Tivozanib, a pan-VEGFR tyrosine kinase inhibitor for the potential treatment of solid tumors.

Tivozanib (AV-951; KRN-951), being developed by AVEO Pharmaceuticals Inc and Kyowa Hakko Kirin Co Ltd, is an orally active, ATP-competitive, small-molecule, quinoline-urea derivative that inhibits VEGFR tyrosine kinase for the potential treatment of cancer. In particular, tivozanib is able to markedly inhibit the ligand-induced phosphorylation of VEGFR-1, VEGFR-2 and VEGFR-3 at picomolar concentrations. In preclinical studies, tivozanib produced a significant inhibition of tumor growth and angiogenesis in several different xenograft tumor models in athymic rats. In a phase I clinical trial, tivozanib was safe and tolerable when administered at oral doses up to 1.5 mg on a schedule of 4 weeks on, 2 weeks off treatment. Results from a phase II clinical trial in patients with advanced renal cell carcinoma reported an overall response rate of 25.4% and a median progression-free survival of 11.8 months in patients treated with tivozanib as a single agent. Hypertension and dysphonia were the most frequent adverse events. At the time of publication, a phase III clinical trial was recruiting patients with advanced renal cancer to assess tivozanib in comparison with sorafenib. Clinical trials are currently ongoing to evaluate the safety and antitumor activity of tivozanib in breast, lung and colorectal cancer. Tivozanib might represent a promising anticancer agent in several different tumor types.