Traumatic Axonal Injury in the Optic Nerve: The Selective Role of SARM1 in the Evolution of Distal Axonopathy.

Traumatic axonal injury (TAI), thought to be caused by rotational acceleration of the head, is a prevalent neuropathology in traumatic brain injury (TBI). TAI in the optic nerve is a common finding in multiple blunt-force TBI models and hence a great model to study mechanisms and treatments for TAI, especially in view of the compartmentalized anatomy of the visual system. We have previously shown that the somata and the proximal, but not distal, axons of retinal ganglion cells (RGC) respond to DLK/LZK blockade after impact acceleration of the head (IA-TBI). Here, we explored the role of the sterile alpha and TIR-motif containing 1 (SARM1), the key driver of Wallerian degeneration (WD), in the progressive breakdown of distal and proximal segments of the optic nerve following IA-TBI with high-resolution morphological and classical neuropathological approaches. Wild type and Sarm1 knockout (KO) mice received IA-TBI or sham injury and were allowed to survive for 3, 7, 14, and 21 days. Ultrastructural and microscopic analyses revealed that TAI in the optic nerve is characterized by variable involvement of individual axons, ranging from apparent early disconnection of a subpopulation of axons to a range of ongoing axonal and myelin perturbations. Traumatic axonal injury resulted in the degeneration of a population of axons distal and proximal to the injury, along with retrograde death of a subpopulation of RGCs. Quantitative analyses on proximal and distal axons and RGC somata revealed that different neuronal domains exhibit differential vulnerability, with distal axon segments showing more severe degeneration compared with proximal segments and RGC somata. Importantly, we found that Sarm1 KO had a profound effect in the distal optic nerve by suppressing axonal degeneration by up to 50% in the first 2 weeks after IA-TBI, with a continued but lower effect at 3 weeks, while also suppressing microglial activation. Sarm1 KO had no evident effect on the initial traumatic disconnection and did not ameliorate the proximal optic axonopathy or the subsequent attrition of RGCs, indicating that the fate of different axonal segments in the course of TAI may depend on distinct molecular programs within axons.

Protective effects of NAMPT or MAPK inhibitors and NaR on Wallerian degeneration of mammalian axons.

Wallerian degeneration (WD) is a conserved axonal self-destruction program implicated in several neurological diseases. WD is driven by the degradation of the NAD+ synthesizing enzyme NMNAT2, the buildup of its substrate NMN, and the activation of the NAD+ degrading SARM1, eventually leading to axonal fragmentation. The regulation and amenability of these events to therapeutic interventions remain unclear. Here we explored pharmacological strategies that modulate NMN and NAD+ metabolism, namely the inhibition of the NMN-synthesizing enzyme NAMPT, activation of the nicotinic acid riboside (NaR) salvage pathway and inhibition of the NMNAT2-degrading DLK MAPK pathway in an axotomy model in vitro. Results show that NAMPT and DLK inhibition cause a significant but time-dependent delay of WD. These time-dependent effects are related to NMNAT2 degradation and changes in NMN and NAD+ levels. Supplementation of NAMPT inhibition with NaR has an enhanced effect that does not depend on timing of intervention and leads to robust protection up to 4 days. Additional DLK inhibition extends this even further to 6 days. Metabolite analyses reveal complex effects indicating that NAMPT and MAPK inhibition act by reducing NMN levels, ameliorating NAD+ loss and suppressing SARM1 activity. Finally, the axonal NAD+/NMN ratio is highly predictive of cADPR levels, extending previous cell-free evidence on the allosteric regulation of SARM1. Our findings establish a window of axon protection extending several hours following injury. Moreover, we show prolonged protection by mixed treatments combining MAPK and NAMPT inhibition that proceed via complex effects on NAD+ metabolism and inhibition of SARM1.

