Bayer has been boosted by late-stage data which shows that its anticoagulant Xarelto is as effective as the standard treatment of deep vein thrombosis, namely Sanofi-Aventis’ Lovenox followed by warfarin.

The Phase III Einstein-DVT study, which involved over 3,400 patients, met the primary efficacy endpoint of non-inferiority to Lovenox (enoxaparin) and warfarin in treating DVT. The data, the full details of which will be presented at the European Society of Cardiology meeting in Stockholm at the end of August, also revealed that rivaroxaban was well tolerated and Bayer said “the rate for the composite of major and clinically relevant non-major bleeding, the primary safety outcome of the study, was similar to current standard therapy”.

Kemal Malik, chief medical officer at Bayer HealthCare and Chief Medical Officer, said “the results of this study confirm that the novel, convenient single drug treatment approach with rivaroxaban could replace the current standard therapy in the treatment of patients suffering from DVT”.

Xarelto, which is being developed with Johnson & Johnson, is currently approved in over 100 countries, including Europe, for venous thromboembolism prevention in adults following elective hip or knee replacement surgery. However the US Food and Drug Administration asked for additional information for that indication in May 2009 and Bayer and Johnson & Johnson have stated they would not be available to file the required data until the second half of this year.

Previously Bayer announced plans to file Xarelto for the potentially more lucrative indication of preventing stroke in patients with atrial fibrillation in the second half of 2010 as well for patients at risk of DVT. The Leverkusen-based firm believes that the drug will be a blockbuster with annual sales topping 2 billion euros.