HealthyNCT00668902
Rapid Screening Phenotype Test To Evaluate CYP 2C19 Enzyme Activity Using Stable Isotope [13C]Pantoprazole
A study testing [13C]Pantoprazole in people with Healthy, run by Indiana University at 1 site in United States.
Trial summary
The purpose of this study is to determine the function of an enzyme that breaks down drugs and helps the removal of drugs from your body. This enzyme is called cytochrome P450 2C19 and is located in your liver. Read more about this study
- Who is it for?
- Ages 18 to 49 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- [13C]Pantoprazole
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteUnited States
- Study dates
- Mar 2007to Jan 2009
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 49 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Asian male or female subjects between 18 and 49 years of age, who are in good physical health with no significant medical problems or laboratory test abnormalities. Subjects should have normal liver and kidney function.
- Subjects with BMI <30 which will be determined by Metropolitan height and weight tables. Subjects must weigh at least 110 pounds.
- Subjects must agree to refrain from taking any prescription and over-the-counter medications, as well as any herbal medications one week before the start of the study and during the study period.
- Subjects must agree to refrain from consuming alcohol 48 hours before the start of the study and during the study period.
- Subjects must be capable of satisfying protocol requirements and be able to sign written informed consent.
Who cannot join
- Subjects who have a history of intolerance or allergy to the study drug: pantoprazole.
- Subjects who have donated blood within the last 60 days of the screening visit or plan to donate blood during the course of the study or within 60 days after study completion.
- Subjects who have had treatment with any investigational drug within the past 30 days.
- Subjects who have used illegal drugs within three months prior to enrollment.
- Female subjects currently taking oral contraceptive birth control pills and who are unwilling or unable to stop oral contraceptives and use a barrier contraceptive method (such as condom, contraceptive foams, etc.) starting from the time of screening phase to the completion of the study.
- Female subjects who are pregnant or lactating.
- Subjects who are unreliable in the opinion of the study physician.
Trial locations and contacts
1 site in 1 country.
About this study
The purpose of this study is to determine the function of an enzyme that breaks down drugs and helps the removal of drugs from your body. This enzyme is called cytochrome P450 2C19 and is located in your liver. Exposure to other medications or variations in genes that you have inherited from your parents, may speed up or slow the function of this enzyme. As a result, some patients may develop unwanted effects from a drug while some other patients may not get benefit from taking the same drug. The aim of this study is to determine the function of this enzyme in your liver. We will do this by performing a series of breath tests and blood samples after you take pantoprazole. Pantoprazole is approved as an oral and intravenous drug by the Food and Drug Administration (FDA).
Read the detailed description
The goal of this study is to develop a quick and reliable method that will diagnose hepatic CYP2C19 function and could be used routinely in clinical practice. Specifically, we propose to test pantoprazole - 13C as a probe for determining CYP2C19 phenotype. Pantoprazole, 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridyl)-methyl]sulfinyl]-1H -benzimidazole, is a substituted benzimidazole sulfoxide and a selective and long-acting proton pump inhibitor. This drug is widely used clinically in the treatment of severe gastroesophageal reflux disease, and for treatment of duodenal and gastric ulceration. Pantoprazole is extensively metabolized in the liver, with almost 80% of an oral or intravenous dose is excreted as metabolites in urine. The main metabolite is formed by O-demethylation at the 4-position of the pyridine ring by CYP2C19, followed by conjugation with sulphate (M2), while pantoprazole sulfone formed by CYP3A represents a minor metabolic pathway(20). The critical role of CYP2C19 in the in vivo clearance of the drugs is further demonstrated by the fact that healthy volunteers that are PMs of this enzyme achieve approximately 6-fold higher pantoprazole exposure than those who are extensive metabolizers of CYP2C19(20). This concept proposal exploits the use of the 13C-label that is incorporated at the O-methyl site of pantoprazole, which specifically designed for the CYP2C19-mediated O-demethylation (Figure 1). Then, during catalysis, CYP2C19-pantoprazole reaction in the liver results in the release of 13CO2 which is then eliminated from the body via the lung expired breath. The subsequent quantification of 13CO2 allows indirect determination of the hepatic CYP2C19 enzyme and thus the pharmacokinetics of its substrates. The salient features of the 13C-breath test means that this test would be non-invasive, non-radioactive, safe and simple. The protocol in general can be performed rapidly (one hour or less after pantoprazole administration) and can be determined directly at the point of care (e.g., hospitals and physicians' offices) using relatively inexpensive instrumentation (UBiT-IR300IR spectrometer; Meretek), and patients do not require waiting for hours or days for diagnostic results. This test may be particularly important to probe the activity of CYP2C19 for infants, children, pregnant and lactating women, seniors averse to the use of needles or in poor health and subjects scared of blood draws.
