Proteostasis Therapeutics, Inc. announced that on June 27, 2016, Christopher K. Mirabelli, Ph.D. notified the company of his resignation from the company's board of directors and from his position as chairman of the Board, effective as of June 30, 2016. Dr. Mirabelli's decision to resign from the Board was not the result of any disagreement with the company. In connection with Dr. Mirabelli's resignation, the Board has appointed M. James Barrett, Ph.D. to serve as chairman of the Board, effective as of June 30, 2016.