Hyperlipidemias: Duenas A

Pandor A, Ara RM, Tumur I, Wilkinson AJ, Paisley S, Duenas A, Durrington PN, Chilcott J. · Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, UK. · J Intern Med. · Pubmed #19141093 No free full text.

Abstract: OBJECTIVES: To study the evidence on the efficacy and safety of ezetimibe monotherapy for the treatment of primary (heterozygous familial and non-familial) hypercholesterolaemia. DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs). METHODS: Eleven electronic bibliographic databases covering the biomedical, scientific and grey literature were searched from inception and supplemented by contact with experts in the field. Two reviewers independently determined the eligibility of RCTs, with a minimum treatment duration of 12 weeks, which compared ezetimibe monotherapy (10 mg per day) with placebo. RESULTS: In the absence of data from clinical outcome trials, surrogate endpoints such as changes in lipid concentrations were used as indicators of clinical outcomes. A meta-analysis of eight randomized, double-blind, placebo-controlled trials (all 12 weeks) showed that ezetimibe monotherapy was associated with a statistically significant mean reduction in LDL cholesterol (from baseline to endpoint) of -18.58%, (95% CI: -19.67 to -17.48, P < 0.00001) compared with placebo. Significant (P < 0.00001) changes were also found in total cholesterol (-13.46%, 95% CI: -14.22 to -12.70), HDL cholesterol (3.00%, 95% CI: 2.06-3.94) and triglyceride levels (-8.06%, 95% CI: -10.92 to -5.20). Ezetimibe monotherapy appeared to be well tolerated with a safety profile similar to placebo. CONCLUSIONS: In a meta-analysis restricted to short-term trials in hypercholesterolaemia, significant potentially favourable changes in lipid and lipoprotein levels relative to baseline occurred with ezetimibe monotherapy. Further long-term studies with cardiovascular and other clinical outcome data are needed to assess the efficacy and safety of ezetimibe more fully.

Ara R, Tumur I, Pandor A, Duenas A, Williams R, Wilkinson A, Paisley S, Chilcott J. · School of Health and Related Research (ScHARR), University of Sheffield, UK. · Health Technol Assess. · Pubmed #18485273 links to  free full text

Abstract: OBJECTIVES: To review the clinical and cost-effectiveness of ezetimibe as a combination therapy or monotherapy for the treatment of primary hypercholesterolaemia in the UK. DATA SOURCES: Twelve electronic databases were searched from inception to June 2006. Searches were supplemented by hand-searching relevant articles, sponsor and other submissions of evidence to the National Institute of Health and Clinical Excellence and conference proceedings. REVIEW METHODS: A systematic review and meta-analysis (where appropriate) of the clinical efficacy evidence was undertaken following recommended guidelines. A Markov model was developed to explore the costs and health outcomes associated with ezetimibe treatment. RESULTS: No published clinical outcome trials (> 12 weeks) were identified. In the absence of clinical end-point data from trials, 13 (of which five were multi-arm) phase III multi-centre randomised controlled trials (RCTs) (of varying methodological quality) of short-term duration (12-48 weeks) with surrogate end-point data were included. For patients not adequately controlled with a statin alone, a meta-analysis of six studies showed that a fixed-dose combination of ezetimibe and statin treatment was associated with a statistically significant reduction in low-density lipoprotein cholesterol (LDL-c) and total cholesterol (Total-c) compared with statin alone (p < 0.00001). Four studies (not eligible for meta-analysis) that titrated (either forced or stepwise) the statin doses to LDL-c targets generally showed that the co-administration of ezetimibe and statin was significantly more effective in reducing plasma LDL-c concentrations than statin monotherapy (p < 0.05 for all studies). For patients where a statin is not considered appropriate, a meta-analysis of seven studies demonstrated that ezetimibe monotherapy significantly reduced LDL-c levels compared with placebo (p < 0.00001). There were no statistically significant differences in LDL-c-lowering effects across different subgroups. Ezetimibe therapy (either in combination with a statin or monotherapy) appeared to be well tolerated compared to statin monotherapy or placebo, respectively. No ezetimibe studies reported data on health-related quality of life (HRQoL). There was a wide range in the economic results depending on the treatment strategies evaluated. When comparing ezetimibe monotherapy with no treatment in individuals with baseline LDL-c values of 3.0-4.0 mmol/l, the results range from 21,000 pounds to 50,000 pounds per quality-adjusted life-year (QALY). Results for individuals with baseline LDL-c values over 5.0 mmol/l are below 30,000 pounds per QALY. When comparing the costs and benefits of adding ezetimibe to ongoing statin treatment compared with maintaining statin treatment at the current dose, the majority of results are above values generally considered to be cost-effective (range 19,000 pounds to 48,000 pounds per QALY). Based on the evidence available, when comparing the costs and benefits associated with adding ezetimibe to ongoing statin treatment compared with a switch to a more potent statin, the results are governed by the difference in the cost of the treatment regimens compared and results range from 1500 pounds to 116,000 pounds per QALY. CONCLUSIONS: The short-term RCT clinical evidence demonstrated that ezetimibe was effective in reducing LDL-c when administered as monotherapy or in combination with a statin. However, when used as a monotherapy, ezetimibe is less effective than statins in lowering LDL-c. Given the limitations in the effectiveness data, there is great uncertainty in the economic results. These suggest that ezetimibe could be a cost-effective treatment for individuals with high baseline LDL-c values, for patients with diabetes and for individuals with heterozygous familial hypercholesterolaemia. Long-term clinical outcome studies are needed to allow more precise cost-effectiveness estimates to be calculated.

