PCSK9 Variants, Low-Density Lipoprotein Cholesterol, and Neurocognitive Impairment: Reasons for Geographic and Racial Differences in Stroke Study (REGARDS).
Mefford Matthew T,Rosenson Robert S,Cushman Mary,Farkouh Michael E,McClure Leslie A,Wadley Virginia G,Irvin Marguerite R,Bittner Vera,Safford Monika M,Somaratne Ransi,Monda Keri L,Muntner Paul,Levitan Emily B
BACKGROUND:Despite concerns about adverse neurocognitive events raised by prior trials, pharmacological PCSK9 (proprotein convertase subtilisin/kexin type-9) inhibition was not associated with neurocognitive effects in a recent phase 3 randomized trial. PCSK9 loss-of-function (LOF) variants that result in lifelong exposure to lower levels of low-density lipoprotein cholesterol can provide information on the potential long-term effects of lower low-density lipoprotein cholesterol on neurocognitive impairment and decline. METHODS:We investigated the association between PCSK9 LOF variants and neurocognitive impairment and decline among black REGARDS study (Reasons for Geographic and Racial Differences in Stroke) participants with (n=241) and without (n=10 454) C697X or Y142X LOF variants. Neurocognitive tests included the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) battery (Word List Learning, World List Delayed Recall, Semantic Animal Fluency) and Six-Item Screener (SIS) assessments, administered longitudinally during follow-up. Neurocognitive impairment was defined as a score ≥1.5 SD below age, sex, and education-based stratum-specific means on 2 or 3 CERAD assessments or, separately, a score <5 on any SIS assessment at baseline or during follow-up. Neurocognitive decline was assessed using standardized continuous scores on individual neurocognitive tests. RESULTS:The mean sample age was 64 years (SD, 9), 62% were women, and the prevalence of neurocognitive impairment at any assessment was 6.3% by CERAD and 15.4% by SIS definitions. Adjusted odds ratios for neurocognitive impairment for participants with versus without PCSK9 LOF variants were 1.11 (95% confidence interval [CI], 0.58-2.13) using the CERAD battery and 0.89 (95% CI, 0.61-1.30) using the SIS assessment. Standardized average differences in individual neurocognitive assessment scores over the 5.6-year (range, 0.1-9.1) study period ranged between 0.07 (95% CI, -0.06 to 0.20) and -0.07 (95% CI, -0.18 to 0.05) among participants with versus without PCSK9 LOF variants. Patterns of neurocognitive decline were similar between participants with and without PCSK9 LOF variants (all >0.10). Odds ratios for neurocognitive impairment per 20 mg/dL low-density lipoprotein cholesterol decrements were 1.02 (95% CI, 0.96-1.08) and 0.99 (95% CI, 0.95-1.02) for the CERAD and SIS definitions of impairment, respectively. CONCLUSIONS:These results suggest that lifelong exposure to low PCSK9 levels and cumulative exposure to lower levels of low-density lipoprotein cholesterol are not associated with neurocognitive effects in blacks.
Effect of the PCSK9 Inhibitor Evolocumab on Total Cardiovascular Events in Patients With Cardiovascular Disease: A Prespecified Analysis From the FOURIER Trial.
Murphy Sabina A,Pedersen Terje R,Gaciong Zbigniew A,Ceska Richard,Ezhov Marat V,Connolly Derek L,Jukema J Wouter,Toth Kalman,Tikkanen Matti J,Im Kyungah,Wiviott Stephen D,Kurtz Christopher E,Honarpour Narimon,Giugliano Robert P,Keech Anthony C,Sever Peter S,Sabatine Marc S
Importance:The PCSK9 inhibitor evolocumab reduced low-density lipoprotein cholesterol and first cardiovascular events in the Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk (FOURIER) trial, but patients remain at high risk of recurrent cardiovascular events. Objective:To evaluate the effect of evolocumab on total cardiovascular events, given the importance of total number of cardiovascular events to patients, clinicians, and health economists. Design, Setting, and Participants:Secondary analysis of a randomized, double-blind clinical trial. The FOURIER trial compared evolocumab or matching placebo and followed up patients for a median of 2.2 years. The study included 27 564 patients with stable atherosclerotic disease receiving statin therapy. Data were analyzed between May 2017 and February 2019. Main Outcomes and Measures:The primary end point (PEP) was time to first cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, or coronary revascularization; the key secondary end point was time to first cardiovascular death, myocardial infarction, or stroke. In a prespecified analysis, total cardiovascular events were evaluated between treatment arms. Results:The mean age of patients was 63 years, 69% of patients were taking high-intensity statin therapy, and the median LDL-C at baseline was 92 mg/dL (to convert to millimoles per liter, multiply by 0.0259). There were 2907 first PEP events and 4906 total PEP events during the trial. Evolocumab reduced total PEP events by 18% (incidence rate ratio [RR], 0.82; 95% CI, 0.75-0.90; P < .001) including both first events (hazard ratio, 0.85; 95% CI, 0.79-0.92; P < .001) and subsequent events (RR, 0.74; 95% CI, 0.65-0.85). There were 2192 total primary events in the evolocumab group and 2714 total events in the placebo group. For every 1000 patients treated for 3 years, evolocumab prevented 22 first PEP events and 52 total PEP events. Reductions in total events were driven by fewer total myocardial infarctions (RR, 0.74; 95% CI, 0.65-0.84; P < .001), strokes (RR, 0.77; 95% CI, 0.64-0.93; P = .007), and coronary revascularizations (RR, 0.78; 95% CI, 0.71-0.87; P < .001). Conclusions and Relevance:The addition of the PCSK9 inhibitor evolocumab to statin therapy improved clinical outcomes, with significant reductions in total PEP events, driven by decreases in myocardial infarction, stroke, and coronary revascularization. More than double the number of events were prevented with evolocumab vs placebo as compared with the analysis of only first events. These data provide further support for the benefit of continuing aggressive lipid-lowering therapy to prevent recurrent cardiovascular events. Trial Registration:ClinicalTrials.gov identifier: NCT01764633.