- Conditions
- Healthy
- Being tested
- [13C]Pantoprazole
- Keywords
- CYP2C19, Pantoprazole, Genotype, Pharmacokinetics, Metabolism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
[13C]PantoprazoleDrug
Also called Breath test
[13C]Pantoprazole was administered to EM, IM and PM of CYP2C19 and enzyme activity was measured through breath test and compared among the genotypes
| Study group | Role | What they receive |
|---|---|---|
| EM of CYP2C19 | Experimental | CYP2C19 enzyme activity in extensive metabolizers of CYP2C19 (CYP2C19*1/*1 genotype, or wild type) was measured by 13C)Pantoprazole breath test. Receives: Drug: [13C]Pantoprazole |
| IM of CYP2C19 | Experimental | CYP2C19 activity in heterozygous for deficient CYP2C19 alleles (*2 and *3, IM of CYP2C19) was measured by (13C)Pantoprazole breath test. Receives: Drug: [13C]Pantoprazole |
| PM of CYP2C19 | Experimental | Homozygous for CYP2C19 null alleles (*2/*2, *2/*3 or *3/*3, Poor metabolizers) was measured by (13C)Pantoprazole breath test. Receives: Drug: [13C]Pantoprazole |
What is being measured
The primary outcome is the main question the study is designed to answer.
DOBmax (Maximum Value of DOB)
The stable isotope [13C]pantoprazole is O-demethylated by cytochrome P450 CYP2C19 and that the 13CO2 produced and exhaled in breath as a result can serve as a safe, rapid, and noninvasive phenotyping marker of CYP2C19 activity in vivo.
Exhaled 13CO2 and 12CO2 were measured by IR spectroscopy before (baseline) and 2.5 to 120 min after dosing. Ratios of 13CO2/12CO2 after [13C]pantoprazole relative to 13CO2/12CO2 at baseline were expressed as change over baseline (DOB).
Measured: baseline and 2.5, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, and 120 min after dosing
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Apr 2008 (estimated)
- Study startMar 2007
- Primary completionDec 2008
- Study completionJan 2009
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 25 participants (actual)
Sponsor and investigators
- Lead sponsor
- Indiana University
- Sponsor type
- University, hospital or other
- Collaborators
- Sponsor Name Pending
- Responsible party
- Principal investigator, Zeruesenay Desta, Indiana University
- Investigators
- Zeruesenay Desta, PhD, Principal investigator, Indiana University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00668902
- Sponsor's protocol ID
- 0611-07
- Status last verified
- Dec 2014
- First submitted
- 17 Jan 2008
- Last updated
- 17 Dec 2014
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
Publications
Desta Z, Zhao X, Shin JG, Flockhart DA. Clinical significance of the cytochrome P450 2C19 genetic polymorphism. Clin Pharmacokinet. 2002;41(12):913-58. doi: 10.2165/00003088-200241120-00002.
PubMed 12222994Goldstein JA. Clinical relevance of genetic polymorphisms in the human CYP2C subfamily. Br J Clin Pharmacol. 2001 Oct;52(4):349-55. doi: 10.1046/j.0306-5251.2001.01499.x.
PubMed 11678778De Morais SM, Wilkinson GR, Blaisdell J, Meyer UA, Nakamura K, Goldstein JA. Identification of a new genetic defect responsible for the polymorphism of (S)-mephenytoin metabolism in Japanese. Mol Pharmacol. 1994 Oct;46(4):594-8.
