CYP2C19 * This study has finished *
Full title: The Pharmacogenetic and Pathological Assessment of CYP2C19 Activity in Patients with Advanced Cancer as determined by omeprazole metabolism
Cancer type: Various
Status: Closed (33 participants recruited)
Brief description:


This study builds on our previous work looking at how the body “processes” cancer drugs. Many drugs are metabolised in the liver by enzymes of the cytochrome P450 family. The level of enzyme activity varies from person to person. This is important, as poor metabolism of some drugs may put some people at greater risk of side effects, while extensive metabolism may mean the drug does not work as well. Cyclophosphamide is an important anticancer drug that is metabolised by a liver enzyme called CYP2C19. About 3% of Caucasian populations are genetically poor metabolisers for CYP2C19. Our recent work suggested that people may actually lose CYP2C19 metabolism simply through the fact of having cancer. It is possible to measure CYP2C19 activity in an individual by giving them a small dose of a test drug such as proguanil. In this study we plan to see how CYP2C19 metabolism changes (i) between people with different amounts of cancer in their body and (ii) in individual people with cancer as time goes on and their cancer changes. The knowledge gained from this study will help us in future as we try to better tailor cancer drug doses to the individual.
Sites: ·        Auckland

·        Wellington

Lead Investigator: Assoc Professor Nuala Helsby
Contact: Sarah Benge (
Sponsor: Not applicable
Funder: Cancer Society
Trial Registry reference: ACTRN12605000393651 (click for more details)
Ethics number: NTX/05/07/083
Publications: NA Helsby, W-Y Lo, K Sharples, G Riley, M Murray, K Spells, M Dzhelai, A Simpson and M Findlay ‘CYP2C19 pharmacogenetics in advanced cancer: compromised function independent of genotype’ British Journal of Cancer (2008) 99, 1251 – 1255

This paper has been highlighted as a favourite paper on the NIH funded Pharmacogenetics and Pharmacogenomics Knowledge Base