-inhibition on tissue composition of renal angiomyolipomas in tuberous sclerosis complex (TSC)

Purpose

Tuberous sclerosis complex (TSC)-associated renal angiomyolipoma (AML) have a high lifetime risk of acute bleeding. MTOR-inhibitors are a promising novel treatment for TSC-AML, however adequate response to therapy can be difficult to assess. Early changes in MRI signal may serve as a novel early indicator for a satisfactory response to mTOR-inhibitor therapy of AML.

Materials and methods

Thirty-eight patients with the definite diagnosis of tuberous sclerosis receiving everolimus therapy and n = 19 patients without specific therapy were included. 1.5 Tesla MRI was performed including sequences with a selective fat suppression. Patients were investigated prior to the initiation of therapy (baseline) and after <3 months (n = 21 patients), 3 to 6 months (n = 32) and 18 to 24 months (n = 28). Signal and size changes of renal AMLs were assessed at all different timepoints. Signal-to-noise-ratio (SNR), contrast-to-noise-ratio (CNR) and size of angiomyolipomas were evaluated.

Results

Signal changes in 273 AMLs were evaluated. A significant and strong decrease of the CNR of AMLs following the initiation of therapy was measured in the fat-suppressed MR sequence at all time points, compared to the baseline: From 7.41±6.98 to 3.84±6.25 (p ≤ 0.05p = 0.002), 3.36±6.93 (p<0.0001), and 2.50±6.68 (p<0.0001) after less than 3 months, 3–6 months or 18–24 months of everolimus treatment, respectively. Also, a significant, however less pronounced, reduction of angiomyolipoma size in the different groups was measured (from baseline 2022.2±2657.7 mm2 to 1854.4±1670.9 mm2 (p = 0.009), 1875.5±3190.1 mm2 (p<0.001), and 1365.8 ± 1628.8 mm2 (p<0.0001) after less than 3 months, 3–6 months or 18–24 months of everolimus treatment, respectively). No significant changes in CNR (p>0.05) and size (p>0.05) were measured in the control group.

Conclusion

mTOR inhibitor therapy in TSC patients results in an early and pronounced fatty transformation of AMLs on MRI. Fatty transformation could represent a novel early indicator of response to therapy in this patient collective.

Evidence of renal angiomyolipoma neoplastic stem cells arising from renal epithelial cells

Renal angiomyolipomas (AML) contain an admixture of clonal tumour cells with features of several different mesenchymal lineages, implying the existence of an unidentified AML neoplastic stem cell. Biallelic inactivation of TSC2 or TSC1 is believed to represent the driving event in these tumours. Here we show that TSC2 knockdown transforms senescence-resistant cultured mouse and human renal epithelial cells into neoplastic stem cells that serially propagate renal AML-like tumours in mice. mTOR inhibitory therapy of mouse AML allografts mimics the clinical responses of human renal AMLs. Deletion of Tsc1 in mouse renal epithelia causes differentiation in vivo into cells expressing characteristic AML markers. Human renal AML and a renal AML cell line express proximal tubule markers. We describe the first mouse models of renal AML and provide evidence that these mesenchymal tumours originate from renal proximal tubule epithelial cells, uncovering an unexpected pathological differentiation plasticity of the proximal tubule.

Renal angiomyolipomas (AML) contain a mix of clonal tumour cells. Here, through reverse tumour engineering experiments, mouse genetics and analyses of human AML tumours, the authors provide evidence that these mesenchymal tumours originate from renal proximal tubule epithelial cells.

Everolimus long-term use in patients with tuberous sclerosis complex: Four-year update of the EXIST-2 study

OBJECTIVES

We examined the long-term effects of everolimus in patients with renal angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis.

METHODS

Following favorable results from the double-blind core phase of EXIST-2 (NCT00790400), patients were allowed to receive open-label everolimus (extension phase). Patients initially randomly assigned to everolimus continued on the same dose; those who were receiving placebo crossed over to everolimus 10 mg/day. Dose modifications were based on tolerability. The primary end point was angiomyolipoma response rate, defined as a ≥50% reduction from baseline in the sum volume of target renal angiomyolipomas in the absence of new target angiomyolipomas, kidney volume increase of >20% from nadir, and angiomyolipoma-related bleeding grade ≥2. The key secondary end point was safety.

