FDA’s top drug regulator George Tidmarsh has resigned from his position just a few months into his tenure, HHS said, after an investigation was initiated into whether he used his authority to target a former business associate. But Tidmarsh told multiple news outlets he was placed on leave after he questioned the legal basis for FDA’s new priority review voucher program and called the agency’s environment “toxic,” specifically criticizing the commissioner’s confidant and chief medical officer Vinay Prasad. Tidmarsh told ABC News he has not resigned.