"Recent clinical data validated KAT6 as a targetable mechanism in the treatment of HR+/HER2- breast cancer, including those with actionable mutations," stated Charles Morris, MBChB, MRCP, Chief Medical Officer of Prelude. "Dual KAT6A/B inhibitors, however, demonstrated overlapping toxicities with current backbone therapies may limit the utility in earlier lines of treatment. Our approach of selectively degrading KAT6A has the potential to address this challenge by maximizing the therapeutic window with enhanced efficacy and improved hematological safety, as supported by our preclinical data. We look forward to advancing PRT13722 into the clinic with the ultimate goal of providing a new therapeutic option for patients with HR+/HER2- breast cancer."

The Phase 1 study is a first-in-human, open-label, multicenter study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics and antitumor activity of PRT13722 as monotherapy and in combination with endocrine and targeted therapies in adults with locally advanced or metastatic HR-positive, HER2-negative breast cancer.

Highly selective KAT6A oral degrader program

KAT6 is an emerging and clinically validated target in the treatment of ER+ breast cancer. Prelude discovered and is developing first-in-class, highly potent, highly selective and orally bioavailable KAT6A degraders. Prelude believes that selectively degrading KAT6A and sparing KAT6B has the potential for improved efficacy, tolerability and combinability with other agents relative to dual inhibitors of KAT6A/B.