Epothilones and the next generation of phase III trials for prostate cancer.

The broad spectrum of anti-neoplastic activity and the diverse clinical applications of taxanes have engendered significant interest in identifying mechanistically similar but structurally distinct compounds. Epothilones emerged as a new class of putative antineoplastic drugs based on in vitro assays designed to competitively inhibit the binding of paclitaxel to microtubules [12]. Epothilones are macrolides extracted from a variety of myxobacteria including Myxococcus xanthus or Sorangium cellulosum [13]. Like paclitaxel and docetaxel, the epothilones function by stabilizing the polymerized microtubule [14]; however, the epothilones are structurally distinct.