Oncothyreon commences enrollment in PX-866 Phase 2 trial for metastatic castration-resistant prostate cancer

Oncothyreon Inc. (Nasdaq: ONTY) today announced enrollment of the first patient in a Phase 2 trial of PX-866 in patients with recurrent or metastatic castration-resistant prostate cancer. PX-866 is a small molecule compound designed to inhibit the activity of phosphatidylinositol-3-kinase (PI-3K), a component of an important cell survival signaling pathway.

The open label Phase 2 trial is being conducted by the NCIC Clinical Trials Group (NCIC CTG), Queen's University in Kingston, Canada.  The trial will enroll approximately 40 patients with castration-resistant prostate cancer who have received no prior chemotherapy.  The primary endpoint of this single-arm screening trial is the proportion of patients with lack of disease progression at 12 weeks from the initiation of therapy with PX-866.

"We look forward to evaluating PX-866 in this group of prostate cancer patients who no longer respond to hormone therapy and for which new treatment agents are needed," said Kim Chi, M.D., Co-chair of the NCIC CTG study. "We believe PX-866 is an interesting therapeutic target for evaluation given that deregulation of the PI3K pathway has been widely implicated in castration-resistant prostate cancer."

"We appreciate the support and interest of the NCIC CTG in initiating the second single-agent Phase 2 clinical trial evaluating PX-866, our novel, irreversible PI-3K inhibitor," said Robert L. Kirkman, M.D., President and CEO of Oncothyreon. "We now have four clinical trials of PX-866 underway, evaluating this agent in a variety of treatment settings and tumor types. We believe this broad Phase 2 program will provide significant information to guide later stage development of this product candidate."