Pfizer and Bristol-Myers have announced that phase three of the clinical trials for their blood thinner antidote, Andexanet Alfa, have concluded.

The aim is that this bleeding antidote would stop internal bleeding incidents for not only the blood thinner, Eliquis.

Pfizer and Bristol-Myers  intended to develop the reversal agent since the release of Eliquis. In collaboration with Portola Pharmaceuticals, the drug companies feel encouraged based on the outcome of the phase three.

The phase three trial was conducted through a double-blind placebo-controlled study, which evaluated the effectiveness of Andexanet Alfa in reversing internal bleeding incidents induced by Eliquis. These trial subjects were older patients between the ages of 50 to 70 years, with the group given Eliquis twice-a-day for four days and then randomly given Andexanet Alfa.

According to the results of the study, the Eliquis bleeding antidote worked with 93.5 percent positive reactions. In lieu of these results, Portola Pharmaceuticals intends to submit the data from their pre-clinical studies.

This includes the initial data from a phase four study, as part of its Biologics License Application (BLA) to be submitted to the Food and Drug Administration (FDA). Furthermore, Portola Pharmaceuticals is also planning to pursue the FDA’s Accelerated Approval pathway for Andexanet Alfa.

Other pharmaceutical companies with a vested interest in this Eliquis antidote include Bayer Pharmaceuticals and Johnson & Johnson’s subsidiary, Janssen Pharmaceuticals, which made the blood thinner Xarelto.

The Eliquis bleeding antidote is intended to help prevent future internal bleeding events in patient who are prescribed the blood thinner.

Overview of the Eliquis Bleeding Concern

Eliquis was approved by the FDA in 2012 and is the most recent addition to the U.S. anticoagulant market. It was released as a joint effort of Bristol-Myers and Pfizer, after witnessing the success of Pradaxa and Xarelto, which were previously released in 2010 and 2011, respectively.

On the other hand, Eliquis was also released in the midst of the litigation drama of Xarelto and Pradaxa bleeding allegations. While each of these products are meant to prevent stroke in high risk patients, each of them are now at the center of major controversy due to serious internal bleeding events.

For the past two years, numerous Pradaxa and Xarelto lawsuits have been filed and settled throughout the federal and state court systems. Now with the first Eliquis wrongful death officially filed, Pfizer and Bristol-Myers may now be on the chopping-block for gross negligence charges.

When Pfizer and Bristol-Myers released Eliquis, they were not only aware of the risks of internal bleeding associated with the new-generation anticoagulants, they had also announced that they were developing a reversal agent for any potential Eliquis bleeding incidents.

Similar to Pradaxa and Xarelto lawsuits, Eliquis lawsuits allege that the drug makes failed to protect consumers from the dangers of their product.

Previously, patients with atrial fibrillation only had Warfarin as their anticoagulant treatment, and had to adhere to the strict prescription requirements of the product. In contrast to the new-generation anticoagulants, Warfarin had a bleeding antidote and had patients frequently visit their doctors for dose adjustments.

Many experts believe that if patients were provided the warning about the lack of reversal agent, and were required to receive dose adjustments for new-generation anticoagulants, then many internal bleeding incidents would have been avoided.