Margaret Hamburg, Stephen Ostroff

After serving as US Food and Drug Administration Commissioner for nearly six years, Margaret Hamburg is stepping step down from the post at the end of March. 

Stephen Ostroff will serve as acting commissioner after Hamburg's departure. Ostroff most recently served as the agency's chief scientist. 

During her tenure, Hamburg has been a strong proponent of personalized medicine and the agency approved new molecularly targeted drugs for lung cancer, breast cancer, melanoma, and cystic fibrosis. The FDA also issued critical guidelines to help industry advance drugs alongside companion diagnostics that identify patients most likely to benefit from treatment. "We have ushered in the era of personalized medicine across all of our medical product centers," she said in a letter posted on the FDA's website announcing her resignation. "A growing percentage of our recent approvals have involved targeted therapies, offering many patients more effective response profiles and/or reduced likelihood of side effects."  

The Personalized Medicine Coalition recently estimated that 20 percent of the new drugs that the agency approved last year involved a biomarker and applauded her dedication to the field. "Her commitment to personalized medicine was second to none," PMC President Edward Abrahams said in a statement. 

Under Hamburg's leadership, the FDA also released draft guidance on laboratory-developed tests last October. Although the move was highly controversial, Hamburg has stood by the agency's authority to regulate such tests and the need for added oversight as the practice of molecular medicine has grown rapidly. "It was under her leadership that the historic Medical Device User Fee Agreement III was struck, bringing significant new resources, accountability, and improvements to the device review process," the diagnostic industry group AdvaMed said in a statement. "In addition, she was a key advocate to strengthen oversight for certain laboratory-developed tests, which have become far more complex and critical to patient care and medical decision making."