Source: European Medicines Agency (EU) Revision Year: 2018 Publisher: Novartis Europharm Limited, Vista Building, Elm Park, Merrion Road, Dublin 4, Ireland
Pharmacotherapeutic group: Antineoplastic agents, other antineoplastic agents, protein kinase inhibitors
ATC code: L01XE10
Everolimus is a selective mTOR (mammalian target of rapamycin) inhibitor. mTOR is a key serine-threonine kinase, the activity of which is known to be upregulated in a number of human cancers. Everolimus binds to the intracellular protein FKBP-12, forming a complex that inhibits mTOR complex-1 (mTORC1) activity. Inhibition of the mTORC1 signalling pathway interferes with the translation and synthesis of proteins by reducing the activity of S6 ribosomal protein kinase (S6K1) and eukaryotic elongation factor 4E-binding protein (4EBP-1) that regulate proteins involved in the cell cycle, angiogenesis and glycolysis. Everolimus can reduce levels of vascular endothelial growth factor (VEGF). In patients with TSC, treatment with everolimus increases VEGF-A and decreases VEGF-D levels. Everolimus is a potent inhibitor of the growth and proliferation of tumour cells, endothelial cells, fibroblasts and blood-vessel-associated smooth muscle cells and has been shown to reduce glycolysis in solid tumours in vitro and in vivo.
Two primary regulators of mTORC1 signalling are the oncogene suppressors tuberin-sclerosis complexes 1 & 2 (TSC1, TSC2). Loss of either TSC1 or TSC2 leads to elevated rheb-GTP levels, a ras family GTPase, which interacts with the mTORC1 complex to cause its activation. mTORC1 activation leads to a downstream kinase signalling cascade, including activation of the S6 kinases. In tuberous sclerosis complex syndrome, inactivating mutations in the TSC1 or the TSC2 gene lead to hamartoma formation throughout the body.
EXIST-2 (study CRAD001M2302), a randomised, controlled phase III study was conducted to evaluate the efficacy and safety of Votubia in patients with TSC plus renal angiomyolipoma. Presence of at least one angiomyolipoma ≥3 cm in longest diameter using CT/MRI (based on local radiology assessment) was required for entry.
The primary efficacy endpoint was angiomyolipoma response rate based on independent central radiology review. The analysis was stratified by use of enzyme-inducing antiepileptics at randomisation (yes/no).
Key secondary endpoints included time to angiomyolipoma progression and skin lesion response rate.
A total of 118 patients were randomised, 79 to Votubia 10 mg daily and 39 to placebo. Median age was 31 years (range: 18 to 61 years; 46.6% were <30 years at enrolment), 33.9% were male, and 89.0% were Caucasian. Of the enrolled patients, 83.1% had angiomyolipomas ≥4 cm (28.8% ≥8 cm), 78.0% had bilateral angiomyolipomas, and 39.0% had undergone prior renal embolisation/nephrectomy; 96.6% had skin lesions at baseline and 44.1% had target SEGAs (at least one SEGA ≥1 cm in longest diameter).
Results showed that the primary objective related to best overall angiomyolipoma response was met with best overall response rates of 41.8% (95% CI: 30.8, 53.4) for the Votubia arm compared with 0% (95% CI: 0.0, 9.0) for the placebo arm (p<0.0001) (Table 4).
Patients initially treated with placebo were allowed to cross over to everolimus at the time of angiomyolipoma progression and upon recognition that treatment with everolimus was superior to treatment with placebo. At the time of the final analysis (4 years following the last patient randomisation), the median duration of exposure to everolimus was 204.1 weeks (range 2 to 278). The angiomyolipoma best overall response rate had increased to 58.0% (95% CI: 48.3, 67.3), with a rate of stable disease of 30.4% (Table 4).
Among patients treated with everolimus during the study, no cases of angiomyolipoma-related nephrectomy and only one case of renal embolisation were reported.
