Yasuji Yamamoto, from the Institute of Molecular and Cellular Biosciences at the University of Tokyo in Japan, said the compound, known as TAS-108, was being assessed in phase l clinical trials at the M.D. Anderson Cancer Center, Houston, USA.
Dr Tetsuji Asao, product director of Taiho Pharmaceutical Co. Ltd the company that developed TAS-108 said: We believe that TAS-108 is a promising anti-oestrogen for the treatment of breast cancer patients. In particular, it appears to inhibit the growth of tamoxifen-resistant tumours. We plan to confirm its efficacy in breast cancer patients who have become resistant to tamoxifen and/or aromatase inhibitors by clinical phase ll and lll trial. We would welcome collaborating in clinical trials with a partner in the States and Europe.
TAS-108 is a steroidal anti-oestrogen which was discovered in 1998 by scientists at two institutions: SRI International in California, USA, and Taiho Pharmaceutical Co. Ltd, based in Tokyo, Japan. As well as inhibiting the growth of oestrogen-dependent breast tumours it also appears to exert a protective effect on the skeleton and the cardiovascular system. Since its discovery Mr Yamamoto and colleagues have been investigating how the compound works at the molecular level.
They compared TAS-108 with other leading anti-oestrogens: tamoxifen, raloxifene and faslodex. They found that only faslodex matched TAS-108 in its ability to inhibit the activities of the oestrogen receptors on the tumour cells, while tamoxifen and raloxifene were only partially successful. In addition, TAS-108 and faslodex were both able to overcome tamoxifen resistance cause
Contact: Emma Mason
Federation of European Cancer Societies