e-Therapeutics (LON:ETX) said chief executive Professor Malcolm Young had become acting chairman of the group with effect from January 1.
It comes after Professor Oliver James's retirement from that role and as a non-executive director at the end of last year.
Brad Hoy, a non-executive director, will chair both the remuneration and audit committees in the interim, the firm told investors.
The biotech firm expects that an additional director will be appointed in due course.
Last month, e-Therapeutics said it had established the safe maximum dose for its potential cancer treatment and lead drug ETS2101.
This is a significant milestone in that it allows researchers to take the drug into the next stage of development.