Lipid lowering with bempedoic acid added to a proprotein convertase subtilisin/kexin type 9 inhibitor therapy: A randomized, controlled trial.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is) lower low-density lipoprotein cholesterol (LDL-C) in patients with hypercholesterolemia. However, some patients receiving PCSK9i therapy might require additional lipid-lowering therapy (LLT) to reach LDL-C goals. Bempedoic acid is an oral, once-daily, ATP-citrate lyase inhibitor that significantly lowers LDL-C in patients with hypercholesterolemia when given alone or as add-on therapy to statins and/or ezetimibe. OBJECTIVE: Assess safety and efficacy of bempedoic acid added to PCSK9i (evolocumab) background therapy in patients with hypercholesterolemia. METHODS: This phase 2, randomized, double-blind, placebo-controlled study was conducted in three phases: 1.5-month screening/washout period including discontinuation of all LLTs, a 3-month period wherein patients initiated background PCSK9i therapy, and a 2-month treatment period in which patients were randomized 1:1 to receive bempedoic acid 180 mg or placebo once daily while continuing PCSK9i therapy. RESULTS: Of 59 patients randomized, 57 completed the study. Mean baseline LDL-C after 3 months of PCSK9i background therapy was 103.1 ± ±â€¯30.4 mg/dL. Bempedoic acid added to background PCSK9i therapy significantly lowered LDL-C by 30.3% (P < .001) vs placebo. Compared with placebo, bempedoic acid significantly lowered apolipoprotein B, non-high-density lipoprotein cholesterol, and total cholesterol (nominal P < .001 for all), and high-sensitivity C-reactive protein (P = .029). When added to background PCSK9i therapy, the safety profile of bempedoic acid was comparable to that observed for placebo. CONCLUSIONS: When added to a background of PCSK9i therapy, bempedoic acid significantly lowered LDL-C levels with a safety profile comparable to placebo in patients with hypercholesterolemia.

Pharmacodynamic relationship between PCSK9, alirocumab, and LDL-C lowering in the ODYSSEY CHOICE I trial.

BACKGROUND: The ODYSSEY CHOICE I study (NCT01926782) evaluated alirocumab 300 mg every 4 weeks (Q4W) in patients with hypercholesterolemia receiving maximally tolerated statin or no statin. OBJECTIVE: The objective of the study was to assess the relationship between alirocumab, proprotein convertase subtilisin/kexin type 9 (PCSK9), and low-density lipoprotein cholesterol (LDL-C) concentrations with the CHOICE I alirocumab dosing regimen. METHODS: This analysis included 803 patients (547 statin-treated, 256 without statin) who were randomized to alirocumab 300 mg Q4W, alirocumab 75 mg every 2 weeks (Q2W), or placebo. 300 mg Q4W and 75 mg Q2W doses were adjusted to 150 mg Q2W at Week 12 if Week 8 LDL-C was >70 or >100 mg/dL, depending on cardiovascular risk, or if LDL-C reduction was <30% from baseline. RESULTS: Most patients remained on 300 mg Q4W without dose adjustment as they achieved study-defined LDL-C goals at Week 8 (statin-treated: 80.7%; no statin: 85.3%). LDL-C was reduced by 60.5%-71.9% over Weeks 20-24 in patients on 300 mg Q4W and 57.2%-63.0% in patients with dose adjustment from 300 mg Q4W to 150 mg Q2W. Statin-treated patients had higher cardiovascular risk as well as higher free PCSK9 and lower alirocumab concentrations (vs no statin), suggesting increased target-mediated clearance. Regardless of statin status, the most common adverse events in alirocumab-treated patients were injection-site reaction and headache. CONCLUSIONS: Data provide further insight on alirocumab's mode of action in terms of relationship between alirocumab, PCSK9, and LDL-C, and disease severity, and support the use of alirocumab 300 mg Q4W as an efficacious dosing regimen for clinically meaningful LDL-C reductions.

Alirocumab in high-risk patients: Observations from the open-label expanded use program.

