Prasugrel (Efient®) with percutaneous coronary intervention for treating acute coronary syndromes (review of TA182): systematic review and economic analysis

Background: Acute coronary syndromes (ACSs) are life-threatening conditions associated with acute myocardial ischaemia. There are three main types of ACS: ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction (NSTEMI) and unstable angina (UA). One treatment for ACS is percutaneous coronary intervention (PCI) plus adjunctive treatment with antiplatelet drugs. Dual therapy antiplatelet treatment [aspirin plus either prasugrel (Efient(R), Daiichi Sankyo Company Ltd UK/Eli Lilly and Company Ltd), clopidogrel or ticagrelor (Brilique(R), AstraZeneca)] is standard in UK clinical practice. Prasugrel is the focus of this review. Objectives: The remit is to appraise the clinical effectiveness and cost-effectiveness of prasugrel within its licensed indication for the treatment of ACS with PCI and is a review of National Institute for Health and Care Excellence technology appraisal TA182. Data sources: Four electronic databases (MEDLINE, EMBASE, The Cochrane Library, PubMed) were searched from database inception to June 2013 for randomised controlled trials (RCTs) and to August 2013 for economic evaluations comparing prasugrel with clopidogrel or ticagrelor in ACS patients undergoing PCI. Methods: Clinical outcomes included non-fatal and fatal cardiovascular (CV) events, adverse effects of treatment and health-related quality of life (HRQoL). Cost-effectiveness outcomes included incremental cost per life-year gained and incremental cost per quality-adjusted life-year (QALY) gained. An independent economic model assessed four mutually exclusive subgroups: ACS patients treated with PCI for STEMI and with and without diabetes mellitus and ACS patients treated with PCI for UA or NSTEMI and with and without diabetes mellitus. Results: No new RCTs were identified beyond that reported in TA182. TRITON-TIMI 38 (Trial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet Inhibition with Prasugrel Thrombolysis in Myocardial Infarction 38) compared prasugrel with clopidogrel in ACS patients scheduled for PCI. No relevant economic evaluations were identified. Our analyses focused on a key subgroup of patients: those aged <75 years who weighed >60 kg (no previous stroke or transient ischaemic attack). For the primary composite end point (death from CV causes, non-fatal myocardial infarction or non-fatal stroke) statistically significantly fewer events occurred in the prasugrel arm (8.3%) than in the clopidogrel arm (11%). No statistically significant difference in major bleeding events was noted. However, there was a significant difference in favour of clopidogrel when major and minor bleeding events were combined (3.0 vs. 3.9%). No conclusions could be drawn regarding HRQoL. The results of sensitivity analyses confirmed that it is likely that, for all four ACS subgroups, within 5-10 years prasugrel is a cost-effective treatment option compared with clopidogrel at a willingness-to-pay threshold of 20,000 pound to 30,000 pound per QALY gained. At the full 40-year time horizon, all estimates are <10,000 pound per QALY gained. Limitations: Lack of data precluded a clinical comparison of prasugrel with ticagrelor; the comparative effectiveness of prasugrel compared with ticagrelor therefore remains unknown. The long-term modelling exercise is vulnerable to major assumptions about the continuation of early health outcome gains. Conclusion: A key strength of the review is that it demonstrates the cost-effectiveness of prasugrel compared with clopidogrel using the generic price of clopidogrel. Although the report demonstrates the cost-effectiveness of prasugrel compared with clopidogrel at a threshold of 20,000 pound to 30,000 pound per QALY gained, the long-term modelling is vulnerable to major assumptions regarding long-term gains. Lack of data precluded a clinical comparison of prasugrel with ticagrelor; the comparative effectiveness of prasugrel compared with ticagrelor therefore remains unknown. Well-audited data are needed from a long-term UK clinical registry on defined ACS patient groups treated with PCI who receive prasugrel, ticagrelor and clopidogrel.