Yale B. Mitchel

Safety of Anacetrapib in Patients with or at High Risk for Coronary Heart Disease

BACKGROUND Anacetrapib is a cholesteryl ester transfer protein inhibitor that raises high-density lipoprotein (HDL) cholesterol and reduces low-density lipoprotein (LDL) cholesterol. METHODS We conducted a randomized, double-blind, placebo-controlled trial to assess the efficacy and safety profile of anacetrapib in patients with coronary heart disease or at high risk for coronary heart disease. Eligible patients who were taking a statin and who had an LDL cholesterol level that was consistent with that recommended in guidelines were assigned to receive 100 mg of anacetrapib or placebo daily for 18 months. The primary end points were the percent change from baseline in LDL cholesterol at 24 weeks (HDL cholesterol level was a secondary end point) and the safety and side-effect profile of anacetrapib through 76 weeks. Cardiovascular events and deaths were prospectively adjudicated. RESULTS A total of 1623 patients underwent randomization. By 24 weeks, the LDL cholesterol level had been reduced from 81 mg per deciliter (2.1 mmol per liter) to 45 mg per deciliter (1.2 mmol per liter) in the anacetrapib group, as compared with a reduction from 82 mg per deciliter (2.1 mmol per liter) to 77 mg per deciliter (2.0 mmol per liter) in the placebo group (P<0.001)--a 39.8% reduction with anacetrapib beyond that seen with placebo. In addition, the HDL cholesterol level increased from 41 mg per deciliter (1.0 mmol per liter) to 101 mg per deciliter (2.6 mmol per liter) in the anacetrapib group, as compared with an increase from 40 mg per deciliter (1.0 mmol per liter) to 46 mg per deciliter (1.2 mmol per liter) in the placebo group (P<0.001)--a 138.1% increase with anacetrapib beyond that seen with placebo. Through 76 weeks, no changes were noted in blood pressure or electrolyte or aldosterone levels with anacetrapib as compared with placebo. Prespecified adjudicated cardiovascular events occurred in 16 patients treated with anacetrapib (2.0%) and 21 patients receiving placebo (2.6%) (P = 0.40). The prespecified Bayesian analysis indicated that this event distribution provided a predictive probability (confidence) of 94% that anacetrapib would not be associated with a 25% increase in cardiovascular events, as seen with torcetrapib. CONCLUSIONS Treatment with anacetrapib had robust effects on LDL and HDL cholesterol, had an acceptable side-effect profile, and, within the limits of the power of this study, did not result in the adverse cardiovascular effects observed with torcetrapib. (Funded by Merck Research Laboratories; ClinicalTrials.gov number, NCT00685776.).

Efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy and coadministered with atorvastatin in dyslipidemic patients.

BACKGROUND High-density lipoprotein cholesterol (HDL-C) levels are inversely associated with cardiovascular risk. Cholesteryl ester transfer protein inhibition is one strategy for increasing HDL-C. This study evaluated the lipid-altering efficacy and safety of the cholesteryl ester transfer protein inhibitor anacetrapib as monotherapy or coadministered with atorvastatin in patients with dyslipidemia. METHODS A total of 589 patients with primary hypercholesterolemia or mixed hyperlipidemia (53.8% of the study population had low HDL-C) were randomized equally to one of 10 groups: 5 groups received background statin therapy of atorvastatin 20 mg and 5 did not, and each of these was randomized to placebo, anacetrapib 10, 40, 150, and 300 mg once daily for 8 weeks. An equal proportion of patients had triglycerides >150 mg/dL in each group. RESULTS For placebo and anacetrapib monotherapy (10, 40, 150, and 300 mg), least squares mean percent changes from baseline to week 8 for low-density lipoprotein cholesterol (LDL-C) were 2%, -16%, -27%, -40%, and -39%, respectively, and for HDL-C were 4%, 44%, 86%, 139%, and 133%, respectively (P < .001 vs placebo for all doses). Coadministration of anacetrapib with atorvastatin produced significant incremental LDL-C reductions and similar HDL-C increases versus atorvastatin monotherapy. For both anacetrapib monotherapy and coadministration with atorvastatin, the LDL-C reductions were similar in patients with baseline triglyceride levels greater than and less than or equal to the median. Anacetrapib was well tolerated, and the incidence of adverse events was similar for placebo and all active treatment groups. There were no increases in systolic or diastolic blood pressure in any treatment arm. CONCLUSIONS Anacetrapib, as monotherapy or coadministered with atorvastatin, produced significant reductions in LDL-C and increases in HDL-C; the net result of treatment with anacetrapib + atorvastatin was approximately 70% lowering of LDL-C and more than doubling of HDL-C. Anacetrapib was generally well tolerated with no discernable effect on blood pressure.

