Wait until ASCO

Aveo Pharmaceuticals Inc. lost 19% of its value last week despite reporting Phase III data for tivozanib that met the primary endpoint of PFS in renal cell carcinoma versus Nexavar sorafenib (11.9 months vs. 9.1 months). The reason: analysts had expected at least 13-month PFS from the selective VEGF receptor inhibitor.

Aveo completed enrollment of 517 RCC patients in the Phase III TIVO-1 trial in August 2010. According to the protocol, the data would be unblinded after 310 PFS events. On a conference call last week, CMO William Slichenmyer said about 260 patients had progressed by late May or early June of 2011. The remaining 50 events took longer to occur, thus delaying the unblinding...