Zastaprazan's effect on clopidogrel platelet response after PCI

Effect of ZaStaprazan on Platelet Reactivity of Clopidogrel After PercuTaneous CoronAry InteRvention: A Randomized Double-Blind Pilot Study (EZ-STAR)

This test will see if zastaprazan, compared with rabeprazole, changes how clopidogrel controls platelets in people on dual antiplatelet therapy after PCI.

Quick facts

• Phase: Phase 4
• Study type: Interventional
• Enrollment: 100 (estimated)
• Ages: 19 Years and up
• Sex: All
• Sponsor: Yonsei University (Academic / other)
• Locations: 1 site (Yongin-si, Gyeonggi-do)
• Trial ID: NCT07471867 on ClinicalTrials.gov

What this trial studies

This phase 4 interventional study compares zastaprazan and rabeprazole when given with clopidogrel in patients with chronic coronary syndrome who have undergone PCI and will remain on dual antiplatelet therapy. The primary outcome is platelet reactivity measured while patients receive the assigned acid-suppressing drug alongside clopidogrel. The protocol focuses on possible drug–drug interactions mediated by CYP2C19 and aims to define an optimal combination that balances antiplatelet efficacy and gastrointestinal protection. Rabeprazole is included as a comparator because it is known to have relatively low CYP2C19 inhibition among PPIs.

Who should consider this trial

Good fit: Adults aged 19 or older with chronic coronary syndrome who have had PCI and are expected to continue dual antiplatelet therapy including clopidogrel for at least six months and who provide informed consent.

Not a fit: People who are not taking clopidogrel, who have hypersensitivity to P-CABs/PPIs/aspirin/clopidogrel, or who have undergone surgeries that alter gastric acid secretion are unlikely to benefit from this comparison.

Why it matters

Potential benefit: If successful, the study could identify an acid-suppression option that protects the stomach without reducing clopidogrel’s antiplatelet effect.

How similar studies have performed: Previous research has shown variable effects of PPIs and some P-CABs on clopidogrel platelet reactivity, with rabeprazole generally having less impact, but direct data on zastaprazan are limited so this comparison is partly novel.

Eligibility criteria

Inclusion Criteria:

1. Age 19 years or older at the time of providing informed consent.
2. Patients with Chronic Coronary Syndrome (CCS) who have undergone Percutaneous Coronary Intervention (PCI) and agreed to participate in the study.
3. Patients who are required to maintain dual antiplatelet therapy (DAPT) including clopidogrel for at least 6 months after PCI.
4. Patients who have voluntarily provided written informed consent to participate in this clinical study.

Exclusion Criteria:

1. History of hypersensitivity to P-CABs, PPIs, benzimidazoles, aspirin, clopidogrel, or any of the excipients in the study drugs.
2. History of or planned surgery that may affect gastric acid secretion, such as upper gastrointestinal resection, acid suppression surgery, or gastric mucosal resection. (However, patients who have undergone simple perforation repair of the stomach or duodenum, appendectomy, cholecystectomy, hysterectomy, or endoscopic/laparoscopic resection of benign tumors are eligible).
3. Diagnosis of Zollinger-Ellison syndrome or inflammatory diseases (e.g., pancreatitis, or inflammatory bowel diseases such as Crohn's disease or ulcerative colitis).
4. Currently receiving HIV protease inhibitors (atazanavir, nelfinavir) or rilpivirine-containing products.
5. Abnormal blood chemistry values within 4 weeks prior to screening: AST, ALT, ALP, or total bilirubin \> 3 times the upper limit of normal (ULN). Estimated Glomerular Filtration Rate (eGFR) \< 30 mL/min/1.73m², calculated using the IDMS-traceable MDRD equation.
6. Recent Medication Use: Use of medications expected to affect the study results, such as P2Y12 inhibitors (other than the prescribed clopidogrel), within 2 weeks prior to baseline.
7. Pregnant or lactating women, or women with a positive pregnancy test.
8. Patients with hereditary problems such as galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption.

Where this trial is running

Yongin-si, Gyeonggi-do

• Yongin Severance Hospital, Yonsei University — Yongin-si, Gyeonggi-do, South Korea (Recruiting)

Study contacts

• Study coordinator: Yongcheol Kim, MD, PhD

Conditions Chronic Coronary Syndrome; zastaprazan