The Food and Drug Administration official who allegedly had an inappropriately cozy relationship with the maker of the controversial Alzheimer's drug Aduhelm is stepping down from his role, effective immediately, according to numerous media reports.

Billy Dunn, head of the FDA's neuroscience office, has been with the agency for around 18 years, during which he was involved in several high-profile drug approvals. But he gained notoriety in the wake of the shocking 2021 approval of Aduhelm, a drug that has not been shown to be effective against Alzheimer's and carries risks of serious brain swelling.

In 2020, the FDA's independent advisory committee voted nearly unanimously that the agency should not approve the drug (11 of 12 committee members voted against, with one voting "uncertain"). Yet, the approval went through anyway, and Aduhelm's maker, Biogen, went on to set the exorbitant price of $56,000 for a year's worth of treatment. Outside researchers called the approval "disgraceful," three advisory members resigned in protest, and Medicare Part B premiums rose by record amounts to accommodate covering the pricey drug for Alzheimer's patients desperate for new treatments.

Subsequent media and congressional investigations alleged that Dunn had an off-the-books meeting with Biogen's head scientist two years prior, which kicked off an unusually close collaboration in the lead-up to the approval. For instance, a congressional report released in December 2022 found that some portions of Biogen's documents regarding the drug were written by the FDA and that the agency worked with the company to create briefing documents together. The congressional report concluded that the FDA failed to follow its own rules in its "atypical" interactions with Biogen and that it "inappropriately collaborated" with the company. It also called Aduhelm's price "unjustifiably high."

On Friday, Dunn reportedly informed leadership that he would be stepping down, according to Stat News. On Monday, Peter Stein, head of the FDA’s office of new drugs, emailed staff about the departure.

"It is with regret that I announce the departure of Dr. Billy Dunn, director of the office of neuroscience," Stein wrote. "After a long and highly productive career in public service, Billy has decided to retire from FDA and explore other opportunities while continuing his focus on improving the lives of patients with neurological diseases."

Teresa Buracchio, the deputy director of the neuroscience office, will replace Dunn as the acting director for now, Stein added.

The departure comes as the FDA is working to recover from various scandals and missteps, including the dire national formula shortage and bungled oversight of vaping products. On Tuesday, the agency reported progress in restructuring its human foods programs in response to the formula fiasco. Last week, it outlined steps to strengthen its tobacco program.