[Development of a new tubulin-interacting agent, docetaxel (taxotere) in Japan]

A new semi-synthetic taxoid, docetaxel (taxotere) was recently developed in Japan. The phase I study was initiated in 1991, and the MTD was determined as 70-90 mg/m2, dose-limiting factor as leukopenia, and recommended dose for the phase II study as 60 mg/m2, every 3-4 weeks. The early and late phase II studies were conducted based on above dose schedule. After the late phase II studies, appreciable responses were obtained against advanced recurrent breast (50.4%) and inoperable lung (22.4%) cancers, and the results were accepted by MHW of the Japanese Government. Docetaxel possesses an unique tubulin-interacting activity (promotion of assembly of stable microtubules) and currently combination studies with other anticancer drugs or radiotherapy are ongoing.