Table 4. EXIST-2 – Angiomyolipoma response
Consistent treatment effects on angiomyolipoma response rate were observed across all subgroups evaluated (i.e. enzyme-inducing antiepileptic use versus enzyme-inducing antiepileptic non-use, sex, age and race) at the primary efficacy analysis.
In the final analysis, reduction in angiomyolipoma volume improved with longer term treatment with Votubia. At weeks 12, 96 and 192, ≥ 30% reductions in volume were observed in 75.0%, 80.6%, and 85.2% of the treated patients, respectively. Similarly, at the same timepoints, ≥50% reductions in volume were observed in 44.2%, 63.3%, and 68.9% of the treated patients, respectively.
Median time to angiomyolipoma progression was 11.4 months in the placebo arm and was not reached in the everolimus arm (HR 0.08; 95% CI: 0.02, 0.37; p<0.0001). Progressions were observed in 3.8% of patients in the everolimus arm compared with 20.5% in the placebo arm. Estimated progression-free rates at 6 months were 98.4% for the everolimus arm and 83.4% for the placebo arm. At the final analysis, median time to angiomyolipoma progression was not reached. Angiomyolipoma progressions were observed in 14.3% of the patients. The estimated angiomyolipoma progression-free rates at 24 months and 48 months were 91.6% and 83.1%, respectively.
At the primary analysis, skin lesion response rates of 26.0% (95% CI: 16.6, 37.2) for the Votubia arm and 0% (95% CI: 0.0, 9.5) for the placebo arm were observed (p=0.0002). At the final analysis, the skin lesion response rate had increased to 68.2% (95% CI: 58.5, 76.9), with one patient reporting a confirmed complete clinical skin lesion response and no patients experiencing progressive disease as their best response.
In an exploratory analysis of patients with TSC with angiomyolipoma who also had SEGA, the SEGA response rate (proportion of patients with ≥50% reduction from baseline in target lesion volumes in the absence of progression) was 10.3% in the everolimus arm in the primary analysis (versus no responses reported in the 13 patients randomised to placebo with a SEGA lesion at baseline) and increased to 48.0% in the final analysis.
Post-hoc sub-group analysis of EXIST-2 (study CRAD001M2302) carried out at time of primary analysis demonstrated that angiomyolipoma response rate is reduced below the threshold of 5 ng/ml (Table 5).
Table 5. EXIST-2 – Angiomyolipoma response rates by time-averaged Cmin category, at primary analysis
EXIST-1 (Study CRAD001M2301), a randomised, double-blind, multicentre phase III study of Votubia versus placebo, was conducted in patients with SEGA, irrespective of age. Patients were randomised in a 2:1 ratio to receive either Votubia or matching placebo. Presence of at least one SEGA lesion ≥1.0 cm in longest diameter using MRI (based on local radiology assessment) was required for entry. In addition, serial radiological evidence of SEGA growth, presence of a new SEGA lesion ≥1 cm in longest diameter, or new or worsening hydrocephalus was required for entry.
The primary efficacy endpoint was SEGA response rate based on independent central radiology review. The analysis was stratified by use of enzyme-inducing antiepileptics at randomisation (yes/no).
Key secondary endpoints in hierarchal order of testing included the absolute change in frequency of total seizure events per 24-hour EEG from baseline to week 24, time to SEGA progression, and skin lesion response rate.
A total of 117 patients were randomised, 78 to Votubia and 39 to placebo. The two treatment arms were generally well balanced with respect to demographic and baseline disease characteristics and history of prior anti-SEGA therapies. In the total population, 57.3% of patients were male and 93.2% were Caucasian. The median age for the total population was 9.5 years (age range for the Votubia arm: 1.0 to 23.9; age range for the placebo arm: 0.8 to 26.6), 69.2% of the patients were aged 3 to <18 years and 17.1% were <3 years at enrolment.
