Portola has been dealt a blow after its anticoagulation reversal drug AndexXa was rejected by the US Food and Drug Administration.

The group was seeking approval for the use of its first-in-class drug in patients treated with a direct (apixaban, rivaroxaban, or edoxaban) or indirect (enoxaparin) Factor Xa inhibitor when reversal of anticoagulation is needed due to life-threatening or uncontrolled bleeding.

The file included data from the Phase III ANNEXA-A trial, which showed that AndexXa (andexanet alfa) rapidly reversed the anticoagulant effect of Pfizer/Bristol-Myers Squibb's Eliquis (apixaban) by 93.5 percent, and sustained a high level of efficacy across the two-hour infusion period.

However, the FDA has sent the firm a Complete Response Letter in which it asks for more information, primarily related to manufacturing.

The agency also wants additional data to support inclusion of edoxaban and enoxaparin in the label, and indicated it needs to finalise its review of the clinical amendments to Portola's post-marketing commitments that recently were submitted.

"Because AndexXa addresses an urgent unmet medical need, we and the FDA are committed to resolving the outstanding questions and determining appropriate next steps," said Bill Lis, the firm's chief executive.

"Portola's goal is to define the most expedient path to approval so we can meet the needs of these patients who have no alternative. We plan to meet with the FDA as soon as possible."