Xarelto matches standard in head-to-head blood clot trial

Citing long-term trial results, Germany's Bayer says that its top pipeline prospect, rivaroxaban (Xarelto), was just as effective as warfarin combined with Lovenox in preventing blood clots and did not raise the risk of bleeding. The data puts Bayer on a fast track toward an application to use the drug to prevent strokes as well as deep vein thrombosis, indications that could help build billions of dollars in annual revenue.

"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 deep vein thrombosis," said Kemal Malik, Bayer's chief medical officer. Non-inferiority was the primary efficacy endpoint in the 3,400-patient study.

Bayer says that it can now refile its application with the FDA in the second half of this year. The agency had requested more information on the therapy when it rejected Bayer's app in May, 2009. The full data will be on display at the Annual Meeting of the European Society of Cardiology in Stockholm, Sweden, at the end of this month. At the end of this year Bayer is also expected to take the wraps off its late-stage study for atrial fibrillation, which analysts believe has the greatest market potential.

As Bloomberg notes this morning, Barclays Capital says that Xarelto can generate more than $8 billion a year if it proves to be better than Boehringer Ingelheim's Pradaxa at preventing strokes for patients with atrial fibrillation. Without a clean success in that category sales could be restricted to $446.8 million.

- here's the Bayer release
- read the Dow Jones report
- check out the story from Bloomberg