Xarelto Has “Least Favorable” Safety Profile Among New Blood Thinners: Study

The side effects of Xarelto may make it the most dangerous of a new generation of blood thinners, according to the findings of a new study that raises questions about the controversial drug, and suggests that the competitor Eliquis is the safest novel oral anticoagulant on the market. 

In a study published in the medical journal Gastroenterology on December 31, researchers with the Mayo Clinic looked at the safety profiles of Xarelto, Eliquis and Pradaxa, which all relatively new blood thinners, known as direct oral anticoagulant (DOAC) agents, which have been introduced as replacements for warfarin.

While warfarin has been the go-to anticoagulant treatment for decades, Xarelto, Eliquis and Pradaxa have been marketed as superior alternatives, with the manufacturers claiming that they are easier to use and require less blood monitoring to maintain the proper dose. However, unlike warfarin, where the blood thinning effects of the drug can be reversed quickly with vitamin K and fresh frozen plasma if bleeding problems develop, no safe and effective antidote has been available for Xarelto or Eliquis. A reversal agent for Pradaxa was made available last year.

Since the drugs have hit the market, thousands of reports involving uncontrollable bleeding problems have plagued the new drugs, and there are currently about 15,000 Xarelto lawsuits pending nationwide, alleging that the Bayer Healthcare and Janssen Pharmaceuticals sold an unreasonably dangerous and defective anticoagulant, without warning about the lack of an available reversal agent.

In the latest study, researchers used data on about 57,000 patients who used Xarelto, Eliquis or Pradaxa between October 1, 2010 through February 28, 2015. All of the patients had non-valve atrial fibrillation and researchers looked for incidents of gastrointestinal bleeding.

According to the findings, rates of GI bleeding increased among all patients older than 75 who took any of the drugs. Xarelto had higher bleeding rates than both Pradaxa and Eliquis, which had the lowest bleeding rates when compared to its two competitors.

“In a population-based study of patients receiving DOAC agents, we found (Eliquis) had the most favorable GI safety profile and (Xarelto) least favorable,” the researchers concluded. “GI bleeding events among patients taking DOACs increased with age; the risk was greatest among persons ≥75 years old.”

A proposed drug, given the brand name AndexXa, was developed by Portola Pharmaceuticals, and has been submitted to the FDA for approval as a reversal agent for Xarelto and Eliquis. However, in September, the FDA indicated that it requires additional information regarding the manufacturing of the drug, and data on whether the drug can be used with the blood thinners Savaysa and Lovenox, before it can be approved.

The approval of a reversal agent for Xarelto and Eliquis has been sought by the drug makers, since it is widely acknowledged that this will make the drugs substantially safer.

The FDA did approve Praxbind in October 2015, which is a reversal agent for Pradaxa, which was the first member of this class to hit the market. The drug became available to doctors in early 2016.

According to allegations raised in product liability lawsuits filed against the drug makers, the new generation anticoagulants never should have introduced before a safe and effective reversal agent was available, seeking damages for severe bleeds and wrongful deaths caused by problems on Xarelto and Eliquis.

A series of Xarelto bellwether trials are expected to begin this year in the federal court system, which are designed to help parties gauge how juries may respond to certain evidence and testimony that is likely to be repeated throughout the litigation.

Thousands of Pradaxa lawsuits were filed against the makers of that competitor drug before the introduction of Praxbind, and the drug makers ultimately agreed to pay $650 million to settle about 4,000 cases.

It is widely expected that Xarelto settlements will require a substantially larger payment, given the larger market share and wider spread reports of problems among users of the controversial anticoagulant.

Despite the better safety profile found in this latest study, there are also a growing number of Eliquis lawsuits being filed in federal courts nationwide.