BACKGROUND: The alirocumab expanded use program provided open-label access to alirocumab before its commercial availability to patients with severe hypercholesterolemia not controlled with maximally tolerated doses of standard-of-care lipid-lowering therapy. OBJECTIVE: To describe the safety and lipid-lowering efficacy of alirocumab in high-risk patients who were likely to be early users of proprotein convertase subtilisin/kexin type 9 inhibitors after approval. METHODS: Patients with heterozygous familial hypercholesterolemia (HeFH) and/or coronary heart disease (CHD) and baseline low-density lipoprotein cholesterol (LDL-C) of ≥160 mg/dL on maximally tolerated lipid-lowering therapy were enrolled and received alirocumab 150 mg every 2 weeks for 24 weeks. Patients were permitted use of all available statins; those not taking any dose of statin could also be enrolled. RESULTS: Of 100 enrolled patients, 93 were white, 62 were women, and overall mean age was 58 years; 61 had HeFH, 3 had unknown type of familial hypercholesterolemia, 66 had CHD, and 30 had both familial hypercholesterolemia and CHD. Sixty-four patients were identified by their providers to have some level of statin intolerance; of these, 47 were not on statin. Alirocumab reduced LDL-C on average from 221 mg/dL at baseline to 102 mg/dL by week 24 (-55%). Treatment-emergent adverse events were experienced in 61% of patients and treatment-emergent adverse events leading to permanent treatment discontinuation in 3% of patients; no deaths occurred. CONCLUSIONS: Safety and efficacy observations from the open-label alirocumab expanded use program of very high-risk patients with HeFH and/or CHD and baseline LDL-C of ≥160 mg/dL uncontrolled by maximally tolerated lipid-lowering therapy were consistent with those in the placebo/ezetimibe-controlled ODYSSEY trials.

Efficacy and Safety of Alirocumab Versus Ezetimibe Over 2 Years (from ODYSSEY COMBO II).

The proprotein convertase subtilisin/kexin type 9 inhibitor alirocumab has been shown to substantially reduce low-density lipoprotein cholesterol (LDL-C). Demonstrating whether efficacy and safety are maintained over a long duration of exposure is vital for clinical decision-making. The COMBO II trial compared the efficacy and safety of alirocumab versus ezetimibe over 2 years. A prespecified first analysis was reported at 52 weeks. Here we report the final end-of-study data (on-treatment) and evaluate post hoc the safety profile with longer versus shorter duration of alirocumab exposure. Patients (n = 720) on maximally tolerated statin dose were treated with alirocumab (75/150 mg every 2 weeks) or ezetimibe (10 mg/day). Overall mean adherence for both treatment groups during the first and second year was >97%. At 2 years, LDL-C was reduced by 49% (alirocumab) versus 17% (ezetimibe; p <0.0001), and LDL-C <70 mg/dl was achieved by 73% of alirocumab-treated versus 40% of ezetimibe-treated patients. Overall safety was similar in both treatment groups at 2 years and during the first versus the second year. Local injection-site reactions were reported by 2.5% (alirocumab) versus 0.8% (ezetimibe) during the first year, and 0.2% versus 0.5% during the second year, indicating early occurrence during prolonged alirocumab exposure. Two consecutive calculated LDL-C values <25 mg/dl were observed in 28% of alirocumab-treated patients (vs 0.4% with ezetimibe). Persistent anti-drug antibody responses were observed in 1.3% (6 of 454) of alirocumab-treated versus 0.4% (1 of 231) of ezetimibe-treated patients. Neutralizing antibodies (that inhibit binding in vitro) were observed in 1.5% (7 of 454) of alirocumab-treated patients (0 with ezetimibe), mostly at isolated time points. Alirocumab sustained substantial LDL-C reductions and was well tolerated up to 2 years in the COMBO II trial.

Effect of ETC-1002 on Serum Low-Density Lipoprotein Cholesterol in Hypercholesterolemic Patients Receiving Statin Therapy.

