It's raining whistleblowers this month. Reuters just reported this morning (click here for full news brief) that a medical reviewer has testified to senators that he or she was pulled off the review of GSK's Avandia after bringing up potential safety issues. This suggests that the FDA (like the drug companies it supervise) may still have a way to go before it reaches its professed goal of establishing an atmosphere of open scientific debate. A senior Food and Drug Administration scientist has told congressional investigators that the FDA removed him or her from work on GlaxoSmithKline Plc's drug Avandia after voicing concerns about the safety of the diabetes pill, two senators said on Tuesday. The unnamed FDA medical officer at one time was the primary reviewer for Avandia, according to a letter sent to the FDA by Senate Finance Committee Chairman Max Baucus, a Democrat, and Sen. Charles Grassley, the panel's top Republican. The scientist has believed since 2005 that there was enough evidence for a strong "black box" warning on Avandia about a risk of congestive heart failure, the senators said. In a statement titled "Senators reveal effort by the FDA to suppress scientific dissent and downplay safety concerns" released with their letter, they said the reviewer was "sidelined after voicing safety concerns" about Avandia. The FDA reviewer "was told to stop participation in the review of potential cardiovascular safety problems associated with Avandia," the senators' letter said. The senators said the scientist was interviewed by committee investigators. "This new allegation is especially significant and raises our level of concern about FDA interference in safety decisions regarding Avandia," the letter said. FDA spokeswoman Julie Zawisza said the FDA had received the senators' letter and would respond.