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.

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

BACKGROUND

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

RESULTS

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

CONCLUSIONS

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

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

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

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

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

French recommendations for the diagnosis and management of lymphangioleiomyomatosis

BACKGROUND

The present article is an English-language version of the French National Diagnostic and Care Protocol, a pragmatic tool to optimize and harmonize the diagnosis, care pathway, management and follow-up of lymphangioleiomyomatosis in France.

METHODS

Practical recommendations were developed in accordance with the method for developing a National Diagnosis and Care Protocol for rare diseases of the Haute Autorité de Santé and following international guidelines and literature on lymphangioleiomyomatosis. It was developed by a multidisciplinary group, with the help of patient representatives and of RespiFIL, the rare disease network on respiratory diseases.

RESULTS

Lymphangioleiomyomatosis is a rare lung disease characterised by a proliferation of smooth muscle cells that leads to the formation of multiple lung cysts. It occurs sporadically or as part of a genetic disease called tuberous sclerosis complex (TSC). The document addresses multiple aspects of the disease, to guide the clinicians regarding when to suspect a diagnosis of lymphangioleiomyomatosis, what to do in case of recurrent pneumothorax or angiomyolipomas, what investigations are needed to make the diagnosis of lymphangioleiomyomatosis, what the diagnostic criteria are for lymphangioleiomyomatosis, what the principles of management are, and how follow-up can be organised. Recommendations are made regarding the use of pharmaceutical specialties and treatment other than medications.

CONCLUSION

These recommendations are intended to guide the diagnosis and practical management of pulmonary lymphangioleiomyomatosis.

Mechanistic Target of Rapamycin (mTOR) Inhibitors

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

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

[Clinical case of delayed diagnosis of tuberous sclerosis]

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

Everolimus 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.

Observational study of characteristics and clinical outcomes of Dutch patients with tuberous sclerosis complex and renal angiomyolipoma treated with everolimus

OBJECTIVE

To compare kidney size (used as proxy for total renal angiomyolipoma [rAML] size) and kidney function outcomes between patients with tuberous sclerosis complex (TSC) and rAML treated and not treated with everolimus.

METHODS

Medical charts of adults with TSC-associated rAML followed at a specialty medical center in the Netherlands (1990-2015). Included patients treated with everolimus (n = 33, of which 27 were included in the kidney size analyses and 27 in the kidney function analyses [21 patients in both]; index date = everolimus initiation) and non-treated patients (n = 39, of which 29 were included in the kidney size analyses and 33 in the kidney function analyses [23 patients in both]; index date = one date among all dates with outcome measurement).Percent change in kidney size and kidney function from the index date to the best measurement in the two years post-index date (best response) compared between patients treated and not treated with everolimus.

RESULTS

Compared with non-treated patients, significantly more everolimus-treated patients experienced a reduction in the size of their largest kidney in the two years post-index date (85.2% vs. 37.9%, p < 0.01). Also, there was a tendency towards more improvement in the estimated glomerular filtration rate (eGFR) among the everolimus-treated patients (55.6% vs. 33.3%, p = 0.08).

CONCLUSIONS

The study results suggest that everolimus is effective in controlling and even reversing the growth of the kidneys, used as a proxy for rAML size, as well as preserving or improving kidney function in patients with TSC and rAML treated in a real-world, observational setting.

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

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.

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.

Everolimus for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis (EXIST-2): a multicentre, randomised, double-blind, placebo-controlled trial

BACKGROUND

Angiomyolipomas are slow-growing tumours associated with constitutive activation of mammalian target of rapamycin (mTOR), and are common in patients with tuberous sclerosis complex and sporadic lymphangioleiomyomatosis. The insidious growth of these tumours predisposes patients to serious complications including retroperitoneal haemorrhage and impaired renal function. Everolimus, a rapamycin derivative, inhibits the mTOR pathway by acting on the mTOR complex 1. We compared the angiomyolipoma response rate on everolimus with placebo in patients with tuberous sclerosis or sporadic lymphanioleiomyomatosis-associated angiomyolipomata.