ETC-1002 is an oral, once-daily medication that inhibits adenosine triphosphate citrate lyase, an enzyme upstream of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, to reduce cholesterol biosynthesis. ETC-1002 monotherapy has demonstrated significant reduction in low-density lipoprotein cholesterol (LDL-C) compared with placebo in phase 2 studies. The objective of this study was to compare the lipid-lowering efficacy of ETC-1002 versus placebo when added to ongoing statin therapy in patients with hypercholesterolemia. This phase 2b, multicenter, double-blind trial (NCT02072161) randomized 134 hypercholesterolemic patients (LDL-C, 115 to 220 mg/dl) on stable background statin therapy to 12 weeks of add-on treatment with ETC-1002 120 mg, ETC-1002 180 mg, or placebo. The primary efficacy end point was the percent change in calculated LDL-C from baseline to week 12. For LDL-C, the least-squares mean percent change ± standard error from baseline to week 12 was significantly greater with ETC-1002 120 mg (-17 ± 4%, p = 0.0055) and ETC-1002 180 mg (-24 ± 4%, p <0.0001) than placebo (-4 ± 4%). ETC-1002 also dose dependently reduced apolipoprotein B by 15% to 17%, non-high-density lipoprotein cholesterol by 14% to 17%, total cholesterol by 13% to 15%, and LDL particle number by 17% to 21%. All these reductions in ETC-1002-treated cohorts were significantly greater than those with placebo. Rates of adverse events (AEs), muscle-related AEs, and discontinuations for AEs with ETC-1002 were similar to placebo. In conclusion, ETC-1002 120 mg or 180 mg added to stable statin therapy significantly reduced LDL-C compared to placebo and has a similar tolerability profile.

Treatment with ETC-1002 alone and in combination with ezetimibe lowers LDL cholesterol in hypercholesterolemic patients with or without statin intolerance.

BACKGROUND: ETC-1002 is an oral, once-daily, first-in-class medication being developed to treat hypercholesterolemia. OBJECTIVES: To compare 2 doses of ETC-1002, alone or combined with ezetimibe 10 mg (EZE), vs EZE monotherapy for lowering low-density lipoprotein cholesterol (LDL-C). METHODS: This phase 2b, multicenter, double-blind trial-evaluated hypercholesterolemic patients (LDL-C, 130 to 220 mg/dL) with (n = 177) or without (n = 171) muscle-related intolerance to ≥2 statins; 1 at lowest approved dose. Subjects were randomized to 12-week treatment with ETC-1002 120 mg or ETC-1002 180 mg alone, EZE alone, ETC-1002 120 mg plus EZE, or ETC-1002 180 mg plus EZE. RESULTS: EZE alone lowered LDL-C by 21%, whereas ETC-1002 monotherapy with 120 mg or 180 mg reduced LDL-C by 27% (P = .0008 vs EZE) and 30% (P < .0001 vs EZE), respectively. The combination of ETC-1002, 120 mg or 180 mg plus EZE reduced LDL-C by 43% and 48%, respectively (both P < .0001 vs EZE). ETC-1002 alone or combined with EZE also reduced non-high-density lipoprotein cholesterol, total cholesterol, apolipoprotein B, LDL particle number, and high-sensitivity C-reactive protein compared with EZE alone. Across all treatment groups, statin-intolerant patients reported more muscle-related adverse events than did statin-tolerant patients. ETC-1002 was safe and well tolerated, and rates of muscle-related adverse events were similar in all treatment groups. CONCLUSIONS: In patients with and without statin intolerance, daily treatment with ETC-1002 120 mg and 180 mg alone or with EZE reduced LDL-C more than EZE alone and had a similar tolerability profile (NCT01941836).

JCL roundtable: PCSK9 inhibitors in clinical practice.

