PHASE-II AND PHASE-III CLINICAL-TRIALS OF TOREMIFENE FOR METASTATIC BREAST-CANCER

Toremifene (Fareston) received FDA approval in 1997 for the first-line treatment of postmenopausal women with estrogen receptor (ER)-positiv e or -unknown metastatic breast cancer. Phase II and III trials have d emonstrated that first-line therapy with toremifene, 60 mg/d, is as ef fective and as well tolerated as tamoxifen (Nolvadex), 20 or 40 mg/d, in such patients. To date, phase III trials have failed to show a stat istically significant advantage of higher toremifene doses over standa rd doses of tamoxifen in these women. Studies appeared to indicate min imal efficacy of high toremifene doses in women with ER-negative tumor s, but the number of patients studied was small. Although results of s ome trials of high-dose (240 mg/d) toremifene in tamoxifen-''refractor y'' patients were negative, other trials that included prolonged (grea ter than or equal to 6 months) stable disease as an indication of clin ical benefit yielded positive results.