DS1025a

DS1025a is an orally bioavailable small molecule inhibitor of the kinesin-like protein KIF18A, currently under development by Daiichi Sankyo for the treatment of advanced solid tumors. KIF18A is a member of the kinesin-8 family that plays a critical role in regulating chromosome positioning and spindle tension during mitosis. By inhibiting KIF18A, DS1025a induces mitotic stress, leading to chromosome misalignment, spindle assembly checkpoint activation, and subsequent apoptosis. This mechanism is particularly effective in cancer cells exhibiting high levels of chromosomal instability (CIN), as these cells are more dependent on KIF18A for successful cell division compared to normal cells. DS1025a is being evaluated in a Phase 1 first-in-human clinical trial to assess its safety, pharmacokinetics, and preliminary efficacy in patients with metastatic or unresectable solid tumors.