A Phase II Trial Of Tipifarnib (R15777, ZARNESTRA) In Combination With Tamoxifen In Subjects With Metastatic Breast Cancer

OBJECTIVES:

• Determine the maximum tolerated dose and recommended phase II dose of tipifarnib administered with tamoxifen in women with hormone receptor-positive metastatic breast cancer (Phase I closed to accrual effective 10/23/2003).
• Determine the acute and chronic toxicity of this regimen in these patients.
• Determine the pharmacokinetics of this regimen in these patients.
• Determine the response rate and time to progression in patients treated with this regimen.

OUTLINE: This is an open-label study of tipifarnib (Phase I closed to accrual effective 10/23/2003). Patients are stratified according to benefit from prior hormonal therapy (yes vs no) (phase II).

• Phase I (closed to accrual effective 10/23/2003): Patients receive oral tipifarnib twice daily on days 1-21. Patients also receive oral tamoxifen daily on days 8-18 (during course I only) and on days 1-28 during all subsequent courses. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

Cohorts of 3-6 patients receive escalating doses of tipifarnib until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which at least 2 of 3 or 2 of 6 patients experience dose-limiting toxicity.