Paclitaxel poliglumex (XYOTAX, CT-2103): a macromolecular taxane

Paclitaxel poliglumex (PPX) is an innovative macromolecular taxane designed to increase the therapeutic index of paclitaxel. This large macromolecular conjugate of paclitaxel and poly-L-glutamic acid accumulates in tumor tissues by taking advantage of the enhanced permeability of tumor vasculature and lack of lymphatic drainage. Preclinical studies in animal tumor models demonstrate that PPX is more effective than standard paclitaxel and is associated with prolonged tumor exposure to active drug while minimizing systemic exposure. Phase 1 and 2 clinical studies with PPX showed encouraging outcomes compared to standard taxanes with reduced neutropenia and alopecia and allowed a more convenient administration schedule without the need for routine premedications. Human pharmacokinetic data are consistent with prolonged tumor exposure to active drug and a limited systemic exposure. Three phase 3 trials in nonsmall cell lung cancer (STELLAR 2, 3, and 4) have completed enrollment and results are expected in 2005.