Shares of Puma Biotechnology (NYSE:PBYI) skyrocket 186% AH on massive volume after the company reported top-line results from its Phase 3 clinical trial evaluating PB272 (neratinib) as a treatment for HER2-positive breast cancer. The study, called ExteNET, enrolled 2,821 patients in 41 countries who had undergone surgery and adjuvant treatment with Herceptin (trastuzumab) (OTCQX:RHHBY). After treatment with trastuzumab, patients were randomized to receive adjuvant treatment with neratinib or placebo for one year. Patients were then followed for recurrent disease, ductal carcinoma in situ (DCIS) or death for a period of two years after randomization.
The primary endpoint was disease-free survival (DFS). The neratinib cohort demonstrated a 33% improvement in DFS versus placebo with a statistically significant hazard ratio of 0.67. The secondary endpoint was DFS including DCIS. In this population, the neratinib cohort demonstrated a 37% improvement compared to placebo.
Puma plans to file for regulatory approval in the extended adjuvant setting in 1H 2015.