Sometimes the cure really is worse than the disease. That's essentially what the FDA concluded about Andexxa, a drug designed to stop dangerous bleeding in patients taking blood thinners. After years of post-approval scrutiny, the agency decided the medication's tendency to cause deadly blood clots has tipped the risk-benefit scale into unfavorable territory.
AstraZeneca Plc (AZN) isn't fighting the decision. The company announced it will voluntarily withdraw Andexxa's biologics license and cease U.S. commercial sales by December 22, 2025. After that date, the drug won't be manufactured for or sold in the American market.
A Troubled History Catches Up
Andexxa received accelerated approval back in 2018 as a recombinant modified human factor Xa protein. Its job was to reverse anticoagulation in patients taking rivaroxaban or apixaban who experienced life-threatening or uncontrolled bleeding. The problem? Even at approval, the product came with a boxed warning highlighting thromboembolic risks.
The accelerated approval pathway allowed Andexxa to reach the market based on reductions in anti-factor Xa activity, a surrogate endpoint regulators considered reasonably likely to predict clinical benefit. But that came with strings attached. AstraZeneca (AZN) was required to conduct a randomized controlled trial proving the drug actually helped patients with intracerebral hemorrhage.
The ANNEXA-I Trial Delivers Bad News
That requirement led to the ANNEXA-I trial, and the results weren't what anyone hoped for. AstraZeneca (AZN) submitted the findings in a supplemental biologics license application in January 2024. By November 2024, the FDA's Cellular, Tissue, and Gene Therapies Advisory Committee convened to review the data, with briefing documents already flagging safety concerns.
The trial data told a concerning story. Patients treated with Andexxa experienced higher rates of thrombosis compared to those receiving usual care. Even more troubling, the Andexxa group saw more thrombosis-related deaths by day 30. And these weren't just marginally higher numbers. More than half of the blood clot events in the Andexxa arm occurred earlier than those in the control group.
The FDA's Final Word
On Thursday, the FDA made its position official. After reviewing postmarketing safety data showing thromboembolic events, including serious and fatal cases in patients treated with Andexxa, the agency concluded the product's risk profile is no longer favorable. It's a damning assessment for a drug that was supposed to save lives by stopping bleeding, not cause deaths through blood clots.
The FDA communicated its findings to AstraZeneca (AZN), and the company responded by requesting to withdraw the biologics license for commercial reasons. It's a cleaner exit than a forced removal, but the outcome is the same: Andexxa is done in the United States.
AZN Price Action: AstraZeneca (AZN) shares were down 0.28% at $91.10 at the time of publication on Monday. The stock is approaching its 52-week high of $94.01.