Food and Drug Administration Commissioner Marty Makary speaks during an announcement at the Department of Health and Human Services December 18, 2025 in Washington, DC.
Alex Wong | Getty Images
Dr. Marty Makary resigned as FDA commissioner Tuesday, ending a controversial tenure at the health agency.
In an article on Truth Social, President Donald Trump said that Kyle Diamantas, who previously worked as the FDA’s top food official, would serve as acting commissioner. In earlier remarks to reporters, Trump called Makary a “wonderful man” and said “He’s going to go on and he’s going to live a great life.”
Trump shared a second message showing a purported resignation text from Makary. In the post, Makary touted his role in the FDA’s priority review process, which expedited approval of certain drugs, among other changes at the agency.
A Truth Social article by US President Donald Trump about FDA Commissioner Marty Makary.
Donald Trump via Truth Social
A senior administration official confirmed that Makary resigned Tuesday, after days of reports that the White House was considering firing him. Health and Human Services Secretary Robert F. Kennedy Jr. made the decision to replace Makary, the official added. The administration hopes to name its nominee to replace Makary in the coming weeks, although the official cautioned that it is too early to name potential replacements.
Makary, a surgical oncologist known for criticizing the government’s handling of the Covid pandemic, led the agency responsible for regulating food, drugs and medical devices for more than a year.
His tenure has been marked by internal dysfunction and turmoil within FDA leadership, as well as growing backlash from drugmakers, doctors and patient groups over regulatory decisions, including the high-profile rejection of some treatments for rare diseases. At the same time, the White House has reportedly become increasingly impatient with what it sees as its slow pace on key Trump policy initiatives, such as the legalization of flavored vapes.
The influential Susan B. Anthony Pro-Life America organization had also called for Makary’s ouster over the FDA’s handling of the abortion pill mifepristone. Makary reportedly slowed review of the safety of the pill, which can be mailed to states that have restricted abortion. Makary’s successor will inherit this review and the sensitive policies associated with abortion.
The senior administration official said he could not identify a single problem that led to Makary’s ouster, but said it was an accumulation of many problems. One such issue was abortion.
Despite controversy over recent drug rejections, the pharmaceutical industry appears wary of a shakeup at the top of the FDA. The pharmaceutical industry is negotiating the reauthorization of the Prescription Drug User Act fees, which specify the fees the FDA collects from drugmakers to fund its reviews.
Morale among the agency’s staff plummeted after layoffs and departures of career scientists from the agency, including longtime cancer regulator Dr. Richard Pazdur, who cited Makary’s leadership as the reason for his departure. In the meantime, distrust of management is said to have increased among remaining staff.
Among Makary’s most controversial appointments was Vinay Prasad, who served as a top official at the agency overseeing vaccines and biotechnology treatments before resigning at the end of April. Prasad, an outspoken academic and podcaster, left the agency after widespread criticism of the FDA from within the biotechnology and pharmaceutical industries and among former health officials.
For example, the FDA initially declined to review Moderna’s flu vaccine — a decision that the biotech company said was inconsistent with the agency’s previous guidance and came specifically from Prasad. The FDA later reversed its policy on the vaccine.
Prasad also faced backlash earlier this year for her rejection of a Huntington’s disease gene therapy offered by uniQure, which claimed the FDA required her to perform fake brain surgery to evaluate whether the treatment worked. In an interview with CNBC in March, Makary appeared to criticize this treatment without naming it.
In April, the FDA rejected Replimune’s drug candidate for melanoma for a second time, following an initial rejection in July. The agency cited insufficient evidence of effectiveness and took issue with the single-arm trial design.
In an interview with CNBC in May, Makary said three independent teams had reached the same conclusion about the drug and that the FDA had not entered into “corrupt sweet dealings.”
“I don’t work for Replimune, I work for the American people and I support the scientists at the FDA,” Makary said in the interview with CNBC’s David Faber.
In March, Sen. Ron Johnson, R-Wisc., announced an investigation into the FDA’s rejection of rare disease treatments.
In order to install a new commissioner, Trump will likely need to secure the support of Sen. Bill Cassidy, a former doctor who nearly blocked the confirmation of Health and Human Services Secretary Robert F. Kennedy Jr. Trump backed a candidate who was trying to unseat the Louisiana Republican, which could complicate that effort.