TREATMENT OF POSTMENOPAUSAL WOMEN WITH AD VANCED BREAST-CANCER WITH DROLOXIFENE - RESULT OF A PHASE-II DOUBLE-BLIND DOSE-FINDING TRIAL

To determine the optimal daily dose of a new antiestrogen, droloxifene , for the treatment of advanced breast cancer, we have conducted a mul ticenter, randomized, double blind trial. Postmenopausal women with ad vanced breast cancer, who could not benefit from loco regional therapy , with positive or unknown estrogen or progesterone receptors were ent ered in this study. Droloxifene was administered in a double blind ran domized design, with daily dose of either 20 (group I), 40 (group II) or 100 mg (group III). None of the patients had received previous syst emic antitumor therapy, with the exception of adjuvant chemotherapy te rminated at least one year before the patient`s recruitement. Patients with at least one measurable tumoral lesion were entered into the tri al. Three hundred and sixty nine patients have been enrolled, 234 are fully evaluable for efficacy. Objective response rate (CR + PR) is 31. 1, 44.6 and 41.9% for the groups I, II and III respectively (P = NS). Time to response has been short: in the three groups, 50% of the respo nses have been observed within the 2 first months of treatment. Time t o disease progression is 6, 8.3 and 6 months respectively for the 20, 40 and 100 mg/day treatment group. Side effects have been moderate and not dose related. Hot flushes and gastro intestinal disorders have be en observed most often. This promising new drug deserves further study and randomized comparison versus tamoxifen.