Comparative Effects of PCSK9 (Proprotein Convertase Subtilisin/Kexin Type 9) Inhibition and Statins on Postprandial Triglyceride-Rich Lipoprotein Metabolism.

OBJECTIVE: Inhibition of PCSK9 (proprotein convertase subtilisin/kexin type 9) and statins are known to lower plasma LDL (low-density lipoprotein)-cholesterol concentrations. However, the comparative effects of these treatments on the postprandial metabolism of TRLs (triglyceride-rich lipoproteins) remain to be investigated. APPROACH AND RESULTS: We performed a 2-by-2 factorial trial of the effects of 8 weeks of subcutaneous evolocumab (420 mg every 2 weeks) and atorvastatin (80 mg daily) on postprandial TRL metabolism in 80 healthy, normolipidemic men after ingestion of an oral fat load. We evaluated plasma total and incremental area under the curves for triglycerides, apo (apolipoprotein)B-48, and VLDL (very-LDL)-apoB-100. We also examined the kinetics of apoB-48 using intravenous D3-leucine administration, mass spectrometry, and multicompartmental modeling. Atorvastatin and evolocumab independently lowered postprandial VLDL-apoB-100 total area under the curves (P<0.001). Atorvastatin, but not evolocumab, reduced fasting plasma apoB-48, apoC-III, and angiopoietin-like 3 concentrations (P<0.01), as well as postprandial triglyceride and apoB-48 total area under the curves (P<0.001) and the incremental area under the curves for plasma triglycerides, apoB-48, and VLDL-apoB-100 (P<0.01). Atorvastatin also independently increased TRL apoB-48 fractional catabolic rate (P<0.001) and reduced the number of apoB-48-containing particles secreted in response to the fat load (P<0.01). In contrast, evolocumab did not significantly alter the kinetics of apoB-48. CONCLUSIONS: In healthy, normolipidemic men, atorvastatin decreased fasting and postprandial apoB-48 concentration by accelerating the catabolism of apoB-48 particles and reducing apoB-48 particle secretion in response to a fat load. Inhibition of PCSK9 with evolocumab had no significant effect on apoB-48 metabolism.

Controlled study of the effect of proprotein convertase subtilisin-kexin type 9 inhibition with evolocumab on lipoprotein(a) particle kinetics.

Aims: Lipoprotein(a) [Lp(a)], a low-density lipoprotein (LDL) particle covalently bound to apolipoprotein(a) [apo(a)], is a potentially potent heritable risk factor for cardiovascular disease. We investigated the mechanism whereby evolocumab, a monoclonal antibody against proprotein convertase subtilisin-kexin type 9 (PCSK9), lowers Lp(a). Methods and results: We studied the kinetics of Lp(a) particles in 63 healthy men, with plasma apo(a) concentration >5 nmol/L, participating in an 8-week factorial trial of the effects of evolocumab (420 mg every 2 weeks) and atorvastatin (80 mg daily) on lipoprotein metabolism. Lipoprotein(a)-apo(a) kinetics were studied using intravenous D3-leucine administration, mass spectrometry, and compartmental modelling; Lp(a)-apoB kinetics were also determined in 16 subjects randomly selected from the treatment groups. Evolocumab, but not atorvastatin, significantly decreased the plasma pool size of Lp(a)-apo(a) (-36%, P < 0.001 for main effect). As monotherapy, evolocumab significantly decreased the production of Lp(a)-apo(a) (-36%, P < 0.001). In contrast, in combination with atorvastatin, evolocumab significantly increased the fractional catabolism of Lp(a)-apo(a) (+59%, P < 0.001), but had no effect on the production of Lp(a)-apo(a). There was a highly significant association between the changes in the fractional catabolism of Lp(a)-apo(a) and Lp(a)-apoB in the substudy of 16 subjects (r = 0.966, P < 0.001). Conclusions: Evolocumab monotherapy lowered the plasma Lp(a) pool size by decreasing the production of Lp(a) particles. In combination with atorvastatin, evolocumab lowered the plasma Lp(a) pool size by accelerating the catabolism of Lp(a) particles. This dual mechanism may relate to an effect of PCSK9 inhibition on Lp(a)-apo(a) production and to marked up-regulation of LDL receptor activity on Lp(a) holoparticle clearance. Clinical Trial Registration Information: NCT02189837.

Factorial Effects of Evolocumab and Atorvastatin on Lipoprotein Metabolism.