Effects of Laropiprant on Nicotinic Acid-Induced Flushing in Patients With Dyslipidemia

Niacin (nicotinic acid) is not optimally used mainly because of flushing, a process mediated primarily by prostaglandin D(2), which leads to poor patient compliance and suboptimal dosing. This phase II dose-ranging study was designed to assess whether the prostaglandin D(2) receptor 1 antagonist laropiprant (LRPT; MK-0524) would (1) reduce extended-release niacin (ERN)-induced flushing in dyslipidemic patients and (2) support a novel accelerated ERN dosing paradigm: initiating ERN at 1 g and advancing rapidly to 2 g. In part A of the study, 154 dyslipidemic patients were randomized to LRPT 150 mg/day or placebo in a 9-week, 2-period crossover study. Patients who completed part A (n = 122) entered part B (after a 2-week washout), together with additional patients who entered part B directly (n = 290). Part B patients were randomized to placebo, ERN 1 g (Niaspan, no previous titration), or ERN 1 g coadministered with LRPT 18.75, 37.5, 75, or 150 mg for 4 weeks, with doubling of the respective doses for the remaining 4 weeks. Patients treated with LRPT plus ERN experienced significantly less ERN-induced flushing than those treated with ERN alone during the initiation of treatment (ERN 1 g, week 1) and the maintenance treatment (ERN 1 to 2 g, weeks 2 to 8). All doses of LRPT were maximally effective in inhibiting niacin-induced flushing. LRPT did not alter the beneficial lipid effects of ERN. LRPT plus ERN was well tolerated. In conclusion, the significant reduction in ERN-induced flushing provided by LRPT plus ERN supports an accelerated ERN dose-advancement paradigm to achieve rapidly a 2-g dose in dyslipidemic patients.

Efficacy and safety of ezetimibe coadministered with simvastatin in patients with primary hypercholesterolemia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE To compare the efficacy and safety of 10 mg of ezetimibe coadministered with simvastatin with the safety and efficacy of simvastatin monotherapy for patients with hypercholesterolemia. PATIENTS AND METHODS This multicenter double-blind, placebo-controlled, factorial study enrolled 887 patients with hypercholesterolemia (low-density lipoprotein cholesterol [LDL-C], 145-250 mg/dL; triglycerides, < or = 350 mg/dL). Patients were randomized to 1 of 10 treatments--placebo, ezetimibe at 10 mg/d, simvastatin at 10, 20, 40, or 80 mg/d, or simvastatin at 10, 20, 40, or 80 mg/d plus ezetimibe at 10 mg/d for 12 weeks. The study began March 13, 2001, and ended January 8, 2002. The primary efficacy end point was the mean percent change in LDL-C levels from baseline to study end point (last available postbaseline LDL-C measurement) for the pooled ezetimibe/simvastatin group vs the pooled simvastatin monotherapy group. RESULTS Coadministration of ezetimibe/simvastatin was significantly (P<.001) more effective than simvastatin alone in reducing LDL-C levels for the pooled ezetimibe/simvastatin vs pooled simvastatin analysis and at each specific dose comparison. The decrease in LDL-C levels with coadministration of ezetimibe and the lowest dose of simvastatin, 10 mg, was similar to the decrease with the maximum dose of simvastatin, 80 mg. A significantly (P<.001) greater proportion of patients in the ezetimibe/simvastatin group achieved target LDL-C levels compared with those in the monotherapy group. Treatment with ezetimibe/simvastatin also led to greater reductions in total cholesterol, triglyceride, non-high-density lipoprotein cholesterol, and apolipoprotein B levels compared with simvastatin alone; both treatments increased high-density lipoprotein cholesterol levels similarly. The safety and tolerability profiles for the ezetimibe/simvastatin and monotherapy groups were similar. CONCLUSION Through dual inhibition of cholesterol absorption and synthesis, coadministration of ezetimibe/simvastatin offers a highly efficacious and well-tolerated lipid-lowering strategy for treating patients with primary hypercholesterolemia.

