sr-16234 and Neoplasm-Metastasis

The objective of this study was to evaluate 3 different doses of (7α)-21-(4-[(diethylamino)methyl]-2 methoxyphenoxy)-7 methyl-19 norpregna-1,3,5(10)-trien-3-ol 2-hydroxy-1,2,3-propanetricarboxylate (TAS-108) in patients with recurrent, hormone-responsive breast cancer.. In this randomized, double-blind, multicenter study, TAS-108 was administered daily at a dose of 40 mg, 80 mg, or 120 mg to postmenopausal patients with locally advanced, or inoperable, or metastatic hormone-receptor positive breast cancer. The primary efficacy outcome was clinical benefit (CB), defined as the total number of patients who achieved a complete response, a partial response, or stable disease for ≥24 weeks. The study was a 2-stage design in which 19 patients per dose group were planned in the first stage. If at least 3 patients in any dose group achieved a CB, then that dose group was to be allowed to continue enrolling for the second stage, and the group could include up to a total of 60 patients.. The 40-mg and 80-mg groups met the criterion and enrolled patients into the second stage. In the 40-mg group, there were 13 CB events in 60 patients (21.7%); and, in the 80-mg group, there were 12 CB events in 60 patients (20%). The 120-mg daily dose was stopped early, because it failed to achieve the criterion. For the 40-mg and 80-mg groups, the median time to progression was 15.0 weeks and 15.9 weeks, respectively. Only 1 drug-related serious adverse event (grade 3 hyperglycemia) was reported.. TAS-108 at 40 mg and 80 mg daily demonstrated clinical activity with an encouraging duration of benefit. Because of its superior safety profile, TAS-108 40 mg daily is recommended for further development.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Breast Neoplasms; Disease-Free Survival; Double-Blind Method; Estradiol; Estrogen Receptor Modulators; Female; Humans; Middle Aged; Neoplasm Metastasis; Neoplasms, Hormone-Dependent; Postmenopause

This randomized phase II study was intended to identify the optimal dose of TAS-108, a novel steroidal antiestrogen, for the treatment of breast cancer in postmenopausal Japanese women. The potential clinical effects of TAS-108 on the uterus, bone, serum lipids, and hormones were also investigated. Postmenopausal women with hormone receptor-positive metastatic breast cancer who had previously received one or two endocrine therapies were randomly assigned to one of the three possible dose levels of TAS-108 (40, 80 or 120 mg/day). Oral TAS-108 was given daily, and the efficacy and safety of the three doses were evaluated. A total of 97 patients (33, 32, and 32 in the 40-, 80-, and 120-mg groups, respectively) were treated with TAS-108. The clinical benefit rate was 30.3% for the 40-mg, 25.0% for the 80-mg, and 25.0% for the 120-mg group. The 40-mg group achieved the prespecified target threshold. TAS-108 at all dose levels was well tolerated and appeared to have no harmful effects in terms of the variables examined in this study. We conclude that the optimal dose of TAS-108 among the three doses is 40 mg, once daily, for further studies. JAPIC Clinical Trials Information number: Japic CTI - 121754.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents, Hormonal; Breast Neoplasms; Estradiol; Female; Humans; Middle Aged; Neoplasm Metastasis; Postmenopause; Treatment Outcome

The potential of TAS-108 for the treatment of breast cancer has been shown by preclinical studies. We therefore investigated the safe dosage, tolerability, and effectiveness on hormone levels and bone metabolism markers and the pharmacokinetics of TAS-108 administered in postmenopausal Japanese women with metastatic breast cancer.. The subjects had previously undergone standard endocrine therapeutic modalities. TAS-108 was given repeatedly to five patients each, at three dose levels (40, 80, and 120 mg p.o.) once a day after the first daily meal for a scheduled 8 weeks. Plasma concentrations of TAS-108 and its metabolites were measured at the scheduled time points.. Fifteen patients received TAS-108 treatment. Orally administered TAS-108 was well tolerated at doses up to 120 mg and did not cause notable changes either in hormone levels or bone metabolism markers. Pharmacokinetic results indicated dose-dependent increases in plasma levels of TAS-108 and its metabolites. A steady state was achieved by 2 weeks at all dose levels, suggesting no marked accumulation. Clinical benefits were confirmed in 5 of 15 patients.. Repeated oral administration of TAS-108 at doses up to 120 mg was well tolerated, and the plasma level of this compound increased dose-dependently.

Topics: Administration, Oral; Aged; Bone Remodeling; Breast Neoplasms; Drug Administration Schedule; Estradiol; Estrogen Receptor Modulators; Female; Humans; Japan; Middle Aged; Neoplasm Metastasis; Postmenopause; Time Factors; Treatment Outcome

TAS-108 is a novel steroidal anti-estrogen compound that has a strong binding affinity to the estrogen receptor and, in preclinical studies, has antitumor activity against tamoxifen-resistant breast cancer cell lines. The objective of this study was to investigate the safety and the pharmacokinetics in patients with previously treated advanced breast cancer.. TAS-108 was administered orally once daily starting at 40 mg/day, with dose escalations of 60, 80, 120, and 160 mg/day. A minimum of three patients were enrolled in each dose level, and, if no drug-related grade 3 or higher adverse events were seen in the first 14 days, the next cohort of patients was treated at the next level. Pharmacokinetic data were obtained on day 1, 2, 15, and 28 of the first course.. A total of 16 patients were enrolled, and most had received six to seven prior therapies. Clinical toxicities included nausea, vomiting, hot flashes, headache, weakness and fatigue; all were grade 1-2. TAS-108 had no effect on endometrial thickness based on trans-vaginal ultrasound evaluation. The average duration of therapy was 17.4 weeks (range, 4-60 weeks). The mean terminal half-life ranged from 8.0 to 10.7 hour in the interval of 12 to 24 hours postdose. The mean C(max) ranged from 2.8 to 21.0 ng/mL and AUC(0-t) from 15.1 to 148.7 ng.h/mL, this showed a linear correlation with the dose.. TAS-108 was well tolerated in the doses studied with no maximum tolerated dose. The drug has linear pharmacokinetics, and in this heavily treated patient population, there was evidence of biological antitumor activity. A multi-institutional phase II study is planned.

Topics: Administration, Oral; Aged; Breast Neoplasms; Dose-Response Relationship, Drug; Estradiol; Female; Half-Life; Humans; Middle Aged; Neoplasm Metastasis; Postmenopause; Survival Analysis