BACKGROUND: Monoclonal antibodies against proprotein convertase subtilisin kexin type 9 (PCSK9), such as evolocumab, lower plasma low-density lipoprotein (LDL)-cholesterol concentrations. Evolocumab is under investigation for its effects on cardiovascular outcomes in statin-treated, high-risk patients. The mechanism of action of PCSK9 monoclonal antibodies on lipoprotein metabolism remains to be fully evaluated. Stable isotope tracer kinetics can effectively elucidate the mode of action of new lipid-regulating pharmacotherapies. METHODS: We conducted a 2-by-2 factorial trial of the effects of atorvastatin (80 mg daily) and subcutaneous evolocumab (420 mg every 2 weeks) for 8 weeks on the plasma kinetics of very-low-density lipoprotein (VLDL)-apolipoprotein B-100 (apoB), intermediate-density lipoprotein-apoB, and LDL-apoB in 81 healthy, normolipidemic, nonobese men. The kinetics of apoB in these lipoproteins was studied using a stable isotope infusion of D3-leucine, gas chromatography/mass spectrometry, and multicompartmental modeling. RESULTS: Atorvastatin and evolocumab independently accelerated the fractional catabolism of VLDL-apoB (P<0.001 and P.032, respectively), intermediate-density lipoprotein-apoB (P=0.021 and P=.002, respectively), and LDL-apoB (P<0.001, both interventions). Evolocumab but not atorvastatin decreased the production rate of intermediate-density lipoprotein-apoB (P=0.043) and LDL-apoB (P<0.001), which contributed to the reduction in the plasma pool sizes of these lipoprotein particles. The reduction in LDL-apoB and LDL-cholesterol concentrations was significantly greater with combination versus either monotherapy (P<0.001). Whereas evolocumab but not atorvastatin lowered the concentration of free PCSK9, atorvastatin lowered the lathosterol/campesterol ratio (a measure of cholesterol synthesis/absorption) and apoC-III concentration. Both interventions decreased plasma apoE, but neither significantly altered lipoprotein lipase and cholesteryl ester protein mass or measures of insulin resistance. CONCLUSIONS: In healthy, normolipidemic subjects, evolocumab decreased the concentration of atherogenic lipoproteins, particularly LDL, by accelerating their catabolism. Reductions in intermediate-density lipoprotein and LDL production also contributed to the decrease in LDL particle concentration with evolocumab by a mechanism distinct from that of atorvastatin. These kinetic findings provide a metabolic basis for understanding the potential benefits of PCSK9 monoclonal antibodies incremental to statins in on-going clinical end point trials. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02189837.

A 52-week placebo-controlled trial of evolocumab in hyperlipidemia.

BACKGROUND: Evolocumab, a monoclonal antibody that inhibits proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced low-density lipoprotein (LDL) cholesterol levels in phase 2 studies. We conducted a phase 3 trial to evaluate the safety and efficacy of 52 weeks of treatment with evolocumab. METHODS: We stratified patients with hyperlipidemia according to the risk categories outlined by the Adult Treatment Panel III of the National Cholesterol Education Program. On the basis of this classification, patients were started on background lipid-lowering therapy with diet alone or diet plus atorvastatin at a dose of 10 mg daily, atorvastatin at a dose of 80 mg daily, or atorvastatin at a dose of 80 mg daily plus ezetimibe at a dose of 10 mg daily, for a run-in period of 4 to 12 weeks. Patients with an LDL cholesterol level of 75 mg per deciliter (1.9 mmol per liter) or higher were then randomly assigned in a 2:1 ratio to receive either evolocumab (420 mg) or placebo every 4 weeks. The primary end point was the percent change from baseline in LDL cholesterol, as measured by means of ultracentrifugation, at week 52. RESULTS: Among the 901 patients included in the primary analysis, the overall least-squares mean (±SE) reduction in LDL cholesterol from baseline in the evolocumab group, taking into account the change in the placebo group, was 57.0±2.1% (P<0.001). The mean reduction was 55.7±4.2% among patients who underwent background therapy with diet alone, 61.6±2.6% among those who received 10 mg of atorvastatin, 56.8±5.3% among those who received 80 mg of atorvastatin, and 48.5±5.2% among those who received a combination of 80 mg of atorvastatin and 10 mg of ezetimibe (P<0.001 for all comparisons). Evolocumab treatment also significantly reduced levels of apolipoprotein B, non-high-density lipoprotein cholesterol, lipoprotein(a), and triglycerides. The most common adverse events were nasopharyngitis, upper respiratory tract infection, influenza, and back pain. CONCLUSIONS: At 52 weeks, evolocumab added to diet alone, to low-dose atorvastatin, or to high-dose atorvastatin with or without ezetimibe significantly reduced LDL cholesterol levels in patients with a range of cardiovascular risks. (Funded by Amgen; DESCARTES ClinicalTrials.gov number, NCT01516879.).

Effects of Evolocumab on Vitamin E and Steroid Hormone Levels: Results From the 52-Week, Phase 3, Double-Blind, Randomized, Placebo-Controlled DESCARTES Study.

RATIONALE: Vitamin E transport and steroidogenesis are closely associated with low-density lipoproteins (LDLs) metabolism, and evolocumab can lower LDL cholesterol (LDL-C) to low levels. OBJECTIVE: To determine the effects of evolocumab on vitamin E and steroid hormone levels. METHODS AND RESULTS: After titration of background lipid-lowering therapy per cardiovascular risk, 901 patients with an LDL-C ≥2.0 mmol/L were randomized to 52 weeks of monthly, subcutaneous evolocumab, or placebo. Vitamin E, cortisol, adrenocorticotropic hormone, and gonadal hormones were analyzed at baseline and week 52. In a substudy (n=100), vitamin E levels were also measured in serum, LDL, high-density lipoprotein, and red blood cell membranes at baseline and week 52. Absolute vitamin E decreased in evolocumab-treated patients from baseline to week 52 by 16% but increased by 19% when normalized for cholesterol. In the substudy, vitamin E level changes from baseline to week 52 mirrored the changes in the lipid fraction, and red blood cell membrane vitamin E levels did not change. Cortisol in evolocumab-treated patients increased slightly from baseline to week 52, but adrenocorticotropic hormone and the cortisol:adrenocorticotropic hormone ratio did not change. No patient had a cortisol:adrenocorticotropic hormone ratio <3.0 (nmol/pmol). Among evolocumab-treated patients, gonadal hormones did not change from baseline to week 52. Vitamin E and steroid changes were consistent across subgroups by minimum postbaseline LDL-C <0.4 and <0.6 mmol/L. CONCLUSIONS: As expected, vitamin E levels changed similarly to lipids among patients treated for 52 weeks with evolocumab. No adverse effects were observed in steroid or gonadal hormones, even at very low LDL-C levels. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01516879.

