Betrixaban, an oral small molecule, inhibits the activity of Factor Xa, which is pivotal in the blood coagulation pathway.
The company intends to begin a Phase 3 betrixaban programme to prevent venous thromboembolism (VTE) in acute medically ill patients in the first half of 2012.
In collaboration with Biogen Idec, Portola will develop PRT062607, an oral Syk-specific kinase inhibitor in thrombosis.
According to the deal, Biogen Idec will provide Portola with an upfront payment of $45m, which includes $36 million in cash and $9 million in Portola equity.