Comparison of antiplatelet efficacy and tolerability of clopidogrel napadisilate with clopidogrel bisulfate in coronary artery disease patients after percutaneous coronary intervention: a prospective, multicenter, randomized, open-label, phase IV, noninferiority trial

The developmental journey of therapies targeting purine receptors: from basic science to clinical trials

Since the discovery of ATP as an extracellular signalling molecule in 1972, purinergic signalling, mediated by extracellular purines and pyrimidines has been identified in virtually all mammalian tissues and is implicated in regulating fundamental cellular processes. In recent years, there has been an increasing focus on the pathophysiology and potential therapeutic interventions based on purinergic signalling. A vast range of compounds targeting purine receptors are in clinical development, and many more are in preclinical studies, which highlights the fast growth in this research field. As a tribute to Professor Geoffrey Burnstock's legacy in purinergic signalling, we present here a brief review of compounds targeting purine receptors that are in different stages of clinical trials. The review highlights the 50-year journey from basic research on purinergic receptors to clinical applications of therapies targeting purine receptors.

The incidence of recurrent cardiovascular events among acute coronary syndrome patients treated with generic or original clopidogrel in relation to their sociodemographic and clinical characteristics. The Aegean study

INTRODUCTION

The use of generic drugs is continuously growing; however, there are limited epidemiological data regarding the therapeutic equivalence of each original drug formulation with its generic counterparts. We evaluated the 12-month composite endpoint of recurrent acute myocardial infarction, ischaemic stroke, cardiac deaths, or hospitalisation due to a major bleeding in acute coronary syndrome (ACS) patients treated with original clopidogrel or a generic clopidogrel formulation, in relation to sociodemographic and clinical characteristics.

MATERIAL AND METHODS

Consecutive Greek ACS patients (n = 1194) hospitalised in the Aegean islands and the Attica region were enrolled. Clopidogrel treatment was recorded either as original clopidogrel hydrogen sulphate (Plavix^®/Iscover^®) or as a generic clopidogrel besylate formulation (Clovelen^®). The composite endpoint was recorded at 12-month follow-up.

RESULTS

The 12-month composite endpoint was 3.9% (4.6% in the Aegean islands and 3.5% in the Attica area, p > 0.05). The respective incidence in men was 4.0% and in women 3.8% (p > 0.05). Overall, generic and original clopidogrel use was 87% and 13% of patients, respectively. No significant differences were observed between original and generic clopidogrel use and 12-month composite endpoint incidence. Subgroup analysis with gender, region of residence, and clinical and lifestyle factors as strata did not reveal any significant outcomes. Haemorrhage incidence did not exceed 1% in the total sample.

CONCLUSIONS

The use of a generic clopidogrel besylate formulation was quite high in both urban and insular areas of Greece and had similar efficacy and safety profile with the original clopidogrel salt, supporting the routine use of this low-cost generic clopidogrel in the management of cardiovascular disease patients.

Comparison of 4 different strategies of DAPT after PCI in ACS real world population from a Northern Italy registry

Aim of the study was to compare four different strategies of dual antiplatelet therapy (DAPT) in patients with acute coronary syndromes (ACS) treated with PCI. DAPT with Clopidogrel, Ticagrelor and Prasugrel has proved to be effective in patients with ACS treated with percutaneous coronary intervention (PCI) by reducing major adverse cardiovascular outcomes (MACE). However, the effect of the different strategies in a real-world population deserves further verification. A retrospective analysis of 2404 discharged ACS patients treated with PCI was performed, with a median follow-up of 1 year. The study population was stratified in four drug treatment cohorts: ASA + Clopidogrel (A-C), ASA + Plavix (A-PLx), ASA + Ticagrelor (A-T), ASA + Prasugrel (A-P). We assessed the incidence of net adverse cardiovascular events (NACE): all-cause death, myocardial infarction (MI), target vessel revascularization (TVR), stroke and bleeding during follow-up. At 1-year, the use of A-C and A-PLx was associated with the highest cumulative incidence of NACE in comparison with A-T and A-P therapies (respectively 14.8 and 29.6% vs. 9.2 and 6%). This difference was mainly driven by the mortality and TVR outcomes. Considering selection bias and differences in the patients baseline characteristics, the association of A-T and A-P seems to be superior in comparison with a DAPT strategy of A-C and A-PLx in low risk ACS-PCI patients from real world. In our Region the prescription is consistent with guidelines recommendations and Clopidogrel and Plavix are still predominantly used in older patients with more comorbidities, and this could partially explain the inferiority of this association.

How important is aspirin adherence when evaluating effectiveness of low-dose aspirin?

