Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT00916786 |
Other study ID # |
200812153M |
Secondary ID |
|
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
August 1, 2009 |
Est. completion date |
July 31, 2012 |
Study information
Verified date |
September 2021 |
Source |
National Taiwan University Hospital |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
The ultimate goal of this study is to find the association between specific polymorphism of
candidate genes and medication response in attention deficit hyperactivity disorder (ADHD)
patients. These results will lead the investigators' team: (1) to resolve controversies over
inconsistent findings in previous pharmacogenetic studies; (2) to study the medication effect
on the neuropsychological functions that are useful candidate endophenotypes for ADHD; (3) to
delineate the nature and the effect of gene-gene interaction in the drug response of ADHD
patients.
Description:
Background: The science of pharmacogenetics seeks to identify patterns of genetic variation
that will direct individually tailored treatment regimens and enhance long-term adherence.
Attention deficit hyperactivity disorder (ADHD), characterized by inattention, hyperactivity
and impulsivity, is an early onset, highly heritable, clinically heterogeneous, long-term
impairing disorder with tremendous impact on individuals, families, and societies. It affects
5-10% of school-aged children worldwide (7.5% in Taiwan) and 2-4% of adults. Although the
efficacy of medications for ADHD is well demonstrated in clinical trials, substantial numbers
of patients fail to remain on therapy, and there is tremendous variability in tolerability
and treatment acceptance. An understanding of genetic predictors of ADHD medication response
is likely to influence future clinical treatments, inform research on treatment-resistant
ADHD patients, and identify patients at increased risk for significant treatment related
adverse events. Although interest in ADHD pharmacogenetics is encouraging, conflicting
results in previous studies may reflect genetic heterogeneity and differences in phenotype,
and medication response in ADHD children likely results from the combined effects of several
potential genes. In addition, the categorical measure of treatment effects and retrospective
study design may not have been sensitive enough to pick up statistically significant
differences in treatment response based on genotype. Further prospective studies including
quantitative measures of medication response are warranted.
Specific Aims:
1. to assess the specific genetic moderators of methylphenidate and atomoxetine response
using repeated outcome measurements;
2. to examine the association between genetic polymorphisms and medication effects on the
neuropsychological functions;
3. to identify the gene-gene interactions in pharmacogenetics for ADHD. Subjects and
Methods: We will recruit 160 drug-naïve ADHD patients and 80 matched normal controls,
aged 7-18. The patients will be randomly assigned to two treatment groups, the
OROS-methylphenidate group (n=80) and the atomoxetine group (n=80), respectively. After
complete assessment at baseline and administration of either OROs-methylphenidate or
atomoxetine, patients with ADHD will be reassessed at Week 2, 4, 8, 12, 16, and 24
mainly for vital signs, behavioral symptoms, and psychosocial functions evaluations
using the SNAP-IV, YSR, CBCL, CGI-ADHD-S, CGI-ADHD-I, SAICA, and Family APGAR-C.
Neuropsychological tests, including CPT, Time Perception Tasks, and CANTAB, will be
performed at Week 4 and 16. The DNA will be collected, and the candidate genes (DAT1,
DRD4, DRD5, SLC6A2, and SLC6A4) hypothesized to influence medication effects or
individual risks for ADHD will be genotyped.
Anticipated Results: We anticipate that this study will delineate the pharmacogenetics for
ADHD by determining the association between medication response and genetic variants in a
Taiwanese sample. The findings of different approaches to identify the effects of genotypes
on the drug response in this study should help us to extend our understanding of the genetic
basis of ADHD. Development of individualized medication regimens based on patient genetic
variability might lead to optimized symptom reduction, improved tolerability, and concomitant
improvements in patient adherence. Conversely, patients with increased genetic risk for
treatment failure or significant adverse effects could be spared exposure to certain
compounds that are of unlikely benefit. Pharmacogenetics also has a potential role in the
development of new compounds for ADHD therapy. The use of genetic screening in dosing will
provide a model for future drug development, in which outcome variability is assessed in
genetic subgroups and not merely on the basis of treatment assignment.