Of the enrolled patients, 79.5% had bilateral SEGAs, 42.7% had ≥2 target SEGA lesions, 25.6% had inferior growth, 9.4% had evidence of deep parenchymal invasion, 6.8% had radiographic evidence of hydrocephalus, and 6.8% had undergone prior SEGA-related surgery. 94.0% had skin lesions at baseline and 37.6% had target renal angiomyolipoma lesions (at least one angiomyolipoma ≥1 cm in longest diameter).
The median duration of blinded study treatment was 9.6 months (range: 5.5 to 18.1) for patients receiving Votubia and 8.3 months (range: 3.2 to 18.3) for those receiving placebo.
Results showed that Votubia was superior to placebo for the primary endpoint of best overall SEGA response (p<0.0001). Response rates were 34.6% (95% CI: 24.2, 46.2) for the Votubia arm compared with 0% (95% CI: 0.0, 9.0) for the placebo arm (Table 6). In addition, all 8 patients on the Votubia arm who had radiographic evidence of hydrocephalus at baseline had a decrease in ventricular volume.
Patients initially treated with placebo were allowed to cross over to everolimus at the time of SEGA progression and upon recognition that treatment with everolimus was superior to treatment with placebo. All patients receiving at least one dose of everolimus were followed until drug discontinuation or study completion. At the time of the final analysis, the median duration of exposure among all such patients was 204.9 weeks (range: 8.1 to 253.7). The best overall SEGA response rate had increased to 57.7% (95% CI: 47.9, 67.0) at the final analysis.
No patient required surgical intervention for SEGA during the entire course of the study.
Table 6. EXIST-1 – SEGA response
Consistent treatment effects were observed across all subgroups evaluated (i.e. enzyme-inducing antiepileptic use versus enzyme-inducing antiepileptic non-use, sex and age) at the primary analysis.
During the double-blind period, reduction of SEGA volume was evident within the initial 12 weeks of Votubia treatment: 29.7% (22/74) of patients had ≥50% reductions in volume and 73.0% (54/74) had ≥30% reductions in volume. Sustained reductions were evident at week 24, 41.9% (31/74) of patients had ≥50% reductions and 78.4% (58/74) of patients had ≥30% reductions in SEGA volume.
In the everolimus treated population (N=111) of the study, including patients who crossed over from the placebo group, tumour response, starting as early as after 12 weeks on everolimus, was sustained at later time points. The proportion of patients achieving at least 50% reductions in SEGA volume was 45.9% (45/98) and 62.1% (41/66) at weeks 96 and 192 after start of everolimus treatment. Similarly, the proportion of patients achieving at least 30% reductions in SEGA volume was 71.4% (70/98) and 77.3% (51/66) at weeks 96 and 192 after start of everolimus treatment.
Analysis of the first key secondary endpoint, change in seizure frequency, was inconclusive; thus, despite the fact that positive results were observed for the two subsequent secondary endpoints (time to SEGA progression and skin lesion response rate), they could not be declared formally statistically significant.
Median time to SEGA progression based on central radiology review was not reached in either treatment arm. Progressions were only observed in the placebo arm (15.4%; p=0.0002). Estimated progression-free rates at 6 months were 100% for the Votubia arm and 85.7% for the placebo arm. The long-term follow-up of patients randomised to everolimus and patients randomised to placebo who thereafter crossed over to everolimus demonstrated durable responses.
At the time of the primary analysis, Votubia demonstrated clinically meaningful improvements in skin lesion response (p=0.0004), with response rates of 41.7% (95% CI: 30.2, 53.9) for the Votubia arm and 10.5% (95% CI: 2.9, 24.8) for the placebo arm. At the final analysis, the skin lesion response rate increased to 58.1% (95% CI: 48.1, 67.7).
A prospective, open-label, single-arm phase II study (Study CRAD001C2485) was conducted to evaluate the safety and efficacy of Votubia in patients with SEGA. Radiological evidence of serial SEGA growth was required for entry.
