The Food and Drug Administration (FDA) has announced its approval of Praxbind, a drug designed to reverse the anticoagulant effects of Pradaxa in bleeding emergencies.

Praxbind is manufacturer Boehringer Ingelheim Pharmaceuticals’ brand name for the drug known generically as idarucizumab. It is the first reversal agent approved specifically for Pradaxa.

Pradaxa, or dabigatran, was originally approved for sale in October 2010. It is one of a small group of new anticoagulant medications introduced since that year that finally provided a useful alternative to warfarin (also sold as Coumadin), which had been the anticoagulant of choice for decades.

Despite warfarin’s long history on the market, it had the disadvantage of requiring regular blood monitoring to ensure that the dosage stayed within a therapeutic range. Pradaxa’s manufacturers promoted it as not needing similar monitoring.

However, Pradaxa was introduced to the market without any available complimentary medication, or “reversal agent,” that could stop excessive bleeding once it started. The lack of a Pradaxa antidote made things complicated for patients on Pradaxa who suffered a bleeding injury or needed emergency surgery.

At the same time, early trials showed Pradaxa was linked to an increased risk of gastrointestinal bleeding. An October 2013 Drug Safety Update from the UK’s Medicines and Healthcare Products Regulatory Agency warned about a risk of hemorrhage associated with Pradaxa and the other new anticoagulants.

Pradaxa Lawsuits

The risk of Pradaxa bleeding ultimately led to the filing of over 4,000 Pradaxa lawsuits that were ultimately consolidated into a single multidistrict litigation in a federal court in Illinois.

Generally, the plaintiffs alleged that Boehringer Ingelheim Pharmaceuticals had aggressively over-promoted Pradaxa, understating the safety risks involved. They say that taking Pradaxa exposed them to an unreasonable risk of life-threatening bleeds, and that the company failed to properly warn patients and physicians about the risks of Pradaxa bleeding.

Plaintiffs also disputed the claim that Pradaxa did not require ongoing blood monitoring and alleged that the once-daily dosing schedule was not safe. Some also alleged that the lack of a Pradaxa antidote made it an unreasonably dangerous drug.

In May 2014, Boehringer Ingelheim Pharmaceuticals agreed to pay $650 million to settle all Pradaxa lawsuits in the multidistrict litigation. Representatives of the Plaintiffs’ Steering Committee expressed satisfaction with the settlement. The agreement does not require Boehringer Ingelheim to admit fault, however, and the company maintains the claims against it had no merit.

Praxbind as a Pradaxa Antidote

Praxbind was approved under the FDA’s accelerated approval program. This program allows for expedited approval for drugs that fill a particular unmet medical need. The initial approval allows patients to get access to the drug sooner, but Boehringer Ingelheim Pharmaceuticals still has to submit more information to confirm the drug’s safety and effectiveness.

In its announcement, the FDA referred to three trials conducted in healthy patients to evaluate the safety of Praxbind. In the 283 healthy patients who took Praxbind after taking Pradaxa, there was an immediate reduction in the bleed levels of Pradaxa.

Another trial in patients who had actual need to reverse the effects of Pradaxa showed the anticoagulant effect was fully reversed within four hours in 89 percent of patients who took Praxbind.