PubMed 7969038de Morais SM, Wilkinson GR, Blaisdell J, Nakamura K, Meyer UA, Goldstein JA. The major genetic defect responsible for the polymorphism of S-mephenytoin metabolism in humans. J Biol Chem. 1994 Jun 3;269(22):15419-22.
PubMed 8195181Ibeanu GC, Blaisdell J, Ghanayem BI, Beyeler C, Benhamou S, Bouchardy C, Wilkinson GR, Dayer P, Daly AK, Goldstein JA. An additional defective allele, CYP2C19*5, contributes to the S-mephenytoin poor metabolizer phenotype in Caucasians. Pharmacogenetics. 1998 Apr;8(2):129-35. doi: 10.1097/00008571-199804000-00006.
PubMed 10022751Ibeanu GC, Goldstein JA, Meyer U, Benhamou S, Bouchardy C, Dayer P, Ghanayem BI, Blaisdell J. Identification of new human CYP2C19 alleles (CYP2C19*6 and CYP2C19*2B) in a Caucasian poor metabolizer of mephenytoin. J Pharmacol Exp Ther. 1998 Sep;286(3):1490-5.
PubMed 9732415Ferguson RJ, De Morais SM, Benhamou S, Bouchardy C, Blaisdell J, Ibeanu G, Wilkinson GR, Sarich TC, Wright JM, Dayer P, Goldstein JA. A new genetic defect in human CYP2C19: mutation of the initiation codon is responsible for poor metabolism of S-mephenytoin. J Pharmacol Exp Ther. 1998 Jan;284(1):356-61.
PubMed 9435198Sim SC, Risinger C, Dahl ML, Aklillu E, Christensen M, Bertilsson L, Ingelman-Sundberg M. A common novel CYP2C19 gene variant causes ultrarapid drug metabolism relevant for the drug response to proton pump inhibitors and antidepressants. Clin Pharmacol Ther. 2006 Jan;79(1):103-13. doi: 10.1016/j.clpt.2005.10.002.
PubMed 16413245
Study at a glance
From the registry record, last updated by the sponsor on 17 Dec 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Rapid Screening Phenotype Test To Evaluate CYP 2C19 Enzyme Activity Using Stable Isotope [13C]Pantoprazole
- ClinicalTrials.gov ID
- NCT00668902
- Acronym / sponsor ID
- 0611-07
- Conditions
- Healthy
- Keywords
- CYP2C19, Pantoprazole, Genotype, Pharmacokinetics, Metabolism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 25 participants (actual)
- Lead sponsor
- Indiana UniversityUniversity, hospital or other
- Collaborators
- Sponsor Name Pending
- Study start
- Mar 2007
- Primary completion
- Dec 2008 (actual)
- Study completion
- Jan 2009 (actual)
- First posted
- 29 Apr 2008 (estimated)
- Results
- Posted 17 Dec 2014
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine the function of an enzyme that breaks down drugs and helps the removal of drugs from your body. This enzyme is called cytochrome P450 2C19 and is located in your liver. Exposure to other medications or variations in genes that you have inherited from your parents, may speed up or slow the function of this enzyme. As a result, some patients may develop unwanted effects from a drug while some other patients may not get benefit from taking the same drug. The aim of this study is to determine the function of this enzyme in your liver. We will do this by performing a series of breath tests and blood samples after you take pantoprazole. Pantoprazole is approved as an oral and intravenous drug by the Food and Drug Administration (FDA).