RESULTS

Of the 112 patients who received ≥1 dose of everolimus, 58% (95% CI, 48.3% to 67.3%) achieved angiomyolipoma response. Almost all patients (97%) experienced reduction in renal lesion volumes at some point during the study period. Median duration of everolimus exposure was 46.9 months. Sixteen (14.3%) patients experienced angiomyolipoma progression at some point in the study. No angiomyolipoma-related bleeding or nephrectomies were reported. One patient on everolimus underwent embolization for worsening right flank pain. Subependymal giant cell astrocytoma lesion response was achieved in 48% of patients and skin lesion response in 68% of patients. The most common adverse events suspected to be treatment-related were stomatitis (42%), hypercholesterolemia (30.4%), acne (25.9%), aphthous stomatitis and nasopharyngitis (each 21.4%). Ten (8.9%) patients withdrew because of an adverse event. Renal function remained stable, and the frequency of emergent adverse events generally decreased over time.

CONCLUSIONS

Everolimus treatment remained safe and effective over approximately 4 years. The overall risk/benefit assessment supports the use of everolimus as a viable treatment option for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00790400.

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

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

Treatment of renal angiomyolipoma in tuberous sclerosis complex (TSC) patients

In adult tuberous sclerosis complex (TSC) patients, renal complications are the leading cause of death. Beginning in childhood, up to 80 % of patients develop renal angiomyolipoma characterized by a size-dependent risk of life-threatening bleeding. After discovery of the two causative genes, TSC1 and TSC2, and the role of mammalian target of rapamycin (mTOR) regulation in the pathogenesis of TSC, an increasing number of clinical studies evaluating mTOR inhibition in TSC patients have shown impressive results in many organ manifestations, such as brain, lung, and kidney. For renal angiomyolipoma, mTOR inhibitor treatment fundamentally changed the approach from preventive embolization or even partial nephrectomy to everolimus treatment in order to preserve kidney function.

Partial Nephrectomy for a Massive Sporadic Renal Angiomyolipoma: Case Report and Review of the Literature

Introduction. Angiomyolipomas are the most common benign tumor of the kidney, associated with Tuberous Sclerosis in 20% of cases and arising sporadically in 80% of cases. Renal angiomyolipomas are neoplasms of mesenchymal origin with varying proportions of vasculature, smooth muscle spindle cells, and adipocytes, making management of such neoplasms a challenging endeavor. Possible management options include partial or radical nephrectomy and segmental renal artery embolization. Case Presentation. A 61-year-old woman admitted for a large retroperitoneal hemorrhage was discovered to have a giant, sporadic, 3818.3 g, 30.0 × 26.5 × 18.0 cm left perinephric angiomyolipoma. Given her hemodynamic instability upon presentation, she underwent segmental arterial embolization, followed by an open left partial nephrectomy. Ten-month follow-up revealed no noticeable loss of renal function. Discussion. Literature review revealed occasional renal angiomyolipomas of comparable size, with all angiomyolipomas larger than this requiring treatment with radical nephrectomy. Conclusion. We show that nephron-sparing surgery may be considered in the treatment of even the largest of renal angiomyolipomas.

Therapeutic Drug Monitoring of Everolimus: A Consensus Report

In 2014, the Immunosuppressive Drugs Scientific Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology called a meeting of international experts to provide recommendations to guide therapeutic drug monitoring (TDM) of everolimus (EVR) and its optimal use in clinical practice. EVR is a potent inhibitor of the mammalian target of rapamycin, approved for the prevention of organ transplant rejection and for the treatment of various types of cancer and tuberous sclerosis complex. EVR fulfills the prerequisites for TDM, having a narrow therapeutic range, high interindividual pharmacokinetic variability, and established drug exposure-response relationships. EVR trough concentrations (C0) demonstrate a good relationship with overall exposure, providing a simple and reliable index for TDM. Whole-blood samples should be used for measurement of EVR C0, and sampling times should be standardized to occur within 1 hour before the next dose, which should be taken at the same time everyday and preferably without food. In transplantation settings, EVR should be generally targeted to a C0 of 3-8 ng/mL when used in combination with other immunosuppressive drugs (calcineurin inhibitors and glucocorticoids); in calcineurin inhibitor-free regimens, the EVR target C0 range should be 6-10 ng/mL. Further studies are required to determine the clinical utility of TDM in nontransplantation settings. The choice of analytical method and differences between methods should be carefully considered when determining EVR concentrations, and when comparing and interpreting clinical trial outcomes. At present, a fully validated liquid chromatography tandem mass spectrometry assay is the preferred method for determination of EVR C0, with a lower limit of quantification close to 1 ng/mL. Use of certified commercially available whole-blood calibrators to avoid calibration bias and participation in external proficiency-testing programs to allow continuous cross-validation and proof of analytical quality are highly recommended. Development of alternative assays to facilitate on-site measurement of EVR C0 is encouraged.

