Taltobulin (HTI-286), a synthetic analogue of the tripeptide hemiasterlin, is a potent antimicrotubule agent that circumvents P-glycoprotein-mediated resistance in vitro and in vivo. Taltobulin inhibits the polymerization of purified tubulin, disrupts microtubule organization in cells, and induces mitotic arrest, as well as apoptosis^[1]. In Vitro: Taltobulin (HTI-286; 0.2-7.3 nM; 3 days) inhibits the growth of 18 tumor cell lines (leukemia, ovarian, NSCLC, breast, colon, and melanoma cell lines) with an average IC₅₀ of 2.5±2.1 nM and a median value of 1.7 nM^[1]. In Vivo: Taltobulin (HTI-286; 1.6 mg/kg i.v.) inhibits the growth of human tumor xenografts (e.g., HCT-15, DLD-1, MX-1W, and KB-8-5) in athymic nu/nu female mice^[1].
Taltobulin (HTI-286; 3 mg/kg; p.o. gavage) inhibits growth by 97.3 % and 82% in athymic nu/nu female mice with Lox melanoma xenografts and KB-3-1 epidermoid xenograft model, respectively^[1].