Mark Gergen, the executive vice president and chief operations officer at Mirati Theraputics Inc., is stepping down, the company announced Wednesday.

"We want to thank Mark for his important contributions and leadership over the past three years during a critical period for the company, and wish him all the best in his next endeavor," said Dr. Charles Baum, president and CEO of Mirati, in a statement.

The company’s current board chairman Rodney Lappe will step into the role of executive chairman, acting as an advisor to the management team.

Mirati Therapeutics (Nasdaq: MRTX), based in San Diego, is developing medicines for targeted oncology. Baum said the company will continue to focus on its glesatinib and sitravatinib programs, and expects the remainder of the year will be dedicated to establishing their clinical efficacy.