Angiographic and volumetric effects of mammalian target of rapamycin inhibitors on angiomyolipomas in tuberous sclerosis

The tuberous sclerosis complex-associated giant renal angiomyolipoma: A case report

Renal angiomyolipoma (RAML), also referred to as renal hamartoma, is a rare benign tumor. There are two types of RAML, which include the tuberous sclerosis complex (TSC)-associated type and the sporadic type. TSC is an autosomal dominant genetic disease characterized by the growth of benign tumors in the skin, brain, kidneys, lung and heart. TSC leads to organ dysfunction, as the normal parenchyma is replaced by a variety of cell types. The current study presents a case of giant RAML in a 20-year-old female, who was hospitalized for epileptic seizures. Large abdominal lesions were detected during hospitalization. Subsequently, she underwent open mass resection and right kidney partial resection. Postoperative pathological examination confirmed that the mass was angiomyolipoma.

Gene therapy for tuberous sclerosis complex type 2 in a mouse model by delivery of AAV9 encoding a condensed form of tuberin

Tuberous sclerosis complex (TSC) results from loss of a tumor suppressor gene - TSC1 or TSC2, encoding hamartin and tuberin, respectively. These proteins formed a complex to inhibit mTORC1-mediated cell growth and proliferation. Loss of either protein leads to overgrowth lesions in many vital organs. Gene therapy was evaluated in a mouse model of TSC2 using an adeno-associated virus (AAV) vector carrying the complementary for a "condensed" form of human tuberin (cTuberin). Functionality of cTuberin was verified in culture. A mouse model of TSC2 was generated by AAV-Cre recombinase disruption of Tsc2-floxed alleles at birth, leading to a shortened lifespan (mean 58 days) and brain pathology consistent with TSC. When these mice were injected intravenously on day 21 with AAV9-cTuberin, the mean survival was extended to 462 days with reduction in brain pathology. This demonstrates the potential of treating life-threatening TSC2 lesions with a single intravenous injection of AAV9-cTuberin.

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 treatment for regrown renal angiomyolipoma associated with tuberous sclerosis complex after transcatheter arterial embolization

BACKGROUND

The aim of this study was to evaluate the effects and the utility of second-line everolimus treatment for regrown renal angiomyolipoma (AML) with tuberous sclerosis complex (TSC) after transcatheter arterial embolization (TAE).

METHODS

We investigated a total of 14 patients who underwent second-line everolimus treatment for TSC-AML that regrew after TAE, and assessed their effects and adverse events. Everolimus treatment was performed for AML with a maximum diameter of 4 cm. To determine the reduction ratio of AML, the volume of AML was measured using multislice helical computed tomography. Adverse events were evaluated according to CTCAE v4.0-JCOG. We further compared the treatment effect and adverse events with those in patients receiving first-line everolimus treatment.

RESULTS

The AML volume decreased in all patients, with a ≥ 50% volume decrease in 57% (8 of 14) of the cases, and the mean reduction rate was 53%. We observed no significant difference in the mean reduction rate of AML between second-line everolimus treatment for regrown TSC-AML after TAE and first-line everolimus treatment for TSC-AML. The adverse events were mild and consistent with those reported in our previous study.

CONCLUSION

Although further studies are needed, everolimus appears to be effective as second-line treatment for TSC-AML that regrew after TAE and a beneficial treatment option for TSC-AML.

Effect of everolimus treatment for renal angiomyolipoma associated with tuberous sclerosis complex: an evaluation based on tumor density

BACKGROUND

The aim of this study was to evaluate the influence of components of angiomyolipoma (AML) on the efficacy of everolimus.

METHODS

We investigated a total of 40 patients with tuberous sclerosis complex (TSC) who had AML ≥4 cm in diameter. The components of the AML were determined using abdominal computed tomography (CT) images. The AML density was measured as the mean Hounsfield unit (HU) values of the whole area of the AML on axial CT images. We classified them into two groups, i.e., a lipid group with a predominant lipid component (HU ≤ -50) and a solid group with predominant vascular and muscle components (HU ≥30). For each patient, we measured the AML reduction rate and transition of the mean HU value.

RESULTS

The mean reduction rate of AML in the lipid group was 24%, whereas it was 68% in the solid group (P < 0.001). The mean tumor density after 6 months was decreased in both groups. In particular, the density significantly decreased compared to the baseline in the solid group (P < 0.001). The tumor density did not change after 6 months in either group.

CONCLUSION

The effect of everolimus on TSC-AML is mainly a reduction of the solid components consisting of angioma and leiomyoma. The tumor density at the start of treatment might be a predictive marker for the response to everolimus in TSC-AML.

