Hamburg will leave office at the end of March.
“I feel so fortunate to have worked at an organization as remarkable and productive as the FDA,” Hamburg wrote in a letter to FDA staff last week announcing her departure.
Hamburg cited expedited reviews of drugs and devices as among the most important achievements of her tenure.
The average time required to approve medical devices has dropped by roughly one-third since 2010, and almost half of new drugs approved last year went through an expedited process, she said.
Hamburg was confirmed in May 2009. She is the longest-serving FDA commissioner since Dr. David Kessler, whose tenure spanned the presidencies of George H.W. Bush and Bill Clinton.
Dr. Stephen Ostroff, who joined the FDA in 2013 and is the agency's chief scientist, will step in as acting commissioner.