Renal angiomyolipoma bleeding in a patient with TSC2/PKD1 contiguous gene syndrome after 17 years of renal replacement therapy

We report the case of a 32-year-old male diagnosed with TSC2/PKD1 contiguous gene syndrome, presenting with tuberous sclerosis (TS) and autosomal dominant polycystic kidney disease simultaneously. He progressed to end-stage renal disease and received a kidney transplant at the age of 12. The native kidneys presented angiomyolipomas (AML), which are common benign tumours in patients with TS. Seventeen years after transplantation, he presented with abdominal pain, anaemia and a retroperitoneal haematoma, the latter caused by renal AML bleeding. Selective embolisation was performed. Our patient could have benefited from the administration of mTOR inhibitors at transplant. This therapy is immunosuppressive and reduces the size of benign tumours in TS as well as the risk of rupture and bleeding. This patient did not receive mTOR inhibitors at the time of the transplant because the relationship between mTOR inhibitors and TS was unknown at that time. This case confirms the persistent risk of renal AML bleeding for both transplanted patients and patients on dialysis. As a result, we would recommend routine check-ups of native kidneys and nephrectomy assessment.

Review of the Tuberous Sclerosis Renal Guidelines from the 2012 Consensus Conference: Current Data and Future Study

Renal-related disease is the most common cause of tuberous sclerosis complex (TSC)-related death in adults, and renal angiomyolipomas can lead to complications that include chronic kidney disease (CKD) and hemorrhage. International TSC guidelines recommend mammalian target of rapamycin (mTOR) inhibitors as first-line therapy for management of asymptomatic, growing angiomyolipomas >3 cm in diameter. This review discusses data regarding patient outcomes that were used to develop current guidelines for embolization of renal angiomyolipomas and presents recent data on 2 available mTOR inhibitors - sirolimus and everolimus - in the treatment of angiomyolipoma. TSC-associated renal angiomyolipomas can recur after embolization. Both sirolimus and everolimus have shown effectiveness in reduction of angiomyolipoma volume, with an acceptable safety profile that includes preservation of renal function with long-term therapy. The authors propose a hypothesis for mTORC1 haploinsufficiency as an additional mechanism for CKD and propose that preventive therapy with mTOR inhibitors might have a role in reducing the number of angiomyolipoma-related deaths. Because mTOR inhibitors target the underlying pathophysiology of TSC, patients might benefit from treatment of multiple manifestations with one systemic therapy. Based on recent evidence, new guidelines should be considered that support the earlier initiation of mTOR inhibitor therapy for the management of renal angiomyolipomas to prevent future serious complications, rather than try to rescue patients after the complications have occurred.

Roles of mTOR complexes in the kidney: implications for renal disease and transplantation

The mTOR pathway has a central role in the regulation of cell metabolism, growth and proliferation. Studies involving selective gene targeting of mTOR complexes (mTORC1 and mTORC2) in renal cell populations and/or pharmacologic mTOR inhibition have revealed important roles of mTOR in podocyte homeostasis and tubular transport. Important advances have also been made in understanding the role of mTOR in renal injury, polycystic kidney disease and glomerular diseases, including diabetic nephropathy. Novel insights into the roles of mTORC1 and mTORC2 in the regulation of immune cell homeostasis and function are helping to improve understanding of the complex effects of mTOR targeting on immune responses, including those that impact both de novo renal disease and renal allograft outcomes. Extensive experience in clinical renal transplantation has resulted in successful conversion of patients from calcineurin inhibitors to mTOR inhibitors at various times post-transplantation, with excellent long-term graft function. Widespread use of this practice has, however, been limited owing to mTOR-inhibitor- related toxicities. Unique attributes of mTOR inhibitors include reduced rates of squamous cell carcinoma and cytomegalovirus infection compared to other regimens. As understanding of the mechanisms by which mTORC1 and mTORC2 drive the pathogenesis of renal disease progresses, clinical studies of mTOR pathway targeting will enable testing of evolving hypotheses.

