A semi-synthetic vinca alkaloid that displays potent anti-mitotic and anti-tumor properties. Its main mechanism of action is thought to be inhibition of microtubule dynamics, which results in mitotic arrest and eventual cell death. Acts as a microtubule destabilizing agent. At high concentrations, it stimulates microtubule depolymerization and mitotic spindle destruction. At lower clinically relevant concentrations, vinorelbine blocks mitotic progression. Its main targets are tubulin and microtubules. Unlike the taxanes, which bind poorly to soluble tubulin, vinorelbine can bind both soluble and microtubule-associated tubulin.