Purpose: To assess the maximum tolerated dose (MTD)/dose-limiting toxicities (DLT), safety, pharmacokinetics, and pharmacodynamics of tivozanib, a potent and selective oralVEGF receptor (VEGFR) tyrosine kinase inhibitor. Experimental Design: Dose levels of 1.0, 1.5, and 2.0 mg/d tivozanib for 28 days followed by 14 days of medication were explored in patients with advanced solid tumors. Results: Forty-one patients were enrolled. Animal data incorrectly predicted toxicity, resulting in DLTs at the starting dose (2.0 mg) consisting of grade 3 proteinuria and hypertension and grade 3 ataxia. At 1.0 mg, no DLT was observed. At an intermediate dose (1.5 mg), 1 patient experienced DLT consisting of grade 3 hypertension. This dose was determined as the MTD. Of 10 additional patients treated at 1.5 mg, 1 patient each experienced grade 3 hypertension and grade 3 fatigue, and 2 patients experienced grade 3 and 4 transaminase elevation. In 12 additional patients treated at 1.0 mg, no DLT was observed. Pharmacokinetics displayed long absorption time, dose proportional exposure, and a half-life of 4.7 days. Plasma levels of VEGF-A and soluble VEGFR-2 showed dose-dependent increases and decreases, respectively. Dynamic contrast-enhanced MRI indicated reduction in tumor perfusion. Clinical activity was observed in renal cell cancer, colorectal cancer, and other tumors. Conclusion: Tivozanib was well tolerated with manageable side effects. The pharmacokinetics profile revealed that tivozanib was suitable for once-daily dosing. Encouraging and durable clinical activity was observed. The recommended daily dose of tivozanib in a 4-week-on and 2-week-off dosing regimen is 1.5 mg.

doi.org/10.1158/1078-0432.CCR-11-0411, hdl.handle.net/1765/71014
Clinical Cancer Research
Erasmus MC: University Medical Center Rotterdam

Eskens, F.A.L.M, de Jonge, M.J.A, Bhargava, B, Isoe, T, Cotreau, M.M, Esteves, B, … Verweij, J. (2011). Biologic and clinical activity of tivozanib (AV-951, KRN-951), a selective inhibitor of VEGF receptor-1, -2, and -3 tyrosine kinases, in a 4-week-on, 2-week-off schedule in patients with advanced solid tumors. Clinical Cancer Research, 17(22), 7156–7163. doi:10.1158/1078-0432.CCR-11-0411