Change in SEGA volume during the core 6-month treatment phase, as assessed via an independent central radiology review, was the primary efficacy endpoint. After the core treatment phase, patients could be enrolled into an extension phase where SEGA volume was assessed every 6 months.
In total, 28 patients received treatment with Votubia; median age was 11 years (range 3 to 34), 61% male, 86% Caucasian. Thirteen patients (46%) had a secondary smaller SEGA, including 12 in the contralateral ventricle.
Primary SEGA volume was reduced at month 6 compared to baseline (p<0.001 [see Table 7]). No patient developed new lesions, worsening hydrocephalus or increased intracranial pressure, and none required surgical resection or other therapy for SEGA.
Table 7. Change in primary SEGA volume over time
The robustness and consistency of the primary analysis were supported by the:
One patient met the pre-specified criteria for treatment success (>75% reduction in SEGA volume) and was temporarily taken off trial therapy; however, SEGA re-growth was evident at the next assessment at 4.5 months and treatment was restarted.
Long-term follow-up to a median duration of 67.8 months (range: 4.7 to 83.2) demonstrated sustained efficacy.
Stomatitis is the most commonly reported adverse reaction in patients treated with Votubia (see sections 4.4 and 4.8). In a post-marketing single-arm study in postmenopausal women with advanced breast cancer (N=92), topical treatment with dexamethasone 0.5 mg/5 ml alcohol-free oral solution was administered as a mouthwash (4 times daily for the initial 8 weeks of treatment) to patients at the time of initiating treatment with Afinitor (everolimus, 10 mg/day) plus exemestane (25 mg/day) to reduce the incidence and severity of stomatitis. The incidence of Grade ≥2 stomatitis at 8 weeks was 2.4% (n=2/85 evaluable patients) which was lower than historically reported. The incidence of Grade 1 stomatitis was 18.8% (n=16/85) and no cases of Grade 3 or 4 stomatitis were reported. The overall safety profile in this study was consistent with that established for everolimus in the oncology and TSC settings, with the exception of a slightly increased frequency of oral candidiasis which was reported in 2.2% (n=2/92) of patients.
The European Medicines Agency has waived the obligation to submit the results of studies with Votubia in all subsets of the paediatric population in angiomyolipoma (see section 4.2 for information on paediatric use).
The European Medicines Agency has deferred the obligation to submit the results of studies with Votubia in one or more subsets of the paediatric population in refractory epilepsy associated with tuberous sclerosis complex (see section 4.2 for information on paediatric use).
In patients with advanced solid tumours, peak everolimus concentrations (Cmax) are reached at a median time of 1 hour after daily administration of 5 and 10 mg everolimus under fasting conditions or with a light fat-free snack. Cmax is dose-proportional between 5 and 10 mg. Everolimus is a substrate and moderate inhibitor of PgP.
In healthy subjects, high fat meals reduced systemic exposure to Votubia 10 mg tablets (as measured by AUC) by 22% and the peak blood concentration Cmax by 54%. Light fat meals reduced AUC by 32% and Cmax by 42%.
In healthy subjects taking a single 9 mg dose (3 × 3 mg) of Votubia dispersible tablets in suspension, high fat meals reduced AUC by 11.7% and the peak blood concentration Cmax by 59.8%. Light fat meals reduced AUC by 29.5% and Cmax by 50.2%.
Food, however, had no apparent effect on the post absorption phase concentration-time profile 24 hours post-dose of either dosage form.
In a relative bioavailability study, AUC0-inf of 5 × 1 mg everolimus tablets when administered as suspension in water was equivalent to 5 × 1 mg everolimus tablets administered as intact tablets, and Cmax of 5 × 1 mg everolimus tablets in suspension was 72% of 5 × 1 mg intact everolimus tablets.
In a bioequivalence study, AUC0-inf of the 5 mg dispersible tablet when administered as suspension in water was equivalent to 5 × 1 mg intact everolimus tablets, and Cmax of the 5 mg dispersible tablet in suspension was 64% of 5 × 1 mg intact everolimus tablets.
