Background~Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 inhibitor is mandatory in patients after percutaneous coronary intervention (PCI). Clopidogrel is the most widely used P2Y12 inhibitor with class I recommendation. However, clopidogrel is a pro-drug which has highly variable antiplatelet effect. Hypo-responsiveness to clopidogrel was associated with increased risk of thrombotic events after PCI.~Increasing the dose of aspirin could not reduce thrombotic risk but resulted in elevated bleeding risk. Although new P2Y12 inhibitors have more potent antiplatelet effect and did reduce thrombotic risk compared with clopidogrel, the benefit was only demonstrated in patients undergoing PCI for moderate to high risk non-ST-segment elevation acute coronary syndrome (NSTE-ACS) or ST-segment elevation myocardial infarction (STEMI) and was also associated with increased bleeding risk. Therefore, how to improve the antiplatelet therapy in patients taking aspirin and clopidogrel after PCI remains unclear.~Berberine is an isoquinoline plant alkaloid which has anti-inflammatory, anti-oxidant, anti-microbial, anti-tumoral and immunomodulatory properties, as well as anti-hypertensive, hypo-glycemic and cholesterol-lowering effects. In small studies conducted in patients with hypertension, hypercholesterolemia and diabetes, berberine with a daily dose of 600-1000 mg for 12 weeks had good safety profile and was well tolerated.~In addition, berberine demonstrated antiplatelet effect. After in vivo administration in animals, berberine inhibited ex vivo platelet activation mediated by P2Y12 receptor and ex vivo platelet aggregation induced by adenosine diphosphate (ADP), arachidonic acid (AA), collagen, and thrombin, et al. After ex vivo administration, berberine inhibited ex vivo thromboxane B2 (TXB2) synthesis induced by ADP, AA, and collagen in animal platelets, as well as ex vivo platelet aggregation induced by collagen in a dose-dependent manner in platelets from healthy human volunteers. However, the antiplatelet effect of berberine has never been investigated in patients receiving DAPT after PCI.~Design~The APLABE-PCI is a single-center, randomized, open-label, controlled, dose-escalating, parallel-group study, which is designed to assess the anti-platelet effect of berberine in approximately 64 patients receiving aspirin and clopidogrel who are at > 8 but ≤ 40 weeks after PCI.~The total study duration is expected to be approximately 19 weeks per patient, including a screening period, a 12±1 week treatment period, and a 4±1 week follow-up period.~The visit schedule will be as follows:~Visit 0 (V0): Day -21 to Day -1, Screening/Enrolment;~Visit 1 (V1): Day 1, Randomization/First dose;~Visit 2 (V2): Week 4±1, Dose adjustment 1;~Visit 3 (V3): Week 8±1, Dose adjustment 2;~Visit 4 (V4): Week 12±1, End of Treatment (EOT) /Last dose; •Visit 5 (V5): Week 16±1, Safety visit.~The screening period will be up to 21 days. Once each patient has signed the informed consent, the eligibility of the patient will be evaluated and related laboratory assessments will be taken (Visit 0). All patients will continue taking aspirin and clopidogrel in the morning during the screening period.~On the first day of the treatment period (Visit 1), eligible patients will return to the study center and be randomized into the Berberine Arm and the Control Arm. In the Berberine Arm, patients will receive berberine 200 mg twice daily for 4±1 weeks (Stage 1); then, 300 mg twice daily for 4±1 weeks (Stage 2); then, 400 mg twice daily for 4±1 weeks (Stage 3) in addition to standard treatment, including aspirin and clopidogrel. In the Control Arm, patients will receive standard treatment, including aspirin and clopidogrel, for 12±1 weeks. During the treatment period, patients in both arms will also take aspirin 100 mg once daily and clopidogrel 75 mg once daily for 12±1 weeks.~The total daily dose of berberine will be taken separately in the morning and in the evening in approximately a 12-hour interval. On the first day of the treatment period (Visit 1), the morning dose (first dose) of berberine will be given 2-4 hour after aspirin and clopidogrel are taken together in the morning and immediately after the blood and urine samples for baseline platelet function tests are collected. Since the second day of the treatment period, the morning dose of berberine will be taken simultaneously with aspirin and clopidogrel in the morning.~At the ends of Stage 1 (Visit 2), Stage 2 (Visit 3), and Stage 3 (Visit 4) (end of treatment, EOT), patients will return to the study center. During each stage, the last morning doses of all antiplatelet agents, including berberine, aspirin, and clopidogrel in the Berberine Arm, as well as aspirin and clopidogrel in the Control Arm, will be administered simultaneously at the study center in the morning on Visit 2, Visit 3, and Visit 4, respectively.~A follow-up period will begin on the next day after Visit 4 and will continue for 4±1 weeks. During the follow-up period, patients in both arms will continue taking aspirin and clopidogrel. At the end of the follow-up period, patients will return to the study center for a safety visit (Visit 5).~In the Berberine Arm, the blood and urine samples for platelet function tests will be obtained 2-4 hour after aspirin and clopidogrel are taken in the morning and before the first morning dose of berberine is taken on Visit 1, and 2-4 hours after the morning doses of berberine, aspirin and clopidogrel are taken on Visit 2, Visit 3, and Visit 4, respectively. In the Control Arm, the blood and urine samples for platelet function tests will be collected 2-4 hours after the morning doses of aspirin and clopidogrel are given on Visit 1, Visit 2, Visit 3, and Visit 4, respectively.~In the Berberine Arm, the blood and urine samples for safety assessment will be collected on Visit 0, and 2-4 hours after the morning doses of berberine, aspirin and clopidogrel are taken on Visit 2, Visit 3, and Visit 4, as well as on Visit 5, respectively. In the Control Arm, the blood and urine samples for safety assessment will be collected on Visit 0, and 2-4 hours after the morning doses of aspirin and clopidogrel are taken on Visit 2, Visit 3, and Visit 4, as well as on Visit 5, respectively.~Adverse events will be collected on Visit 1, Visit 2, Visit 3, Visit 4, and Visit 5, respectively. Cardiac ischemic events and bleeding events will be collected on Visit 2, Visit 3, and Visit 4, respectively.~The primary endpoint of the study is P2Y12 reaction unit (PRU) assessed by VerifyNow assay 2-4 h after all the antiplatelet agents are taken simultaneously in the morning at the end of the treatment period (Visit 4, EOT), i.e., on the 12th (11th-13th) week of treatment.~Conclusions~The APLABE-PCI study will assess the anti-platelet effect of berberine in patients receiving aspirin and clopidogrel after PCI. The result of the present study would provide pharmacodynamical data for the design of future outcome studies.
The APLABE-PCI is a single-center, randomized, open-label, controlled, dose-escalating, parallel-group study, which is designed to assess the anti-platelet effect of berberine in approximately 64 patients receiving aspirin and clopidogrel who are at > 8 but ≤ 40 weeks after percutaneous coronary intervention.