Pradaxa sales likely to rebound with expected approval of antidote

Positive results of the Phase III trial of idarucizumab (Boehringer Ingelheim), an antidote for Pradaxa (dabigatran; Boehringer Ingelheim), may spark a growth in Pradaxa sales in a competitive novel oral anticoagulant (NOAC) market.

The positive interim Phase III results have been submitted to the US Food and Drug Administration (FDA) by Boehringer Ingelheim in support of its application for approval of idarucizumab. The approval of this antidote will help mitigate physician concerns about the lack of reversibility of Pradaxa’s effects in emergency situations. With its potential to be the first NOAC with an approved antidote, Pradaxa is expected to gain an advantage over its competitors and experience an associated rise in sales.

On 22 June 2015, Boehringer Ingelheim released the interim results of the Phase III RE-VERSE AD trial of idarucizumab, its novel reversal agent. The published trial results were based on 90 patients who were receiving Pradaxa, and who subsequently experienced either uncontrollable bleeding or required emergency surgery. Administration of idarucizumab resulted in immediate reversal of the anticoagulant effects of Pradaxa. Complete reversal of the effects was evident in 80 of the 81 patients that presented with elevated baseline anticoagulation levels. Boehringer Ingelheim will submit these positive results to the FDA in support of its application for idarucizumab’s approval.

Idarucizumab is a fully humanized antibody fragment that works by binding to Pradaxa and reversing its anticoagulation effects. An antidote for Pradaxa is necessary in situations when patients experience uncontrollable or excessive bleeding and are unable to form blood clots because of their anticoagulant medication. Without the ability to reverse the effect of the anticoagulant medication, these situations can become life-threatening. Idarucizumab’s application for approval was submitted in March 2015 and Datamonitor Healthcare estimates that FDA approval will occur in November 2015. Idarucizumab is currently the only NOAC antidote to have been submitted for review.

Idarucizumab’s approval could help Pradaxa recover after the drug experienced its first year of declining sales since entering the market in October 2010. Much of Pradaxa’s decline may have been caused by a drop in physician confidence in prescribing the drug, due to the dangers associated with the lack of a reversal agent. Public confidence in Pradaxa has also been impacted, and public lawsuits against Boehringer Ingelheim have forced the company to pay out $650m in more than 4,000 cases. Many of the public complaints about Pradaxa cited poor labeling and inadequate warnings with respect to the lack of antidote. The approval of idarucizumab would assure the safety of patients receiving Pradaxa in emergency situations. This increased confidence in the safety of Pradaxa-treated patients is expected to boost uptake of the drug as physicians begin to transition back to Pradaxa as a safer anticoagulant.

The approval of idarucizumab would also allow Pradaxa to gain an edge over competing NOACs Eliquis (apixaban; Bristol-Myers Squibb/Pfizer), Xarelto (rivaroxaban; Bayer/Johnson & Johnson), and Savaysa (edoxaban; Daiichi Sankyo). These three NOACs are all factor Xa inhibitors, while Pradaxa inhibits thrombin directly. Andexanet alfa, an antidote for the factor Xa inhibitors, is currently being developed by Portola. However, although Phase III trials are underway, Portola has yet to file for FDA approval. Therefore, idarucizumab’s potential first-in-class status could allow Boehringer Ingelheim to establish a strong market position for its anticoagulant-antidote pair, while Eliquis, Xarelto, and Savaysa await the approval of their antidote. Datamonitor Healthcare forecasts that the approval of idarucizumab will increase Pradaxa’s sales by over $500m within the first five years of the antidote’s release.