Navigating the Future of Cardiovascular Drug Development-Leveraging Novel Approaches to Drive Innovation and Drug Discovery: Summary of Findings from the Novel Cardiovascular Therapeutics Conference.

PURPOSE: The need for novel approaches to cardiovascular drug development served as the impetus to convene an open meeting of experts from the pharmaceutical industry and academia to assess the challenges and develop solutions for drug discovery in cardiovascular disease. METHODS: The Novel Cardiovascular Therapeutics Summit first reviewed recent examples of ongoing or recently completed programs translating basic science observations to targeted drug development, highlighting successes (protein convertase sutilisin/kexin type 9 [PCSK9] and neprilysin inhibition) and targets still under evaluation (cholesteryl ester transfer protein [CETP] inhibition), with the hope of gleaning key lessons to successful drug development in the current era. Participants then reviewed the use of innovative approaches being explored to facilitate rapid and more cost-efficient evaluations of drug candidates in a short timeframe. RESULTS: We summarize observations gleaned from this summit and offer insight into future cardiovascular drug development. CONCLUSIONS: The rapid development in genetic and high-throughput drug evaluation technologies, coupled with new approaches to rapidly evaluate potential cardiovascular therapies with in vitro techniques, offer opportunities to identify new drug targets for cardiovascular disease, study new therapies with better efficiency and higher throughput in the preclinical setting, and more rapidly bring the most promising therapies to human testing. However, there must be a critical interface between industry and academia to guide the future of cardiovascular drug development. The shared interest among academic institutions and pharmaceutical companies in developing promising therapies to address unmet clinical needs for patients with cardiovascular disease underlies and guides innovation and discovery platforms that are significantly altering the landscape of cardiovascular drug development.

PCSK9 inhibition-mediated reduction in Lp(a) with evolocumab: an analysis of 10 clinical trials and the LDL receptor's role.

Lipoprotein (a) [Lp(a)] is independently associated with CVD risk. Evolocumab, a monoclonal antibody (mAb) to proprotein convertase subtilisin/kexin type 9 (PCSK9), decreases Lp(a). The potential mechanisms were assessed. A pooled analysis of Lp(a) and LDL cholesterol (LDL-C) in 3,278 patients from 10 clinical trials (eight phase 2/3; two extensions) was conducted. Within each parent study, biweekly and monthly doses of evolocumab statistically significantly reduced Lp(a) at week 12 versus control (P < 0.001 within each study); pooled median (quartile 1, quartile 3) percent reductions were 24.7% (40.0, 3.6) and 21.7% (39.9, 4.2), respectively. Reductions were maintained through week 52 of the open-label extension, and correlated with LDL-C reductions [with and without correction for Lp(a)-cholesterol] at both time points (P < 0.0001). The effect of LDL and LDL receptor (LDLR) availability on Lp(a) cell-association was measured in HepG2 cells: cell-associated LDL fluorescence was reversed by unlabeled LDL and Lp(a). Lp(a) cell-association was reduced by coincubation with LDL and PCSK9 and reversed by adding PCSK9 mAb. These studies support that reductions in Lp(a) with PCSK9 inhibition are partly due to increased LDLR-mediated uptake. In most situations, Lp(a) appears to compete poorly with LDL for LDLR binding and internalization, but when LDLR expression is increased with evolocumab, particularly in the setting of low circulating LDL, Lp(a) is reduced.

Inhibition of PCSK9 with evolocumab in homozygous familial hypercholesterolaemia (TESLA Part B): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Homozygous familial hypercholesterolaemia is a rare, serious disorder caused by very low or absent plasma clearance of LDL, substantially raised LDL cholesterol, and accelerated development of cardiovascular disease. Conventional lipid-lowering treatments are modestly effective. Evolocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), reduced LDL cholesterol by 16% in a pilot study. We now report results with evolocumab in a randomised, double-blind, placebo-controlled phase 3 trial. METHODS: This randomised, double-blind, placebo-controlled phase 3 trial was undertaken at 17 sites in ten countries in North America, Europe, the Middle East, and South Africa. 50 eligible patients (aged ≥12 years) with homozygous familial hypercholesterolaemia, on stable lipid-regulating therapy for at least 4 weeks, and not receiving lipoprotein apheresis, were randomly allocated by a computer-generated randomisation sequence in a 2:1 ratio to receive subcutaneous evolocumab 420 mg or placebo every 4 weeks for 12 weeks. Randomisation was stratified by LDL cholesterol at screening (<11 mmol/L or ≥11 mmol/L) and implemented by a computerised interactive voice-response system. Patients, study personnel, and the funder were masked to treatment and to the efficacy results by the central laboratory not returning LDL cholesterol or any lipid results to the clinical sites after the baseline visit. The primary endpoint was percentage change in ultracentrifugation LDL cholesterol from baseline at week 12 compared with placebo, analysed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01588496. FINDINGS: Of the 50 eligible patients randomly assigned to the two treatment groups, 49 actually received the study drug and completed the study (16 in the placebo group and 33 in the evolocumab group). Compared with placebo, evolocumab significantly reduced ultracentrifugation LDL cholesterol at 12 weeks by 30·9% (95% CI -43·9% to -18·0%; p<0·0001). Treatment-emergent adverse events occurred in ten (63%) of 16 patients in the placebo group and 12 (36%) of 33 in the evolocumab group. No serious clinical or laboratory adverse events occurred, and no anti-evolocumab antibody development was detected during the study. INTERPRETATION: In patients with homozygous familial hypercholesterolaemia receiving stable background lipid-lowering treatment and not on apheresis, evolocumab 420 mg administered every 4 weeks was well tolerated and significantly reduced LDL cholesterol compared with placebo. FUNDING: Amgen Inc.

