NEJM: Xarelto at least equal to warfarin

Bayer's new anti-clotting drug may not be superior to the old standby, warfarin, a new journal article suggests. But it is certainly just as good. And as co-author Gregory Zoppo told Reuters, "Non-inferiority is not a bad thing."

The New England Journal of Medicine piece analyzed data from a comparative trial that had some folks scratching their heads: The trial concluded that Xarelto was 21% better at preventing stroke in atrial fibrillation patients than warfarin was. But that conclusion relied on an analysis that left out some patients who began the study. When those patients were included, the results put Xarelto more on par with warfarin.

After taking a close look, the authors concluded the following: "I think we can say safely that [Xarelto] is not inferior to warfarin," Zoppo told the news service. "I don't think we can say it is superior." The NEJM editorial also put forward two caveats: One, the fact that new clot preventers such as Xarelto don't have antidotes that will quickly reverse their effects if serious bleeding occurs. Two, warfarin wasn't used optimally in the Xarelto study.

Now, the question is how Xarelto--and its new rivals in the warfarin-alternative space, including Boehringer Ingelheim's Pradaxa--will fare against the older treatment. The newer drugs are much easier to take; warfarin is something of a dosing nightmare. That ease of use is "exciting," Zoppo said. But will everyone switch? "I think the answer is 'No.' Patients who are managed very well on warfarin should stay on it."

And then there's the whole Xarelto vs. new competitors question. Pradaxa has some superior-to-warfarin data, efficacy-wise. And the yet-to-be-approved blood thinner from Pfizer and Bristol-Myers Squibb, Equilis, went one better in a recent trial, showing an edge over warfarin in stroke prevention and bleeding risk.

- read the Reuters news
- get the release from Bayer