– Top/HDAC-IN-3 (Compound 31) is a dual inhibitor of Topoisomerase and HDAC with oral activity. It induces DNA damage by elevating reactive oxygen species (ROS) levels, consequently inhibiting the clonal formation and migration of cancer cells, and triggering apoptosis (Apoptosis) and cell cycle arrest. Top/HDAC-IN-3 demonstrates a significant antitumor effect in NSCLC models, exhibiting a tumor growth inhibition (TGI = 77.5%, 100 mg/kg) superior to that of the HDAC inhibitor SAHA and the combination of SAHA with the topoisomerase inhibitor Irinotecan.