Novartis to Start Final-Stage Test of Blood Thinner

Portola Pharmaceuticals Inc. said its partner Novartis AG will begin final-stage testing of the experimental blood thinner elinogrel after researchers found it worked quickly in patients who had surgery to unblock an artery.

Elinogrel took effect within a half hour to keep the blood’s platelets from sticking together and forming a clot, researchers who conducted an earlier study said at the European Society of Cardiology conference in Stockholm. The drug left patients at a higher risk of bleeding requiring medical attention and liver complications than the standard therapy of Sanofi-Aventis SA and Bristol-Myers Squibb Co.’s Plavix.