Feds Probing Pfizer's Kidney Drug May Want to Check a Certain Pharma Gossip Site ...

Last Updated Mar 11, 2010 7:58 PM EST

Turns out the Oklahoma branch of the Department of Justice is investigating sales of Pfizer (PFE)'s organ transplant drug Rapamune -- but no one knows why. The company didn't give any details in its annual report, and prosecutors would be fools to describe their case before they've made it.

But a couple of coincidences regarding Rapamune, which is taken by kidney transplant patients to stop their bodies from rejecting the new organ, lend themselves to speculation that Pfizer sales reps might have broken FDA rules by pushing the drug for an unapproved use -- specifically, in switching (or "converting") patients from calcineurin inhibitors (another type of organ transplant drug) to Rapamune.

That practice is warned against on Rapamune's "prescribing information," the FDA-approved instructions for the drug, because tests of the practice have resulted in more people dying.

In its annual report, Pfizer said:

The U.S. Attorney's Office for the Western District of Oklahoma is conducting a criminal investigation with respect to Wyeth's promotional practices relating to Rapamune.
Wyeth was acquired by Pfizer last year. And that, officially, is all we know about the probe. A series of posts on the drug industry gossip site CafePharma, however, suggest that Wyeth reps were touting the drug for "off-label" unapproved uses before Pfizer bought the company. In 2006, one anonymous commenter wrote:
Not sure about layoffs but shakedown yes - caught wind of this on the west coast apparently docs have reported bad rep behavior to FDA promo off-label is out of control & big suits know it Novartis has been watching us promote conversion all over the place
In late 2009 another commenter made some remarks about an executive who had transferred out of Wyeth to an unrelated company, Cephalon (CEPH):
Part of why he is paranoid is the off label promotion by his sales forces. Protonix iv and rapamune. Example he knew for years that nearly 100% of rapamune was used off label but acted shocked when his superiors learned truth. He then launched an investigation firing all dirs & approx half of reps to find blame and cover himself.
The prescribing information, or "PI," for Rapamune specifically warns against "conversion." It says that an ongoing study of converting patients from calcineurin inhibitors to Rapamune was stopped because in a subset of patients "there was a higher rate of serious adverse events, including pneumonia, acute rejection, graft loss and death, in this stratum of the Rapamune treatment arm." Among those patients that didn't die, conversion to Rapamune showed no benefit, the PI says. An extra warning against conversion was added to the PI in 2008.

There have been at least seven clinical trials looking at conversion of calcineurin inhibitor patients to Rapamune, and six of those were sponsored by Wyeth, according to the ClinicalTrials.gov database. The earliest one was begun in 2004.

None of this proves anything, of course. Companies are legally entitled to study new uses for their drugs. And comments on CafePharma are notoriously unreliable (although they've been used in litigation before). In fact, the only concrete thing we know about Rapamune on this issue -- aside from the fact that the feds are digging into it -- is that none of Wyeth's research on conversion has yet prompted the FDA to change its instructions for the drug, which were last revised in November 2009.

Pfizer did not respond immediately to a message requesting comment.