The roundtable this month will involve a discussion of two new drugs that have been approved by the Food and Drug Administration for the reduction of low-density lipoprotein cholesterol (LDL-C). The Food and Drug Administration approved the first of these, alirocumab as an "adjunct to diet and maximally tolerated statin therapy for the treatment of adults with heterozygous familial hypercholesterolemia or clinical atherosclerotic cardiovascular disease, who require additional lowering of LDL [low-density lipoprotein]-cholesterol." Evolucumab has similar indications plus an indication specifically for treatment of homozygous familial hypercholesterolemia. This sets the stage for their clinical use and in this roundtable, we will discuss with two experts, the implications of these indications for the practicing physician. Dr McKenney and Dr Moriarty have had extensive experience in the conduct of clinical trials that provided the evidence of safety and efficacy of these so called PCSK9 inhibitors.

Effect of alirocumab on specific lipoprotein non-high-density lipoprotein cholesterol and subfractions as measured by the vertical auto profile method: analysis of 3 randomized trials versus placebo.

BACKGROUND: The effect of alirocumab on potentially atherogenic lipoprotein subfractions was assessed in a post hoc analysis using the vertical auto profile (VAP) method. METHODS: Patients from three Phase II studies with low-density lipoprotein cholesterol (LDL-C) ≥ 2.59 mmol/L (100 mg/dL) at baseline on stable statin therapy were randomised to receive subcutaneous alirocumab 50-150 mg every 2 weeks (Q2W) or 150-300 mg every 4 weeks (according to study) or placebo for 8-12 weeks. Samples from patients treated with alirocumab 150 mg Q2W (n = 74; dose common to all three trials) or placebo (n = 71) were analysed by VAP. Percent change in lipoprotein subfractions with alirocumab vs. placebo was analysed at Weeks 6, 8 or 12 using analysis of covariance. RESULTS: Alirocumab significantly reduced LDL-C and the cholesterol content of subfractions LDL1, LDL2 and LDL3+4. Significant reductions were also observed in triglycerides, apolipoproteins CII and CIII and the cholesterol content of very low-density, intermediate-density, and remnant lipoproteins. CONCLUSION: Alirocumab achieved reductions across a spectrum of atherogenic lipoproteins in patients receiving background statin therapy. TRIAL REGISTRATION: Clinicaltrials.gov identifiers: NCT01288443, NCT01288469, NCT01266876.

National Lipid Association Recommendations for Patient-Centered Management of Dyslipidemia: Part 2.

An Expert Panel convened by the National Lipid Association previously developed a consensus set of recommendations for the patient-centered management of dyslipidemia in clinical medicine (part 1). These were guided by the principle that reducing elevated levels of atherogenic cholesterol (non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol) reduces the risk for atherosclerotic cardiovascular disease. This document represents a continuation of the National Lipid Association recommendations developed by a diverse panel of experts who examined the evidence base and provided recommendations regarding the following topics: (1) lifestyle therapies; (2) groups with special considerations, including children and adolescents, women, older patients, certain ethnic and racial groups, patients infected with human immunodeficiency virus, patients with rheumatoid arthritis, and patients with residual risk despite statin and lifestyle therapies; and (3) strategies to improve patient outcomes by increasing adherence and using team-based collaborative care.

Effect of PCSK9 Inhibition by Alirocumab on Lipoprotein Particle Concentrations Determined by Nuclear Magnetic Resonance Spectroscopy.

