The anticoagulant Eliquis, manufactured jointly by Pfizer and Bristol-Myers Squibb, claims to reduce deaths in people with atrial fibrillation, but an FDA reviewer is questioning the validity of this claim.

A clinical trial of Eliquis side effects found that patients receiving the drug were 11 percent less likely to die from any cause compared with those receiving warfarin.

Because key data relating to Eliquis side effects was missing from the trial, however, FDA reviewer Thomas Marciniak concluded that one more death among Eliquis patients or one less warfarin death would mean the benefit was no longer statistically significant.

Marciniak said in a December 2012 memo that more than 300 Eliquis patients had missing data. “Some of the responsibility for the data quality problems rests with us, the FDA: We have approved drugs ignoring similar data quality issues, granting superiority claims and not discussing in the labels the data quality issues,” he wrote. “We must stop doing this.”

Eliquis Problems

Eliquis—which had the generic name of apixaban– is in the category of new anticoagulant drugs that inhibit one of the basic factors in bleeding and clotting, Factor Xa.  It is jointly sold by two pharmaceutical giants, Pfizer and Bristol-Myers Squibb.  The other drugs in this same category are Pradaxa and Xarelto.

Eliquis is touted by its makers as more convenient than warfarin (Coumadin), a drug which has proven its safety in 60 years of use.

While each maker of these drugs claims their respective product is a safe and effective treatment and does not require constant monitoring of a patient’s blood or dietary restrictions, only the makers of Eliquis are claiming its drug has been shown to actually lower the death rate for patients suffering from Atrial Fibrillation or AFib.

As part of a clinical trial involving Eliquis side effects, the company reported patients taking their anticoagulant were 11 percent less likely to die from any medical condition than patients who were taking warfarin, which is the traditional treatment for Afib.

While this sounds like a strong claim, Marciniak questioned the trial because vital data about deaths was not included in the trial. He questioned whether the results were statistically significant, noting that, if one more patient on Eliquis died, the numbers would not be very impressive.

There were over 300 patients in the study taking Eliquis, however data about whether they lived or died was not included in the study. With such a large gap in the data, Marciniak was skeptical that the claims of an 11 percent reduction would be accurate or have any statistical importance.

Somewhat ironically, it may be that the study was unable to follow up with some patients because of their death and therefore categorized them as failing to complete the study. Many patients in studies such as this drop out, which is also a failure to complete. The problem seems to be that they included these patients in the death rate calculation.

In a response memo, other FDA officials have discounted Marciniak’s comments as “somewhat unrealistic” and said that the missing data was not “especially large.”

“Perhaps some (patient data) were lost to follow-up because they had a stroke or died, which potentially biases the study results,” they wrote. “However, there is no reason to believe that this was more likely in the apixaban arm than in the warfarin arm. We cannot directly address whether the missing data are biased in one direction.”

In an email, representatives of Pfizer and Bristol-Myers Squibb, which co-market the drug, stated that data compiled in the Eliquis trial was derived from more than 1,000 sites in 40 countries.

The Eliquis trial data was “thorough and complete, despite inherent challenges with following such a large and diverse population,” the drug makers said. “As the FDA ultimately decided, the small fraction of patients lost to follow-up did not adversely alter the interpretation of superior results vs. warfarin.”

Eliquis Side Effects Lawsuits

Lawsuits are being filed alleging that Eliquis problems can lead to significant bleeding, deep vein thrombosis (DVT), and other serious Eliquis side effects.

Plaintiffs in these cases contend that Pfizer and Bristol-Meyers Squibb failed to adequately warn doctors and patients that there is no antidote to reverse the blood-thinning effects of Eliquis once bleeding begins.

Complaints have also been filed on behalf of individuals who died due to complications from uncontrollable bleeding events, allegedly as a result of Eliquis side effects.

If you have been injured by Eliquis problems or side effects, you should contact an experienced drug injury attorney. You may be entitled to compensation by filing an Eliquis lawsuit against the manufacturer.