PCSK9 inhibition with evolocumab (AMG 145) in heterozygous familial hypercholesterolaemia (RUTHERFORD-2): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Heterozygous familial hypercholesterolaemia is characterised by low cellular uptake of LDL cholesterol, increased plasma LDL cholesterol concentrations, and premature cardiovascular disease. Despite intensive statin therapy, with or without ezetimibe, many patients are unable to achieve recommended target levels of LDL cholesterol. We investigated the effect of PCSK9 inhibition with evolocumab (AMG 145) on LDL cholesterol in patients with this disorder. METHODS: This multicentre, randomised, double-blind, placebo-controlled trial was undertaken at 39 sites (most of which were specialised lipid clinics, mainly attached to academic institutions) in Australia, Asia, Europe, New Zealand, North America, and South Africa between Feb 7 and Dec 19, 2013. 331 eligible patients (18-80 years of age), who met clinical criteria for heterozygous familial hypercholesterolaemia and were on stable lipid-lowering therapy for at least 4 weeks, with a fasting LDL cholesterol concentration of 2·6 mmol/L or higher, were randomly allocated in a 2:2:1:1 ratio to receive subcutaneous evolocumab 140 mg every 2 weeks, evolocumab 420 mg monthly, or subcutaneous placebo every 2 weeks or monthly for 12 weeks. Randomisation was computer generated by the study sponsor, implemented by a computerised voice interactive system, and stratified by LDL cholesterol concentration at screening (higher or lower than 4·1 mmol/L) and by baseline ezetimibe use (yes/no). Patients, study personnel, investigators, and Amgen study staff were masked to treatment assignments within dosing frequency groups. The coprimary endpoints were percentage change from baseline in LDL cholesterol at week 12 and at the mean of weeks 10 and 12, analysed by intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01763918. FINDINGS: Of 415 screened patients, 331 were eligible and were randomly assigned to the four treatment groups: evolocumab 140 mg every 2 weeks (n=111), evolocumab 420 mg monthly (n=110), placebo every 2 weeks (n=55), or placebo monthly (n=55). 329 patients received at least one dose of study drug. Compared with placebo, evolocumab at both dosing schedules led to a significant reduction in mean LDL cholesterol at week 12 (every-2-weeks dose: 59·2% reduction [95% CI 53·4-65·1], monthly dose: 61·3% reduction [53·6-69·0]; both p<0·0001) and at the mean of weeks 10 and 12 (60·2% reduction [95% CI 54·5-65·8] and 65·6% reduction [59·8-71·3]; both p<0·0001). Evolocumab was well tolerated, with rates of adverse events similar to placebo. The most common adverse events occurring more frequently in the evolocumab-treated patients than in the placebo groups were nasopharyngitis (in 19 patients [9%] vs five [5%] in the placebo group) and muscle-related adverse events (ten patients [5%] vs 1 [1%]). INTERPRETATION: In patients with heterozygous familial hypercholesterolaemia, evolocumab administered either 140 mg every 2 weeks or 420 mg monthly was well tolerated and yielded similar and rapid 60% reductions in LDL cholesterol compared with placebo. FUNDING: Amgen Inc.

Clinical Profile of Statin Intolerance in the Phase 3 GAUSS-2 Study.

PURPOSE: Recent evidence suggests that statin intolerance may be more common than reported in randomized trials. However, the statin-intolerant population is not well characterized. The goal of this report is to characterize the population enrolled in the phase 3 Goal Achievement after Utilizing an anti-PCSK9 antibody in Statin Intolerant Subjects Study (GAUSS-2; NCT 01763905). METHODS: GAUSS-2 compared evolocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9) to ezetimibe in hypercholesterolemic patients who discontinued statin therapy due to statin-associated muscle symptoms (SAMS). GAUSS-2 was a 12-week, double-blind, placebo-controlled, randomized study that enrolled patients with elevated LDL-C who were either not on a statin or able to tolerate only a low-dose due to SAMS. Patients had received ≥2 statins and were unable to tolerate any statin dose or increase in dose above a specified weekly dose due to SAMS. RESULTS: Three hundred seven patients (mean [SD] age, 62 [10] years; 54 % males) were randomized 2:1 (evolocumab:ezetimibe). Mean (SD) LDL-C was 4.99 (1.51) mmol/L. Patients had used ≥2 (100 %), ≥3 (55 %), or ≥4 (21 %) statins. Coronary artery disease was present in 29 % of patients. Statin-intolerant symptoms were myalgia in 80 % of patients, weakness in 39 %, and more serious complications in 20 %. In 98 % of patients, SAMS interfered with normal daily activity; in 52 %, symptoms precluded moderate exertion. CONCLUSION: Evaluation of the GAUSS-2 trial population of statin-intolerant patients demonstrates that most patients were high risk with severely elevated LDL-C and many had statin-associated muscle symptoms that interfered with their quality of life.

Efficacy and Tolerability of Evolocumab vs Ezetimibe in Patients With Muscle-Related Statin Intolerance: The GAUSS-3 Randomized Clinical Trial.

