IG-105 is a potent microtubule inhibitor with potential anticancer activity. IG-105 inhibits microtubule assembly by binding at colchicine pocket. IG-105 shows a potent anticancer activity in vitro and in vivo and has good safety in mice. IG-105 showed a potent activity against human leukemia and solid tumors in breast, liver, prostate, lung, skin, colon, and pancreas with IC(50) values between 0.012 and 0.298 mumol/L. It was also active in drug-resistant tumor cells and not a P-glycoprotein substrate. It inhibited microtubule assembly followed by M-phase arrest, Bcl-2 inactivation, and then apoptosis through caspase pathways.