Oncothyreon Announces Data for ONT-380 in HER2-Positive Breast Cancer Patients With and Without Brain Metastases at the San Antonio Breast Cancer Symposium

Oncothyreon Inc.

today announced updated data from the company's ongoing trials of ONT-380, an orally active, reversible and selective small-molecule HER2 inhibitor being developed for the treatment of HER2-positive metastatic breast cancer.  The data will be the subject of two presentations at the San Antonio Breast Cancer Symposium (SABCS) being held December 8-12, 2015 in San Antonio, TX. The first presentation (Abstract P4-14-20) highlights data from a Phase 1b trial  of ONT-380 in combination with Kadcyla® (ado-trastuzumab emtansine or T-DM1) in patients who have previously failed treatment with Herceptin® (trastuzumab) and a taxane for HER2-positive breast cancer (ClinicalTrials.gov Identifier NCT01983501).  The data demonstrate an overall response rate of 41% and a clinical benefit rate (CBR) of 59% in an advanced stage patient population, 60% of whom have a history of central nervous system (CNS) metastases. The CNS CBR for patients with response assessable CNS metastases was 64%. The second presentation (Abstract P4-14-19) combines data for patients with response assessable brain metastases from two trials, the