The manufacturer of a blood-thinning drug tried to hide results of an internal study that the manufacturer feared would hurt sales of the widely-advertised medication, according to recently-unsealed court documents.

Boehringer Ingelheim, manufacturer of Pradaxa, is being sued by patients and their families, charging it failed to properly warn users about possible dangers of the drug. More than 1,000 of those using Pradaxa have died from bleeding, Katie Thomas of The New York Times reported.

Some of the papers released by Chief Judge David R. Herndon of the United States District Court in East St. Louis, Ill., indicated that a research paper would contradict the company’s claims that regular blood monitoring is not necessary while taking Pradaxa. The lack of regular monitoring is one of the main selling points of the drug over warfarin, a drug long used in the prevention of blood clots and strokes. Warfarin requires frequent blood monitoring and attention to diet.

Boehringer Ingelheim emails released by the court show concern about the effect a change in recommended monitoring would have on sales of Pradaxa. “This may not be a onetime test and could result in a more complex message (regular monitoring), and a weaker value proposition … vs. competitors,” one employee wrote.

An email from another employee expressed concern about the drug’s safety risks in older patients, and said “there may be a role” for one or two blood tests in Pradaxa patients.

The case highlights the fact that much of the research on drugs is performed by the drug makers themselves, who have a financial interest in ensuring their products are approved by regulators.

The research paper, written by Paul A. Reilly, a clinical program director at Boehringer Ingelheim, found that some patients absorb too little of the drug to prevent strokes. It also said another group absorbs so much that they are at a higher risk for bleeding. These issues could be addressed with blood monitoring to ensure that patients have the proper levels of the drug in their bloodstream. Draft versions of the paper gave optimal levels of Pradaxa in a patient’s bloodstream.

Reilly’s paper was published in the February 2014 issue of the Journal of the American College of Cardiology, but some of the conclusions about blood monitoring that appeared in the draft version aren’t in the final report.

In a statement, Boehringer Ingelheim said the unsealed documents “represent small fragments of the robust discussion and debate that is a vital component in all scientific inquiry, and in the research and development of any important medication such as Pradaxa.”

One company supervisor, Dr. Jutta Heinrich-Nols, warned that publishing Reilly’s paper could make it “extremely difficult” for the company to defend its claims that Pradaxa did not require regular blood monitoring, the Times said.

In addition, there is so far no antidote to Pradaxa’s effects. With warfarin, physicians can administer doses of Vitamin K to counteract that drug’s effects in case a patient starts hemorrhaging.

The Justice Department has previously cited the company for intentionally making “unsubstantiated claims about the efficacy” of their drug Aggrenox, which is intended to prevent subsequent strokes, or strokes due to blood clots.

The Pradaxa documents were released the same week that Physicians for Integrity in Medical Research sued the Food and Drug Administration over the heart medication roflumilast, claiming it should be pulled off the market. The drug, made by Forest Laboratories and intended to treat chronic obstructive pulmonary disease (COPD), does more harm than good, according to the plaintiff.

-Steve Straehley

To Learn More:

Study of Drug for Blood Clots Caused a Stir, Records Show (by Katie Thomas, New York Times)

New Emails in Pradaxa Case Show Concern Over Profit (by Katie Thomas, New York Times)

A Promising Drug With a Flaw (by Katie Thomas, New York Times)

Pradaxa Manufacturer Has History of Illegal Activities, Ties To Controversial Groups (by Alisha Mims, Ring of Fire)

Doctors Group Sues FDA to Withdraw Approval of Heart Drug (by Noel Brinkerhoff, AllGov)