METHODS

In this double-blind, placebo-controlled, phase 3 trial, patients aged 18 years or older with at least one angiomyolipoma 3 cm or larger in its longest diameter (defined by radiological assessment) and a definite diagnosis of tuberous sclerosis or sporadic lymphangioleiomyomatosis were randomly assigned, in a 2:1 fashion with the use of an interactive web response system, to receive oral everolimus 10 mg per day or placebo. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in total volume of target angiomyolipomas relative to baseline. This study is registered with ClinicalTrials.gov number NCT00790400.

RESULTS

118 patients (median age 31·0 years; IQR 18·0–61·0) from 24 centres in 11 countries were randomly assigned to receive everolimus (n=79) or placebo (n=39). At the data cutoff, double-blind treatment was ongoing for 98 patients; two main reasons for discontination were disease progression (nine placebo patients) followed by adverse events (two everolimus patients; four placebo patients). The angiomyolipoma response rate was 42% (33 of 79 [95% CI 31–53%]) for everolimus and 0% (0 of 39 [0–9%]) for placebo (response rate difference 42% [24–58%]; one-sided Cochran-Mantel-Haenszel test p<0·0001). The most common adverse events in the everolimus and placebo groups were stomatitis (48% [38 of 79], 8% [3 of 39], respectively), nasopharyngitis (24% [19 of 79] and 31% [12 of 39]), and acne-like skin lesions (22% [17 of 79] and 5% [2 of 39]).

INTERPRETATION

Everolimus reduced angiomyolipoma volume with an acceptable safety profile, suggesting it could be a potential treatment for angiomyolipomas associated with tuberous sclerosis.

FUNDING

Novartis Pharmaceuticals.

Similar trends in serum VEGF-D levels and kidney angiomyolipoma responses with longer duration sirolimus treatment in adults with tuberous sclerosis

Context

We have previously shown that serum VEGF-D is elevated at baseline, correlates with kidney angiomyolipoma size at baseline and 12 months, and decreases with sirolimus treatment in adults with tuberous sclerosis complex (TSC). To further investigate the utility of serum VEGF-D for longer term monitoring of TSC kidney disease, we present VEGF-D level results with 24 month follow-up.

Objective

To compare 24 month VEGF-D levels in two subgroups of sirolimus treated patients (OFF SIROLIMUS AFTER 12 MONTHS or ON SIROLIMUS AFTER 12 MONTHS).

Design and Intervention(s)

Serum VEGF-D was measured in samples collected from subjects enrolled in a phase 2 multicenter trial evaluating sirolimus for the treatment of kidney angiomyolipomas associated with TSC or TSC/LAM. All participants were treated with sirolimus from 0–12 months. During months 12–24, sirolimus was discontinued in one subgroup. The other subgroup was treated with additional sirolimus.

Setting

Adult TSC participants were recruited from six clinical sites in the United States (comprehensive TSC clinics, 5; urology clinic, 1).

Patients

There were 28 TSC patients who completed all 24 months of the study and serum samples were available at 24 months from 18/28 patients.

Main Outcome Measure(s)

We compared the percent change in VEGF-D levels (baseline to 24 months) in patients from the two treatment subgroups.

Results

At 24 months, VEGF-D levels decreased by 67% compared with baseline (to 787±426 pg/ml) in the ON SIROLIMUS AFTER 12 MONTHS group versus a 13% decrease (to 2971±4014 pg/ml) in the OFF SIROLIMUS AFTER 12 MONTHS group (p = 0.013, Mann-Whitney test). A similar trend was observed in kidney angiomyolipoma size but not in pulmonary function tests.

Conclusions Serum VEGF-D may be useful for monitoring response to treatment with sirolimus and kidney angiomyolipoma size in patients with TSC, but confirmation is needed.

Trial Registration

Clinical trials.gov NCT00126672.

Clinical and molecular insights into tuberous sclerosis complex renal disease

Patients with tuberous sclerosis complex are at great risk of developing renal lesions as part of their disease. These lesions include renal cysts and tumors. Significant advances in understanding the cell biology of these renal lesions has already led to clinical trials demonstrating that pharmacological interventions are likely possible. This review focuses on the pathology of these renal lesions, their underlying cell biology, and the possible therapeutic strategies that may prove to significantly improve care for these patients.

