Xarelto Makers Try to Overcome FDA Fears of New Blood Thinner Bleeding

Johnson & Johnson and Bayer are trying to obtain FDA approval for expanded use of Xarelto, submitting additional information to the agency in an attempt to overcome concerns about the risk of bleeding problems associated with the new class of anti-coagulants that the medication is a part of, which also includes the controversial drug Pradaxa. 

After the FDA rejected a bid earlier this summer to extend approval for Xarelto to include use in preventing heart attacks and strokes in certain patients, the drug makers submitted a “Complete Response” to the federal drug regulatory agency on September 7.

Expanded use of Xarelto was previously denied amid increasing concerns over deaths and severe bleeding events associated with the class of blood thinners, known as “direct thrombin inhibitors”.

At the time the original application to extend approval for Xarelto, the FDA also raised concerns about missing data from a clinical trial, after about 1,300 patients dropped out of the 15,526-subject trial during its final phase. There was inadequate information about why the numbers dropped, and the participants withdrew consent to access their health records.

New Blood Thinners Raise Bleeding Risk Cause Concerns

Direct thrombin inhibitors affect the enzyme in the blood that causes blood to clot. The drugs have been promoted as superior to warfarin, the go-to-anticoagulant for decades, because they require less monitoring during treatment. However, when severe bleeding problems develop with warfarin, reversal agents are available to stop the blood thinning effects of the older drug, while such quick antidotes are not readily available with the new line of drugs.

Pradaxa (dabigatran) was the first drug from this class to be approved in October 2010. However, it quickly became one of the drugs most commonly associated with adverse event reports submitted to the FDA, causing severe hemorrhages and deaths at numbers that have caused substantial concerns within the medical community.

According to a report issued earlier this year by the Institute for Safe Medication Practices (ISMP), which analyzed all adverse event reports submitted to the FDA during 2011, there were 2,367 reports of Pradaxa bleeding problems, as well as 542 reports of death among Pradaxa users during the first full year it was on the market. By comparison, warfarin was linked to 1,106 adverse event reports, including 72 patient deaths.

Xarelto (rivaroxaban) was introduced in November 2011, as the second drug in this new class. The FDA approved the medication despite staff recommendations against the medication, after independent advisory committee voted 9-2-1 to recommend approval of the medication for stroke prevention in atrial fibrillation.

Pfizer and Bristol-Myer Squibb are attempting to receive approval for a third member of the class, which would be marketed as Eliquis. However, the FDA has delayed approval for the new blood thinner amid similar concerns.

All of the manufacturers of these new drugs are attempting to position their medication as market leader in this new class, which could propel the drugs to block-buster status.

Although Boehringer Ingelheim, the makers of Pradaxa, had the advantage of being the first to market with their anticoagulant, the drug maker has been the focus of a growing number of product liability lawsuits that allege they failed to provide adequate warnings about the Pradaxa bleeding risks and the lack of a reversal agent.

Last month, the U.S. Judicial Panel on Multidistrict Litigation centralized all federal Pradaxa lawsuits as part of an MDL (multidistrict litigation), which has been centralized in the U.S. District Court for the Southern District of Illinois.

There are already about 80 complaints that have been transferred to the MDL from federal district couts throughout the United States, and lawyers expect that hundreds, if not thousands, of injury claims and Pradaxa wrongful death lawsuits will ultimately be filed.