A randomised study of CGS 16949A (fadrozole) versus tamoxifen previously untreated postmenopausal patients with metastatic breast cancer

Abstract

Background: Fadrozole, a potent, highly specific inhibitor of aromatase activity, has only been used as second-line therapy in treatment of post-menopausal women with advanced breast cancer. A prospectively randomised study was therefore undertaken to compare relative clinical efficacy of fadrozole as first-line treatment to that of tamoxifen. Patients and methods: Eighty postmenopausal women who had not received prior treatment for advanced/metastatic breast cancer were randomised to receive either fadrozole, 1 mg twice daily, or tamoxifen, 20 mg daily. Results: Toxicity was not statistically different on the two treatment arms. Only mild to moderate toxicity was documented: hot flashes in 37%, headaches in 6.5%, mild fatigue in 2.6%. There were also no statistically significant differences in objective response rates, survival or time to treatment failure (TTF). Objective response rate on fadrozole was 50% (complete response (CR) 8.3% and partial response (PR) 42%). On tamoxifen objective response was 44.7% (CR 21% and PR 24%). Median TTF was 4.9 months on fadrozole and 5 months on tamoxifen. Median survival was 22.7 months on fadrozole and 27.5 months on tamoxifen. Conclusion: While response rates, survival and TTF were not statistically significantly different, there were more complete responses on tamoxifen and duration of objective response (CR + PR) was significantly longer in the patients treated with tamoxifen.