Tocosol Paclitaxel Provides Higher Exposure to Active Paclitaxel Than Taxol

Sonus Pharmaceuticals has reported the results of a clinical pharmacology study, showing that a single 175 mg/m2 dose of Tocosol Paclitaxel, the company's novel paclitaxel product, administered over 15 minutes delivered 67 percent more active paclitaxel into the circulation over time compared to an identical dose of Taxol given over three hours.

Tocosol Paclitaxel is a vitamin E-based emulsion formulation that allows a dose of paclitaxel to be infused over 15 minutes, and that has generated encouraging data on safety and antitumor activity in Phase II trials in breast, ovarian, non-small cell lung and bladder cancers.

The primary goal of the study was to characterize the pharmacokinetics of total paclitaxel in blood and of unbound (active) paclitaxel in plasma in patients receiving equivalent 175 mg/m2 paclitaxel doses administered as Tocosol Paclitaxel and Taxol. Single doses were given in random order at least three weeks apart. In addition to delivering greater amounts of unbound paclitaxel, Tocosol Paclitaxel produced 108 percent higher exposure to total paclitaxel. The clinical pharmacology study enrolled 36 patients with advanced cancers.