Phase I study of 5-day continuous infusion fluorodeoxyuridine and high-dose folinic acid with oral hydroxyurea.

Journal Article (Clinical Trial;Journal Article)

Fluorodeoxyuridine (FUdR), the deoxynucleoside metabolite of 5-fluorouracil (5-FU), can be converted in a single step to fluorodeoxyuridine monophosphate (FdUMP), which binds covalently to thymidylate synthase (TS). Ribonucleotide reductase, an obligatory enzyme in the synthesis of deoxynucleotides, can be inhibited by hydroxyurea. Recognizing the well-established synergism between 5-FU and folinic acid (leucovorin), we hypothesized that the simultaneous administration of FUdR, leucovorin, and hydroxyurea might afford more effective inhibition of TS. Thirty-six patients with neoplastic disease considered refractory to standard therapy were entered into this phase I protocol. Treatment was administered on days 1 through 5 of a 28-day cycle and consisted of folinic acid (500 mg m-2 day-1) and FUdR at escalating doses of 0.1, 0.15, or 0.2 mg kg-1 day-1 both administered by continuous i.v. infusion, and hydroxyurea given p.o. once per day at doses ranging from 0 to 250o mg in 500-mg increments. The hydroxyurea and FUdR levels were escalated in a sequential fashion. The majority of patients had refractory breast or lung cancer. Dose-limiting toxicities were mucositis and diarrhea at the maximally tolerated dose of 0.15 mg/kg FUdR and 2000 mg hydroxyurea per day in conjunction with high-dose folinic acid. Hematological toxicity was minor. Of the 18 patients in whom response could be evaluated, none had evidence of objective disease regression. Mucositis and diarrhea are the dose-limiting toxicities when continuous infusions of FUdR and high-dose folinic acid are combined with oral hydroxyurea, effects that are consistent with the observed toxicities for FUdR when administered alone or in combination with leucovorin.

Full Text

Duke Authors

Cited Authors

  • Raschko, JW; Akman, SA; Leong, LA; Margolin, KA; Morgan, RJ; Newman, E; Somlo, G; Ahn, C; Doroshow, JH

Published Date

  • 1994

Published In

Volume / Issue

  • 35 / 2

Start / End Page

  • 161 - 164

PubMed ID

  • 7987994

International Standard Serial Number (ISSN)

  • 0344-5704

Digital Object Identifier (DOI)

  • 10.1007/BF00686640


  • eng

Conference Location

  • Germany