According to the American Heart Association, 92.1 million Americans live with some form of cardiovascular disease. Many of them rely on prescription blood thinners to control their disease symptoms. For years, doctors preferred warfarin for preventing blood clots, strokes and heart attacks. But recently, newer oral blood thinners called Factor Xa inhibitors began stealing warfarin’s patients. While these drugs, including best-selling Xarelto (generic: rivaroxaban), have some benefits over warfarin, they also carry additional health risks. Perhaps most alarming is the fact that Xarelto has no antidote, leaving patients vulnerable to uncontrolled bleeding episodes. As a result, Portola Pharmaceuticals, Inc. started developing its Xarelto antidote, andexanet alfa (brand name: AndexXa). After fast-tracking AndexXa, the U.S. Food and Drug Administration refused to approve andexanet alfa in August 2016.
Portola Resubmits Andexanet Alfa for FDA Review
Before rushing to judgment, first, let’s look at why the FDA refused to clear andexanet alfa for the U.S. market in 2016. The FDA specifically stated that Portola’s initial application didn’t include sufficient data about how the company manufactures andexanet alfa. In addition, the agency wanted data regarding AndexXa’s efficacy as a reversal agent for other Factor Xa inhibitors besides Xarelto. After that initial denial, Portola regrouped and put in another application for the FDA to review (and hopefully, approve) andexanet alfa in August 2017.
The newer, resubmitted biologics application (BLA) that Portola submitted to the FDA includes all Factor Xa inhibitors, not just Xarelto.
Why FDA Approval for Andexanet Alfa Matters
To date, Portola is the only pharmaceutical company that’s developed a potential Xarelto reversal agent for the market. That’s why Portola desperately wants FDA approval for andexanet alfa: With zero market competition, AndexXa could be a pharmaceutical game-changer. Since day one, Xarelto patients put themselves at risk for life-threatening or uncontrollable bleeding, which could result in their deaths. While Vitamin K easily reverses warfarin’s effects (or doctors could infuse patients with fresh frozen plasma), Xarelto has no antidote. Portola aims to change that with AndexXa, which is also currently under review for market distribution in the EU.
Portola’s ongoing ANNEXA-4 study evaluates AndexXa’s safety and efficacy as a reversal agent for anticoagulant patients taking Factor Xa inhibitors. In fact, the company published a preliminary data analysis in September 2016. The study observed 67 Xarelto patients, 47 of whom were eligible for inclusion and analysis. All participants experienced acute major bleeding within 18 hours after taking Factor Xa inhibitors, including apixaban, rivaroxaban, edoxaban or enoxaparin. At the 18-hour mark, doctors dosed all study subjects with andexanet alfa in hopes of reversing their acute bleeding episodes. After analyzing the drug’s effects, researchers found that andexanet alfa “promptly and significantly” reversed anticoagulant activity by 89%.
Portola’s statement about the study’s results asserted: “Considering the substantial clinical burden of bleeding associated with use of FXa inhibitors, the lack of clinical data to support existing management strategies… and the fact that none of the currently used agents reverse anti-FXa activity, effective bleeding management for patients taking FXa inhibitors remains an unmet clinical need.”
UPDATE: FDA Finally Approves Andexanet Alpha In May 2018
After several failed attempts, the FDA finally approved Xarelto antidote Andexanet Alpha on May 4, 2018. This makes AndexXa the first FDA-approved reversal agent for Xarelto and Eliquis patients. If you’re taking either Xarelto or Eliquis and experience uncontrolled bleeding, your doctor can administer this antidote. However, anyone suffering from uncontrolled bleeds prior to May 2018 may now qualify for a major cash settlement.
Check Your Eligibility Online to Claim Part of $775 Million Xarelto Settlement
If you or a loved one suffered life-threatening Xarelto side effects, you’re not alone. Because so many people suffered uncontrolled bleeds (and some even died), Xarelto’s manufacturers agreed to settle over 25,000 claims in March 2019. To check your eligibility for some money from this $775 million Xarelto settlement, complete your free claim review online now. Once you’ve submitted your information, an experienced lawyer on this case will call to discuss your case. This is the first required step in claiming your share of this multimillion-dollar payout. Time to file your claim is limited, so don’t wait! Complete your free, no-obligation online claim review with us today.
Related: Xarelto vs Warfarin: Comparing Blood Thinner Medications
Mandy Voisin
Mandy Voisin is a freelance writer, blogger, and author of Girls of the Ocean and Star of Deliverance. As an accomplished content marketing consultant, mom of four and doctor's wife, Mandy has written hundreds of articles about dangerous drugs and medical devices, medical issues that impact disabled Americans, veterans' healthcare and workers' compensation issues since 2016.