Nixon Ellis, president of Trimeris, has left the company.

Trimeris issued a statement Wednesday saying that the company and Ellis “mutually agreed to end his employment.” The company said it is seeking a replacement.

Ellis joined Trimeris as executive vice president and chief business officer in April of 2000. He was named president in 2002. Ellis helped shepherd Trimeris’ AIDS drug Fuzeon through the regulatory process.

“Dr. Ellis was instrumental in the late-stage development and regulatory approval of Fuzeon,” said Dani Bolognesi, CEO of Trimeris.