Puma Biotech rockets on new neratinib data; amends deal with Pfizer

US development-stage company Puma Biotechnology (NYSE: PBYI) saw its share more than triple to $190 in after-hours trading yesterday, when the released positive research results with its investigational breast cancer drug neratinib.

Puma announced top line results from the Phase III clinical trial of PB272 (neratinib) for the extended adjuvant treatment of breast cancer (ExteNET Trial). The ExteNET trial is a double-blind, placebo-controlled, Phase III trial of neratinib versus placebo after adjuvant treatment with trastuzumab (Herceptin) in women with early stage HER2-positive breast cancer.

More specifically, the ExteNET trial enrolled 2,821 patients in 41 countries with early-stage HER2-positive breast cancer who had undergone surgery and adjuvant treatment with trastuzumab. After completion of adjuvant treatment with trastuzumab, patients were randomized to receive extended adjuvant treatment with either neratinib or placebo for a period of one year. Patients were then followed for recurrent disease, ductal carcinoma in situ (DCIS), or death for a period of two years after randomization in the trial.