Effects of rapamycin on angiomyolipomas in patients with tuberous sclerosis

BACKGROUND

Tuberous sclerosis (TS) is a systemic disease, with an autosomal dominant pattern of inheritance caused by mutations in two genes (TSC1 and TSC2) that cause tumours (angiomyolipomas [AML], angiofibromas, astrocytomas). Constant and inadequate proliferation occurring in TS may be blocked by mTOR inhibitors (mammalian target of rapamycin), such as rapamycin.

MATERIAL AND METHODS

At present, our study includes 17 patients with TS. All had at least one AML greater than 2cm in diameter diagnosed by MRI. They received rapamycin during 12 months. Plasma levels remained stable between 4-8ng/dl. The AML size was monitored every six months by abdominal MRI.

RESULTS

At 12 months of inclusion, MRI indicated a decrease in the size of AML in all patients showing at least a 50% reduction in 82.4% (14/17, 95% CI [56.57%, 96.20%]). The mean percent reduction was 66.3% (95% CI [56.9%, 75.6%], P<.0001). The major side effects observed were: oral aphthous ulcers (5/17); hypertriglyceridemia (3/17); microcytosis and hypochromia (3/17); diarrhea (2/17); acne (1/17); acute pyelonephritis (1/17); and proteinuria (1/17).

CONCLUSIONS

These preliminary clinical data suggest that rapamycin can play a beneficial role in the treatment of TS. Our experience in 17 patients treated for 12 months demonstrates safety and efficacy in reducing AML volume.

Malignant epithelioid angiomyolipoma in the kidney and liver of a patient with pulmonary lymphangioleiomyomatosis: lack of response to sirolimus

A 26-year-old woman with lymphangioleiomyomatosis (LAM) was hospitalized for the surgical excision of a giant abdominal tumor of right kidney origin. The pathological diagnosis of the tumor was conventional angiomyolipoma (AML). After 8 months, 2 liver tumors appeared and grew rapidly. The tumors were resected, and the pathological finding of these tumors was epithelioid AML. Thereafter, metastatic multiple lung tumors appeared, and there was local recurrence of the liver tumors. Sirolimus, an mTOR protein inhibitor, was used to treat epithelioid AML. However, the drug did not inhibit the rapid growth of the tumor at all. This finding suggests that sirolimus might not be effective against epithelioid AML, and in such cases, complete surgical resection should be the treatment of choice.

Massive hepatic angiomyolipoma in a young woman with tuberous sclerosis complex: significant clinical improvement during tamoxifen treatment

BACKGROUND/AIMS

Isolated liver angiomyolipomas (AMLs) occur in about 40% of TSC patients. Because of their slow growth, these tumors are often asymptomatic. Since AMLs express estrogen and progesteron receptors we suggest the possible benefits of tamoxifen for the treatment of liver AMLs.

METHODS

We report the case of a 26-year-old female affected by tuberous sclerosis (TSC2) with cerebral, renal and hepatic involvement admitted to the Liver Unit for severe malnutrition, anorexia and abdominal pain. MRI showed a grossly enlarged liver, causing severe gastric compression. The liver was entirely filled with multiple nodular lesions of different sizes. Liver biopsy showed tumoral tissue with microscopic and ultrastructural features of angiomyolipoma. All liver function tests were repeatedly normal. Prior to considering the patient for partial hepatectomy, she was administered tamoxifen (20mg b.i.d).

RESULTS

After 6 months of tamoxifen treatment a greatly improved quality of life and a significant weight gain were observed. After 12 months the clinical conditions further improved and the MRI showed a significant reduction of the largest lesion with a liquid central area and a diminished compression of the stomach.

CONCLUSIONS

This is to our knowledge the first report in which tamoxifen has been successfully used in a TSC patient with multiple liver angiomyolipomas.

Sirolimus for angiomyolipoma in tuberous sclerosis complex or lymphangioleiomyomatosis

BACKGROUND

Angiomyolipomas in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis are associated with mutations in tuberous sclerosis genes resulting in constitutive activation of the mammalian target of rapamycin (mTOR). The drug sirolimus suppresses mTOR signaling.