IMPORTANCE: Muscle-related statin intolerance is reported by 5% to 20% of patients. OBJECTIVE: To identify patients with muscle symptoms confirmed by statin rechallenge and compare lipid-lowering efficacy for 2 nonstatin therapies, ezetimibe and evolocumab. DESIGN, SETTING, AND PARTICIPANTS: Two-stage randomized clinical trial including 511 adult patients with uncontrolled low-density lipoprotein cholesterol (LDL-C) levels and history of intolerance to 2 or more statins enrolled in 2013 and 2014 globally. Phase A used a 24-week crossover procedure with atorvastatin or placebo to identify patients having symptoms only with atorvastatin but not placebo. In phase B, after a 2-week washout, patients were randomized to ezetimibe or evolocumab for 24 weeks. INTERVENTIONS: Phase A: atorvastatin (20 mg) vs placebo. Phase B: randomization 2:1 to subcutaneous evolocumab (420 mg monthly) or oral ezetimibe (10 mg daily). MAIN OUTCOME AND MEASURES: Coprimary end points were the mean percent change in LDL-C level from baseline to the mean of weeks 22 and 24 levels and from baseline to week 24 levels. RESULTS: Of the 491 patients who entered phase A (mean age, 60.7 [SD, 10.2] years; 246 women [50.1%]; 170 with coronary heart disease [34.6%]; entry mean LDL-C level, 212.3 [SD, 67.9] mg/dL), muscle symptoms occurred in 209 of 491 (42.6%) while taking atorvastatin but not while taking placebo. Of these, 199 entered phase B, along with 19 who proceeded directly to phase B for elevated creatine kinase (N = 218, with 73 randomized to ezetimibe and 145 to evolocumab; entry mean LDL-C level, 219.9 [SD, 72] mg/dL). For the mean of weeks 22 and 24, LDL-C level with ezetimibe was 183.0 mg/dL; mean percent LDL-C change, -16.7% (95% CI, -20.5% to -12.9%), absolute change, -31.0 mg/dL and with evolocumab was 103.6 mg/dL; mean percent change, -54.5% (95% CI, -57.2% to -51.8%); absolute change, -106.8 mg/dL (P < .001). LDL-C level at week 24 with ezetimibe was 181.5 mg/dL; mean percent change, -16.7% (95% CI, -20.8% to -12.5%); absolute change, -31.2 mg/dL and with evolocumab was 104.1 mg/dL; mean percent change, -52.8% (95% CI, -55.8% to -49.8%); absolute change, -102.9 mg/dL (P < .001). For the mean of weeks 22 and 24, between-group difference in LDL-C was -37.8%; absolute difference, -75.8 mg/dL. For week 24, between-group difference in LDL-C was -36.1%; absolute difference, -71.7 mg/dL. Muscle symptoms were reported in 28.8% of ezetimibe-treated patients and 20.7% of evolocumab-treated patients (log-rank P = .17). Active study drug was stopped for muscle symptoms in 5 of 73 ezetimibe-treated patients (6.8%) and 1 of 145 evolocumab-treated patients (0.7%). CONCLUSIONS AND RELEVANCE: Among patients with statin intolerance related to muscle-related adverse effects, the use of evolocumab compared with ezetimibe resulted in a significantly greater reduction in LDL-C levels after 24 weeks. Further studies are needed to assess long-term efficacy and safety. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01984424.

Efficacy and safety of longer-term administration of evolocumab (AMG 145) in patients with hypercholesterolemia: 52-week results from the Open-Label Study of Long-Term Evaluation Against LDL-C (OSLER) randomized trial.

BACKGROUND: Evolocumab (AMG 145), a monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9), significantly reduced low-density lipoprotein cholesterol (LDL-C) in phase 2 studies of 12 weeks' duration. The longer-term efficacy and safety of PCSK9 inhibition remain undefined. METHODS AND RESULTS: Of 1359 randomized and dosed patients in the 4 evolocumab phase 2 parent studies, 1104 (81%) elected to enroll into the Open-Label Study of Long-term Evaluation Against LDL-C (OSLER) study. Regardless of their treatment assignment in the parent study, patients were randomized 2:1 to receive either open-label subcutaneous evolocumab 420 mg every 4 weeks with standard of care (SOC) (evolocumab+SOC, n=736) or SOC alone (n=368). Ninety-two percent of patients in the evolocumab+SOC group and 89% of patients in the SOC group completed 52 weeks of follow-up. Patients who first received evolocumab in OSLER experienced a mean 52.3% [SE, 1.8%] reduction in LDL-C at week 52 (P<0.0001). Patients who received 1 of 6 dosing regimens of evolocumab in the parent studies and received evolocumab+SOC in OSLER had persistent LDL-C reductions (mean reduction, 50.4% [SE, 0.8%] at the end of the parent study versus 52.1% [SE, 1.0%] at 52 weeks; P=0.31). In patients who discontinued evolocumab on entry into OSLER, LDL-C levels returned to near baseline levels. Adverse events and serious adverse events occurred in 81.4% and 7.1% of the evolocumab+SOC group patients and 73.1% and 6.3% of the SOC group patients, respectively. CONCLUSION: Evolocumab dosed every 4 weeks demonstrated continued efficacy and encouraging safety and tolerability over 1 year of treatment in the largest and longest evaluation of a PCSK9 inhibitor in hypercholesterolemic patients to date. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov. Unique identifier: NCT01439880.

Efficacy and safety of evolocumab (AMG 145), a fully human monoclonal antibody to PCSK9, in hyperlipidaemic patients on various background lipid therapies: pooled analysis of 1359 patients in four phase 2 trials.

