A Phase I Clinical Trial to Investigate the Correlation Between UGT1A1 Genotype and Irinotecan (CPT-11) Pharmacokinetics and Toxicity in Cancer Patients

OBJECTIVES: I. Classify patients with solid tumors or lymphoma according to UGT1A1 promoter (TATA box) and coding region (Gly71Arg) mutation, and CYP3A4 promoter (G to A) polymorphisms. II. Identify UGT1A1 enzyme glucuronidator and irinotecan oxidizer phenotypes in these patients and determine the correlation between the two metabolic reactions in vivo. III. Determine the relationship between UGT1A1 genotype (promoter and/or coding region mutation) and CYP3A4 promoter genotype vs gastrointestinal or bone marrow toxicity, and pharmacokinetics of irinotecan in these patients. IV. Determine the pharmacokinetics of irinotecan in these patients. OUTLINE: Patients are genotyped for UGT1A1 enzyme and classified as "Gilbert's" (7/7), "heterozygotes" (6/7), and "homozygotes for allele 6" (6/6). The DNA is analyzed for the UGT1A1 coding region mutation (Gly71Arg) and CYP3A4 promoter polymorphism. Patients are also examined for glucuronidator ratio of SN-38, the active metabolite of irinotecan, and classified as "low/slow" (very low or zero SN-38G/SN-38 ratio), "intermediate" (less than 50% normal ratio), or "normal". Patients receive irinotecan IV over 90 minutes once every 3 weeks. Treatment continues for at least 2 courses in the absence of disease progression or unacceptable toxicity.