Pharmacotherapeutic group: Antineoplastic agents, protein kinase inhibitors, ATC code: L01EG02
Mechanism of action
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 TSC syndrome, inactivating mutations in the TSC1 or the TSC2 gene lead to hamartoma formation throughout the body.
Clinical efficacy and safety
Renal angiomyolipoma associated with TSC
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
| | Primary analysis3 | Final analysis4 |
| | Votubia | Placebo | p-value | Votubia |
| n=79 | n=39 | | n=112 |
| Primary analysis |
| Angiomyolipoma response rate1,2 – % | 41.8 | 0 | <0.0001 | 58.0 |
| 95% CI | 30.8, 53.4 | 0.0, 9.0 | | 48.3, 67.3 |
| Best overall angiomyolipoma response – % |
| Response | 41.8 | 0 | | 58.0 |
| Stable disease | 40.5 | 79.5 | | 30.4 |
| Progression | 1.3 | 5.1 | | 0.9 |
| Not evaluable | 16.5 | 15.4 | | 10.7 |
| 1 According to independent central radiology review 2 Angiomyolipoma responses were confirmed with a repeat scan. Response was defined as: ≥50% reduction in the sum of angiomyolipoma volume relative to baseline, plus absence of new angiomyolipoma ≥1.0 cm in longest diameter, plus no increase in renal volume >20% from nadir, plus absence of grade ≥2 angiomyolipoma-related bleeding. 3 Primary analysis for double blind period 4 Final analysis includes patients who crossed over from the placebo group; median duration of exposure to everolimus of 204.1 weeks |
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
| Time-averaged Cmin category | Number of patients | Response rate | 95% confidence interval |
| ≤5 ng/ml | 20 | 0.300 | 0.099, 0.501 |
| >5 ng/ml | 42 | 0.524 | 0.373, 0.675 |
| Difference1 | | -0.224 | -0.475, 0.027 |
| 1 Difference is “≤5 ng/ml” minus “>5 ng/ml” |
SEGA associated with TSC
Phase III study in SEGA patients
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 medicinal product 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
| | Primary analysis3 | | Final analysis4 |
| | Votubia | Placebo | p-value | Votubia |
| N=78 | N=39 | | N=111 |
| SEGA response rate1,2 - (%) | 34.6 | 0 | <0.0001 | 57.7 |
| 95% CI | 24.2, 46.2 | 0.0, 9.0 | | 47.9, 67.0 |
| Best overall SEGA response - (%) | | | | |
| Response | 34.6 | 0 | | 57.7 |
| Stable disease | 62.8 | 92.3 | | 39.6 |
| Progression | 0 | 7.7 | | 0 |
| Not evaluable | 2.6 | 0 | | 2.7 |
| 1 according to independent central radiology review 2 SEGA responses were confirmed with a repeat scan. Response was defined as: ≥50% reduction in the sum of SEGA volume relative to baseline, plus no unequivocal worsening of non-target SEGA lesions, plus absence of new SEGA ≥1 cm in longest diameter, plus no new or worsening hydrocephalus 3 Primary analysis for double blind period 4 Final analysis includes patients who crossed over from the placebo group; median duration of exposure to everolimus of 204.9 weeks |
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).
Phase II study in patients with SEGA
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
| SEGA volume (cm3) | Independent central review |
| | Baseline n=28 | Month 6 n=27 | Month 12 n=26 | Month 24 n=24 | Month 36 n=23 | Month 48 n=24 | Month 60 n=23 |
| Primary tumour volume |
| Mean (standard deviation) | 2.45 (2.813) | 1.33 (1.497) | 1.26 (1.526) | 1.19 (1.042) | 1.26 (1.298) | 1.16 (0.961) | 1.24 (0.959) |
| Median | 1.74 | 0.93 | 0.84 | 0.94 | 1.12 | 1.02 | 1.17 |
| Range | 0.49 - 14.23 | 0.31 - 7.98 | 0.29 - 8.18 | 0.20 - 4.63 | 0.22 - 6.52 | 0.18 - 4.19 | 0.21 - 4.39 |
| Reduction from baseline |
| Mean (standard deviation) | | 1.19 (1.433) | 1.07 (1.276) | 1.25 (1.994) | 1.41 (1.814) | 1.43 (2.267) | 1.44 (2.230) |
| Median | | 0.83 | 0.85 | 0.71 | 0.71 | 0.83 | 0.50 |
| Range | | 0.06 - 6.25 | 0.02 - 6.05 | -0.55 - 9.60 | 0.15 - 7.71 | 0.00 - 10.96 | -0.74 - 9.84 |
| Percentage reduction from baseline, n (%) |
| ≥50% | | 9 (33.3) | 9 (34.6) | 12 (50.0) | 10 (43.5) | 14 (58.3) | 12 (52.2) |
| ≥30% | | 21 (77.8) | 20 (76.9) | 19 (79.2) | 18 (78.3) | 19 (79.2) | 14 (60.9) |
| >0% | | 27 (100.0) | 26 (100.0) | 23 (95.8) | 23 (100.0) | 23 (95.8) | 21 (91.3) |
| No change | | 0 | 0 | 0 | 0 | 1 (4.2) | 0 |
| Increase | | 0 | 0 | 1 (4.2) | 0 | 0 | 2 (8.7) |
The robustness and consistency of the primary analysis were supported by the:
- change in primary SEGA volume as per local investigator assessment (p<0.001), with 75.0% and 39.3% of patients experiencing reductions of ≥30% and ≥50%, respectively
- change in total SEGA volume as per independent central review (p<0.001) or local investigator assessment (p<0.001).
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.
Other studies
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.
Paediatric population
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 TSC (see section 4.2 for information on paediatric use).