The Design, Synthesis, and Evaluation of Hypoxia-Activated Prodrugs of the KDAC Inhibitor Panobinostat

The design and synthesis of four hypoxia-activated prodrugs of the KDAC inhibitor panobinostat is described. Initial validation of these compounds using isolated enzymes, and in two human cancer cell lines, reveals that the nitroimidazole-based prodrug (NI-Pano, CH-03) undergoes efficient bioreduction and fragmentation to release the parent drug, panobinostat. NI-Pano was identified as the optimum compound for use in further studies in cells, spheroid tumor models, and in vivo.