AVEO/Astellas' kidney cancer drug tivozanib fails to beat Nexavar

US biotech AVEO Oncology (Nasdaq: AVEO) and Japanese drug major Astellas Pharma (TYO: 4503) have announced disappointing overall survival (OS) for tivozanib, an investigational agent, from the Phase III TIVO-1 (TIvozanib Versus sOrafenib in 1st line advanced RCC) study in patients with advanced renal cell carcinoma (RCC).

The final OS analysis, as specified by the protocol, shows a median OS of 28.8 months (95% confidence interval [CI]: 22.5–NA) for tivozanib versus a median OS of 29.3 months (95% CI: 29.3–NA) for the comparator arm, sorafenib (Bayer and Onyx Pharmaceuticals’ already marketed Nexavar). No statistical difference between the two arms (HR=1.245, p=0.105) was observed. The OS data are included in the tivozanib New Drug Application filing (The Pharma Letter October 2, 2012) and will be presented on February 16 at the 2013 American Society for Clinical Oncology Genitourinary Cancers Symposium (ASCO GU).

Overall survival is a secondary endpoint of the TIVO-1 study. A one-sided crossover for patients randomized to the sorafenib (comparator) arm was offered pursuant to a separate, long-term treatment protocol to allow trial participants to receive tivozanib upon disease progression. This resulted in a substantial difference in the use of subsequent therapies. Of the patients who discontinued their initial therapy, 10% originally on the tivozanib arm received subsequent anti-VEGF therapy (36% received any subsequent therapy) while 70% of patients originally on the comparator arm received subsequent anti-VEGF therapy (74% received any subsequent therapy).