METHODS

We conducted a 24-month, nonrandomized, open-label trial to determine whether sirolimus reduces the angiomyolipoma volume in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. Sirolimus was administered for the first 12 months only. Serial magnetic resonance imaging of angiomyolipomas and brain lesions, computed tomography of lung cysts, and pulmonary-function tests were performed.

RESULTS

Of the 25 patients enrolled, 20 completed the 12-month evaluation, and 18 completed the 24-month evaluation. The mean (+/-SD) angiomyolipoma volume at 12 months was 53.2+/-26.6% of the baseline value (P<0.001) and at 24 months was 85.9+/-28.5% of the baseline value (P=0.005). At 24 months, five patients had a persistent reduction in the angiomyolipoma volume of 30% or more. During the period of sirolimus therapy, among patients with lymphangioleiomyomatosis, the mean forced expiratory volume in 1 second (FEV1) increased by 118+/-330 ml (P=0.06), the forced vital capacity (FVC) increased by 390+/-570 ml (P<0.001), and the residual volume decreased by 439+/-493 ml (P=0.02), as compared with baseline values. One year after sirolimus was discontinued, the FEV1 was 62+/-411 ml above the baseline value, the FVC was 346+/-712 ml above the baseline value, and the residual volume was 333+/-570 ml below the baseline value; cerebral lesions were unchanged. Five patients had six serious adverse events while receiving sirolimus, including diarrhea, pyelonephritis, stomatitis, and respiratory infections.

CONCLUSIONS

Angiomyolipomas regressed somewhat during sirolimus therapy but tended to increase in volume after the therapy was stopped. Some patients with lymphangioleiomyomatosis had improvement in spirometric measurements and gas trapping that persisted after treatment. Suppression of mTOR signaling might constitute an ameliorative treatment in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis. (ClinicalTrials.gov number, NCT00457808.)

Antitumoral Activity of Rapamycin in Renal Angiomyolipoma Associated With Tuberous Sclerosis Complex

A 19-year old patient with tuberous sclerosis presented with a renal angiomyolipoma. Because animal trials of tuberous sclerosis showed an effect of rapamycin on renal tumors, our patient was administered rapamycin for 6 months. During this time, the renal angiomyolipoma shrank significantly, regrew during an 8-month period, and decreased in size again after readministration of rapamycin.

[Anti-angiogenic therapy of a renal angiomyolipoma in a seriously disabled patient suffering from multiple sclerosis]

INTRODUCTION

Angiomyolipoma, although rare, belong together with oncocytomas to the most common benign renal neoplasms. Although angiomyolipoma is usually a non-invasive tumor that does not metastasize, chirurgical intervention, especially in case of large or enlarging tumors, is recommended due to their capacity to cause haemorrhage and other significant clinical complications.

CASE REPORT

We report the case of a renal angiomyolipoma in a female patient seriously disabled by multiple sclerosis with reduced physical and nutritional condition. The woman already underwent a nephrectomy 20 years ago due to an angiomyolipoma of the opposite kidney. The patient received oral gefitinib at a dose of 500 mg/day for 28 days. By a four-weekly course of EGFR-inhibitor gefitinib (Iressa), we achieved a control of the angiomyolipoma and were able to prevent nephrectomy.

CONCLUSIONS

The use of EGFR inhibitors, whose anti-proliferative activity in renal cell tumors derives not only from direct inhibition of cell proliferation, but also from the inhibition of angiogenesis, requires further investigation.

Lack of response of a metastatic renal perivascular epithelial cell tumor (PEComa) to successive courses of DTIC based-therapy and imatinib mesylate

An 11 year-old girl presented with two large abdominal masses in the left flank and epigastrium and left supraclavicular lymphadenopathy. Subsequent investigations led to the diagnosis of metastatic perivascular epithelioid cell tumor (PEComa) arising from the left kidney. Effective treatment for this rare tumor is not yet known. The tumor did not respond to an initial treatment of two cycles of a dacarbazine (DTIC) based regimen. She was placed on a trial of imatinib mesylate based on tumor expression of c-KIT, a tyrosine kinase targeted by this drug. This report highlights the first documented case of the use of imatinib for PEComa. Lack of response and adverse effects of the drug required discontinuation of therapy.