Biopharmaceutics of Paclitaxel (Taxol): Formulation, Activity, and Pharmacokinetics

Paclitaxel (Taxol), a novel antineoplastic agent,1 is active clinically against advanced ovarian and breast cancer,2,3 and under investigation for therapy of a variety of other cancers. One of the most striking features of Paclitaxel is the antitumor activity observed in ovarian cancer patients who have undergone therapy with platinum-based agents and in whom platinum-resistant disease has recurred; for these patients, there exist few treatment alternatives. In phase II clinical trials, a response rate of 30% was achieved in heavily pretreated patients with advanced and refractory ovarian cancer.3 The overall response rate was 56% in phase D trials in pretreated patients with metastatic breast cancer.4 Recently, the U.S. Food and Drug Administration (FDA) approved Paclitaxel for use against refractory ovarian cancer.