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

Background

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

Methods and Findings

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

Conclusions

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

Trial Registration

ClinicalTrials.gov NCT00789828

Tuberous sclerosis complex-associated renal angiomyolipomas: A single center study of 17 consecutive cases

The aim of the present study was to investigate the treatment options for patients with tuberous sclerosis complex (TSC)-associated renal angiomyolipomas (AMLs). A total of 17 patients who were consecutively diagnosed with TSC-associated renal AMLs at the Department of Urology of Zhongshan Hospital between 1998 and 2012 were included in the study. The patient cohort included 7 males and 10 females with a mean age of 37.6 years (range, 18-62 years). A total of 12 patients were diagnosed with renal AML with TSC during physical examination (PE), while 5 patients were admitted to the Emergency Department of Zhongshan Hospital due to spontaneous rupture of renal AMLs. All renal lesions were examined by ultrasonography and abdominal computed tomography prior to treatment. The primary outcome measure was the kidney reservation rate (patients that had not received nephrectomies) in the rupture group and PE group. Both abdominal ultrasonography and CT revealed AMLs in all patients and the mean tumor size was 10.0±4.0 cm (range, 3.0-17.5 cm). Overall, 9 patients underwent surgery, which included unilateral nephrectomy in 4 patients and unilateral partial nephrectomy/tumor enucleation in 5 patients. The remaining 8 patients received medical treatment. All patients were followed-up for between 10 and 67 months. One patient succumbed as a result of multiple organ failure, which was caused by hypovolemic shock due to the spontaneous rupture of renal AML. The kidney reservation rate during surgery was 87.5% (7/8) in the PE group and 25% (1/4) in the spontaneous rupture group. The management of TSC-associated renal AMLs differs from that of solitary sporadic AMLs. Surgical therapy is recommended following careful risk-benefit analysis.

Pharmacokinetics and pharmacodynamics of everolimus in patients with renal angiomyolipoma and tuberous sclerosis complex or lymphangioleiomyomatosis

AIMS

The purpose was to determine the exposure-response relationship of everolimus in patients with angiomyolipoma from the EXIST-2 trial and to analyze the correlation between exposure and plasma concentrations of angiogenic biomarkers in these patients.

METHODS

One hundred and eighteen patients with angiomyolipoma associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (sLAM) were randomly assigned 2 : 1 to receive everolimus 10 mg (n = 79) or placebo (n = 39) once daily. Blood samples for determining everolimus concentration were collected at weeks 2, 4, 12, 24 and 48 during double-blind treatment. Plasma samples for biomarker analysis were collected at baseline and weeks 4, 12, 24, 36, 48 and at the end of treatment. Concentrations of eight angiogenic biomarkers associated with tumour growth were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Peak and trough concentrations of everolimus in blood remained stable over time and similar to those reported in other indications. Substantial pharmacodynamic effects were observed in the everolimus, but not placebo, arm for three biomarkers: After 24 weeks of treatment, reduction of vascular endothelial growth factor D (VEGF-D) and collagen type IV (COL-IV) (mean fold-changes with 95% confidence intervals [CI] were 0.36 [0.33, 0.40], and 0.54 [0.51, 0.57], respectively, P < 0.001 for both), along with increased VEGF-A (mean fold-change of 1.59 [1.39, 1.80], P < 0.001), were seen. Furthermore, baseline VEGF-D and COL-IV levels were associated with angiomyolipoma size at baseline and with angiomyolipoma response to everolimus.

CONCLUSIONS

These findings suggest that plasma angiogenic markers may provide an objective measure of patient response to everolimus.

Differentiation of Sporadic Versus Tuberous Sclerosis Complex-Associated Angiomyolipoma

OBJECTIVE

We review the imaging of renal angiomyolipomas, including differentiation of tuberous sclerosis complex (TSC)-associated and sporadic renal angiomyolipomas and other solid renal tumors. We also focus on radiologic interventions and molecular targeting of the TSC genetic pathway.

CONCLUSION

Imaging plays a central role in the diagnosis and management of renal angiomyolipomas. It provides essential information to make the best therapeutic decisions about the interventional and pharmacologic options to help prevent bleeding and preserve functional parenchyma.

