Brand-name drug manufacturers have long used controversial tactics to keep their generic competitors off the market, but a new report by the Senate Finance Committee sheds light on how one firm leveraged hidden financial ties with reputable medical groups to undermine its generic rivals.

Facing what it called “an imminent threat” to its brand-name blood thinner Lovenox, pharmaceutical company Sanofi-Aventis launched an advocacy campaign to influence the U.S. Food and Drug Administration to delay generic competitors, according to the report. It did so by contacting medical societies and researchers, urging them to write in to the FDA—or in one case, to write an advertorial for the Wall Street Journal—to raise safety concerns about generics.

The medical groups—the Society of Hospital Medicine and the North American Thrombrosis Forum—each received more than $2.3 million from Sanofi between 2007 and 2010. A Duke University researcher who wrote the FDA received more than $260,000. None of the letters mentioned financial ties to Sanofi. (The Journal first reported on the two groups’ letters to the FDA last year, sparking the Senate investigation.)

ProPublica has reported on the ways that drug and device makers have sought to influence professional medical societies and health advocacy groups through millions in donations and advertising revenue at conferences. And while we’ve repeatedly raised questions about how the corporate cash influences these groups, there are limits to what reporters can expose about all that happens behind the scenes.

But Senate investigators have subpoena power, and they’ve produced a report drawing on Sanofi documents and emails between the drugmaker and these supposedly independent medical groups. It’s worth reading in full. Here’s some of the email correspondence between Sanofi and the CEO of the Society of Hospital Medicine after the drug company encouraged the group to contact the FDA. From the report (emphasis ours):

SHM has no history of making similar comments to the FDA or any government agency of this kind. While the Ec [Executive Committee] might be supportive they may feel this is not something that SHM has the expertise or knowledge to say much about. ... That being said when something is important to any of our partners (like Sanofi) that we have a long term relationship with we want to give any issue that is important to our partner careful consideration.

The Society of Hospital Medicine did end up sending a letter to the FDA. The group’s CEO sent Sanofi a draft of the letter, and he even asked for the name and address of the intended recipient at the FDA.

A senior manager at Sanofi, in an internal email, later listed the letter as a “key accomplishment” for Sanofi’s public relations team.

Emails also show Sanofi representatives worrying about keeping the appearance of these groups’ independence for fear that Sanofi’s involvement—if reported—could tarnish the groups’ credibility.

After the North American Thrombrosis Forum wrote an advertorial for Lovenox that ran in the Journal, a public relations firm hired by Sanofi emailed the piece to some reporters. That set off some alarm bells for one Sanofi spokeswoman, who worried that Sanofi’s involvement might be too obvious: “I’m a little concerned about how this activity by an agency of ours can be perceived by the media, in terms of any s-a [Sanofi-Aventis] involvement in this activity,” she wrote. (A reporter inquiring about the ad asked about the financial ties between Sanofi and the NATF. She was told to ask the NATF.)

The Society of Hospital Medicine told the Journal that the group has new transparency policies, and “if we were writing the FDA now, we would be very clear about our relationship with any partner, including financial support.” The North American Thrombrosis Forum told the Journal that Sanofi’s funding was not intended “to shape public policy.”

As for the Duke University doctor, Dr. Victor Tapson, the Project on Government Oversight posted one of his letters [PDF] to the FDA. Worth noting, as POGO did, that it’s on Duke University letterhead. Tapson told the Journal that parts of the Senate report were “very incorrect,” but didn’t explain further. (Read our story on med schools and their policies on doctors receiving payments from pharmaceutical companies. Here’s Duke’s policy.)

As for Sanofi, it maintains that the comments from the experts “brought legitimate and important patient safety facts and considerations to the attention of the FDA,” the Journal reported.

The FDA approved the first generic version of Lovenox in July of last year.

Keeping generics off the market costs consumers and the government billions in potential savings every year, according to the Federal Trade Commission. The agency has strongly opposed the industry practice known as “pay for delay,” whereby drug companies intent on protecting their monopoly on a particular drug pay off generics companies to get them to drop their patent challenges.

Drug companies have argued that the practice of reaching these settlements doesn’t prevent competition once the patents expire—something happening for several major brand-name drugs over the next few years. The FTC, however, has said the practice costs consumers and the government more than $3 billion annually.