(ChemotherapyAdvisor) – No significant difference in overall survival (OS) was found between tivozanib and sorafenib in patients with advanced renal cell carcinoma (RCC), according to final data from the phase 3 TIVO-1 trial and its open-label, multicenter extension study, reported during the 2013 Genitourinary Cancers Symposium in Orlando, FL.

“The high rate of utilization of second-line tivozanib in patients following disease progression on sorafenib may have affected the OS outcome,” noted Robert John Motzer MD, of the Genitourinary Service, Memorial Sloan-Kettering Cancer Center, New York, NY, and colleagues. Previously, the TIVO-1 results had shown “superior progression-free survival and overall response rate” for tivozanib compared with sorafenib.

The study randomly assigned 517 patients to tivozanib 1.5 mg/day (3 weeks on; 1 week off) or sorafenib 400 mg/day (twice daily, continuously). In the extension study, patients who experienced disease progression on sorafenib were eligible to receive tivozanib, and those who progressed on tivozanib received regional standard-of-care treatment.

“Final OS analysis was planned to be conducted after all patients had died or were lost to follow-up, or when all patients in follow-up had been on study for at least 2 years, whichever occurred first,” Dr. Motzer explained.


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In this case, final OS analysis occurred 2 years after the last patient was enrolled. Of the 219 deaths, 118 patients (45.4%) were enrolled in the tivozanib arm and 101 (39.3%) in the sorafenib arm (stratified hazard ratio, 1.245; 95% CI: 0.954–1.624; P=0.105). The trend favored the sorafenib arm, he noted.

Median OS was 28.8 months (95% CI: 22.5–NA) for tivozanib and 29.3 months (95% CI: 29.3–NA) for sorafenib. Of 257 patients on sorafenib, 155 (60.3%) had started next-line tivozanib at the time of the analysis.

The 2013 Genitourinary Cancers Symposium is co-sponsored by the American Society of Clinical Oncology (ASCO), the American Society for Radiation Oncology (ASTRO) and the Society of Urologic Oncology (SUO).

Abstract

Clinicaltrials.gov ID: NCT01030783