UPDATED: FDA gives Boehringer's Pradaxa antidote a boost with fast-track review

Boehringer Ingelheim already had the FDA's "breakthrough" designation on idarucizumab, an antidote to its blockbuster anticoagulant Pradaxa. Now, the reversal agent has stepped on the agency's fast track, which cuts review time by four months.

That means Pradaxa is set to become the first next-gen anticoagulant to get an FDA-approved antidote, Boehringer said in a statement. One in a class of warfarin-alternative pills, Pradaxa competes with Bristol-Myers Squibb ($BMY) and Pfizer's ($PFE) Eliquis, and Johnson & Johnson ($JNJ) and Bayer's Xarelto.

As the first in its class to market, Pradaxa enjoyed a competitive advantage as Xarelto launched, and then as Eliquis joined the party. At first, that is--the drug lost market share to Xarelto, as reports of serious bleeding in Pradaxa patients mounted. Eliquis is now coming on strong as well, after faltering a bit out of the gate. Though Xarelto and Eliquis each posted growth in 2014 sales, Pradaxa's dipped slightly, to 1.2 billion euros ($1.3 billion).

The FDA has reviewed Pradaxa and deemed it safe when used as directed; those directions now include recommendations for kidney testing to make sure the drug will clear properly. Some doctors have been leery of Pradaxa--and its rivals, for that matter--because they lack a quick antidote. Warfarin, on the other hand, can be reversed with Vitamin K.

Enter idarucizumab, which could give Pradaxa the advantage it needs to slug back at Xarelto and Eliquis. If approved, the antidote "has the potential to be a significant evolution in care by providing physicians with an option for Pradaxa patients in rare emergency situations that may require rapid reversal of the anticoagulation effect of dabigatran," said Dr. Sabine Luik, EVP of medicine and regulator affairs at the company.

That's not to say Pradaxa's rivals don't have forthcoming antidotes, though. Portola Pharma has been testing andexanet alfa with Eliquis and Xarelto; both drugs work by inhibiting Factor Xa, whereas Pradaxa is a direct thrombin inhibitor. Portola figures it will file for FDA approval by year's end.

- see the release from Boehringer

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Editor's note: This story was revised to describe idarucizumab as a reversal agent, rather than a clotting agent.