Tracey Beth Hoeg, the acting head of the U.S. Food and Drug Administration's Center for Drug Evaluation and Research, was fired Friday after six months in the role. She's the fifth person to run CDER in the 15 months of President Donald Trump's second term, and her exit comes just days after Commissioner Marty Makary resigned.

Hoeg confirmed the news on X, noting the timing — exactly six months to the day she took over. In an interview with MD Reports, she said two FDA officials showed up at her office and gave her a choice: resign or be terminated. She chose neither. "I said I'm not signing a letter of resignation if it's not my choice," she told them. The officials said the decision came from someone "way above their pay grade." Reuters had reported her expected departure earlier Friday.

This isn't just a one-off firing. It's part of a bigger reset at the Department of Health and Human Services. White House-appointed HHS Deputy Chris Klomp has been working to replace controversial appointees with more conventional picks, according to Reuters. Several lower-level officials brought in by Makary — including chief of staff Jim Traficant, deputy chief of staff Samuel Doran, and policy director Sanjula Jain-Nagpal — are also expected to leave.

Hoeg's tenure at CDER included safety reviews of RSV treatments from Merck & Co., Inc. (MRK), Sanofi S.A. (SNY), and AstraZeneca PLC (AZN). With her departure, there's potentially some near-term regulatory uncertainty hanging over those pipelines. The FDA's drug division is now looking for its sixth leader in just over a year.