Recommendations for imaging-based diagnosis and management of renal angiomyolipoma associated with tuberous sclerosis complex

Renal angiomyolipomas are found in up to 80% of tuberous sclerosis complex (TSC) patients. Although these tumours are usually asymptomatic, lesions >3 cm in diameter are prone to bleeding and up to 10% of TSC patients may experience a massive and potentially fatal retroperitoneal haemorrhage. Diagnosis can be complicated because of the initial lack of symptoms and the fat-poor content of atypical renal angiomyolipomas. After diagnosis, tumour growth and the emergence of new tumours must be monitored. Treatment with mammalian target of rapamycin (mTOR) inhibitors can reduce tumour size and is indicated in patients with TSC-associated renal angiomyolipomas >3 cm in diameter. Imaging-based assessment of kidney disease is essential to the diagnosis and management of patients with TSC. The aims of imaging studies in this context are to detect and characterize tumours, assess and detect the risk of complications and evaluate the response to treatment, especially in patients treated with mTOR inhibitors. A multidisciplinary expert panel developed a series of recommendations based on current evidence and professional experience for imaging studies in adults and children with TSC-associated renal angiomyolipoma. The recommendations cover radiological diagnosis and follow-up of the classic and atypical or fat-poor TSC-associated renal angiomyolipomas, biopsy indications, minimal requirements for radiological requests and reports and recommended technical features and protocols for computed tomography and magnetic resonance imaging.

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.

Efficacy and safety of Everolimus in children with TSC - associated epilepsy - Pilot data from an open single-center prospective study

BACKGROUND

Epilepsy occurs in up to 90 % of all individuals with tuberous sclerosis complex (TSC). In 67 % disease onset is during childhood. In ≥ 50 % seizures are refractory to currently available treatment options. The mTOR-Inhibitor Everolimus (Votubia®) was approved for the treatment of subependymal giant cell astrocytoma (SEGA) and renal angiomyolipoma (AML) in Europe in 2011. It's anticonvulsive/antiepileptic properties are promising, but evidence is still limited. Study aim was to evaluate the efficacy and safety of Everolimus in children and adolescents with TSC-associated epilepsies.

METHODS

Inclusion-criteria of this investigator-initiated, single-center, open, prospective study were: 1) the ascertained diagnosis of TSC; 2) age ≤ 18 years; 3) treatment indication for Votubia® according to the European Commission guidelines; 4) drug-resistant TSC-associated epilepsy, 5) prospective continuous follow-up for at least 6 months after treatment initiation and 6) informed consent to participate. Votubia® was orally administered once/day, starting with 4.5 mg/m2 and titrated to achieve blood trough concentrations between 5 and 15 ng/ml. Primary endpoint was the reduction in seizure frequency of ≥ 50 % compared to baseline.

RESULTS

Fifteen patients (nine male) with a median age of six (range; 1-18) years fulfilled the inclusion criteria. 26 % (4/15) had TSC1, 66 % (10/15) had TSC2 mutations. In one patient no mutation was found. Time of observation after treatment initiation was median 22 (range; 6-50) months. At last observation, 80 % (12/15) of the patients were responders, 58 % of them (7/12) were seizure free. The overall reduction in seizure frequency was 60 % in focal seizures, 80 % in generalized tonic clonic seizures and 87 % in drop attacks. The effect of Everolimus was seen already at low doses, early after treatment initiation. Loss of efficacy over time was not observed. Transient side effects were seen in 93 % (14/15) of the patients. In no case the drug had to be withdrawn.

CONCLUSION

Everolimus seems to be an effective treatment option not only for SEGA and AML, but also for TSC-related epilepsies. Although there are potential serious side effects, treatment was tolerated well by the majority of patients, provided that patients are under close surveillance of epileptologists who are familiar with immunosuppressive agents.

Outcomes of everolimus treatment for renal angiomyolipoma associated with tuberous sclerosis complex: A single institution experience in Japan

OBJECTIVES

To evaluate the efficacy and toxicity profiles of everolimus in Japanese patients with renal angiomyolipoma associated with tuberous sclerosis complex.

METHODS

Patients with a 4-cm or larger angiomyolipoma meeting the diagnostic criteria of tuberous sclerosis complex were selected as participants of our investigation. In each case, we assessed tuberous sclerosis complex-associated symptoms, the treatment effect and adverse events. The treatment effect was evaluated by measuring the tumor volume reduction rate using abdominal computed tomography or magneitc resonance imaging. Adverse events were investigated using CTCAE v4.0-JCOG. The dose of everolimus was set at 10 mg once a day for adults. For childhood angiomyolipoma, everolimus administration was initiated at a dose of 5 mg once a day. Blood everolimus level was measured, and the dose was adjusted to maintain this within a range of 5-15 ng/mL.

RESULTS

The angiomyolipoma volume decreased in 46 of 47 cases, and the mean reduction rate for all cases was 60% in 12 months. The angiomyolipoma volume markedly decreased in the first 3 months, and the size leveled off after 6 months. The main adverse events related to everolimus treatment were stomatitis (91%) and irregular menstruation (65%). Grade 3 or severer adverse events were noted in three cases (6%). All patients developed some adverse events in the first 6 months. The incidence markedly decreased to 40-50% after 13 months.

CONCLUSION

The tumor volume-reducing effect of everolimus in a Japanese population was equivalent to or higher than that in Western populations. A wide variety of everolimus treatment-related adverse events can be observed, but most cases are very mild. Special attention should be given to stomatitis, irregular menstruation and interstitial lung disease as adverse events.