The blood-to-plasma ratio of everolimus, which is concentration-dependent over the range of 5 to 5,000 ng/ml, is 17% to 73%. Approximately 20% of the everolimus concentration in whole blood is confined to plasma of cancer patients given Votubia 10 mg/day. Plasma protein binding is approximately 74% both in healthy subjects and in patients with moderate hepatic impairment. In patients with advanced solid tumours, Vd was 191 l for the apparent central compartment and 517 l for the apparent peripheral compartment.
Nonclinical studies in rats indicate:
There are no clinical data on the distribution of everolimus in the human brain. Non-clinical studies in rats demonstrated distribution into the brain following administration by both the intravenous and oral routes.
Everolimus is a substrate of CYP3A4 and PgP. Following oral administration, everolimus is the main circulating component in human blood. Six main metabolites of everolimus have been detected in human blood, including three monohydroxylated metabolites, two hydrolytic ring-opened products, and a phosphatidylcholine conjugate of everolimus. These metabolites were also identified in animal species used in toxicity studies, and showed approximately 100 times less activity than everolimus itself. Hence, everolimus is considered to contribute the majority of the overall pharmacological activity.
Mean CL/F of everolimus after 10 mg daily dose in patients with advanced solid tumours was 24.5 l/h. The mean elimination half-life of everolimus is approximately 30 hours.
No specific excretion studies have been undertaken in cancer patients; however, data are available from the studies in transplant patients. Following the administration of a single dose of radiolabelled everolimus in conjunction with ciclosporin, 80% of the radioactivity was recovered from the faeces, while 5% was excreted in the urine. The parent substance was not detected in urine or faeces.
After administration of everolimus in patients with advanced solid tumours, steady-state AUC0-τ was dose-proportional over the range of 5 to 10 mg daily dose. Steady-state was achieved within 2 weeks. Cmax is dose-proportional between 5 and 10 mg. tmax occurs at 1 to 2 hours post-dose. There was a significant correlation between AUC0-τ and pre-dose trough concentration at steady-state.
The safety, tolerability and pharmacokinetics of Votubia were evaluated in two single oral dose studies of Votubia tablets in 8 and 34 adult subjects with impaired hepatic function relative to subjects with normal hepatic function.
In the first study, the average AUC of everolimus in 8 subjects with moderate hepatic impairment (Child-Pugh B) was twice that found in 8 subjects with normal hepatic function.
In the second study of 34 subjects with different impaired hepatic function compared to normal subjects, there was a 1.6-fold, 3.3-fold and 3.6-fold increase in exposure (i.e. AUC0-inf) for subjects with mild (Child-Pugh A), moderate (Child-Pugh B) and severe (Child-Pugh C) hepatic impairment, respectively.
Simulations of multiple dose pharmacokinetics support the dosing recommendations in subjects with hepatic impairment based on their Child-Pugh status.
Based on the results of the two studies, dose adjustment is recommended for patients with hepatic impairment (see sections 4.2 and 4.4).
In a population pharmacokinetic analysis of 170 patients with advanced solid tumours, no significant influence of creatinine clearance (25-178 ml/min) was detected on CL/F of everolimus. Post-transplant renal impairment (creatinine clearance range 11-107 ml/min) did not affect the pharmacokinetics of everolimus in transplant patients.
In patients with SEGA, everolimus Cmin was approximately dose-proportional within the dose range from 1.35 mg/m² to 14.4 mg/m².
In patients with SEGA, the geometric mean Cmin values normalised to mg/m² dose in patients aged <10 years and 10-18 years were lower by 54% and 40%, respectively, than those observed in adults (>18 years of age), suggesting that everolimus clearance was higher in younger patients. Limited data in patients <3 years of age (n=13) indicate that BSA-normalised clearance is about two-fold higher in patients with low BSA (BSA of 0.556 m²) than in adults. Therefore it is assumed that steady-state could be reached earlier in patients <3 years of age (see section 4.2 for dosing recommendations).