BACKGROUND: In patients with discordance between low-density lipoprotein (LDL) cholesterol and LDL particle (LDL-P) concentrations, cardiovascular risk more closely correlates with LDL-P. METHODS AND RESULTS: We investigated the effect of alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9, on lipoprotein particle concentration and size in hypercholesterolemic patients, using nuclear magnetic resonance spectroscopy. Plasma samples were collected from patients receiving alirocumab 150 mg every 2 weeks (n=26) or placebo (n=31) during a phase II, double-blind, placebo-controlled trial in patients (LDL cholesterol ≥100 mg/dL) on a stable atorvastatin dose. In this post hoc analysis, percentage change in concentrations of LDL-P, very-low-density lipoprotein particles, and high-density lipoprotein particles from baseline to week 12 was determined by nuclear magnetic resonance. Alirocumab significantly reduced mean concentrations of total LDL-P (-63.3% versus -1.0% with placebo) and large (-71.3% versus -21.8%) and small (-54.0% versus +17.8%) LDL-P subfractions and total very-low-density lipoprotein particle concentrations (-36.4% versus +33.4%; all P<0.01). Total high-density lipoprotein particles increased with alirocumab (+11.2% versus +1.4% with placebo; P<0.01). There were greater increases in large (44.6%) versus medium (17.7%) or small high-density lipoprotein particles (2.8%) with alirocumab. LDL-P size remained relatively unchanged in both groups; however, very-low-density and high-density lipoprotein particle sizes increased to a significantly greater extent with alirocumab. CONCLUSIONS: Alirocumab significantly reduced LDL-C and LDL-P concentrations in hypercholesterolemic patients receiving stable atorvastatin therapy. These findings may be of particular relevance to patients with discordant LDL-C and LDL-P concentrations. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT01288443.

Safety and tolerability of extended-release niacin-laropiprant: Pooled analyses for 11,310 patients in 12 controlled clinical trials.

BACKGROUND: The Heart Protection Study 2-Treatment of HDL to Reduce the Incidence of Vascular Events (HPS2-THRIVE) showed that adding extended-release niacin-laropiprant (ERN-LRPT) to statin provided no incremental cardiovascular benefit vs placebo (PBO). ERN-LRPT was also associated with an excess of serious adverse experiences (AEs), some of which were unexpected (infections and bleeding). These findings led to the withdrawal of ERN-LRPT from all markets. OBJECTIVE: We examined the safety profile of ERN-LRPT vs the comparators ERN alone and statins in the ERN-LRPT development program to assess whether similar safety signals were observed to those seen in HPS-THRIVE and whether these might be attributed to ERN or LRPT. METHODS: Postrandomization safety data from 12 clinical studies, 12 to 52 weeks in duration and involving 11,310 patients, were analyzed across 3 treatments: (1) ERN-LRPT; (2) ERN-NSP (ERN, Merck & Co, Inc or Niaspan [NSP], Abbott Laboratories); and (3) statin-PBO (statin or PBO). RESULTS: The safety profiles of ERN-LRPT and ERN-NSP were similar, except for less flushing with ERN-LRPT. Nonflushing AEs reported more frequently with ERN-LRPT or ERN-NSP than with statin-PBO were mostly nonserious and typical of niacin (nausea, diarrhea, and increased blood glucose). There was no evidence for an increased risk of serious AEs related to diabetes, muscle, infection, or bleeding. CONCLUSIONS: Pooled data from 11,310 patients revealed that, except for reduced flushing, the safety profile of ERN-LRPT was similar to that of ERN-NSP; LRPT did not appear to adversely affect the side-effect profile of ERN. The inability to replicate the unexpected AE findings in HPS2-THRIVE could be because of the smaller sample size and substantially shorter duration of these studies.

Something important is missing in the ACC/AHA cholesterol treatment guidelines.

OBJECTIVE: To discuss factors surrounding development of the 2013 American College of Cardiology/American Heart Association (ACC/AHA) cholesterol guidelines and reasons they have not yet been adopted by clinicians. SUMMARY: The new ACC/AHA cholesterol guidelines were released in November 2013. The guidelines are based on randomized controlled trial evidence and, if fully implemented, are likely to result in a reduction of atherosclerotic cardiovascular disease (ASCVD) in Americans. Despite this, the guidelines have not been adopted by clinicians. This is because the guidelines are missing something very important-guidance for the clinician and the public. Guidelines are supposed to give guidance to clinicians on how to manage the various clinical presentations encountered in daily practice and to help them translate science into practice. Guidelines are also supposed to help the public define dyslipidemias in a way they can understand and thus seek treatment and actively follow the progress of their treatment. CONCLUSION: The National Lipid Association (NLA) stepped in to help fill the void in the ACC/AHA cholesterol guidelines and offered recommendations for treating individual patients who have increased risk of ASCVD. The NLA recommendations give clinicians the expert guidance and LDL-C goal rudder they need to successfully manage their patient's cholesterol.

