Experts are looking forward to an international cardiology meeting this weekend to help answer a key question: Will Eliquis become the leading substitute for warfarin?
The drug's developers, Bristol-Myers Squibb and Pfizer, certainly hope so. And many analysts have been predicting that Eliquis (apixaban) will come to dominate in the market for warfarin replacements, ever since the companies reported topline findings from the phase III Aristotle trial last June.
The trial showed that, when compared to patients taking warfarin, the drug met its primary endpoint (non-inferiority) and two secondary endpoints (superior efficacy and safety), according to the companies' press release.
Since then, it's become almost a fait accompli that Eliquis will have an edge over Boehringer Ingelheim's Pradaxa and J&J/Bayer's Xarelto—the two new anti-coagulants already approved in the US. Neither Pradaxa (dabigatran) nor Xarelto (rivaroxaban) has as strong a claim on superiority for either safety or efficacy as the BMS/Pfizer drug.
Xarelto was cleared by the FDA in July for preventing clots after surgery. A trial of its use for preventing stokes in atrial fibrillation, Rocket-AF, used multiple statistical analyses, which “muddied the waters regarding [Xarelto's] efficacy and effectiveness over warfarin,” noted an August 10 editorial in The New England Journal of Medicine. (J&J/Bayer have filed for an approval in stroke prevention and are expected to hear from FDA later this year.)
Pradaxa's approval was based on the Re-ly trial, whose primary endpoint was non-inferiority to warfarin, which the drug demonstrated. BI kicked off a Pradaxa DTC campaign last May talking up the blood thinner for atrial fibrillation, following unbranded disease awareness efforts.
But for those yet to be convinced of Eliquis' advantage, detailed results of the Aristotle study should provide more color. Full data are expected to be presented during a “Hot Line” session this Sunday at the European Society of Cardiology (ESC) Congress 2011 in Paris. (Click here for a news story on those results.)
One knock on the BMS/Pfizer drug is that a phase III trial comparing it to placebo in patients with acute coronary syndrome (ACS) was stopped last fall due to an increase in bleeding. The fact that it failed in that arena has not dampened expectations in others.
Eliquis is already approved in the EU for preventing clots in adults following orthopedic surgery, but not for preventing stroke in patients with atrial fibrillation. The latter indication, known as SPAF, is the more important one.
Barclays Capital analyst Tony Butler wrote exuberantly to investors that, “Eliquis against warfarin in SPAF represents the biggest revenue replacement opportunity to expiring worldwide patents.”
He expects Aristotle, which tested apixaban vs. warfarin in patients with AF, to clearly demonstrate Eliquis' ability to reduce hemorrhagic stroke as well as critical/fatal bleeding and thinks the drug will go on to capture 50% of the SPAF market.
Leerink Swann's Seamus Fernandez concurred that Eliquis will outduel Pradaxa and Xarelto: “Given the positive top line release in June & feedback from MEDACorp physicians as well as BMY, we believe these data will be strongly positive and that apixaban could become the leader in the $10B+ warfarin-replacement market.”
After being presented this weekend, Aristotle results will then under go peer review. Fernandez said he expects publication in a major medical journal the same day. That could lead to US and European regulatory filings by BMS and Pfizer for atrial fibrillation in the third or fourth quarter of this year.