The pharmacokinetics of everolimus have not been studied in patients younger than 1 year of age. It is reported, however, that CYP3A4 activity is reduced at birth and increases during the first year of life, which could affect the clearance in this patient population.
A population pharmacokinetic analysis including 111 patients with SEGA who ranged from 1.0 to 27.4 years (including 18 patients 1 to less than 3 years of age with BSA 0.42 m 2 to 0.74 m²) showed that BSA-normalised clearance is in general higher in younger patients. Population pharmacokinetic model simulations showed that a starting dose of 7 mg/m² would be necessary to attain Cmin within the 5 to 15 ng/ml range in patients younger than 3 years of age. A higher starting dose of 7 mg/m² is therefore recommended for patients 1 to less than 3 years of age with SEGA (see section 4.2).
In a population pharmacokinetic evaluation in cancer patients, no significant influence of age (27-85 years) on oral clearance of everolimus was detected.
Oral clearance (CL/F) is similar in Japanese and Caucasian cancer patients with similar liver functions. Based on analysis of population pharmacokinetics, oral clearance (CL/F) is on average 20% higher in black transplant patients.
The non-clinical safety profile of everolimus was assessed in mice, rats, minipigs, monkeys and rabbits. The major target organs were male and female reproductive systems (testicular tubular degeneration, reduced sperm content in epididymides and uterine atrophy) in several species; lungs (increased alveolar macrophages) in rats and mice; pancreas (degranulation and vacuolation of exocrine cells in monkeys and minipigs, respectively, and degeneration of islet cells in monkeys), and eyes (lenticular anterior suture line opacities) in rats only. Minor kidney changes were seen in the rat (exacerbation of age-related lipofuscin in tubular epithelium, increases in hydronephrosis) and mouse (exacerbation of background lesions). There was no indication of kidney toxicity in monkeys or minipigs.
Everolimus appeared to spontaneously exacerbate background diseases (chronic myocarditis in rats, coxsackie virus infection of plasma and heart in monkeys, coccidian infestation of the gastrointestinal tract in minipigs, skin lesions in mice and monkeys). These findings were generally observed at systemic exposure levels within the range of therapeutic exposure or above, with the exception of the findings in rats, which occurred below therapeutic exposure due to a high tissue distribution.
In a male fertility study in rats, testicular morphology was affected at 0.5 mg/kg and above, and sperm motility, sperm head count, and plasma testosterone levels were diminished at 5 mg/kg, which is within the range of therapeutic exposure and which caused a reduction in male fertility. There was evidence of reversibility.
In animal reproductive studies female fertility was not affected. However, oral doses of everolimus in female rats at ≥0.1 mg/kg (approximately 4% of the AUC0-24h in patients receiving the 10 mg daily dose) resulted in increases in pre-implantation loss.
Everolimus crossed the placenta and was toxic to the foetus. In rats, everolimus caused embryo/foetotoxicity at systemic exposure below the therapeutic level. This was manifested as mortality and reduced foetal weight. The incidence of skeletal variations and malformations (e.g. sternal cleft) was increased at 0.3 and 0.9 mg/kg. In rabbits, embryotoxicity was evident in an increase in late resorptions.
In juvenile rat toxicity studies, systemic toxicity included decreased body weight gain, food consumption, and delayed attainment of some developmental landmarks, with full or partial recovery after cessation of dosing. With the possible exception of the rat-specific lens finding (where young animals appeared to be more susceptible), it appears that there is no significant difference in the sensitivity of juvenile animals to the adverse reactions of everolimus as compared to adult animals. Toxicity study with juvenile monkeys did not show any relevant toxicity.
Genotoxicity studies covering relevant genotoxicity endpoints showed no evidence of clastogenic or mutagenic activity. Administration of everolimus for up to 2 years did not indicate any oncogenic potential in mice and rats up to the highest doses, corresponding respectively to 4.3 and 0.2 times the estimated clinical exposure.
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