Clinical management of tuberous sclerosis complex over the lifetime of a patient

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by nonmalignant tumors (hamartomas) that can occur in various organ systems, including the brain, kidneys, lungs, skin, eyes, and heart. Clinical manifestations of TSC can occur at any age, thereby making the diagnosis difficult. No typical disease presentation is known, and the clinical presentation usually differs between pediatric and adult patients. Furthermore, variable penetrance of the genetic mutation causes a range of disease severity from very mild to severe, and affected individuals can go undetected for years because many of the clinical manifestations of TSC lack specificity. Once a diagnosis is made, TSC management strategies should be tailored to address the symptoms and risks most relevant to the age of the patient. Improved understanding of the genetic basis of TSC and of the central issue of mTOR overactivation has led to use of pharmacotherapies such as the mTOR inhibitors everolimus and sirolimus in the treatment of TSC disease. In Phase II and III studies, everolimus has demonstrated efficacy and safety in the treatment of both brain (subependymal giant cell astrocytoma) and renal (angiomyolipoma) manifestations associated with TSC. It is important to bear in mind that TSC is a lifelong condition, and for those diagnosed as children, a continuum of care will be needed as they transition from pediatric to adult health services. Clearly identifying the likely differences among diagnosis, monitoring, and management of pediatric and adult patients with TSC is an important step in enabling efficiencies to be maximized without compromising the care provided to patients.

Everolimus for renal angiomyolipoma in patients with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis: extension of a randomized controlled trial

BACKGROUND

Mammalian target of rapamycin (mTOR) inhibitors are recommended as first-line treatment of renal angiomyolipoma associated with tuberous sclerosis complex (TSC) or sporadic lymphangioleiomyomatosis (sporadic LAM), but follow-up is limited. Longer term efficacy and tolerability data from a Phase 3, double-blind, placebo-controlled trial are presented.

METHODS

Following favorable results from the primary analysis (data cutoff 30 June 2011) of the EXIST-2 trial, patients still receiving study treatment were allowed to enter an open-label extension. Everolimus was initiated at 10 mg once daily and titrated based on tolerability. The primary outcome was angiomyolipoma response rate (≥ 50% reduction from baseline in target lesion volumes). Safety was a secondary endpoint.

RESULTS

As of the cutoff date (1 May 2013), 112 patients had received everolimus, and the response rate in 107 patients with angiomyolipoma (median duration of medication exposure of 28.9 months) was 54%. The proportion of patients achieving angiomyolipoma reductions of ≥ 30% and ≥ 50% increased over time, reaching 81.6% (62/76) and 64.5% (49/76), respectively, by Week 96. No everolimus-treated patients experienced renal bleeding. The long-term safety profile was consistent with previous reports; adverse events (AEs) were mostly Grade 1/2, and there were no new safety issues. The frequency of emerging AEs and severe AEs lessened over time.

CONCLUSIONS

Longer term everolimus treatment appeared safe and effective in patients with TSC- or sporadic LAM-associated renal angiomyolipoma not requiring surgical intervention. Continued reduction in angiomyolipoma volume was demonstrated, and there was no angiomyolipoma-related bleeding; AEs were predictable and generally manageable.

TRIAL REGISTRATION

clinicaltrialsgov identifier: NCT00790400 (http://clinicaltrials.gov/ct2/show/NCT00790400).

Long-Term Everolimus Treatment in Individuals With Tuberous Sclerosis Complex: A Review of the Current Literature

BACKGROUND

Tuberous sclerosis complex is a genetic disease usually caused by mutations to either TSC1 or TSC2, where its gene products are involved in the inhibition of the mammalian target of rapamycin pathway. Under normal cellular conditions, mammalian target of rapamycin (mTOR) regulates cell growth and proliferation in response to signals from nutrients or growth factors, but loss of TSC1 or TSC2 leads to overactivation of mTOR and uncontrolled cellular proliferation. Everolimus is an mTOR inhibitor approved for use in a number of indications where mTOR overactivation is implicated, including tuberous sclerosis complex.

METHODS AND PATIENTS

We conducted a literature search of PubMed to identify published articles about the long-term efficacy and safety of everolimus in patients with tuberous sclerosis complex.

RESULTS

The short-term efficacy and safety of everolimus in patients with tuberous sclerosis complex has been demonstrated in placebo-controlled trials, and open-label extension studies are ongoing to monitor long-term effects, including safety. Examples of regrowth following discontinuation of mTOR inhibitors suggest that everolimus needs to be given indefinitely to maintain suppression of subependymal giant cell astrocytoma and other tuberous sclerosis complex-associated disease manifestations. No additional safety concerns have been reported to date with long-term administration of everolimus, but published long-term data (>1 year treatment) are currently limited to a small open-label trial and case reports for this relatively rare condition.

CONCLUSIONS

From the limited data available, long-term administration of everolimus appears feasible with few safety concerns beyond those associated with short-term use. Further investigation is needed to determine the long-term efficacy and safety of everolimus in patients with tuberous sclerosis complex.