Vandetanib (Zactima™)

Vandetanib (trade name Zactima™) is a new anti-cancer medication still undergoing clinical trials. Its primary indication is for Non Small Cell Lung Cancer (NSCLC), however there are several clinical trials underway investigating its possibilities to treat thyroid cancer as well. Vandetanib (Zactima) is an orally available Tyronine Kinase Inhibitor (TKI) under development by Astra Zeneca. This classification of anti-neoplastics inhibit protein tyrosine kinases which are enzymes in the switch mechanism in cellular signal pathways. The protein kinases are involved in many cellular processes such as cell proliferation and growth including cancer cells. Tyrosine kinases are known to be activated in cancer cells and drive tumor growth. Tyrosine kinase inhibitors block kinase activity before metastasis occurs.

Vandetanib works by inhibiting both the development of the tumor’s blood supply through inhibition of VEGFR (vascular endothelial growth receptor factor) and the growth and survival of the tumor itself through inhibition of EFGR (epidermal growth factor receptor). Both VEGFR and EFGR are tyronine kinases. The drug also inhibits RET kinase, an important growth factor in certain types of thyroid cancer. Vandetanib has shown promising anti-tumor activity in NSCLC when used alone and in combination with docetaxel in Phase II trials.

It has also shown encouraging early data in hereditary medullary thyroid cancer and has been awarded FDA and EU orphan drug status, and FDA fast track designation for this indication. Vandetanib is currently in clinical development in a range of tumors. The Vandetanib (Zactima) clinical trials are now on Phase III development in a broad population of patients with advanced NSCLC. The use of the drug as a single treatment (monotherapy) compared to erlotinib and anti-EGFR therapy are included in the trials and other combination therapy regiments with other several antineoplastic agents are also being studied.