Shares in Portola plunged on news of the FDA rejection, and the company is holding an investors briefing this morning to give more information on the status of the programme.

The agency said that it also needs more time to complete its review of certain clinical amendments to Portola's post-marketing commitments that were submitted recently. Portola was seeking approval for use of its drug when patients receiving the NOACs experience a life-threatening or uncontrolled bleeding incident, but the FDA has said it needs additional information from the company on manufacturing as well as the inclusion of recently-approved edoxaban and enoxaparin on the label. The US regulator turned down Portola's application to market AndexXa (andexanet alfa) as an antidote to three direct Factor Xa inhibitors - Pfizer/Bristol-Myers Squibb's Eliquis (apixaban), Bayer/Johnson & Johnson's Xarelto (rivaroxaban) or Daiichi Sankyo's Savaysa (edoxaban) - as well as generic indirect inhibitor enoxaparin.

The FDA's surprise rejection of Portola's reversal agent for the Factor Xa inhibitor class of novel oral anticoagulants (NOACs) could be a boost for a rival drug from Boehringer Ingelheim.

Praxbind fda approval