Tailored Treatment of H. Pylori Infection Based Polymorphisms of CYP2C19 and 23S rRNA of H. Pylori

September 8, 2006 updated by: Hamamatsu University

Pharmacogenomics-Based Tailor-Made Strategy for Eradication of Helicobacter Pylori

The eradication rate of the standard H. pylori eradication therapy (such as the triple therapy with a proton pump inhibitor [PPI], amoxicillin and clarithromycin) depends on bacterial susceptibility to clarithromycin and genotypes of CYP2C19 in patients. The investigators intend to investigate whether the tailored therapy based on the two above-mentioned factors increases the cure rate of the initial eradication therapy.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Current treatment strategies for the eradication of H. pylori include a proton pump inhibitor (PPI) and one or two anti-bacterial agents, such as amoxicillin, clarithromycin, and metronidazole.

PPIs, such as lansoprazole and omeprazole, are mainly metabolized in the liver by a genetically determined enzyme, S-mephenytoin 4'-hydroxylase (CYP2C19). Plasma concentrations of PPIs and their activity for acid inhibition depend to a significant extent on the genetic differences in the activity of this enzyme. The acid inhibition attained by the standard dose of a PPI is sometimes therapeutically insufficient in individuals with the rapid extensive metabolizer (RM) genotype of CYP2C19, whereas that in individuals with poor metabolizer (PM) genotype of CYP2C19 is in most cases clinically sufficient. We have reported that the CYP2C19 genotype status is one of the determinants of H. pylori eradication therapy. In the triple therapy with a PPI, amoxicillin, and clarithromycin, bacterial susceptibility to clarithromycin as well as the CYP2C19 genotype status was significantly related to eradication rates of H. pylori. Therefore, the tailored treatment based on these two factors is expected to increase the eradication rates of the initial therapy.

Interestingly, both of CYP2C19 genotypes and bacterial susceptibility to clarithromycin can be measured by the genetic test of the single nucleotide polymorphisms (SNPs) of the CYP2C19 gene and the 23S rRNA gene of H. pylori, respectively. We have recently developed the inexpensive and reliable high-throughput method for measurement of such SNPs by the invader assay. Polymorphisms of CYP2C19 of patients and mutations of 23S rRNA of H. pylori associated with susceptibility to clarithromycin can be detected from the gastric tissue samples infected with H. pylori, such as the gastric tissue sample already used for rapid urease test (RUT).

Then, we treat H. pylori-positive patients by the tailored regimen based on genotypes of CYP2C19 of patients and 23S rRNA of H. pylori or the standard regimen and test the therapeutic efficacy of this pharmacogenomics-based tailored strategy in a prospective manner.

Patients were randomly assigned to the standard or tailored regimen group with the use of a computer-generated randomization list based on a blocked randomization method.

Patients assigned to the standard regimen group were treated with 30 mg of lansoprazole bid, 400 mg of clarithromycin bid, and 750 mg of amoxicillin bid for one week, which had been approved under the Japanese formulary regulation regardless of any pharmacogenomic backgrounds of H. pylori-infected peptic ulcer patients.

In the tailored regimen group, patients infected with a clarithromycin-sensitive strain of H. pylori are treated with triple therapy consisting of clarithromycin 200 mg tid, amoxicillin 500 mg tid and the individualized doses of lansoprazole dose (i.e., 30 mg tid in RMs, 15 mg tid in IMs, and 15 mg bid in PMs) for one week, while patients infected with a clarithromycin-resistant strain of H. pylori are treated with dual therapy consisting of amoxicillin 500 mg qid and the individualzed dose of lansoprazole (i.e., 30 mg qid in RMs, 15 mg qid in IMs, and 15 mg bid in PMs) for two weeks.

Study Type

Interventional

Enrollment

296

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Japan
    • Shizuoka
      • Hamamatsu, Shizuoka, Japan, 431-3192
        • Recruiting
        • Hamamatsu University School of Medicine
        • Contact:
        • Principal Investigator:
          • Takahisa Furuta, MD, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

15 years to 90 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with H. pylori infection

Exclusion Criteria:

  • Patients without H. pylori infection

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Whether the tailored treatment yields a higher eradication rate in comparison with the standard treatment

Secondary Outcome Measures

Outcome Measure
Cost-effectiveness of the tailored strategy

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hamamatsu University

Collaborators

Yokoyama Foundation for Clinical Pharmacology

Investigators

  • Study Chair: Takahisa Furuta, MD, PhD, Center for Clinical Research, Hamamatsu University School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

April 1, 2003

Study Registration Dates

First Submitted

September 6, 2005

First Submitted That Met QC Criteria

September 6, 2005

First Posted (Estimate)

September 8, 2005

Study Record Updates

Last Update Posted (Estimate)

September 11, 2006

Last Update Submitted That Met QC Criteria

September 8, 2006

Last Verified

September 1, 2005

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Hp.CYP.001

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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