Novel enhanced delivery taxanes: an update.

Taxanes are widely used for many solid tumors, including metastatic breast cancer. Enhanced-delivery taxanes (EDTs) were specifically designed to improve the efficacy and tolerability of taxanes through the utilization of biocompatible, tumor-selective, taxane delivery vehicles, removing the need for drug delivery in toxic, conventional solvents. Nab-paclitaxel is a first-generation EDT that consists of paclitaxel encapsulated in albumin-bound nanoparticles that utilize a standard, endogenous serum albumin pathway to deliver paclitaxel to tumor cells. Second-generation EDTs, including Tocosol Paclitaxel (Sonus Pharmaceuticals, Inc., Bothell, Washington) and paclitaxel poliglumex, use biocompatible drug delivery vehicles that not only eliminate the need for toxic conventional solvents but also exploit tumor pathophysiological phenomena such as enhanced permeability and retention. Emerging evidence suggests that the use of EDTs may promote a more favorable and predictable pharmacokinetic profile with increased bioavailability of taxanes at the tumor site, limiting their exposure to normal tissues and improving the therapeutic benefits associated with taxane treatment.