ZK 219477 is a fully synthetic analogue of Epothilone B, a naturally occurring cytotoxic substance. ZK 219477 inhibits microtubule depolymerization, causing cell cycle blockage in G2/M phase and induction to apoptosis. This mechanism of action is similar to that of taxanes (paclitaxel and docetaxel), but epothilones retain activity against multi-drug resistance (MDR) tumours. ZK 219477 demonstrated both in vitro and in vivo considerable anti-tumour activity against a wide range of malignancies, and it is now about to enter phase II studies in a number of selected indications. In pre-clinical model ZK 219477 has demonstrated anti-tumorigenic activity for gliomas tumours both in vitro and in vivo.