Detailed description
The goal of this study is to develop a quick and reliable method that will diagnose hepatic CYP2C19 function and could be used routinely in clinical practice. Specifically, we propose to test pantoprazole - 13C as a probe for determining CYP2C19 phenotype. Pantoprazole, 5-(difluoromethoxy)-2-[[(3,4-dimethoxy-2-pyridyl)-methyl]sulfinyl]-1H -benzimidazole, is a substituted benzimidazole sulfoxide and a selective and long-acting proton pump inhibitor. This drug is widely used clinically in the treatment of severe gastroesophageal reflux disease, and for treatment of duodenal and gastric ulceration. Pantoprazole is extensively metabolized in the liver, with almost 80% of an oral or intravenous dose is excreted as metabolites in urine. The main metabolite is formed by O-demethylation at the 4-position of the pyridine ring by CYP2C19, followed by conjugation with sulphate (M2), while pantoprazole sulfone formed by CYP3A represents a minor metabolic pathway(20). The critical role of CYP2C19 in the in vivo clearance of the drugs is further demonstrated by the fact that healthy volunteers that are PMs of this enzyme achieve approximately 6-fold higher pantoprazole exposure than those who are extensive metabolizers of CYP2C19(20). This concept proposal exploits the use of the 13C-label that is incorporated at the O-methyl site of pantoprazole, which specifically designed for the CYP2C19-mediated O-demethylation (Figure 1). Then, during catalysis, CYP2C19-pantoprazole reaction in the liver results in the release of 13CO2 which is then eliminated from the body via the lung expired breath. The subsequent quantification of 13CO2 allows indirect determination of the hepatic CYP2C19 enzyme and thus the pharmacokinetics of its substrates. The salient features of the 13C-breath test means that this test would be non-invasive, non-radioactive, safe and simple. The protocol in general can be performed rapidly (one hour or less after pantoprazole administration) and can be determined directly at the point of care (e.g., hospitals and physicians' offices) using relatively inexpensive instrumentation (UBiT-IR300IR spectrometer; Meretek), and patients do not require waiting for hours or days for diagnostic results. This test may be particularly important to probe the activity of CYP2C19 for infants, children, pregnant and lactating women, seniors averse to the use of needles or in poor health and subjects scared of blood draws.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| EM of CYP2C19 | Experimental | Drug: [13C]PantoprazoleCYP2C19 enzyme activity in extensive metabolizers of CYP2C19 (CYP2C19*1/*1 genotype, or wild type) was measured by 13C)Pantoprazole breath test. |
| IM of CYP2C19 | Experimental | Drug: [13C]PantoprazoleCYP2C19 activity in heterozygous for deficient CYP2C19 alleles (*2 and *3, IM of CYP2C19) was measured by (13C)Pantoprazole breath test. |
| PM of CYP2C19 | Experimental | Drug: [13C]PantoprazoleHomozygous for CYP2C19 null alleles (*2/*2, *2/*3 or *3/*3, Poor metabolizers) was measured by (13C)Pantoprazole breath test. |
Who may qualify
- Ages
- 18 to 49 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Asian male or female subjects between 18 and 49 years of age, who are in good physical health with no significant medical problems or laboratory test abnormalities. Subjects should have normal liver and kidney function.
- Subjects with BMI <30 which will be determined by Metropolitan height and weight tables. Subjects must weigh at least 110 pounds.
- Subjects must agree to refrain from taking any prescription and over-the-counter medications, as well as any herbal medications one week before the start of the study and during the study period.
- Subjects must agree to refrain from consuming alcohol 48 hours before the start of the study and during the study period.
- Subjects must be capable of satisfying protocol requirements and be able to sign written informed consent.
Key exclusion criteria (7 listed)
- Subjects who have a history of intolerance or allergy to the study drug: pantoprazole.
- Subjects who have donated blood within the last 60 days of the screening visit or plan to donate blood during the course of the study or within 60 days after study completion.
- Subjects who have had treatment with any investigational drug within the past 30 days.
- Subjects who have used illegal drugs within three months prior to enrollment.
