Drugs for Metastatic Kidney Cancer Offer Similar Survival
ORLANDO, Fla.—Tivozanib and sorafenib treatment for patients with advanced renal cell carcinoma offer similar overall survival (OS), a researcher reported at the Genitourinary Cancers Symposium.
Lead investigator Robert J. Motzer, MD, a medical oncologist at Memorial Sloan-Kettering Cancer Center in New York, presented final overall survival data from phase 3 TIVO-1 and its open-label multicenter extension study. In TIVO-1, 517 patients were randomized to receive either tivozanib 1.5 mg/day (three weeks on, one week off) or sorafenib 400 mg/day (twice daily, continuously). Previously, TIVO-1 data showed that patients on tivozanib had significantly improved progression-free survival (the primary endpoint of the study) compared with sorafenib.
In the extension study, patients who progressed on sorafenib were eligible to receive tivozanib. The 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 two years.
At the time of final OS analysis, which was two years after the last patient was enrolled, 219 deaths had occurred, 118 (45.4%) in the tivozanib arm and 101 (39.3%) in the sorafenib arm. Median survival rates were 28.8 months for tivozanib and 29.3 months for sorafenib, a nonsignificant difference between the groups.
“The reason why the overall survival was slightly longer in the sorafenib arm was because there was a crossover built in,” said Dr. Motzer, noting that patients who progressed on sorafenib treatment could be placed on tivozanib.
Of the 257 patients on sorafenib at randomization, 155 (60.3%) had started next-line tivozanib at the time of the analysis.
Many of the side effects that are troublesome to patients, including skin toxicity, diarrhea, nausea, fatigue, occur very uncommonly with tivozanib, and this is an attractive feature of the drug as first-line therapy for advanced kidney cancer, Dr. Motzer said.