ARQ 621 是一种变构的有效的选择性 Eg5 抑制剂，Eg5 是一种参与细胞分裂的基于微管的 ATPase 运动蛋白。ARQ 621 具有抗肿瘤活性。ARQ 621 是一种驱动蛋白 (kinesin) 抑制剂 Information ARQ 621 ARQ 621 is an allosteric, and selective Eg5 mitotic motor protein inhibitor. Phase 1. Targets Eg5 mitotic motor protein In vitro ARQ 621 demonstrates anti-tumor activity against a wide range of human cancer cell lines including colon, lung, endometrial, bladder, and hematologic cancer cell lines, with significantly less cytotoxicity against hematopoietic cells. In vivo ARQ 621, as a novel clinical stage drug candidate, inhibits a number of xenografts grown in athymic mice, such as pancreatic, breast, prostate, and ovarian carcinomas with no hematological changes. Furthermore, for ARQ 621, there is no envidence of bone marrow toxicity in pre-clinical mouse efficacy models or safety studies in rats and dogs.