Portola Pharmaceuticals announced it received a complete response letter from the FDA that its reversal agent for Factor Xa inhibitor anticoagulants will not be approved at this time.
The agent, andexanet alfa (AndexXa), was developed for reversal of uncontrolled bleeding in patients treated with direct Factor Xa inhibitors such as apixaban (Eliquis, Bristol Myers-Squibb/Pfizer), edoxaban (Savaysa, Daiichi Sankyo) and rivaroxaban (Xarelto, Janssen Pharmaceuticals) and indirect Factor Xa inhibitors such as enoxaparin, according to a press release issued by the company. Factor Xa inhibitors are often used for stroke prevention in patients with nonvalvular atrial fibrillation and for treatment of deep vein thrombosis and pulmonary embolism.
There is no reversal agent for Factor Xa inhibitors approved in the United States; the FDA in 2013 designated andexanet alfa as a breakthrough therapy and in 2015 designated it as an orphan drug, both enabling expedited review.
According to the release, the FDA in the letter asked for additional information related to manufacturing and for more data supporting an indication for reversal of edoxaban and enoxaparin. The agency also wrote that it has not yet finalized its review of clinical amendments related to postmarketing studies, the company stated.
“Because AndexXa addresses an urgent unmet medical need, we and the FDA are committed to resolving the outstanding questions to determine the appropriate next steps,” Bill Lis, CEO of Portola, said in the release. “We plan to meet with the FDA as soon as possible.”
Lis is an employee of Portola Pharmaceuticals.