Dr Eric Abadie has resigned as chair of the European Medicines Agency's Committee for Medicinal Products for Human Use (CHMP), a position he has held since 2007.
The EMA said its executive director Guido Rasi has accepted Abadie's resignation with immediate effect. Tomas Salmonson, the CHMP vice-chair, will lead the Committee in the meantime "to ensure continuity of operations" while the agency prepares to carry out elections for a new chair.
Salmonson will chair the next scheduled meeting of the CHMP, which is due to take place next week.
Abadie's resignation comes after the termination of his contract as scientific advisor to the Agence Francaise de Securite Sanitaire des Produits de Sante (AFSSAPS), the French medicines regulatory authority.
An AFFSAPS statement confirmed that he will leave his position there at the end of his contract as announced on December 14, 2011.
The chairmanship of the CHMP is not a paid position, so he was forced to relinquish that role as a consequence of losing the AFSSAPS contract. The EMA was asked to provide reimbursement for the role but "could not respond favourably to that request", according to the French agency.
AFSSAPS has been in the throes of a revamp in recent months amid a medicine safety scandal involving Servier's diabetes drug Mediator (benfluorex), which was withdrawn from the market in 2009 after 30 years on sale.
The agency's offices were raided in February as part of an investigation into its handling of the affair.
In addition to serving as chair of the CHMP, Abadie was a member of the EMA's Committee for Orphan Medicinal Products and has been chair of its Pharmacogenetics Working Party since 2001.
Salmonson, who is employed by Sweden's Medical Products Agency, has been a member of the CHMP since 2004. He is also a member of the EMA's Working Party on Pharmacokinetics.