Germany’s Bayer is planning to start pivotal trials of a drug for venous thromboembolism (VTE) before the end of the year, continuing a run of good news for its once-ailing healthcare business [[10/05/05a]].

Bayer Healthcare said it plans to move onto a Phase III programme for BAY 59-7939, an orally acting direct Factor Xa inhibitor for preventing VTE, after reporting positive results from two Phase II trials of the drug at the 20th Congress of the International Society on Thrombosis & Haemostasis in Sydney, Australia, earlier today.

As an oral drug, BAY 59-7939 could represent a more patient-friendly alternative to low molecular weight heparins, the current gold standard for preventing VTE, which have to be delivered by injection. Analysts have suggested this profile could make it a blockbuster drug with sales in excess of $1 billion a year.

The two studies presented at the ISTH showed that BAY 59-7939 was as effective as Sanofi-Aventis’ low molecular weight heparin Lovenox (enoxaparin) in preventing the incidence of venous thromboembolism in patients undergoing either knee or hip replacement surgery. Lovenox leads the VTE prevention market and brought in sales of just under 1 billion euros in the first half of this year [[19/07/05c]].

BAY 59-7939 is also pitched as a rival to AstraZeneca’s direct thrombin inhibitor Exanta (ximelegatran), another orally active antithrombotic which was first launched in Europe last year for short-term VTE prevention [[22/06/04d]]. However, progress in the important US market was stymied when the Food and Drug Administration turned down a marketing application for the drug in October 2004, and AstraZeneca is reticent about its plans for the drug in the USA now [[10/02/05c]]. Meanwhile, the product suffered another blow when France requested more information before Exanta could be considered for approval of long-term use in Europe [[12/11/04b]].

While BAY 59-7939 is still some way behind Exanta in development, the latter drug’s problems provide a catch-up opportunity, particularly if Bayer’s drug can achieve compelling results in its three initial indications: VTE prevention after major orthopaedic surgery, VTE treatment and stroke prevention in atrial fibrillation.

Bayer said it currently plans to apply for approval in VTE prevention by the end of 2007, with filings for the other indications planned for 2009.