National lipid association recommendations for patient-centered management of dyslipidemia: part 1--full report.

The leadership of the National Lipid Association convened an Expert Panel to develop a consensus set of recommendations for patient-centered management of dyslipidemia in clinical medicine. An Executive Summary of those recommendations was previously published. This document provides support for the recommendations outlined in the Executive Summary. The major conclusions include (1) an elevated level of cholesterol carried by circulating apolipoprotein B-containing lipoproteins (non-high-density lipoprotein cholesterol and low-density lipoprotein cholesterol [LDL-C], termed atherogenic cholesterol) is a root cause of atherosclerosis, the key underlying process contributing to most clinical atherosclerotic cardiovascular disease (ASCVD) events; (2) reducing elevated levels of atherogenic cholesterol will lower ASCVD risk in proportion to the extent that atherogenic cholesterol is reduced. This benefit is presumed to result from atherogenic cholesterol lowering through multiple modalities, including lifestyle and drug therapies; (3) the intensity of risk-reduction therapy should generally be adjusted to the patient's absolute risk for an ASCVD event; (4) atherosclerosis is a process that often begins early in life and progresses for decades before resulting a clinical ASCVD event. Therefore, both intermediate-term and long-term or lifetime risk should be considered when assessing the potential benefits and hazards of risk-reduction therapies; (5) for patients in whom lipid-lowering drug therapy is indicated, statin treatment is the primary modality for reducing ASCVD risk; (6) nonlipid ASCVD risk factors should also be managed appropriately, particularly high blood pressure, cigarette smoking, and diabetes mellitus; and (7) the measurement and monitoring of atherogenic cholesterol levels remain an important part of a comprehensive ASCVD prevention strategy.

Understanding PCSK9 and anti-PCSK9 therapies.

Inhibitors of proprotein convertase subtilisin kexin type 9 (PCSK9) represent a new therapeutic category of drugs for the treatment of dyslipidemia and atherosclerotic cardiovascular disease. To appreciate the efficacy of these agents and interpret research results, it is important to understand the dynamic relationship between PCSK9, low-density lipoprotein-receptors, intrahepatic cholesterol synthesis, and blood cholesterol levels. Drugs which negate the action of PCSK9 can produce substantial reductions in atherogenic lipoprotein cholesterol-carrying particles and thereby hold the potential for further reducing events associated with atherosclerotic cardiovascular disease. This article will describe and discuss PCSK9 interactive mechanisms and apply them to the interpretation of clinical trial results, which involve PCSK9 monoclonal antibodies.

Efficacy and safety of alirocumab in high cardiovascular risk patients with inadequately controlled hypercholesterolaemia on maximally tolerated doses of statins: the ODYSSEY COMBO II randomized controlled trial.

