Boehringer's blood-thinner also fights clots-study

FRANKFURT, Dec 6 (Reuters) - Boehringer Ingelheim said its blood-thinning pill Pradaxa was shown to prevent dangerous blood clots to form again, as the privately-held group continues to set the pace of development against rival Bayer.

Germany's Boehringer said on Sunday that Pradaxa was just as good at preventing the recurrence of thrombosis -- a blood clot that can travel to the lungs and cause deadly clogging -- as decades-old standard treatment Warfarin.

The study data is being presented at the annual meeting of the American Society of Hematology in New Orleans.

Boehringer is racing with Bayer, which collaborates with J&J , in the development of a new generation of blood thinning pills to win market share from standard heparin injections and from Warfarin, with billions of dollars in potential revenues.

Boehringer said that for patients using Pradaxa, the risk of harmful bleeding, the main danger associated with anti-blood-clotting treatments, was 37 percent lower than for those on Warfarin.

The about 2,500 patients taking part in the trial had already suffered a thrombosis or lung embolism.

Pradaxa, also known as dabigatran etexilate, was shown in the study not to cause liver damage, a side effect that in 2006 thwarted an early attempt by AstraZeneca to bring a new oral blood thinner to market.

Warfarin, introduced in 1954, interacts with food and other medicines and doctors must monitor patients' blood frequently. The new generation of anti-clotting pills does not to have these drawbacks.

Both Pradaxa and Bayer's drug Xarelto are already approved in some markets to prevent blood clots in patients bed-ridden after major orthopaedic surgery.

Their blockbuster potential, however, lies in the future market for prevention of strokes in patients suffering from atrial fibrilation, a common form of irregular heartbeat.

Boehringer has said it is about one and a half years ahead of Bayer in the race for the mass market of stroke prevention, but analysts say it remains open to question how it will fare against Xarelto.

Bristol-Myers Squibb and Pfizer are working on a similar compound called apixaban.

(Reporting by Ludwig Burger) Keywords: BOEHRINGER/PRADAXA ([e-mail]; [phone]; Reuters Messaging: [e-mail]) COPYRIGHT Copyright Thomson Reuters 2009. All rights reserved. The copying, republication or redistribution of Reuters News Content, including by framing or similar means, is expressly prohibited without the prior written consent of Thomson Reuters.