SB-743921

SB-743921 is a synthetic small molecule inhibitor of the kinesin spindle protein (KSP), also known as Eg5. It selectively inhibits the ATP-binding domain of KSP with high potency (Ki = 0.1 nM) and demonstrates over 40,000-fold selectivity for KSP compared to other kinesins[1][3][8]. By inhibiting KSP, which is essential for mitotic spindle assembly during cell division in proliferating cells, SB-743921 induces mitotic arrest and apoptosis in cancer cells[8]. Preclinical studies have shown anti-tumor activity against a range of human cancer models both in vitro and in vivo—including colon, prostate, leukemia, lung, and breast cancers[7][8]. Clinical trials have investigated its use primarily for advanced solid tumors and relapsed/refractory lymphoma (including non-Hodgkin's lymphoma)[2][4][5][6][9]. The most common dose-limiting toxicity observed was neutropenia; other toxicities included hypophosphatemia and transaminitis but without significant neurotoxicity or alopecia[6][9]. The recommended phase II dose as a one-hour infusion every three weeks is 4 mg/m²[8][9].

Other names

SB-743921 hydrochlorideSB743921 hydrochlorideSB 743921 hydrochlorideSB-743921 HClSB743921 HClSB 743921 HCl