The Efficacy and Six-Week Tolerability of Simvastatin 80 and 160 mg/Day

The hydroxymethylglutaryl coenzyme A reductase inhibitor simvastatin is the most effective of the currently approved hypolipidemic drugs and has been shown to reduce mortality and coronary morbidity in patients with coronary artery disease. For these patients the United States National Cholesterol Education Program advocates reducing low-density lipoprotein (LDL) cholesterol to <100 mg/dl. However, in some patients this cannot be achieved using monotherapy with simvastatin 40 mg/day, the current maximal recommended dose. To evaluate the effectiveness of extending the dosage range, 156 subjects with LDL cholesterol >160 mg/dl and triglycerides (TG) <350 mg/dl were randomized to simvastatin at doses of 40, 80, and 160 mg/day in a 26 week, double-blind, 3-period, complete block crossover study. Each active treatment period was 6 weeks in duration with intervening 2 week washout periods. Median reductions from baseline in LDL cholesterol were 41%, 47%, and 53% in the 40-, 80-, and 160-mg groups, respectively. The corresponding reductions in plasma TG were 21%, 23%, and 33%. High-density lipoprotein (HDL) cholesterol increased by 6% to 8% in each group. One patient (0.7%) taking 160 mg developed myopathy; 1 patient (0.7%) taking 80 mg, and 3 (2.1%) taking 160 mg had transaminase elevations > 3 times the upper limit of normal. No new or unexpected adverse effects were observed. We conclude that simvastatin at doses of 80 and 160 mg/day provides additional efficacy with a low short-term incidence of adverse effects; our results support the continued investigation of simvastatin at these doses.

Effect of Cholesterol-Lowering Therapy on Coronary Endothelial Vasomotor Function in Patients With Coronary Artery Disease

BACKGROUND Improved endothelial function may contribute to the beneficial effects of cholesterol-lowering therapy. METHODS AND RESULTS In this randomized, double-blind study, we compared the effect of 6 months of simvastatin (40 mg/d) treatment with that of placebo on coronary endothelial vasomotor function in 60 patients with coronary artery disease. Simvastatin lowered LDL-cholesterol by 40+/-12% from 130+/-28 mg/dL (P<0.001). Peak intracoronary acetylcholine infusion produced epicardial coronary constriction at baseline in both the simvastatin (-17+/-13%) and placebo (-24+/-16%) groups. After treatment, acetylcholine produced less constriction in both groups (-12+/-19% and -15+/-14%, respectively, P=0.97). The increase in coronary blood flow during infusion of the peak dose of substance P was blunted at baseline in both the simvastatin (42+/-50%) and placebo (55+/-71%) groups, reflecting impaired endothelium-dependent dilation of coronary microvessels. After treatment, the flow increase was 82+/-81% in the simvastatin group and 63+/-53% in the placebo group (P=0.16). CONCLUSIONS Six months of cholesterol-lowering therapy has no significant effect on coronary endothelial vasomotor function in the study population of patients with coronary artery disease and mildly elevated cholesterol levels. These findings suggest that the effects of cholesterol lowering on endothelial function are more complex than previously thought.

Lipid-modifying efficacy and tolerability of extended-release niacin/laropiprant in patients with primary hypercholesterolaemia or mixed dyslipidaemia.

Background:  Improving lipids beyond low‐density lipoprotein cholesterol (LDL‐C) lowering with statin monotherapy may further reduce cardiovascular risk. Niacin has complementary lipid‐modifying efficacy to statins and cardiovascular benefit, but is underutilised because of flushing, mediated primarily by prostaglandin D2 (PGD2). Laropiprant (LRPT), a PGD2 receptor (DP1) antagonist that reduces niacin‐induced flushing has been combined with extended‐release niacin (ERN) into a fixed‐dose tablet.

Expanded-dose simvastatin is effective in homozygous familial hypercholesterolaemia

Patients with homozygous familial hypercholesterolaemia (HFH) have abnormalities in both low-density lipoprotein (LDL) receptor alleles, resulting in severe hypercholesterolaemia and premature coronary heart disease. Limited treatment options are available and the response to drug therapy has been poor. In the present paper, we have evaluated the efficacy and safety of simvastatin at doses beyond the current maximal dose of 40 mg/day in patients with HFH. After a 4 week placebo diet run-in period, 12 patients with well-characterized HFH were randomized to simvastatin 80 mg/day administered in three divided doses (n = 8; group 1) or 40 mg once daily (n = 4; group 2). After 9 weeks, the dose in group 1 was increased to 160 mg/day while the dose in group 2 was kept at 40 mg/day, but with the drug given in three divided doses and treatment continued for an additional 9 weeks. All 12 patients completed the study and there were no serious or unexpected adverse effects. LDL-cholesterol concentrations fell by 14% at the 40 mg/day dose, but were reduced further at the higher doses (25% at the 80 mg/day and by 31% at the 160 mg/day dosage, P < 0.0001). Excretion of urinary mevalonic acid, as an index of in vivo cholesterol biosynthesis, was reduced but did not correlate with reduction in LDL-cholesterol in the individual patients. The magnitude of response to therapy was not predicted by the LDL-receptor gene defect as patients with the same LDL-receptor mutations responded differently to the same dose of simvastatin therapy. The ability of expanded doses of simvastatin (80 or 160 mg/day) to reduce LDL-cholesterol levels in patients with HFH, even if receptor negative, suggests that at these doses, the drug reduces LDL production. Simvastatin therapy, at doses of 80 or 160 mg/day, should therefore be considered in all patients with HFH, either as an adjunct to apheresis, or as monotherapy for those patients who do not have access to apheresis or other such treatment modalities.

