Drug developer AstraZeneca is to press ahead with plans to submit its ticagrelor drug, Brilinta, for regulatory approval in the fourth quarter of 2009 after positive results from a major trial.The company hailed results from a trial which showed ticagrelor reduced cardiovascular death and heart attacks over clopidogrel in acute coronary syndromes (ACS) patients.Astra said that results from the phase III head to head trial PLATO (a study of Platelet Inhibition and Patient Outcomes), showed that ticagrelor achieved greater efficacy in the primary endpoint, reduction of cardiovascular events (CV death, MI, stroke) over clopidogrel without an increase in major bleeding.Ticagrelor is the first investigational antiplatelet that has demonstrated a reduction in CV death versus clopidogrel in patients with acute coronary syndromes, the company said.