PegBio (HKG:2565) said its cornerstone investor Yizekangrui Medical (HK) agreed to continue holding on to the company's shares for a further four months, according to a Hong Kong bourse filing Monday.

Yizekangrui Medical bought 9.6 million H shares of the company during its IPO and agreed to hold the stocks under a lock-up period expiring Dec. 31.

The investor has agreed to extend the lock-up period to April 30 and may continue to hold on to the shares as it reviews the company's performance, PegBio said.