In the four years since Pradaxa was approved to treat people at risk of blood clots and stroke, it has generated more than $2 billion in sales. But had people known what the manufacturer knew, its success might have been less meteoric.
According to the New York Times, Boehringer Ingelheim, the German drug maker, was so concerned that an internal study would compromise sales of Pradaxa, it pressured the paper’s author to revise it, then said the whole report should be suppressed.
Legal documents made available a few weeks ago indicate that Boehringer Ingelheim exerted internal pressure; thousands of lawsuits claim that the company failed to warn patients about the risks of taking Pradaxa. About 850,000 people have been prescribed the drug, says The Times, and it has been linked to more than 1,000 deaths.
Boehringer Ingelheim says the drug was proven through clinical trials and that the FDA confirms it safety. (See our blog, “FDA Supports Pradaxa, But Many Doctors Don’t.”)
The newly released documents include emails, memos and internal presentations concerning whether a forthcoming research paper would undercut one of Pradaxa’s claimed benefits – that it does not require regular blood tests to ensure it’s working.
The point is key to physicians who treat heart and stroke patients, because not everybody metabolizes Pradaxa the same way, and because it has less dosing flexibility than other treatments. Older patients and those with compromised kidney function are of particular concern.
There are no tests available in the U.S. for monitoring Pradaxa patients who might be most at risk.
Pradaxa and two other recently approved drugs, Xarelto and Eliquis, compete for market share with warfarin, a generic drug that has been the longstanding treatment to prevent blood clots and strokes. Warfarin — its old brand name is Coumadin — requires frequent blood tests, adherence to a certain diet and other drugs.
The new drugs are promoted as equivalent to warfarin, or better, for patients suffering from the heart-rhythm disorder atrial fibrillation, commonly called A-fib.
The documents disclosed the unease caused by a research paper written by Dr. Paul A. Reilly, a clinical program director at the company. It showed that that some patients could benefit from monitoring their blood, and that some absorb too little of the drug to prevent strokes effectively. It also showed that some patients absorb so much Pradaxa that they are at a higher risk for bleeding.
As the paper circulated within the company, one supervisor emailed other employees that she could not believe the company was planning to publish research contradicting a decade’s worth of work proving that patients taking Pradaxa don’t need regular tests, and that doing so could make it “extremely difficult” for Boehringer Ingelheim to defend its claim to regulators that Pradaxa didn’t require testing. She also said disclosing the results would “undermine” efforts to compete with Xarelto and Eliquis.
Another company executive was concerned about legal repercussions arising from the paper’s identification of a specific range of Pradaxa blood levels within which the drug worked best.
Some employees, according to The Times, acknowledged that the paper addressed serious concerns that practitioners already were raising.
“In these situations, where the stakes are really high, how crazy is it that [important information about drug safety is] in the hands of people who are so conflicted?” Dr. Lisa M. Schwartz of the Dartmouth Institute for Health Policy and Clinical Practice told The Times.
Reilly’s paper was published last week in the Journal of the American College of Cardiology, but references to a patient’s optimal blood-level range of Pradaxa did not appear in the article. Boehringer Ingelheim said the scientists’ thinking had evolved, that they had concluded that no single blood-level range is ideal for all patients.
Pradaxa is approved in doses of 150 and 75 milligrams (the lower dose is for patients with low kidney function). Europeans have the option of a 110-milligram dose, but it is not approved by the FDA, which believes it does not benefit most patients.
Although some doctors applauded Boehringer Ingelheim for finally addressing an area of intense interest among cardiologists, said The Times, others said the newly released documents show that drug makers and regulators had been too eager to approve such powerful drugs without more careful monitoring.
“The one-size-fits-all was a mistake for a drug with this kind of risk,” Thomas J. Moore, a senior scientist at the Institute for Safe Medication Practices (ISMP), told the paper. His organization tracks safety reports submitted to the FDA. He rated anticoagulants including warfarin and Pradaxa as the most serious safety problem in 2011 and 2012.
If you take Pradaxa, or are considering it, discuss with your doctor the need for monitoring, and proper dosing. If you want to report a problem with Pradaxa, or read about them, link to the FDA’s MedWatch page.