GSK hits back over Avandia

GlaxoSmithKline (GSK) is mounting a strong response to allegations from lawmakers that the company did not properly monitor the safety of its diabetes drug Avandia (rosiglitazone) or share potentially disturbing safety information with the US Food and Drug Administration (FDA).

The Staff Report from the powerful Senate Finance Committee this week asserted that in the face of evidence linking Avandia to an increased risk of heart attack, the company behaved unethically in a myriad of ways.

"GSK executives attempted to intimidate independent physicians, focused on strategies to minimise or misrepresent findings that Avandia may increase cardiovascular risk, and sought ways to downplay findings that a competing drug (Takeda's Actos) might reduce cardiovascular risk," the report said.

The report's assertions were immediately picked up by major news outlets, creating a public relations crisis for GSK. However, GSK has now issued its own white paper in response, arguing that the Staff Report "fails to present an accurate, balanced, or complete view of the currently available information on Avandia (and includes) errors of fact, omission, and inference."

The company criticises the Staff Report for failing to include discussion of the final results of three major GSK studies (known as ADOPT, DREAM and RECORD) that were evaluated by an FDA advisory committee in 2007, after which the advisors voted 22-1 in favour of keeping Avandia on the market. The RECORD study compared Avandia plus metformin or sulfonylurea to metformin and sulfonylurea alone and found no statistically significant difference after 5.5 years in terms of cardiovascular hospitalisation or cardiovascular death, according to GSK.

The Staff Report instead relies on a 2007 meta-analysis "which has been criticised widely, and contradicted by larger, more recent meta-analyses," the white paper asserts.

To contradict the lawmakers' assertions that GSK did not work to actively monitor the safety of Avandia or inform the FDA of its investigations, the white paper includes a timeline of key dates "that demonstrate the ongoing and open exchange of information that has characterised the FDA's active review of this medicine and GSK's efforts to provide data and respond to the agency's inquiries."

GSK also asserted that it has been within its rights and ethical boundaries concerning its responses to independent studies of the drug. "GSK does not condone the silencing of critics, nor did it attempt to subvert the independence of scientific debate around Avandia.  However, GSK will seek to correct inaccuracies and misstatements to ensure that physicians have the most accurate information available about its medicines when making prescribing choices for patients," the company said.

The latest skirmish is part of a longer battle over Avandia that has been raging since before the 2007 FDA advisory committee meeting regarding the drug's safety. The FDA is planning another advisory committee meeting in July of this year, in part to discuss data from an ongoing GSK clinical study called TIDE, which includes a safety comparison of Avandia and Actos as well as a comparison to placebo.