Head of FDA stepping down, chief scientist to take over

(AP)—From food safety to tobacco and politically charged drug approvals, Margaret Hamburg reset the course of the embattled Food and Drug Administration, an agency that had often been seen as ineffective.

After nearly six years on the job, Hamburg announced her resignation Thursday in an email to staff. She said the agency's chief scientist, Stephen Ostroff, will serve as acting commissioner

She is among the longest-serving commissioners to head the agency and helped oversee the creation of a new food safety system, reforms in how drugs are reviewed and new tobacco regulations.

President Barack Obama named Hamburg to the post in 2009, following a series of high-profile safety problems at the agency ranging from contaminated blood thinners to salmonella-tainted peanut butter that required one of the largest food recalls in U.S. history.

Under Hamburg's tenure, the FDA was more active on food policy than it had been since nutrition labeling rules were first written in the early 1990s. The agency has worked to put new food safety rules in place, phased out artery-clogging trans fats from the food supply, proposed updates to nutrition facts on the backs of food packaging and required restaurants and retailers to label calories on menus.

In her goodbye note to staffers, she emphasized the importance of science in these decisions and other reforms aimed at speeding up drug reviews and overseeing tobacco products.

"At the heart of all of these accomplishments is a strong commitment to science as the foundation of our regulatory decision-making and of our integrity as an agency," Hamburg said.

She took control of the agency at a time when its reputation had been tarnished by accusations that agency officials were allowing politics to influence their decisions. A federal judge ruled that in 2006 the agency deliberately delayed making a decision on the Plan B morning-after pill at the behest of the Bush administration.

The same contraceptive became a political liability under Hamburg when the FDA attempted to approve its sale over-the-counter for teenagers. But at the eleventh hour the head of the department of Health and Human Services intervened and overruled FDA, deciding that young girls shouldn't be able to buy the pill on their own. Hamburg stood by her agency's decision and the drug was approved for non-prescription use in 2013.

In another high-stakes drug controversy, Hamburg personally made the decision to revoke the blockbuster drug Avastin's approval to treat advanced breast cancer, based on evidence that it did not actually help patients live longer. The ruling came despite heavy lobbying by the drug's maker Genentech and cancer patients who believed the drugs was helping them.

Before joining the FDA, Hamburg, 59, was primarily known as a bioterrorism expert who served as New York City health commissioner

News of Hamburg's departure comes just a week after the agency announced that Robert Califf, a prominent cardiologist from Duke University, would take on the agency's No. 2 leadership position. Califf was considered for the agency's top job under the administrations of President George H.W. Bush and George W. Bush. Many FDA observers expect him to eventually move into the commissioner position.