Genotype Guided Antiplatelet Therapy in Ischemic Stroke
NCT ID: NCT05763862
Last Updated: 2024-11-15
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.
RECRUITING
NA
350 participants
INTERVENTIONAL
2023-04-24
2025-12-31
Brief Summary
Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.
Clopidogrel is one of the mainstays of antiplatelet secondary prevention therapy in patients with ischemic stroke. CYP2C19 loss of function (LOF) mutations impair the effectiveness of clopidogrel \[Ref 4\]. The prevalence of LOF mutations is approximately 60% in the local population \[Ref 5\], rendering the effectiveness of empiric clopidogrel treatment doubtful. For patients who have LOF mutations, other treatment options for secondary prevention of ischemic stroke need to be tested. This study aims to determine the feasibility and clinical impact of genetic testing guided antiplatelet therapy in ischemic stroke patients on the prevention of major adverse cardiovascular or cerebrovascular events.
Clopidogrel naive ischemic stroke or TIA patients aged 21 years and above will be randomised to genetic testing guided antiplatelet therapy or standard medical therapy within 7 days of their index event. Patients allocated to testing group will have blood sample drawn for diagnosis of CYP2C19 LOF mutations. Patients who test positive for an LOF mutation (intermediate and poor metabolisers) will be offered alternative antiplatelet therapy in the form of aspirn (for those who need monotherapy) or aspirin plus ticagrelor or dipyridamole (for those who need dual antiplatelet therapy) to be decided by the managing physician. Patients who test negative for LOF mutation will continue on clopidogrel. Platelet reactivity index (enables the identification of patients with an inadequate response to antiplatelet agents) will be measured at baseline.
Related Clinical Trials
Explore similar clinical trials based on study characteristics and research focus.
Optimal Regimen in Endovascular Therapy in Ischemic Cerebrovascular Disease Based on Clopidogrel Resistance
NCT01925872
Clopidogrel Preventive Effect Based on CYP2C19 Genotype in Ischemic Stroke
NCT04072705
The Influence of CYP2C19 Polymorphism and Clinical Outcomes in Stroke Patients
NCT02711410
Clopidogrel Response and CYP2C19 Genotype in Ischemic Stroke Patients
NCT03385538
Genotype Guided Comparison of Clopidogrel and Prasugrel Outcomes Study
NCT00995514
Detailed Description
Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.
The study will include three visits: Baseline (within 1 week of index event), 3 months, and 12 months. Randomisation will be performed for patients with unknown CYP2C19 status while no randomisation will be done for patients with known CYP2C19 status at the time of recruitment. Baseline visit will need to be in-person, whle the 3-month and 12-month follow-ups can either be inperson or via telephone. Data on antiplatelet regimen, MACCE outcomes, and GUSTO outcomes will be collected at the follow-up visits. Blood tests will be performed on the genetic testing guided antiplatelet therapy arm and standard medical therapy arm at baseline to determine the platelet reactivity index (PRI).
Patients with unknown CYP2C19 status will be randomised to genetic testing versus standard medical therapy in a 1:1 ratio, via a block randomisation process. The block randomisation sequence will be generated by a web-based randomisation service in blocks of four for each recruitment site. Blinding is not applicable for the treatment assigned.
Patients randomised to testing will have blood drawn for testing of the CYP2C19 LOF mutations. Physicians of patients who test positive for an LOF mutation (intermediate and poor metabolizers) will be notified of the mutation with recommendations of possible alternative antiplatelet regimens suggested. Aspirin will be the recommended monotherapy, and aspirin in combination with ticagrelor or dipyridamole will be the recommended dual antiplatelet regimen. The decision of alternative medications used in patients with LOF mutations will be left to the discretion of the primary physician. Patients in the standard medical therapy group, and patients in the genotype guided antiplatelet therapy group who do not have LOF mutations (normal metabolisers) will be left to continue the original intended antiplatelet regimen - this may be clopidogrel monotherapy, or in combination with aspirin. Patients who experience recurrent events during follow-up, or who have drug intolerance can be changed from the antiplatelet regimen as per primary physician's discretion. Information on all medications, including antiplatelet regimen at discharge and at subsequent reviews will be collected.
