Sillajen CEO Moon Eun-sang has resigned from his post.

Moon’s resignation came as the company struggled to normalize management and resume stock market transactions while distancing itself from negative news surrounding Moon.

"Moon has stepped down from the top management position, and the company plans to hold a board meeting soon to elect a new CEO," a company spokesperson told Korea Biomedical Review Tuesday. "After appointing the next CEO, the company plans to focus on R&D for Pexa-Vec, our oncolytic viral therapy candidate for liver cancer."

Moon tendered his resignation after the Seoul Southern District Court issued a warrant to arrest him on May 12 on charges of using undisclosed information to sell his company's stocks and committing other irregularities.

Moon is suspected of avoiding massive losses by selling large amounts of his stocks using inside information on the suspension of the clinical trial of Pexa-Vec. Prosecutors also suspect that Moon unfairly acquired a stake in the company without any capital by taking over bonds with warrants (BWs) through setting up a paper company.

Since Moon's arrest, Sillajen, once one of the most prominent biopharmaceutical companies in Korea, has faced possible delisting from the stock market. Top managers’ alleged embezzlement can be a reason for evaluating their companies’ eligibility for listing on the stock market under the exchange's regulations.

The Korea Exchange initially planned to decide whether to review the company for delisting on May 29 but postponed the meeting to Friday this week.