"Given the weight of evidence regarding cardiovascular risks with rosiglitazone, we believe that TIDE is an unethical study and that it was unethical before it was started," the reviewers wrote.
At next week's meeting, the Endocrinologic and Metabolic Drugs and the Drug Safety and Risk Management Advisory Committees might vote to halt the TIDE study, or else modify it in some way.
In the company's briefing documents, GlaxoSmithKline said it remains committed to finishing the TIDE trial.
The FDA hopes to avoid some of the sticky ethical questions washed up by the TIDE trial. It asked the Institute of Medicine (IOM) to come up with a framework for obtaining informed consent when comparing two drugs, one of which is believed to carry an increased risk.
On Friday, the IOM published a number of recommendations for the FDA when planning a postmarketing, randomized safety trial, including that the agency only order such trials when the a responsible policy decision cannot be made without the new evidence, and that the informed consent process continues throughout the trial to include relevant findings that might influence a "participant's willingness to accept the risks associated with the trial."
Panelists at next week's meeting likely will heavily weigh an analysis based on data from the Centers for Medicare and Medicaid Services that was published online two weeks ago.
That observational retrospective cohort study of 227,571 Medicare patients age 65 and older from July 2006 to June 2009 found rosiglitazone was associated with a significantly elevated risk of all other endpoints including stroke, heart failure, death and a composite of all four endpoints.
A spokeswoman for GlaxoSmithKline said the company stands behind the safety and efficacy of rosiglitazone.
"Avandia has a positive benefit-risk profile. When you look at the science and the totality of the data -- especially the most rigorous scientific studies -- Avandia has been shown to be a safe and effective diabetes medicine when used appropriately according to its labeling," said Mary Anne Rhyne, director of U.S. media relations for GlaxoSmithKline. "Avandia is an important medicine for the treatment of type 2 diabetes [patients], who often need two or three medicines to hep maintain their blood sugar levels."
Following the United State's lead, Europe's version of the FDA also will launch a review into rosiglitazone. The European Medicines Agency announced Friday its Committee for Medicinal Products for Human will review the safety of rosiglitazone when it meets July 19 to July 22. The committee may decide to suspend marketing for rosiglitazone or remove it from the market.