AIMS: To compare the efficacy [low-density lipoprotein cholesterol (LDL-C) lowering] and safety of alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin 9, compared with ezetimibe, as add-on therapy to maximally tolerated statin therapy in high cardiovascular risk patients with inadequately controlled hypercholesterolaemia. METHODS AND RESULTS: COMBO II is a double-blind, double-dummy, active-controlled, parallel-group, 104-week study of alirocumab vs. ezetimibe. Patients (n = 720) with high cardiovascular risk and elevated LDL-C despite maximal doses of statins were enrolled (August 2012-May 2013). This pre-specified analysis was conducted after the last patient completed 52 weeks. Patients were randomized to subcutaneous alirocumab 75 mg every 2 weeks (plus oral placebo) or oral ezetimibe 10 mg daily (plus subcutaneous placebo) on a background of statin therapy. At Week 24, mean ± SE reductions in LDL-C from baseline were 50.6 ± 1.4% for alirocumab vs. 20.7 ± 1.9% for ezetimibe (difference 29.8 ± 2.3%; P < 0.0001); 77.0% of alirocumab and 45.6% of ezetimibe patients achieved LDL-C <1.8 mmol/L (P < 0.0001). Mean achieved LDL-C at Week 24 was 1.3 ± 0.04 mmol/L with alirocumab and 2.1 ± 0.05 mmol/L with ezetimibe, and were maintained to Week 52. Alirocumab was generally well tolerated, with no evidence of an excess of treatment-emergent adverse events. CONCLUSION: In patients at high cardiovascular risk with inadequately controlled LDL-C, alirocumab achieved significantly greater reductions in LDL-C compared with ezetimibe, with a similar safety profile. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01644188.

ODYSSEY MONO: effect of alirocumab 75 mg subcutaneously every 2 weeks as monotherapy versus ezetimibe over 24 weeks.

ABSTRACT Alirocumab is a fully human monoclonal antibody to PCSK9. The ODYSSEY MONO study was the first alirocumab Phase III study to test a previously unused dose of 75 mg subcutaneously every 2 weeks in a population on no lipid-lowering therapy. A total of 103 patients were randomly assigned to alirocumab starting at 75 mg subcutaneously every 2 weeks or ezetimibe 10 mg per os every day with alirocumab dose uptitration at 12 weeks based on achieved LDL-cholesterol level at week 8 and followed to week 24. At the week-24 primary end point, the alirocumab intent-to-treat group showed a 47.2% (least square [LS] mean) reduction in LDL-cholesterol compared with a 15.6% (LS mean) reduction with ezetimibe (LS mean difference of 31.6%; p < 0.0001). Safety parameters and adverse events were similar between the two groups.

Safety and efficacy of alirocumab 150 mg every 2 weeks, a fully human proprotein convertase subtilisin/kexin type 9 monoclonal antibody: A Phase II pooled analysis.

BACKGROUND: Alirocumab, a fully human monoclonal antibody to proprotein convertase subtilisin/kexin type 9, is in Phase III development for the treatment of hypercholesterolemia. In Phase II studies, 150 mg every 2 weeks (Q2W) was the highest Q2W dose studied, and it is currently the highest Q2W dose under development. To better assess the safety and efficacy of this dose, data across three Phase II studies were pooled. METHODS: We analyzed data from three double-blind, randomized, placebo-controlled Phase II studies of 8 or 12 weeks' duration. In the current analysis, 77 patients were randomized to the control group and 108 were randomized to alirocumab 150 mg Q2W administered via a single 1 mL subcutaneous injection. RESULTS: Adverse events (AEs) occurred in 58.3% of alirocumab patients compared with 54.5% of placebo-controlled patients. The most common AE was mild, transient injection-site reactions. No signal for muscle symptoms such as myalgia and no cases of neurocognitive effects were reported or observed. One alirocumab patient, also receiving atorvastatin 80 mg/day, had an increase in aspartate transaminase 3 to 5 times the upper limit of normal. Alirocumab 150 mg Q2W reduced low-density lipoprotein cholesterol (LDL-C) from baseline by 68.4% compared with 10.5% for the control group. More than 90% of patients achieved an LDL-C target of < 70 mg/dL with alirocumab versus 8% with control. Marked reductions in other atherogenic lipids and modest increases in high-density lipoprotein cholesterol were also observed. CONCLUSION: At the highest Q2W dose under development (150 mg), alirocumab appears well tolerated and produces robust LDL-C reductions. These data suggest that alirocumab 150 mg Q2W is an appropriate dose for further evaluation in Phase III trials.