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 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 IC 50 of 2.5±2.1 nM and a median value of 1.7 nM. MCE has not independently confirmed the accuracy of these methods. They are for reference only. Cell Proliferation AssayCell Line: Leukemia CCRF-CEM cell line; ovarian 1A9 cell line; NSCLC A549 and NCI-H1299 cell lines; breast MX-1W and MCF-7 cell lines; colon HCT-116, DLD-1, Colo205, KM20, SW620, S1, HCT-15 and Moser cell lines; melanoma A375, Lox and SK-Mel-2 cell lines Concentration: 0.2-7.3 nM Incubation Time: 3 days Result: Inhibited the growth of tumor cell lines with IC 50 s of 0.2±0.03 nM (for leukemia CCRF-CEM cell line), 0.6±0.1 nM (for ovarian 1A9 cell line), 1.1±0.5 and 6.8±6.1 nM ( for NSCLC A549 and NCI-H1299 cell lines), 1.8±0.6, 7.3±2.3 nM (for breast MX-1W, MCF-7 cell lines), 0.7±0.2, 1.1±0.4, 1.5±0.6, 1.8±0.6, 3.6±0.8, 3.7±2.0, 4.2±2.5, and 5.3±4.1 nM ( for colon HCT-116, DLD-1, Colo205, KM20, SW620, S1, HCT-15, and Moser cell lines), 1.1±0.8, 1.4±0.6 and 1.7±0.5 nM (for melanoma A375, Lox and SK-Mel-2 cell lines). 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 . ?\nTaltobulin (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 . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Athymic nu/nu female mice with Lox melanoma model (5-6 weeks of age) Dosage: 1.6 mg/kg Administration: Administered i.v.;for 35 days Result: Growth of Lox tumors was inhibited by 96-98% on day 12 compared with vehicle-treated controls. Growth of KB-8-5 tumors was inhibited by 84% on day 14 compared with vehicle-treated controls. Growth of MX-1W tumors was inhibited by 97% compared with vehicle-treated controls. Growth of DLD-1 and HCT-15 tumors was inhibited by 80 and 66%, respectively. Form:Solid IC50& Target:Traditional Cytotoxic Agents