Erica L. Mayer, MD, MPH, assistant professor of medicine at Harvard Medical School and Dana-Farber Cancer Institute, describes studies involving tivozanib, a potent VEGF receptor tyrosine kinase inhibitor.

A phase I study investigated tivozanib as a monotherapy for patients with renal cell carcinoma. Tivozanib was active and well tolerated, demonstrating common toxicities of angiogenesis inhibitors such as hypertension and hoarse voice.

In a phase III trial, patients with renal cell carcinoma were randomized to tivozanib or sorafenib. Patients in the tivozanib arm had superior progression-free survival (PFS) (11.9 months vs 9.1 months) and needed fewer dose reductions.

Tivozanib has also been studied in breast cancer. In a phase I dose escalation trial, tivozanib was combined with weekly paclitaxel and demonstrated an overall response rate of 28 percent. The most common toxicities experienced in the trial were fatigue, gastrointestinal toxicity, mild neutropenia, and neuropathy. The maximum tolerated doses identified were tivozanib at 1.5 mg/day and paclitaxel at 90 mg/m² weekly.