June 18, 2008

Oncothyreon Initiates Enrollment for Phase I Trial of Tumor Drug

Oncothyreon has announced enrollment of the first patient in a Phase I trial of PX-866 in patients with advanced solid tumors.

The Phase I trial is expected to enroll up to 63 patients with advanced metastatic cancer who have failed or are intolerant of standard therapy. Patients will receive PX-866 orally once per day on days one through five and eight through 12 during a four-week treatment cycle.

Primary objectives of the study include establishment of a maximum tolerated dose, evaluation of safety, and analysis of the pharmacodynamic and pharmacokinetic profiles of PX-866.

In addition to the PX-866 trial, Oncothyreon is conducting a Phase II trial of PX-12, an inhibitor of thioredoxin-1, in advanced pancreatic cancer, a Phase Ib trial of PX-12 in advanced metastatic cancer, and a Phase I trial of PX-478, a small molecule inhibitor of hypoxia inducible factor-1 alpha, in patients with advanced solid tumors or lymphomas.

PX-866 is a small molecule compound designed to inhibit the activity of phosphatidylinositol-3-kinase (PI-3K), an important cell survival signaling pathway.

Lynn Kirkpatrick, chief scientific officer of Oncothyreon, said: "We believe that the mechanism of action of PX-866, which irreversibly inhibits PI-3K, will have pharmacokinetic and pharmacodynamic advantages that will distinguish PX-866 in the competitive field of PI-3K inhibitors."