Hayward, Calif.-based Impax tapped J. Kevin Buchi, who joined the board last month, as interim president and CEO.
Shares of Impax were trading at $13.40 on Tuesday morning, up 2.7%.
"The company's board has come to a mutual agreement with G. Frederick Wilkinson that Mr. Wilkinson separate from his positions as President and Chief Executive Officer and as a member of the Board, effective immediately," Impax said in the announcement.
The press release did not specify the reason for the departure. But Impax is among nearly a dozen companies that have reported receiving subpoenas from the U.S. Department of Justice related to a federal investigation into alleged price fixing among generic makers. Those companies also include Mylan(MYL) - Get Report , Teva Pharmaceutical(TEVA) - Get Report , Lannett(LCI) - Get Report , Taro Pharmaceutical(TARO) - Get Report , Covis Pharma, Sun Pharmaceutical, Mayne Pharma, Endo International(ENDP) - Get Report unit Par Pharmaceutical and Actavis's generic unit, which Teva acquired from Allergan(AGN) - Get Report in a deal completed in August.
Wilkinson was named Impax's president and CEO in April 2014. Previously, he was president of Actavis Global Research and Development.
Taro CEO Kal Sundaram has announced he will step down by the end of this year and return as the head of Sun Pharmaceutical's business and emerging markets effort. Sun is Taro's parent company. Two former officials at another generic maker, Heritage Pharmaceuticals, were charged earlier this month in the Eastern District of Pennsylvania in Philadelphia as a result of Justice Department's investigation.
Impax spokesman Mark Donohue said Wilkinson's departure has no connection to the DOJ investigation or any specific issue at Impax.
Impax Chairman Robert L. Burr noted Wilkinson's contribution to Impax operations in recent years.
"Fred has been instrumental in Impax's ability to remove the warning letter regarding the company's Hayward facility, which has allowed us to regain generic approvals from that facility," said Impax chairman Robert L. Burr in a statement on Tuesday. Impax in September of last year announced the resolution of a warning letter made by the U.S. Food and Drug Administration in May 2011 relating to its Hayward manufacturing facility.
"Additionally, we appreciate his contributions in helping to get Rytary approved and launched, and enhancing the Company's generic and brand portfolio with the acquisition of the Tower entities," Burr said in the announcement on Tuesday. "On behalf of the Board, we wish him well in his future endeavors."
Buchi was appointed to Impax's board on Nov. 23. He is president, CEO and a board member of TetraLogic Pharmaceuticals. Buchi plans to retire from his roles as TetraLogic president and CEO at yearend in connection with TetraLogic's asset sale to Medivir AB in a transaction expected to close by Dec. 31.