iving placebo.
No complete response (CR) according to RECIST was observed. The overall response rate (CR + partial response (PR) per independent radiological assessment was higher in the sorafenib group (24 patients, 12.2%) than in the placebo group (1 patient, 0.5%), one-sided p<0.0001. The median duration of response was 309 days (95% CI: 226,505 days) in sorafenib treated patients who experienced a PR.
A post-hoc subgroup analysis by maximum tumour size showed a treatment effect for PFS in favour of sorafenib over placebo for patients with maximum tumour size of 1.5 cm or larger (HR 0.54 (95% CI: 0.41 - 0.71)) whereas a numerically lower effect was reported in patients with a maximum tumour size of less than 1.5 cm (HR 0.87 (95% CI: 0.40 - 1.89).
A post-hoc subgroup analysis by thyroid carcinoma symptoms at baseline showed a treatment effect for PFS in favour of sorafenib over placebo for both symptomatic and asymptomatic patients. The HR of progression free survival was 0.39 (95% CI: 0.21 - 0.72) for patients with symptoms at baseline and 0.60 (95% CI: 0.45 - 0.81) for patients without symptoms at baseline.
QT interval prolongation
In a clinical pharmacology study, QT/QTc measurements were recorded in 31 patients at baseline (pre-treatment) and post-treatment. After one 28-day treatment cycle, at the time of maximum concentration of sorafenib, QTcB was prolonged by 4 ±19 msec and QTcF by 9 ±18 msec, as compared to placebo treatment at baseline. No subject showed a QTcB or QTcF >500 msec during the post-treatment ECG monitoring (see section 4.4).
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies, in all subsets of the paediatric population, in kidney and renal pelvis carcinoma (excluding nephroblastoma, nephroblastomatosis, clear cell sarcoma, mesoblastic nephroma, renal medullary carcinoma and rhabdoid tumour of the kidney) and liver and intrahepatic bile duct carcinoma (excluding hepatoblastoma) and differentiated thyroid carcinoma (see section 4.2 for information on paediatric use).
Absorption and distribution
After administration of sorafenib tablets the mean relative bioavailability is 38 - 49 % when compared to an oral solution. The absolute bioavailability is not known. Following oral administration sorafenib reaches peak plasma concentrations in approximately 3 hours. When given with a high-fat meal sorafenib absorption was reduced by 30 % compared to administration in the fasted state.
Mean Cmax and AUC increased less than proportionally beyond doses of 400 mg administered twice daily. In vitro binding of sorafenib to human plasma proteins is 99.5 %.
Multiple dosing of sorafenib for 7 days resulted in a 2.5- to 7-fold accumulation compared to single dose administration. Steady state plasma sorafenib concentrations are achieved within 7 days, with a peak to trough ratio of mean concentrations of less than 2.
The steady-state concentrations of sorafenib administered at 400 mg twice daily were eva luated in DTC, RCC and HCC patients. The highest mean concentration was observed in DTC patients (approximately twice that observed in patients with RCC and HCC), though variability was high for all tumour types. The reason for the increased concentration in DTC patients is unknown.
Biotransformation and elimination
The elimination half-lif