Ara R, Pandor A, Tumur I, Paisley S, Duenas A, Williams R, Rees A, Wilkinson A, Durrington P, Chilcott J. · Health Economics and Decision Science, ScHARR, University of Sheffield, Regent Court, 30 Regent Street, Sheffield S1 4DA, UK. · Am J Cardiovasc Drugs. · Pubmed #19159125 No free full text.

Abstract: OBJECTIVE: To evaluate the cost effectiveness of long-term ezetimibe monotherapy in patients with established cardiovascular disease (CVD) who do not tolerate statins or in whom they are contraindicated. METHODS: A Markov model was used to estimate the potential costs and benefits associated with ezetimibe monotherapy compared with no treatment. The benefits associated with ezetimibe treatment were informed by a systematic review of clinical evidence and a published relationship linking changes in low-density lipoprotein cholesterol (LDL-C) levels to cardiovascular events. RESULTS: In the absence of data from clinical outcome trials, surrogate endpoints such as changes in lipid levels were used as indicators of clinical outcomes. A meta-analysis of seven placebo-controlled trials included in the review showed that ezetimibe was associated with a statistically significant mean reduction (from baseline to endpoint) in LDL-C of 18.56% (95% CI -19.68, -17.44; p < 0.00001) compared with placebo. Using 10,000 Monte Carlo simulations, it is estimated that ezetimibe monotherapy would prevent an average of 49 nonfatal myocardial infarctions, 11 nonfatal strokes, and 37 cardiovascular deaths in a cohort of 1,000 patients aged 55 years with a baseline LDL-C concentration of 4.0 mmol/L. Events avoided provide an additional 211 quality-adjusted life-years (QALYs) over the 45 years modeled. With a mean incremental cost of pound 4,861,000 (year 2006 value), the discounted cost per QALY is pound 23,026 (Jackknife CI 22 979, 23 074). The model is reasonably robust to variations in key parameters. Incremental cost-effectiveness ratios fall below pound 20,000 per QALY for cohorts with baseline LDL-C values >4.5 mmol/L. CONCLUSION: Ezetimibe monotherapy compared with no treatment is a cost-effective alternative for individuals with a history of CVD and high LDL-C levels, who do not tolerate statins or in whom they are contraindicated.

Ara R, Pandor A, Tumur I, Paisley S, Duenas A, Williams R, Wilkinson A, Durrington P, Chilcott J. · Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom. · Clin Ther. · Pubmed #18803993 No free full text.

Abstract: BACKGROUND: Ezetimibe has been reported to improve lipid control in patients with established cardiovascular disease (CVD). OBJECTIVE: The aim of this study was to estimate the potential long-term impact on health status of prescribing ezetimibe in combination with statin therapy in patients with established CVD and evaluate its cost-effectiveness in a health economic model. METHODS: A Markov model was used to compare ezetimibe and statin combination therapy with statin monotherapy. A published relationship linking changes in low-density lipoprotein cholesterol and cardiovascular events was used to estimate the cardiovascular events avoided through lipid-lowering therapies. The model was populated using results of extensive literature searches and a meta-analysis of clinical evidence. An adjustment was applied to model second-line lipid-lowering benefits. Conservative assumptions were used to extend the patient pathway beyond the clinical evidence. The analysis took the perspective of the UK Department of Health; therefore, only direct costs were included. Costs were calculated as year-2006 British pounds. RESULTS: For a cohort of 1,000 hypothetical male patients aged 55 years, ezetimibe coadministered with current statin therapy was estimated to prevent a mean of 43 nonfatal myocardial infarctions, 7 nonfatal strokes, and 26 cardiovascular deaths over a lifetime, compared with doubling the current statin dose. The events avoided would provide a mean of 134 additional quality-adjusted life-years (QALYs). With a mean incremental cost of pound 3,693,000, the lifetime discounted cost per QALY gained would be pound 27,475 (95% CI, pound 27,331- pound 27,620) and would rise to pound 32,000 for men aged 75 years. CONCLUSIONS: The results suggest that, in some instances, ezetimibe coadministration may be cost-effective compared with statin monotherapy, but there are several limitations with this model. The economic effects of ezetimibe must be revisited when long-term effectiveness and safety data become available.