Elisa Fontana, MD, PhD, Sarah Cannon Research Institute UK, London, UK, explains the mechanism of action of the novel ATR inhibitor, RP-3500, and discusses the Phase I/II TRESR trial (NCT04497116) of this drug in patients with advanced solid tumors. Phase I results were presented at ESMO TAT 2022, and investigated the efficacy and safety of 3 dosing schedules, with the aim of determining the recommended Phase II dose. The toxicity of the recommended schedule was manageable, with the most common side effect being anemia. The trial is currently moving into Phase II, and there is also investigation into the combination of RP-3500 being used in combination with PARP inhibitors or chemotherapy. This interview was conducted at the virtual European Society for Medical Oncology Targeted Anti-Cancer Therapies (ESMO TAT) Congress 2022.
