title: Five-day infusion of fluorodeoxyuridine with high-dose oral leucovorin: a phase I study.
abstract: Fluorodeoxyuridine (FUdR) interferes with cellular metabolism by inhibiting thymidylate synthase. Therefore, we sought to modulate its activity with leucovorin (LV) and to identify the maximally tolerated dose given as a 5-day continuous intravenous infusion in combination with oral administration of LV at a dose of 100 mg every hour for four doses immediately preceding the start of the FUdR infusion and then every 4 h for the entire duration of FUdR treatment. Patients were evaluated at six FUdR dose levels ranging from 0.1 to 0.375 mg/kg per day. Severe or life-threatening mucositis was first observed in two of six patients treated at 0.25 mg/kg daily. Further escalation of the dose to 0.3 mg/kg per day resulted in grade 2 mucositis in four of six patients and in grade 3 mucositis in two cases. A dose of 0.375 mg/kg daily resulted in grade 3 toxicity in all three patients treated. Other types of toxicities included skin rash and hand-foot syndrome, but no hematologic toxicities were observed. Stable disease was observed in 11 of 24 evaluable patients, including 3 subjects with renal cell carcinoma. Our recommended dose for phase II trials is 0.3 mg/kg FUdR per day.
authors.affiliation: Department of Medicine, University of Chicago Pritzker School of Medicine, IL 60637.
authors.forename: E E
authors.initials: EE
authors.lastname: Vokes
authors.forename: J W
authors.initials: JW
authors.lastname: Raschko
authors.forename: N J
authors.initials: NJ
authors.lastname: Vogelzang
authors.forename: E E
authors.initials: EE
authors.lastname: Warfield
authors.forename: M J
authors.initials: MJ
authors.lastname: Ratain
authors.forename: J H
authors.initials: JH
authors.lastname: Doroshow
authors.forename: R L
authors.initials: RL
authors.lastname: Schilsky
mesh_terms: D000368:Aged; D004305:Dose-Response Relationship, Drug; D004341:Drug Evaluation; D004359:Drug Therapy, Combination; D005260:Female; D005467:Floxuridine / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007262:Infusions, Intravenous; D002955:Leucovorin / Q000008:administration & dosage* / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy*; D012074:Remission Induction; D013997:Time Factors
chemical_list: D005467:Floxuridine; D002955:Leucovorin