AIMS: Prior trials with monoclonal antibodies to proprotein convertase subtilizin/kexin type 9 (PCSK9) reported robust low density lipoprotein cholesterol (LDL-C) reductions. However, the ability to detect potentially beneficial changes in other lipoproteins such as lipoprotein (a), triglycerides, high-density lipoprotein cholesterol (HDL-C), and apolipoprotein (Apo) A1, and adverse events (AEs) was limited by sample sizes of individual trials. We report a pooled analysis from four phase 2 studies of evolocumab (AMG 145), a monoclonal antibody to PCSK9. METHODS AND RESULTS: The trials randomized 1359 patients to various doses of subcutaneous evolocumab every 2 weeks (Q2W) or 4 weeks (Q4W), placebo, or ezetimibe for 12 weeks; 1252 patients contributed to efficacy and 1314, to safety analyses. Mean percentage (95% CI) reductions in LDL-C vs. placebo ranged from 40.2% (44.6%, 35.8%) to 59.3% (63.7%, 54.8%) among the evolocumab groups (all P < 0.001). Statistically significant reductions in apolipoprotein B (Apo B), non-high-density lipoprotein cholesterol (non-HDL-C), triglycerides and lipoprotein (a) [Lp(a)], and increases in HDL-C were also observed. Adverse events (AEs) and serious AEs with evolocumab were reported in 56.8 and 2.0% of patients, compared with 49.2% and 1.2% with placebo. Adjudicated cardiac and cerebrovascular events were reported in 0.3 and 0% in the placebo and 0.9 and 0.3% in the evolocumab arms, respectively. CONCLUSION: In addition to LDL-C reduction, evolocumab, dosed either Q2W or Q4W, demonstrated significant and favourable changes in other atherogenic and anti-atherogenic lipoproteins, and was well tolerated over the 12-week treatment period.

PCSK9 inhibition fails to alter hepatic LDLR, circulating cholesterol, and atherosclerosis in the absence of ApoE.

LDL cholesterol (LDL-C) contributes to coronary heart disease. Proprotein convertase subtilisin/kexin type 9 (PCSK9) increases LDL-C by inhibiting LDL-C clearance. The therapeutic potential for PCSK9 inhibitors is highlighted by the fact that PCSK9 loss-of-function carriers exhibit 15-30% lower circulating LDL-C and a disproportionately lower risk (47-88%) of experiencing a cardiovascular event. Here, we utilized pcsk9(-/-) mice and an anti-PCSK9 antibody to study the role of the LDL receptor (LDLR) and ApoE in PCSK9-mediated regulation of plasma cholesterol and atherosclerotic lesion development. We found that circulating cholesterol and atherosclerotic lesions were minimally modified in pcsk9(-/-) mice on either an LDLR- or ApoE-deficient background. Acute administration of an anti-PCSK9 antibody did not reduce circulating cholesterol in an ApoE-deficient background, but did reduce circulating cholesterol (-45%) and TGs (-36%) in APOE*3Leiden.cholesteryl ester transfer protein (CETP) mice, which contain mouse ApoE, human mutant APOE3*Leiden, and a functional LDLR. Chronic anti-PCSK9 antibody treatment in APOE*3Leiden.CETP mice resulted in a significant reduction in atherosclerotic lesion area (-91%) and reduced lesion complexity. Taken together, these results indicate that both LDLR and ApoE are required for PCSK9 inhibitor-mediated reductions in atherosclerosis, as both are needed to increase hepatic LDLR expression.

Effect of the proprotein convertase subtilisin/kexin 9 monoclonal antibody, AMG 145, in homozygous familial hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia is a rare, serious disorder with a substantial reduction in low-density lipoprotein (LDL) receptor function, severely elevated LDL cholesterol, cardiovascular disease, and often death in childhood. Response to conventional drug therapies is modest. Monoclonal antibodies to proprotein convertase subtilisin/kexin 9 (PCSK9) reduce LDL cholesterol in heterozygous familial hypercholesterolemia. The effect in homozygous familial hypercholesterolemia is unknown and uncertain. We evaluated the efficacy and safety of AMG 145 in an open-label, single-arm, multicenter, dose-scheduling pilot study in patients with homozygous familial hypercholesterolemia. METHODS AND RESULTS: Eight patients with LDL receptor-negative or -defective homozygous familial hypercholesterolemia on stable drug therapy were treated with subcutaneous 420 mg AMG 145 every 4 weeks for ≥12 weeks, followed by 420 mg AMG 145 every 2 weeks for an additional 12 weeks. All patients completed both treatment periods. Mean change from baseline in LDL cholesterol at week 12 was -16.5% (range, 5.2% to -43.6%; P=0.0781) and -13.9% (range, 39.9% to -43.3%; P=0.1484) with 4- and 2-week dosing, respectively. No reduction was seen in the 2 receptor-negative patients. Over the treatment periods, mean±SD LDL cholesterol reductions in the 6 LDL receptor-defective patients were 19.3±16% and 26.3±20% with 4- and 2-week dosing, respectively (P=0.0313 for both values), ranging from 4% to 48% with 2-week dosing. No serious side effects were reported. CONCLUSION: This study demonstrates significant and dose-related LDL cholesterol lowering with a PCSK9 monoclonal antibody in homozygous familial hypercholesterolemia patients with defective LDL receptor activity but no reduction in those who were receptor negative.

Effect of evolocumab or ezetimibe added to moderate- or high-intensity statin therapy on LDL-C lowering in patients with hypercholesterolemia: the LAPLACE-2 randomized clinical trial.

