As part of its discussions with regulators, Portola agreed to provide data on a usual care cohort that participated in the Phase 3 ANNEXA-4 study of AndexXa. A year later, the agency agreed to review a revised Biologics License Application for AndexXa, and set a target action date of Feb. In August 2016, the FDA rejected AndexXa due to issues with the drug's manufacturing, proposed label and post-market clinical requirements. As such, Portola's drug surely has to clear a very high bar for safety and efficacy should it stand a chance at getting approved.īut the road to market has been a bumpy one. Reversal agents fall into the primary care market, meaning millions of patients could ultimately take AndexXa. The FDA's apprehension, while frustrating for Portola and its investors, isn't completely unfounded. Portola's looking to change that with AndexXa (andexanet alfa), which could serve as an antidote to Eliquis and Xarelto. So far, Pradaxa is the only NOAC with an FDA-approved reversal agent, Praxbind ( idarucizumab). Without those reversal agents, physicians were initially more hesitant to prescribe NOACs given the safety risks.

That's partly because its blood-thinning effects can easily be reversed via vitamin K - a valuable characteristic in certain situations, such as when patients taking the drug need emergency surgery. Even with those gains, warfarin is proving to be a tough competitor to edge out.

Andexxa trial