Accent Therapeutics, a clinical-stage biopharmaceutical company pioneering novel, targeted, small molecule cancer therapeutics, today announced that the first patient has been dosed in the Phase 1/2 clinical trial evaluating the safety and tolerability of ATX-559, a first-in-class oral DHX9 inhibitor. The company also announced the retirement of Robert A. Copeland, Ph.D., Co-Founder, President, and Chief Scientific Officer (CSO), and the promotion of Serena Silver, Ph.D., to CSO.