Abstract
6-Thioguanine (6-TG) is a purine analog that has marked variability in plasma concentration after oral administration. Following the development of a multiple-day i.v. regimen, we performed a phase II trial of this agent as first-line chemotherapy in women with metastatic breast cancer. Forty-one patients with measurable (31 patients) or evaluable (10 patients) disease were entered into this trial. 6-TG was administered i.v. over a 10 min period daily for 5 consecutive days, with a planned cycle length of 35 days. The daily dosage level was 55 mg/m2 in the first 15 patients, but this was increased to 65 mg/m2 in the remaining patients due to inadequate myelosuppression at the lower dose. Six patients, all with measurable disease, achieved a complete response (CR) (two patients) or a partial response (PR) (four patients). Three responses occurred at the 55 mg/m2 level and three at the 65 mg/m2 level. The 95% confidence interval (CI) for the true response rate among patients with measurable disease was 6-39%. The median time to progression was 140 days and median survival time was 460 days. The regimen was well tolerated. We conclude that 6-TG, as given in this study, has limited activity as first-line chemotherapy for women with metastatic breast cancer.
Original language | English (US) |
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Pages (from-to) | 69-72 |
Number of pages | 4 |
Journal | American Journal of Clinical Oncology: Cancer Clinical Trials |
Volume | 20 |
Issue number | 1 |
DOIs | |
State | Published - Feb 1997 |
Keywords
- 6-Thioguanine
- Chemotherapy
- Metastatic breast cancer
- Phase II clinical trial
ASJC Scopus subject areas
- Oncology
- Cancer Research