IMPORTANCE: In phase 2 studies, evolocumab, a fully human monoclonal antibody to PCSK9, reduced LDL-C levels in patients receiving statin therapy. OBJECTIVE: To evaluate the efficacy and tolerability of evolocumab when used in combination with a moderate- vs high-intensity statin. DESIGN, SETTING, AND PATIENTS: Phase 3, 12-week, randomized, double-blind, placebo- and ezetimibe-controlled study conducted between January and December of 2013 in patients with primary hypercholesterolemia and mixed dyslipidemia at 198 sites in 17 countries. INTERVENTIONS: Patients (n = 2067) were randomized to 1 of 24 treatment groups in 2 steps. Patients were initially randomized to a daily, moderate-intensity (atorvastatin [10 mg], simvastatin [40 mg], or rosuvastatin [5 mg]) or high-intensity (atorvastatin [80 mg], rosuvastatin [40 mg]) statin. After a 4-week lipid-stabilization period, patients (n = 1899) were randomized to compare evolocumab (140 mg every 2 weeks or 420 mg monthly) with placebo (every 2 weeks or monthly) or ezetimibe (10 mg or placebo daily; atorvastatin patients only) when added to statin therapies. MAIN OUTCOMES AND MEASURES: Percent change from baseline in low-density lipoprotein cholesterol (LDL-C) level at the mean of weeks 10 and 12 and at week 12. RESULTS: Evolocumab reduced LDL-C levels by 66% (95% CI, 58% to 73%) to 75% (95% CI, 65% to 84%) (every 2 weeks) and by 63% (95% CI, 54% to 71%) to 75% (95% CI, 67% to 83%) (monthly) vs placebo at the mean of weeks 10 and 12 in the moderate- and high-intensity statin-treated groups; the LDL-C reductions at week 12 were comparable. For moderate-intensity statin groups, evolocumab every 2 weeks reduced LDL-C from a baseline mean of 115 to 124 mg/dL to an on-treatment mean of 39 to 49 mg/dL; monthly evolocumab reduced LDL-C from a baseline mean of 123 to 126 mg/dL to an on-treatment mean of 43 to 48 mg/dL. For high-intensity statin groups, evolocumab every 2 weeks reduced LDL-C from a baseline mean of 89 to 94 mg/dL to an on-treatment mean of 35 to 38 mg/dL; monthly evolocumab reduced LDL-C from a baseline mean of 89 to 94 mg/dL to an on-treatment mean of 33 to 35 mg/dL. Adverse events were reported in 36%, 40%, and 39% of evolocumab-, ezetimibe-, and placebo-treated patients, respectively. The most common adverse events in evolocumab-treated patients were back pain, arthralgia, headache, muscle spasms, and pain in extremity (all <2%). CONCLUSIONS AND RELEVANCE: In this 12-week trial conducted among patients with primary hypercholesterolemia and mixed dyslipidemia, evolocumab added to moderate- or high-intensity statin therapy resulted in additional LDL-C lowering. Further studies are needed to evaluate the longer-term clinical outcomes and safety of this approach for LDL-C lowering. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01763866.

Low-density lipoprotein cholesterol-lowering effects of AMG 145, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 serine protease in patients with heterozygous familial hypercholesterolemia: the Reduction of LDL-C with PCSK9 Inhibition in Heterozygous Familial Hypercholesterolemia Disorder (RUTHERFORD) randomized trial.

BACKGROUND: Despite statin treatment, many patients with heterozygous familial hypercholesterolemia do not reach desired low-density lipoprotein cholesterol (LDL-C) targets. AMG 145, a fully human monoclonal antibody against proprotein convertase subtilisin/kexin type 9 (PCSK9) serine protease, demonstrated significant reductions in LDL-C in phase 1 studies. This phase 2, multicenter, double-blind, randomized, placebo-controlled, dose-ranging study evaluated the efficacy and safety of AMG 145 in heterozygous familial hypercholesterolemia patients. METHODS AND RESULTS: Patients with heterozygous familial hypercholesterolemia diagnosed by Simon Broome criteria with LDL-C ≥2.6 mmol/L (100 mg/dL) despite statin therapy with or without ezetimibe were randomized 1:1:1 to AMG 145 350 mg, AMG 145 420 mg, or placebo-administered subcutaneously every 4 weeks. The primary end point was percentage change from baseline in LDL-C at week 12. Of 168 patients randomized, 167 received investigational product and were included in the full analysis set (mean [SD] age, 50 [13] years; 47% female; 89% white; mean [SD] baseline LDL-C, 4.0 [1.1] mmol/L (156 [42] mg/dL)). At week 12, LDL-C reduction measured by preparative ultracentrifugation (least squares mean [standard error (SE)]) was 43 (3)% and 55 (3)% with AMG 145 350 mg and 420 mg, respectively, compared with 1 (3)% increase with placebo (P<0.001 for both dose groups). Serious adverse events (not considered treatment-related) occurred in 2 patients on AMG 145. CONCLUSIONS: AMG 145 administered every 4 weeks yielded rapid and substantial reductions in LDL-C in heterozygous familial hypercholesterolemia patients despite intensive statin use, with or without ezetimibe, with minimal adverse events and good tolerability. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01375751.

