A Phase I Study to Determine Biological Endpoints of Up to 21 Day Dosing of the Farnesyltransferase Inhibitor R115777 (IND# 52,302) for Refractory and Relapsed Adult Leukemias (Summary Last Modified 9/1999)

OBJECTIVES: I. Determine toxicities and pharmacokinetics of oral R115777 in adults with refractory acute leukemia or accelerated or blastic phase chronic myelogenous leukemia. II. Determine the effect of R115777 on farnesylation within leukemia cells. III. Determine any clinical response (at least 50% decrease in circulating leukemia cells) to R115777 by these patients.

OUTLINE: This is a dose escalation, multicenter study. Patients receive oral R115777 for 7-21 days. Patients who achieve complete response (CR) or partial response (PR) following 1-4 courses of treatment may receive up to 4 additional courses. Patients with stable disease may receive another 7-21 day course. If CR or PR is then achieved, patients may receive up to 4 additional courses. Cohorts of 6-12 patients receive escalating doses of R115777 until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose at which between 17% and 33% of patients experience dose limiting toxicity.

PROJECTED ACCRUAL: A total of 24 patients will be accrued for this study within 2 years.