There will be no randomisation for patients with known CYP2C19 status prior to recruitment. Patients with known CYP2C19 status will be recruited as a comparison arm for outcomes measurements.
CYP2C19 genotyping will be performed by the Singapore General Hospital's clinical laboratory services. Turnaround time for CYP2C19 is approximately 7 days. Patient will be notified of CYP2C10 LOF mutation result.
Demographic characteristics that will be ascertained includes age, sex, ethnicity, education level, date of study randomisation. Past medical history will be recorded: hypertension, diabetes, hyperlipidemia, ischemic heart disease, atrial fibrillation, smoking, peripheral vascular disease, previous ischemic stroke/transient ischemic attack, intracranial bleeding, clinically significant bleeding, smoking and alcohol. Information pertaining to hospital admission, stroke characteristics, medications that the patients are on, particularly antiplatelet, anticoagulation, proton pump inhibitor, histamine H2 receptor antagonists, and cardiovascular medication prior to the admission and at discharge will be assessed. Use of single versus dual antiplatelet therapy, and duration of dual antiplatelet therapy will be considered confounders.
For subjects randomised to the standard medical therapy arm, genetic testing for CYP2C19 LOF mutations may be performed for clinical purpose after randomisation and before the end of subject's participation in the study, which could result in treatment changes. Such cases will not be considered as a protocol violation. These subjects will continue with treatment as per advised by the primary physician and may continue study follow ups till the end of the study.
If subjects are identified after randomisation to have cardioembolism or prothrombotic state necessitating the use of anticoagulation, the treating physician should manage as per standard medical care. These will not be considered as protocol violation as the diagnoses were made after randomisation. As these subjects will no longer be on antiplatelet therapy, there is no need to continue with study follow up and this will be deemed as withdrawn from study participation.
Subject may withdraw his/her consent from study participation voluntarily at any time without prejudice to him/her or effect on the subject's medical care.
The Principal Investigator may stop a subject's participation in the study at any time for justified reasons. If a subject withdraws voluntarily from participation in the study for any reason, the data that have been collected until the time of his/her withdrawal will be kept and analysed. The reason is to enable a complete and comprehensive evaluation of the study. Standard medical care will continue for all subjects who withdrew from the study.
Conditions
See the medical conditions and disease areas that this research is targeting or investigating.
Study Design
Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.
RANDOMIZED
PARALLEL
TREATMENT
NONE
Study Groups
Review each arm or cohort in the study, along with the interventions and objectives associated with them.
Genetic testing
Patients randomised to testing will have blood drawn for testing of CYP2C19 LOF mutations. Physicians of patients who test positive for an LOF mutation (intermediate and poor metabolizers) will be notified of the mutation with recommendations of possible alternative antiplatelet regimens suggested. Aspirin will be the recommended monotherapy, and aspirin in combination with ticagrelor or dipyridamole will be the recommended dual antiplatelet regimen. Decision of alternative medications used in patients with LOF mutations will be left to the discretion of the primary physician. Patients in the genotype guided antiplatelet therapy group who do not have LOF mutations will be left to continue the original intended antiplatelet regimen (this may be clopidogrel monotherapy, or in combination with aspirin).
No randomisation for patients with known CYP2C19 status prior to recruitment as these patients will be recruited as a comparison arm for outcomes measurements.
Genetic testing
Same information as details in the experimental arm.
Standard medical therapy
Patients on this arm will be placed on clopidogrel monotherapy, or in combination with aspirin, which is the original intended antiplatelet regimen.
No interventions assigned to this group
Interventions
Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.
Genetic testing
Same information as details in the experimental arm.
Other Intervention Names
Discover alternative or legacy names that may be used to describe the listed interventions across different sources.
Eligibility Criteria
Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.
Inclusion Criteria
* Age 21 years to 100 years.
* Can be randomised within 7 days of onset of index event \[Refer to footnote 1\].
* Clopidogrel naive immediately prior to index event \[Refer to footnote 2\].
Exclusion Criteria
* Known diagnosis of a life limiting illness with life expectancy of less than 1 year.
