GlaxoSmithKline is upping the ante in its bid to win market share from Sanofi-Aventis’ number one clotbusting drug, Lovenox (enoxaparin), and yesterday unveiled data at the European Society of Cardiology showing that Arixtra (fondaparinux) was as effective as Lovenox in preventing death, heart attack and ischaemia, and offered a superior benefit in reducing major bleeds and death rates.

The study results showed an incidence of 5.9% and 5.8% in the Arixtra and Lovenox groups, respectively, for the combined cardiovascular endpoint. However, Arixtra was associated with a 47% reduction in major bleeding over Lovenox (21.% and 4.0%, repectively) – one of the critical complications of clotbuster therapy –and also pulled in a superior mortality rate of 2.9% versus 3.5%, or a 17% reduction. This survival benefit was also in evidence after six months, with 5.8% of the Arixtra group dying compared to 6.6% of the Lovenox arm – representing an 11% reduction in mortality.

GSK actually acquired Arixtra in the fallout from the merger of Sanofi-Synthelabo with Germany’ Aventis last year, but has faced somewhat of a challenge in its marketing, as did Sanofi previously [[13/04/04a]], [[02/09/04a]]. GSK’s mission was to take over the mantle of additional clinical studies for Arixtra in order to broaden the drug's label and appeal to the cardiovascular community: most recently it won European approval for Arixtra in the prevention of venous thromboembolic events in patients undergoing abdominal surgery [[13/07/05e]].

Arixtra is not currently approved in the USA or Europe for patients with acute coronary syndromes, but a green light in this indication would open up a door into a significant marketplace. A regulatory submission is anticipated in the near future.