This randomized phase I trial is studying the side effects and best dose of O(6)-benzylguanine when given together with ifosfamide and to see how well it works compared to ifosfamide alone in treating patients with unresectable metastatic solid tumors. Drugs used in chemotherapy, such as ifosfamide and O(6)-benzylguanine, work in different ways to stop tumor cells from dividing so they stop growing or die. Combining ifosfamide with O(6)-benzylguanine may kill more tumor cells
PRIMARY OBJECTIVES: I. Determine the maximum tolerated dose of O6-benzylguanine when administered with standard high-dose ifosfamide in patients with unresectable, metastatic solid tumors. II. Determine whether O6-benzylguanine enhances ifosfamide-mediated myelosuppression in patients treated with this regimen. III. Determine the relationship between O6-benzylguanine dose and intra-individual variability in the degree of myelosuppression in patients treated with this regimen. IV. Determine the safety and toxicity of this regimen in these patients. SECONDARY OBJECTIVES: I. Determine the effect of O6-benzylguanine on pharmacodynamic endpoints, including apoptosis and DNA damage, in patients treated with this regimen. II. Determine the pharmacokinetics of O6-benzylguanine and its major metabolite, 8-oxoBG, in patients treated with this regimen. OUTLINE: This is a randomized, open-label, multicenter, dose-escalation study of O6-benzylguanine. Course 1: All patients receive high-dose ifosfamide IV continuously over 72 hours on days 1-3. Course 2: Patients are randomized to 1 of 2 treatment arms. Arm I: Patients receive high-dose ifosfamide as in course 1. Arm II: Patients receive a bolus dose of O6-benzylguanine (BG) IV over 1 hour on day 1 followed by BG IV continuously and high-dose ifosfamide IV continuously over 72 hours on days 1-3. Cohorts of 6-12 patients receive escalating doses of BG (administered as a bolus and as a continuous infusion during course 2) until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 3 of 6 or 4 of 12 patients experience dose-limiting toxicity. Course 3 and all subsequent courses: All patients receive BG (at the MTD determined in course 2, arm II) and high-dose ifosfamide as in course 2, arm II. In all courses, all patients also receive filgrastim (G-CSF) beginning on day 5 and continuing until blood counts recover. In all courses and in both arms, treatment repeats every 21 days in the absence of disease progression or unacceptable toxicity.
Study Type
INTERVENTIONAL
Allocation
Given IV
Given IV
University of Chicago Comprehensive Cancer Center
Chicago, Illinois, United States
Change in degree of myelosuppression (thrombocytopenia and neutropenia) quantified by both duration of neutropenia and severity of neutropenia
Time frame: Baseline up to 1 year
Maximum tolerated dose (MTD) of O6-benzylguanine defined as the dose preceding that at which 3 of 6 or 4 of 12 patients experience dose-limiting toxicity
DLT is defined as any \>= grade 3 non-hematologic toxicity, grade 4 thrombocytopenia, or prolonged neutropenia.
Time frame: 21 days
Pharmacodynamics including apoptosis and DNA damage
Time frame: Up to 1 year
Pharmacokinetics of O6-benzylguanine
Summarized using descriptive statistics (mean, median, standard deviation, and interquartile range). Estimated via nonlinear regression.
Time frame: Up to day 3 of course 2
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RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
32