GSK-923295 is a novel antimitotic inhibitor of centromere-associated protein E (CENP-E) with potential anticancer activity. GSK923295A demonstrated significant antitumor activity against solid tumor models, inducing CRs in Ewing sarcoma, rhabdoid, and rhabdomyosarcoma xenografts. Clinical study showed that GSK923295 had dose-proportional pharmacokinetics and a low number of grade 3 or 4 adverse events. The observed incidence of myelosuppression and neuropathy was low. Further investigations may provide a more complete understanding of the potential for GSK923295 as an antiproliferative agent.