Low-dose aspirin (LDA) is advocated for women at high-risk of pre-eclampsia, providing a modest, 10%, reduction in risk. Cardiology meta-analyses demonstrate 18% reduction in serious vascular events with LDA. Non-responsiveness to aspirin (sometimes termed aspirin resistance) and variable clinical effectiveness are often attributed to suboptimal adherence. The aim of this review was to identify the scope of adherence assessments in RCTs evaluating aspirin effectiveness in cardiology and obstetrics and discuss the quality of information provided by current methods. We searched MEDLINE, EMBASE and the Cochrane Library, limited to humans and English language, for RCTs evaluating aspirin in cardiology; 14/03/13-13/03/16 and pregnancy 1957-13/03/16. Search terms; 'aspirin', 'acetylsalicylic acid' appearing adjacent to 'myocardial infarction' or 'pregnancy', 'pregnant', 'obstetric' were used. 38% (25/68) of obstetric and 32% (20/62) of cardiology RCTs assessed aspirin adherence and 24% (6/25) and 29% (6/21) of obstetric and cardiology RCTs, respectively, defined acceptable adherence. Semi-quantitative methods (pill counts, medication weighing) prevailed in obstetric RCTs (93%), qualitative methods (interviews, questionnaires) were more frequent in obstetrics (67%). Two obstetric RCTs quantified serum thromboxane B₂ and salicylic acid, but no quantitative methods were used in cardiology Aspirin has proven efficacy, but suboptimal adherence is widespread and difficult to accurately quantify. Little is currently known about aspirin adherence in pregnancy. RCTs evaluating aspirin effectiveness show over-reliance on qualitative adherence assessments vulnerable to inherent inaccuracies. Reliable adherence data is important to assess and optimise the clinical effectiveness of LDA. We propose that adherence should be formally assessed in future trials and that development of quantitative assessments may prove valuable for trial protocols.

Generic versus brand-name drugs used in cardiovascular diseases

This meta-analysis aimed to compare the efficacy and adverse events, either serious or mild/moderate, of all generic versus brand-name cardiovascular medicines. We searched randomized trials in MEDLINE, Scopus, EMBASE, Cochrane Controlled Clinical Trial Register, and ClinicalTrials.gov (last update December 1, 2014). Attempts were made to contact the investigators of all potentially eligible trials. Two investigators independently extracted and analyzed soft (including systolic blood pressure, LDL cholesterol, and others) and hard efficacy outcomes (including major cardiovascular adverse events and death), minor/moderate and serious adverse events. We included 74 randomized trials; 53 reported ≥1 efficacy outcome (overall sample 3051), 32 measured mild/moderate adverse events (n = 2407), and 51 evaluated serious adverse events (n = 2892). We included trials assessing ACE inhibitors (n = 12), anticoagulants (n = 5), antiplatelet agents (n = 17), beta-blockers (n = 11), calcium channel blockers (n = 7); diuretics (n = 13); statins (n = 6); and others (n = 3). For both soft and hard efficacy outcomes, 100 % of the trials showed non-significant differences between generic and brand-name drugs. The aggregate effect size was 0.01 (95 % CI -0.05; 0.08) for soft outcomes; -0.06 (-0.71; 0.59) for hard outcomes. All but two trials showed non-significant differences in mild/moderate adverse events, and aggregate effect size was 0.07 (-0.06; 0.20). Comparable results were observed for each drug class and in each stratified meta-analysis. Overall, 8 serious possibly drug-related adverse events were reported: 5/2074 subjects on generics; 3/2076 subjects on brand-name drugs (OR 1.69; 95 % CI 0.40-7.20). This meta-analysis strengthens the evidence for clinical equivalence between brand-name and generic cardiovascular drugs. Physicians could be reassured about prescribing generic cardiovascular drugs, and health care organization about endorsing their wider use.

Comparison of antiplatelet effect and safety of clopidogrel napadisilate with clopidogrel bisulfate in stroke patients: multicenter, randomized, open-label, phase 4, non-inferiority clinical trial

OBJECTIVE

Clopidogrel napadisilate has better chemical stability than clopidogrel bisulfate. Our trial's objective was to compare the efficacy and safety of clopidogrel napadisilate with clopidogrel bisulfate in participants with ischemic stroke.

RESEARCH DESIGN AND METHODS

The study was a phase 4, 4 week, randomized, parallel-group, non-inferiority trial. Patients with ischemic stroke were randomized to receive either clopidogrel napadisilate 75 mg or clopidogrel bisulfate 75 mg. The primary study endpoint was change from baseline in P2Y12 percentage inhibition at week 4. The primary analysis was conducted in the per-protocol population. Non-inferiority was confirmed if the lower limit of the 95% confidence interval (CI) of the treatment difference was greater than or equal to -9.0% points.

RESULTS

Sixty-one participants were randomly assigned clopidogrel napadisilate and 60 were randomly assigned clopidogrel bisulfate. Thirty-nine participants in the clopidogrel napadisilate group and 39 in the clopidogrel bisulfate group were analyzed for the primary endpoint. At 4 weeks, mean P2Y12 percentage inhibition had increased in both treatment groups. The estimated mean change from baseline was 22.3% with clopidogrel napadisilate and 21.4% with clopidogrel bisulfate; the estimated treatment difference of 0.9% (95% CI, -8.6 to 10.4) confirmed the non-inferiority of clopidogrel napadisilate to clopidogrel bisulfate.

CONCLUSIONS

Clopidogrel napadisilate was non-inferior to clopidogrel bisulfate as assessed by change in P2Y12 percentage inhibition. Rates of adverse events were similar between the two groups. Therefore, clopidogrel napadisilate is a useful alternative option for the dosing of ischemic stroke patient populations.