* Known cardioembolism or prothrombotic state necessitating the use of anticoagulation, or having a contraindication to clopidogrel.
Footnote 3: "Known diagnosis of dementia" will be defined as clinical diagnosis of dementia prior to the index stroke event as indicated in the patient's medical records.
21 Years
100 Years
ALL
No
Sponsors
Meet the organizations funding or collaborating on the study and learn about their roles.
Singapore General Hospital
OTHER
National Neuroscience Institute
OTHER
Responsible Party
Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.
Principal Investigators
Learn about the lead researchers overseeing the trial and their institutional affiliations.
Kaavya Narasimhalu
Role: PRINCIPAL_INVESTIGATOR
National Neuroscience Institute
Locations
Explore where the study is taking place and check the recruitment status at each participating site.
Singapore General Hospital
Singapore, , Singapore
Countries
Review the countries where the study has at least one active or historical site.
Central Contacts
Reach out to these primary contacts for questions about participation or study logistics.
Facility Contacts
Find local site contact details for specific facilities participating in the trial.
Elaine Ang
Role: primary
Deidre De Silva
Role: backup
Kaavya Narasimhalu
Role: backup
References
Explore related publications, articles, or registry entries linked to this study.
Lovett JK, Coull AJ, Rothwell PM. Early risk of recurrence by subtype of ischemic stroke in population-based incidence studies. Neurology. 2004 Feb 24;62(4):569-73. doi: 10.1212/01.wnl.0000110311.09970.83.
Petty GW, Brown RD Jr, Whisnant JP, Sicks JD, O'Fallon WM, Wiebers DO. Ischemic stroke subtypes : a population-based study of functional outcome, survival, and recurrence. Stroke. 2000 May;31(5):1062-8. doi: 10.1161/01.str.31.5.1062.
Purroy F, Montaner J, Molina CA, Delgado P, Ribo M, Alvarez-Sabin J. Patterns and predictors of early risk of recurrence after transient ischemic attack with respect to etiologic subtypes. Stroke. 2007 Dec;38(12):3225-9. doi: 10.1161/STROKEAHA.107.488833. Epub 2007 Oct 25.
CAPRIE Steering Committee. A randomised, blinded, trial of clopidogrel versus aspirin in patients at risk of ischaemic events (CAPRIE). CAPRIE Steering Committee. Lancet. 1996 Nov 16;348(9038):1329-39. doi: 10.1016/s0140-6736(96)09457-3.
Wang Y, Zhao X, Lin J, Li H, Johnston SC, Lin Y, Pan Y, Liu L, Wang D, Wang C, Meng X, Xu J, Wang Y; CHANCE investigators. Association Between CYP2C19 Loss-of-Function Allele Status and Efficacy of Clopidogrel for Risk Reduction Among Patients With Minor Stroke or Transient Ischemic Attack. JAMA. 2016 Jul 5;316(1):70-8. doi: 10.1001/jama.2016.8662.
Johnston SC, Easton JD, Farrant M, Barsan W, Conwit RA, Elm JJ, Kim AS, Lindblad AS, Palesch YY; Clinical Research Collaboration, Neurological Emergencies Treatment Trials Network, and the POINT Investigators. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA. N Engl J Med. 2018 Jul 19;379(3):215-225. doi: 10.1056/NEJMoa1800410. Epub 2018 May 16.
Humbert M, Nurden P, Bihour C, Pasquet JM, Winckler J, Heilmann E, Savi P, Herbert JM, Kunicki TJ, Nurden AT. Ultrastructural studies of platelet aggregates from human subjects receiving clopidogrel and from a patient with an inherited defect of an ADP-dependent pathway of platelet activation. Arterioscler Thromb Vasc Biol. 1996 Dec;16(12):1532-43. doi: 10.1161/01.atv.16.12.1532.
Scott SA, Sangkuhl K, Stein CM, Hulot JS, Mega JL, Roden DM, Klein TE, Sabatine MS, Johnson JA, Shuldiner AR; Clinical Pharmacogenetics Implementation Consortium. Clinical Pharmacogenetics Implementation Consortium guidelines for CYP2C19 genotype and clopidogrel therapy: 2013 update. Clin Pharmacol Ther. 2013 Sep;94(3):317-23. doi: 10.1038/clpt.2013.105. Epub 2013 May 22.
