AstraZeneca’s Andexxa has reached the endpoint of its study has made the decision to terminate its postmarketing study of the bleeding reversal agent, Andexxa, ahead of schedule. This decision was prompted by the study meeting its primary endpoint sooner than anticipated, and it was recommended by a data monitoring board. The study involved a significant cohort of over 450 patients who were suffering from intracranial bleeding and were being treated with factor Xa inhibitors, which are blood thinners.
In a comparative analysis with a control group receiving standard care, the patients who received Andexxa demonstrated superior hemostatic efficacy, indicating a greater ability to halt life-threatening brain bleeds. Mene Pangalos, the Executive Vice President of BioPharmaceuticals R&D at AstraZeneca, stressed the importance of offering an approved treatment that specifically targets and reverses FXa inhibitor activity, thereby aiding in achieving hemostasis.
The acquisition of Andexxa came about through AstraZeneca’s purchase of Alexion in a significant deal valued at $39 billion towards the end of 2020. Alexion had initially obtained the drug through its acquisition of Portola Pharmaceuticals for $1.4 billion. Prior to receiving accelerated approval in 2018, Portola had faced obstacles related to manufacturing, resulting in a complete response letter from the FDA in 2016.. It should be noted that factor Xa inhibitors, while effective in managing clots, carry a notable risk of inducing severe bleeding.
Therefore, the availability of specific reversal agents like Andexxa is essential in managing these complications. Andexxa, a recombinant protein meticulously designed to bind to factor Xa inhibitors and reverse their anticoagulant effects, achieved revenues of $150 million in the previous year, representing a respectable 5% growth.
Another trial known as ANNEXA-I, which assessed the efficacy and safety of Andexxa in patients experiencing intracranial hemorrhage while on oral FXa-inhibitor treatment, will also be concluded prematurely. The decision to end the trial was based on meeting pre-established criteria for superior hemostatic efficacy compared to standard care. The Data and Safety Monitoring Board, responsible for overseeing the trial, recommended this course of action following an interim analysis that revealed the reversal benefits of Andexxa were observed earlier than originally anticipated. Stuart J. Connolly, a Senior Scientist at the Population Health Research Institute and Professor Emeritus at McMaster University, lauded the study’s outcomes, highlighting the improved control of bleeding when compared to standard care. Moving forward, AstraZeneca plans to share the comprehensive efficacy and safety results from the trial after conducting further analysis.
Mene Pangalos reiterated the significance of providing a treatment that effectively reverses the activity of FXa inhibitors and contributes to achieving hemostasis. This is particularly important considering the millions of individuals globally who rely on FXa inhibitors to prevent the formation of harmful blood clots. Andexxa, developed with the specific purpose of rapidly reversing the anticoagulant effects of direct oral FXa inhibitors, has already obtained accelerated approval in the United States and conditional approval in the European Union, Switzerland, and the United Kingdom. Additionally, it has gained approval in Japan for use with specific FXa inhibitors.
With the early termination of the ANNEXA-I trial, AstraZeneca will proceed to conclude the study and initiate the necessary regulatory filings in both the United States and the European Union to convert the accelerated approvals into full nods. The ultimate goal is to obtain full label approval for Andexxa, affirming its efficacy and safety. To further disseminate these findings, AstraZeneca plans to present the complete efficacy and safety results at a forthcoming medical meeting and publish them in due course.