Regarding the ongoing head-to-head trial pitting Avandia against Actos, the reviewers said "any proposed head-to-head trial of rosiglitazone vs. pioglitazone would be unethical and exploitative."
"After reading these documents, we would like to know what steps the FDA has taken to protect patients in [the trial], and why this trial is allowed to continue," the senators told Hamburg in their letter.
Defending the trial, GSK said it "has been approved by an independent review board and appropriate safety boards that are responsible for assessing the safety of conducting the trial."
FDA spokeswoman Karen Riley said, "The FDA takes very seriously concerns and issues raised in the recent inquiry from Senators Baucus and Grassley."
Dr. Janet Woodcock, director of the FDA's Center for Drug Evaluation and Research, issued a memo in December 2009 requesting that all appropriate offices within the Center rapidly evaluate the new data with the aim of presenting it to an FDA Advisory Committee in the summer of 2010, Riley said in a statement.
The agency posted an announcement about the July meeting on its Web site Monday. It will combine a panel of endocrinology and metabolic drug specialists with drug safety experts to examine the Avandia data that has been collected since 2007.
"FDA awaits the recommendations of the advisory committee, and in the meantime Dr. Hamburg plans to meet with FDA scientists and outside experts to gain a full understanding and awareness of all of the data and issues involved," Riley said.