A GSK / Sirtris Wrap-Up

 |  Includes: GSK, SIRT
by: Derek Lowe

Nature Biotechnology weighs in on the GlaxoSmithKline (NYSE:GSK)/Sirtris (SIRT) controversy. They have a lot of good information, and I'm not just saying that because someone there has clearly read over the comments that have showed up to my posts on the subject. The short form:

The controversy over Sirtris drugs reached a tipping point in January with a publication by Pfizer (NYSE:PFE) researchers led by Kay Ahn showing that resveratrol activates SIRT1 only when linked to a fluorophore. Although Ahn declined to be interviewed by Nature Biotechnology, a statement issued by Pfizer says the group's findings “call into question the mechanism of action of resveratrol and other reported activators of the SIRT1 enzyme.”

Most experts, however, say it's too soon to write off Sirtris' compounds altogether, assuming they're clinically useful by mechanisms that don't involve sirtuin binding. And for its part, GSK won't concede that Sirtris' small molecules don't bind the targets. In an e-mailed statement, Ad Rawcliffe, head of GSK's WorldWide Business Development group, says, “There is nothing that has happened to date, including the publication [by Pfizer,] that suggests otherwise.”

We'll see if GSK and Sirtris have some more publications ready to silence their detractors. But what will really do that, and what we'll all have to wait for, are clinical results.