- Female subjects currently taking oral contraceptive birth control pills and who are unwilling or unable to stop oral contraceptives and use a barrier contraceptive method (such as condom, contraceptive foams, etc.) starting from the time of screening phase to the completion of the study.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| [13C]PantoprazoleAlso: Breath test[13C]Pantoprazole was administered to EM, IM and PM of CYP2C19 and enzyme activity was measured through breath test and compared among the genotypes | Drug | EM of CYP2C19, IM of CYP2C19, PM of CYP2C19 |
Primary outcome
DOBmax (Maximum Value of DOB)
Time frame: baseline and 2.5, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, and 120 min after dosing
The stable isotope [13C]pantoprazole is O-demethylated by cytochrome P450 CYP2C19 and that the 13CO2 produced and exhaled in breath as a result can serve as a safe, rapid, and noninvasive phenotyping marker of CYP2C19 activity in vivo. Exhaled 13CO2 and 12CO2 were measured by IR spectroscopy before (baseline) and 2.5 to 120 min after dosing. Ratios of 13CO2/12CO2 after [13C]pantoprazole relative to 13CO2/12CO2 at baseline were expressed as change over baseline (DOB).
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 17 Dec 2014.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Background: PubMed 12222994Desta Z, Zhao X, Shin JG, Flockhart DA. Clinical significance of the cytochrome P450 2C19 genetic polymorphism. Clin Pharmacokinet. 2002;41(12):913-58. doi: 10.2165/00003088-200241120-00002.
- Background: PubMed 11678778Goldstein JA. Clinical relevance of genetic polymorphisms in the human CYP2C subfamily. Br J Clin Pharmacol. 2001 Oct;52(4):349-55. doi: 10.1046/j.0306-5251.2001.01499.x.
- Background: PubMed 7969038De Morais SM, Wilkinson GR, Blaisdell J, Meyer UA, Nakamura K, Goldstein JA. Identification of a new genetic defect responsible for the polymorphism of (S)-mephenytoin metabolism in Japanese. Mol Pharmacol. 1994 Oct;46(4):594-8.
- Background: PubMed 8195181de Morais SM, Wilkinson GR, Blaisdell J, Nakamura K, Meyer UA, Goldstein JA. The major genetic defect responsible for the polymorphism of S-mephenytoin metabolism in humans. J Biol Chem. 1994 Jun 3;269(22):15419-22.
- Background: PubMed 10022751Ibeanu GC, Blaisdell J, Ghanayem BI, Beyeler C, Benhamou S, Bouchardy C, Wilkinson GR, Dayer P, Daly AK, Goldstein JA. An additional defective allele, CYP2C19*5, contributes to the S-mephenytoin poor metabolizer phenotype in Caucasians. Pharmacogenetics. 1998 Apr;8(2):129-35. doi: 10.1097/00008571-199804000-00006.
- Background: PubMed 9732415Ibeanu GC, Goldstein JA, Meyer U, Benhamou S, Bouchardy C, Dayer P, Ghanayem BI, Blaisdell J. Identification of new human CYP2C19 alleles (CYP2C19*6 and CYP2C19*2B) in a Caucasian poor metabolizer of mephenytoin. J Pharmacol Exp Ther. 1998 Sep;286(3):1490-5.
- Background: PubMed 9435198Ferguson RJ, De Morais SM, Benhamou S, Bouchardy C, Blaisdell J, Ibeanu G, Wilkinson GR, Sarich TC, Wright JM, Dayer P, Goldstein JA. A new genetic defect in human CYP2C19: mutation of the initiation codon is responsible for poor metabolism of S-mephenytoin. J Pharmacol Exp Ther. 1998 Jan;284(1):356-61.
- Background: PubMed 16413245Sim SC, Risinger C, Dahl ML, Aklillu E, Christensen M, Bertilsson L, Ingelman-Sundberg M. A common novel CYP2C19 gene variant causes ultrarapid drug metabolism relevant for the drug response to proton pump inhibitors and antidepressants. Clin Pharmacol Ther. 2006 Jan;79(1):103-13. doi: 10.1016/j.clpt.2005.10.002.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Zeruesenay Desta, PhD principal investigator
Indiana University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing [13C]Pantoprazole in people with Healthy, run by Indiana University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 17 Dec 2014. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 17 Dec 2014). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
DOBmax (Maximum Value of DOB) (time frame: baseline and 2.5, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90, and 120 min after dosing). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00668902, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Dec 2014.