GlaxoSmithKline’s anticoagulant drug Arixtra has proved to be more effective and safe than heparin in severely-ill patients with acute coronary syndrome in a clinical trial reported at the American College of Cardiology annual meeting.

The OASIS 6 trial – carried out in 12,000 patients with so-called ST segment elevation myocardial infarction (STEMI) – found that Arixtra (fondaparinux sodium) reduced death or recurrent heart attack by 14% and all cause mortality by 13% compared to unfractionated heparin (UFH) or placebo.

The results of the study were reported at the ACC and simultaneously released online on the New England Journal of Medicine website, while an earlier study of the drug, OASIS 5, was published in the printed version of the journal.

Dr Salim Yusuf of McMaster University and Hamilton Heath Sciences, Ontario, Canada - the principal investigator of the study - said that, in addition to the effect on mortality and morbidity, “the bleeding incidences observed in OASIS 5 and 6...demonstrated that fondaparinux offered a positive net-benefit risk profile in patients across a range of ACS."

Dr Lawson Macartney, senior vice president of cardiovascular and metabolic medicine development at GSK, said: "We look forward to submitting these data to regulatory authorities worldwide for review so that we may bring fondaparinux to physicians and patients for use in the treatment of ACS." A filing should take place wihin the next few months, said GSK.

Arixtra is already approved for the treatment and prevention of deep vein thrombosis and pulmonary embolism, but extension of its labelling to include acute coronary syndromes could lend some extra sales momentum to the product, which brought in just over $40 million last year, well behind the current market leader, Sanofi-Aventis’ low-molecular weight heparin Clexane/Lovenox (enoxaparin), which generated fourth-quarter 2005 sales of $680 million.

The OASIS-6 data were presented at the ACC on the same day as the ExTRACT trial of Lovenox, which also found a significant benefit for the drug in STEMI patients.