An FDA effort to speed the approval of drugs and devices - something von Eschenbach has advocated at the National Cancer Institute - is also proceeding. The FDA announced one bid to speed up the development of drugs last month, when it issued new guidelines on early study of experimental treatments that make it easier for researchers to produce and then test.
The commissioner's role, former officials say, is setting policy priorities, implementing reforms and securing the biggest budget possible. It's in those realms where a commissioner, trusted by the White House and confirmed by the Senate, can make a difference.
"There are issues that are out of the routine that require the leadership of a commissioner," said Michael Taylor, a former FDA deputy commissioner for policy now at the University of Maryland. "It's on the new-initiative side where lack of permanent leadership is a factor."
As long as he stays at the FDA, von Eschenbach might be better positioned than previous acting commissioners to make a difference because of his ties to the president.
"But the fact that he's on good terms with the White House doesn't necessarily mean he's on good terms with the Congress," said Richard A. Merrill, a University of Virginia law professor who was an FDA counsel in the 1970s.
The Federal Drug and Food Administration under the Bush administration
Jan. 2001: President Bush comes to office and President Bill Clinton's FDA commissioner resigns. Dr. Bernard A. Schwetz, acting principal deputy commissioner, effectively leads the agency.
Feb. 2002: Bush appoints Dr. Lester M. Crawford Jr. to be deputy FDA commissioner. He effectively runs the agency.
Nov. 2002: Dr. Mark B. McClellan begins serving as FDA commissioner.
March 2004: McClellan leaves FDA to oversee Medicare and Medicaid. Crawford begins serving as acting FDA commissioner.
July 2005: Crawford becomes permanent FDA commissioner.
Sept. 2005: Crawford abruptly resigns. Bush appoints Dr. Andrew C. von Eschenbach to serve as acting FDA commissioner.