UPDATED: Bayer, J&J test Xarelto uses, even as ACS indication eludes

Johnson & Johnson ($JNJ) and Bayer AG are looking on the bright side of things when it comes to Xarelto. They are undertaking new trials they hope will lead to much wider use of the new kind of blood thinner. The announcement comes days after the FDA for the second time rebuffed their bid to get it a coveted approval for treatment of acute coronary syndrome (ACS).

Bayer said the companies will test the pill in a Phase III trial on patients with chronic heart failure and significant coronary artery disease. They said it is the first of the new anticoagulants to be evaluated for this patient group and point out that heart failure is a big problem worldwide. J&J's Janssen Research & Development outlined 5 trials being undertaken. 

The drug is already approved for 6 uses, but the FDA has now twice refused to give the drugmakers approval for treatment of ACS, an indication the partners badly want because there are 1.2 million ACS patients sent to the hospital each year. The FDA initially asked for more data, including on bleeding risks, but this week said that what it was given still fell short of what it needs to allay concerns. J&J said Monday it was evaluating what the FDA had to say.

Xarelto is one of several drugs that have came on the market to challenge warfarin, which has been the standard treatment for years but which comes with its own troubling side effects. Pradaxa from Boehringer Ingelheim was the first warfarin alternative to market and is now used by millions of patients globally.

Bayer and J&J have big expectations for Xarelto. In a recent R&D update, Bayer CEO Marijn Dekkers touted his estimates for Xarelto once again, saying Bayer could realize $2.5 billion in annual sales from the drug. But bleeding risks continue to hold back the potential for the new drugs because, unlike warfarin, there is no antidote for that. Last month, Bayer and J&J said they had teamed up with Portola Pharmaceuticals to test PRT4445, an agent that may be able to counteract heavy bleeding. If it works, doctors wary of the warfarin alternatives would be more likely to choose Xarelto over warfarin. Boehringer is working to identify its own antidote for Pradaxa, a thrombin inhibitor, and points out that instances of severe bleeding in Pradaxa patients are still less common than in warfarin patients.

- here's the Bayer release
- here's the Janssen release
more from Reuters

Editor's note: The story was updated to make clear that the antidote being developed by Portola Pharamaceuticals is only for Factor Xa inhibitors.