OSI-300

OSI-300 is a potent and selective small-molecule inhibitor of the kinesin spindle protein (KSP), also known as Eg5 or KIF11. KSP is a member of the kinesin-5 family of motor proteins and is essential for the formation and maintenance of the bipolar mitotic spindle during the early stages of mitosis. By inhibiting KSP, OSI-300 prevents the separation of centrosomes, leading to the formation of monoastral spindles and subsequent mitotic arrest in the prometaphase stage. This arrest typically triggers programmed cell death (apoptosis) in rapidly dividing cancer cells. Developed by OSI Pharmaceuticals, OSI-300 was investigated in Phase 1 clinical trials for the treatment of advanced solid tumors, where it was administered as an intravenous infusion. However, clinical development of the compound was discontinued, and it is no longer being actively pursued in clinical trials.

Other names

KSP inhibitor OSI-300