Pharmacology-driven Dosing of Fluoropyrimidines in Cancer Patients — FLOXTOX2  

Colorectal Cancer Clinical Trial

Official title: Pharmacogenetics and Therapeutic Drug Monitoring for the Optimization of Fluoropyrimidine Treatment in Patients With Advanced Colorectal Cancer

Status Completed

Clinical Trial Summary

The fluoropyrimidines 5-fluorouracil (5FU) and capecitabine (Cp) are among the most commonly used anticancer drugs. Still, there is much controversy about the correct dosing, and the fact that a minority of patients experience severe, sometimes even lethal toxicity following treatment. One important factor predisposing patients to severe toxicity is deficiency in the 5FU-catabolic enzyme dihydropyrimidine dehydrogenase (DPD). Our group identified 4 DPD risk alleles in over 300 Swiss cancer patients, that resulted in a 8-times increased risk of experiencing severe toxicity from 5FU or Cp. In patients receiving 5FU as a continuous infusion, there are accumulating data that keeping the AUC of 5FU between 20-30 mg*h/L is beneficial in terms of treatment toxicity and activity. In this study, patients carrying at least 1/4 DPD risk alleles will receive a 50% dose reduction of either 5FU or Cp, with the potential of later dose increases in the abscence of severe toxicity. Additionally, patients receiving i.v. 5FU will undergo therapeutic drug monitoring at the end of the 2-day continuous infusion, with subsequent dose adaptations to target a 5FU AUC of 20-30 mg*h/L. The primary study objective is to reduce the incidence of severe treatment-related toxicity from 13% (in historical controls) to 5% in study patients.

Clinical Trial Description

n/a

Study Design

Endpoint Classification: Safety Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Colorectal Cancer
• Colorectal Neoplasms

• NCT number: NCT01641458
• Study type: Interventional
• Source: Cantonal Hospital of St. Gallen
• Status: Completed
• Phase: Phase 4
• Start date: October 2012
• Completion date: November 2015