AstraZeneca announced that the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have accepted regulatory submissions for review of the investigational drug vandetanib in the treatment of patients with advanced medullary thyroid cancer (MTC). The FDA also granted priority review status for the new drug application and set a Prescription Drug User Fee Act (PDUFA) action date of 7 January 2011.
The submissions are supported by the results from the ZETA study evaluating the safety and efficacy of vandetanib compared to placebo in patients with advanced MTC. AstraZeneca is consulting with regulatory authorities on a proposed trade name.
ZETA was a phase III, double-blind, placebo-controlled study that randomized 331 patients with advanced MTC to oral once-daily vandetanib 300mg or placebo. The study results were presented on 7 June 2010 at the American Society of Clinical Oncology annual meeting in Chicago. Results from ZETA showed that treatment with vandetanib significantly extended progression-free survival, the primary endpoint of the study, in patients with advanced MTC. In ZETA, vandetanib demonstrated a 54 per cent reduction in the rate of progression compared to placebo (HR=0.46, p=0.0001). The objective response rate (ORR), a secondary endpoint, was 45 per cent versus 13 per cent across the two groups (p<0.0001).
The most common adverse events (incidence >25 per cent) associated with vandetanib in the ZETA study included diarrhoea, rash, nausea, hypertension and headache. The incidence of protocol-defined QTc prolongation was 8%. The safety profile of vandetanib in this study was similar to what has been previously observed in other studies in medullary thyroid and non-small cell lung cancer.
Vandetanib targets the vascular endothelial growth factor receptor (VEGFR), epidermal growth factor receptor (EGFR), and rearranged during transfection (RET) pathways—all pathways involved in tumour growth.
The American Cancer Society estimates that more than 44,000 new cases of thyroid cancer will be diagnosed in the United States in 2010. Across Europe the incidence is over 50,000 cases per year. MTC accounts for 5% of all thyroid cancers.