Efficacy, safety, and tolerability of a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 as monotherapy in patients with hypercholesterolaemia (MENDEL): a randomised, double-blind, placebo-controlled, phase 2 study.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) increases serum LDL-cholesterol (LDL-C) concentrations. We assessed the effects of AMG 145, a human monoclonal antibody against PCSK9, in patients with hypercholesterolaemia in the absence of concurrent lipid-lowering treatment. METHODS: In a phase 2 trial done at 52 centres in Europe, the USA, Canada, and Australia, patients (aged 18-75 years) with serum LDL-C concentrations of 2·6 mmol/L or greater but less than 4·9 mmol/L were randomly assigned equally through an interactive voice response system to subcutaneous injections of AMG 145 70 mg, 105 mg, or 140 mg, or placebo every 2 weeks; subcutaneous AMG 145 280 mg, 350 mg, or 420 mg or placebo every 4 weeks; or oral ezetimibe 10 mg/day. The primary endpoint was percentage change from baseline in LDL-C concentration at week 12. Analysis was by modified intention to treat. Study personnel and patients were masked to treatment assignment of AMG 145 or placebo. Ezetimibe assignment was open label. This trial is registered with ClinicalTrials.gov, number NCT01375777. FINDINGS: 406 patients were assigned to AMG 145 70 mg (n=45), 105 mg (n=46), or 140 mg (n=45) every 2 weeks; AMG 145 280 mg (n=45), 350 mg (n=45), or 420 mg (n=45) every 4 weeks; placebo every 2 weeks (n=45) or every 4 weeks (n=45); or ezetimibe (n=45). AMG 145 significantly reduced LDL-C concentrations in all dose groups (mean baseline LDL-C concentration 3·7 mmol/L [SD 0·6]; changes from baseline with every 2 weeks AMG 145 70 mg -41·0% [95% CI -46·2 to -35·8]; 105 mg -43·9% [-49·0 to -38·7]; 140 mg -50·9% [-56·2 to -45·7]; every 4 weeks AMG 145 280 mg -39·0% [-44·1 to -34·0]; 350 mg -43·2% [-48·3 to -38·1]; 420 mg -48·0% [-53·1 to -42·9]; placebo every 2 weeks -3·7% [-9·0 to 1·6]; placebo every 4 weeks 4·5% [-0·7 to 9·8]; and ezetimibe -14·7% [-18·6 to -10·8]; p<0·0001 for all doses vs placebo or ezetimibe). Treatment-emergent adverse events occurred in 136 (50%) of 271 patients in the AMG 145 groups, 41 (46%) of 90 patients in the placebo groups, and 26 (58%) of 45 patients in the ezetimibe group; no deaths or serious treatment-related adverse events were reported. INTERPRETATION: The results of our study support the further assessment of AMG 145 in long-term studies with larger and more diverse populations including patients with documented statin intolerance. FUNDING: Amgen.

Effect of a monoclonal antibody to PCSK9 on low-density lipoprotein cholesterol levels in statin-intolerant patients: the GAUSS randomized trial.

CONTEXT: An estimated 10% to 20% of patients cannot tolerate statins or adequate doses to achieve treatment goals. Plasma proprotein convertase subtilisin/kexin type 9 (PCSK9) binds to low-density lipoprotein (LDL) receptors, promoting their degradation and increasing LDL cholesterol levels. In phase 1 studies, a human monoclonal antibody to PCSK9, AMG145, was well tolerated and reduced LDL cholesterol levels. OBJECTIVE: To assess the efficacy and tolerability of AMG145 in patients with statin intolerance due to muscle-related side effects. DESIGN, SETTING, AND PATIENTS: A 12-week, randomized, double-blind, placebo- and ezetimibe-controlled, dose-ranging study conducted between July 2011 and May 2012 in statin-intolerant adult patients at 33 international sites. INTERVENTION: Patients were randomized equally to 1 of 5 groups: AMG145 alone at doses of 280 mg, 350 mg, or 420 mg; AMG145 at 420 mg plus 10 mg of ezetimibe; or 10 mg of ezetimibe plus placebo. AMG145 or placebo was administered subcutaneously every 4 weeks. MAIN OUTCOME MEASURES: The primary end point was percentage change from baseline to week 12 in ultracentrifugation-measured LDL cholesterol. Other end points included measures of safety and tolerability of different doses of AMG145 and AMG145 plus ezetimibe. RESULTS: Of 236 patients screened, 160 were randomized (mean age, 62 years; 64% female; mean baseline LDL cholesterol, 193 mg/dL); all patients had intolerance to 1 or more statins because of muscle-related events. At week 12, mean changes in LDL cholesterol levels were -67 mg/dL (-41%; 95% CI, -49% to -33%) for the AMG145, 280-mg, group; -70 mg/dL (-43%; 95% CI, -51% to -35%) for the 350-mg group; -91 mg/dL (-51%; 95% CI, -59% to -43%) for the 420-mg group; and -110 mg/dL (-63%; 95% CI, -71% to -55%) for the 420-mg/ezetimibe group compared with -14 mg/dL (-15%; 95% CI, -23% to -7.0%) for the placebo/ezetimibe group (P < .001). Four serious adverse events were reported with AMG145 (coronary artery disease, acute pancreatitis, hip fracture, syncope). Myalgia was the most common treatment-emergent adverse event during the study, occurring in 5 patients (15.6%) in the 280-mg group (n = 32); 1 patient (3.2%) in the 350-mg group (n = 31), 1 patient (3.1%) in the 420-mg group (n = 32), 6 patients (20.0%) receiving 420-mg AMG145/ezetimibe, and 1 patient (3.1%) receiving placebo/ezetimibe. CONCLUSION: In this phase 2 study in statin-intolerant patients, subcutaneous administration of a monoclonal antibody to PCSK9 significantly reduced LDL cholesterol levels and was associated with short-term tolerability. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01375764.