Portola’s andexanet alfa reverses Eliquis anticoagulant effect

A Phase III clinical trial has found that Portola Pharmaceuticals' (Nasdaq: PTLA) andexanet alfa reverses the effects of the anticoagulant apixaban, with the news leading to a 4.1% rise to $28.50 in the company’s share price.

Results from the first part of the Phase III ANNEXA-A (Andexanet Alfa a Novel Antidote to the Anticoagulant Effects of fXA Inhibitors – Apixaban) studies were announced by Portola and partners Bristol-Myers Squibb (NYSE: BMY) and Pfizer (NYSE: PFE) - which market the blood thinner Eliquis (apixaban) - showing the product produced rapid and nearly complete reversal (by around 94%, p value < 0.0001) of the anticoagulant effect of Eliquis in healthy volunteers aged 50-75.

Andexanet alfa represents a potential important advance to the field of anticoagulation for Factor Xa inhibitor patients who suffer a major bleeding event or those requiring emergency surgery.