Indibulin (ZIO-301) is currently in a late phase I trial in Europe and the United States, and two separate Phase I/II studies are currently underway, one in combination with Tarceva® and the other in combination with Xeloda®.



Indibulin is one of a class of cancer therapeutics that includes the taxanes (paclitaxel and docetaxel) and Vinca alkaloids, some of the most effective anti-cancer agents available today. Indibulin, like the taxanes and Vinca alkaloids, interferes with the function of microtubules by binding to their building blocks, tubulin. However, the specific tubulin binding site for indibulin is different from that of taxanes and Vinca alkaloids. The observed lack of neurotoxicity in preclinical studies is thought to be related to this difference in binding site, and in particular, to the observation that indibulin does not bind to neuronal-specific tubulin.

Recent phase I data from an open-label, dose-escalating trial to evaluate safety in patients with advanced solid tumors showed indibulin to be well tolerated and to show promise of activity in a variety of advanced solid tumors. Indibulin has potential in a number of important indications including colorectal, breast, lung, prostate, bladder, head and neck, and renal cancers.

While the development program for indibulin is evolving, potential application of indibulin is possible in a wide variety of cancer types.