Goh LL, Lim CW, Sim WC, Toh LX, Leong KP. Analysis of Genetic Variation in CYP450 Genes for Clinical Implementation. PLoS One. 2017 Jan 3;12(1):e0169233. doi: 10.1371/journal.pone.0169233. eCollection 2017.
Meschia JF, Walton RL, Farrugia LP, Ross OA, Elm JJ, Farrant M, Meurer WJ, Lindblad AS, Barsan W, Ching M, Gentile N, Ross M, Nahab F, Easton JD, Kim AS, Zurita KG, Cucchiara B, Johnston SC. Efficacy of Clopidogrel for Prevention of Stroke Based on CYP2C19 Allele Status in the POINT Trial. Stroke. 2020 Jul;51(7):2058-2065. doi: 10.1161/STROKEAHA.119.028713. Epub 2020 Jun 17.
Narasimhalu K, Ang YK, Tan DSY, De Silva DA, Tan KB. Cost Effectiveness of Genotype-Guided Antiplatelet Therapy in Asian Ischemic Stroke Patients: Ticagrelor as an Alternative to Clopidogrel in Patients with CYP2C19 Loss of Function Mutations. Clin Drug Investig. 2020 Nov;40(11):1063-1070. doi: 10.1007/s40261-020-00970-y.
Mehran R, Rao SV, Bhatt DL, Gibson CM, Caixeta A, Eikelboom J, Kaul S, Wiviott SD, Menon V, Nikolsky E, Serebruany V, Valgimigli M, Vranckx P, Taggart D, Sabik JF, Cutlip DE, Krucoff MW, Ohman EM, Steg PG, White H. Standardized bleeding definitions for cardiovascular clinical trials: a consensus report from the Bleeding Academic Research Consortium. Circulation. 2011 Jun 14;123(23):2736-47. doi: 10.1161/CIRCULATIONAHA.110.009449. No abstract available.
Johnston SC, Amarenco P, Denison H, Evans SR, Himmelmann A, James S, Knutsson M, Ladenvall P, Molina CA, Wang Y; THALES Investigators. Ticagrelor and Aspirin or Aspirin Alone in Acute Ischemic Stroke or TIA. N Engl J Med. 2020 Jul 16;383(3):207-217. doi: 10.1056/NEJMoa1916870.
Gaglia MA, Torguson R, Pakala R, Xue Z, Sardi G, Suddath WO, Kent KM, Satler LF, Pichard AD, Waksman R. Correlation between light transmission aggregometry, VerifyNow P2Y12, and VASP-P platelet reactivity assays following percutaneous coronary intervention. J Interv Cardiol. 2011 Dec;24(6):529-34. doi: 10.1111/j.1540-8183.2011.00670.x. Epub 2011 Sep 15.
Lee CR, Sriramoju VB, Cervantes A, Howell LA, Varunok N, Madan S, Hamrick K, Polasek MJ, Lee JA, Clarke M, Cicci JD, Weck KE, Stouffer GA. Clinical Outcomes and Sustainability of Using CYP2C19 Genotype-Guided Antiplatelet Therapy After Percutaneous Coronary Intervention. Circ Genom Precis Med. 2018 Apr;11(4):e002069. doi: 10.1161/CIRCGEN.117.002069.
Carreras ET, Hochholzer W, Frelinger AL 3rd, Nordio F, O'Donoghue ML, Wiviott SD, Angiolillo DJ, Michelson AD, Sabatine MS, Mega JL. Diabetes mellitus, CYP2C19 genotype, and response to escalating doses of clopidogrel. Insights from the ELEVATE-TIMI 56 Trial. Thromb Haemost. 2016 Jul 4;116(1):69-77. doi: 10.1160/TH15-12-0981. Epub 2016 Mar 24.
Other Identifiers
Review additional registry numbers or institutional identifiers associated with this trial.
GGAT Protocol
Identifier Type: -
Identifier Source: org_study_id
More Related Trials
Additional clinical trials that may be relevant based on similarity analysis.