Design of the DEFINE trial: Determining the EFficacy and Tolerability of CETP INhibition with AnacEtrapib

BACKGROUND Residual cardiovascular (CV) risk often remains high despite statin therapy to lower low-density lipoprotein cholesterol (LDL-C). New therapies to raise high-density lipoprotein cholesterol (HDL-C) are currently being investigated. Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor that raises HDL-C and reduces LDL-C when administered alone or with a statin. Adverse effects on blood pressure, electrolytes, and aldosterone levels, seen with another drug in this class, have not been noted in studies of anacetrapib to date. METHODS Determining the EFficacy and Tolerability of CETP INhibition with AnacEtrapib (DEFINE) is a randomized, double-blind, placebo-controlled trial to assess the efficacy and safety profile of anacetrapib in patients with coronary heart disease (CHD) or CHD risk equivalents (clinical trials.gov NCT00685776). Eligible patients at National Cholesterol Education Program-Adult Treatment Panel III LDL-C treatment goal on a statin, with or without other lipid-modifying medications, are treated with anacetrapib, 100 mg, or placebo for 18 months, followed by a 3-month, poststudy follow-up. The primary end points are percent change from baseline in LDL-C and the safety and tolerability of anacetrapib. Comprehensive preplanned interim safety analyses will be performed at the 6- and 12-month time points to examine treatment effects on key safety end points, including blood pressure and electrolytes. A preplanned Bayesian analysis will be performed to interpret the CV event distribution, given the limited number of events expected in this study. RESULTS A total of 2,757 patients were screened at 153 centers in 20 countries, and 1,623 patients were randomized into the trial. Lipid results, clinical CV events, and safety outcomes from this trial are anticipated in 2010.

A Comparison of Simvastatin and Atorvastatin up to Maximal Recommended Doses in a Large Multicenter Randomized Clinical Trial

OBJECTIVE At higher doses, simvastatin has been shown to produce significantly greater increases in high-density lipoprotein (HDL) cholesterol and apolipoprotein (apo) A-I than atorvastatin. To extend and confirm these findings, a 36-week, randomized, double-blind, dose-titration study was performed in 826 hypercholesterolemic patients to compare the effects of simvastatin and atorvastatin on HDL cholesterol, apo A-I, and clinical and laboratory safety. PRIMARY HYPOTHESIS: Simvastatin, across a range of doses, will be more effective than atorvastatin at raising HDL cholesterol and apo A-I levels. METHODS A total of 826 hypercholesterolemic patients were enrolled in this double-blind, randomized, parallel, 36-week, dose-escalation study. Patients randomized to simvastatin received 40 mg/day for the first 6 weeks, 80 mg/day for the next 6 weeks, and remained on 80 mg/day for the final 24 weeks. Patients randomized to atorvastatin received 20 mg/day for the first 6 weeks, 40 mg/day for the next 6 weeks, and 80 mg/day for the remaining 24 weeks. RESULTS During the first 12 weeks of the study, simvastatin increased HDL cholesterol and apo A-I more than the comparative doses of atorvastatin, while producing slightly lower reductions in low-density lipoprotein (LDL) cholesterol and triglycerides. At the maximal dose comparison, simvastatin 80 mg and atorvastatin 80 mg, the HDL cholesterol and apo A-I differences favoring simvastatin were larger than at the lower doses. In addition, at the maximal dose comparison, the incidence of drug-related clinical adverse experiences was approximately two-fold higher with atorvastatin 80 mg than with simvastatin 80 mg (23 versus 12%, p < 0.001), due predominantly to a greater incidence of gastrointestinal symptoms with atorvastatin (10 versus 3%, p < 0.001). The incidence of clinically significant alanine aminotransferase elevations was also higher with atorvastatin 80 mg than with simvastatin 80 mg (3.8 versus 0.5%, p < 0.010), especially in women (6.0 versus 0.6%). CONCLUSIONS At the doses compared in this study, simvastatin led to greater increases in HDL cholesterol and apo A-I levels than atorvastatin. At the maximum dose comparison, there were fewer drug-related gastrointestinal symptoms and clinically significant aminotransferase elevations with simvastatin.