Now that the FDA panel has decided Glaxo’s diabetes drug can stay on the market - but with unspecified warnings and restrictions - the drugmaker has an opportunity to blunt any further damage. And so what better way to do so than to throw darts at the study that caused the ruckus in the first place?

That study, of course, was the recent meta-analysis published in The New England Journal of Medicine by Steve Nissen, the controversial Cleveland Clinic cardiologist, who found that Avandia increased the risk of a heart attack by 43 percent. Despite criticism that a meta-analysis can have limitations, Nissen continues to argue its a good way to assess safety.

Today, though, Glaxo sent e-mails to the media touting the conclusion of a new study published in The Annals of Internal Medicine by George Diamond and Sanjay Kaul of Cedars-Sinai Medical Center in Los Angeles, who reported there were no financial conflicts of interest. The study, by the way, was summarized during public testimony at the recent FDA Advisory Committee meeting.

The study points out “flaws in (Nissen’s) analysis which hypothesized an association for increased risk of myocardial infarction and cardiovascular death with Avandia,” Glaxo’s public relations department wrote. Here’s what they concluded:

“The meta-analysis was not based on a comprehensive search for all studies that might yield evidence about (Avandia’s) cardiovascular effects. Studies were combined on the basis of a lack of statistical heterogeneity, despite substantial variability in study design and outcome assessment. The meta-analytic approach that was used required the exclusion of studies with zero events in the treatment and control groups. Alternative meta-analytic approaches that use continuity corrections show lower odds ratios that are not statistically significant. We conclude that the risk for myocardial infarction and death from cardiovascular disease for diabetic patients taking rosiglitazone is uncertain: Neither increased nor decreased risk is established.”

In other words, Glaxo isn’t content to fight this battle behind closed FDA doors. To revive Avandia in the eyes of the medical community, the drugmaker has to send such missives. The question is, What’s next?