Lipoprotein(a), PCSK9 Inhibition, and Cardiovascular Risk.
O'Donoghue Michelle L,Fazio Sergio,Giugliano Robert P,Stroes Erik S G,Kanevsky Estella,Gouni-Berthold Ioanna,Im KyungAh,Lira Pineda Armando,Wasserman Scott M,Češka Richard,Ezhov Marat V,Jukema J Wouter,Jensen Henrik K,Tokgözoğlu S Lale,Mach François,Huber Kurt,Sever Peter S,Keech Anthony C,Pedersen Terje R,Sabatine Marc S
BACKGROUND:Lipoprotein(a) [Lp(a)] may play a causal role in atherosclerosis. PCSK9 (proprotein convertase subtilisin/kexin 9) inhibitors have been shown to significantly reduce plasma Lp(a) concentration. However, the relationship between Lp(a) levels, PCSK9 inhibition, and cardiovascular risk reduction remains undefined. METHODS:Lp(a) was measured in 25 096 patients in the FOURIER trial (Further Cardiovascular Outcomes Research with PCSK9 Inhibition in Subjects with Elevated Risk), a randomized trial of evolocumab versus placebo in patients with established atherosclerotic cardiovascular disease (median follow-up, 2.2 years). Cox models were used to assess the independent prognostic value of Lp(a) and the efficacy of evolocumab for coronary risk reduction by baseline Lp(a) concentration. RESULTS:The median (interquartile range) baseline Lp(a) concentration was 37 (13-165) nmol/L. In the placebo arm, patients with baseline Lp(a) in the highest quartile had a higher risk of coronary heart disease death, myocardial infarction, or urgent revascularization (adjusted hazard ratio quartile 4: quartile 1, 1.22; 95% CI, 1.01-1.48) independent of low-density lipoprotein cholesterol. At 48 weeks, evolocumab significantly reduced Lp(a) by a median (interquartile range) of 26.9% (6.2%-46.7%). The percent change in Lp(a) and low-density lipoprotein cholesterol at 48 weeks in patients taking evolocumab was moderately positively correlated ( r=0.37; 95% CI, 0.36-0.39; P<0.001). Evolocumab reduced the risk of coronary heart disease death, myocardial infarction, or urgent revascularization by 23% (hazard ratio, 0.77; 95% CI, 0.67-0.88) in patients with a baseline Lp(a) >median, and by 7% (hazard ratio, 0.93; 95% CI, 0.80-1.08; P interaction=0.07) in those ≤median. Coupled with the higher baseline risk, the absolute risk reductions, and number needed to treat over 3 years were 2.49% and 40 versus 0.95% and 105, respectively. CONCLUSIONS:Higher levels of Lp(a) are associated with an increased risk of cardiovascular events in patients with established cardiovascular disease irrespective of low-density lipoprotein cholesterol. Evolocumab significantly reduced Lp(a) levels, and patients with higher baseline Lp(a) levels experienced greater absolute reductions in Lp(a) and tended to derive greater coronary benefit from PCSK9 inhibition. CLINICAL TRIAL REGISTRATION:URL: https://www.clinicaltrials.gov . Unique identifier: NCT01764633.
Low-Density Lipoprotein Cholesterol Lowering With Evolocumab and Outcomes in Patients With Peripheral Artery Disease: Insights From the FOURIER Trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk).
Bonaca Marc P,Nault Patrice,Giugliano Robert P,Keech Anthony C,Pineda Armando Lira,Kanevsky Estella,Kuder Julia,Murphy Sabina A,Jukema J Wouter,Lewis Basil S,Tokgozoglu Lale,Somaratne Ransi,Sever Peter S,Pedersen Terje R,Sabatine Marc S
BACKGROUND:The PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor evolocumab reduced low-density lipoprotein cholesterol and cardiovascular events in the FOURIER trial (Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk). We investigated the efficacy and safety of evolocumab in patients with peripheral artery disease (PAD) as well as the effect on major adverse limb events. METHODS:FOURIER was a randomized trial of evolocumab versus placebo in 27 564 patients with atherosclerotic disease on statin therapy followed for a median of 2.2 years. Patients were identified as having PAD at baseline if they had intermittent claudication and an ankle brachial index of <0.85, or if they had a prior peripheral vascular procedure. The primary end point was a composite of cardiovascular death, myocardial infarction, stroke, hospital admission for unstable angina, or coronary revascularization. The key secondary end point was a composite of cardiovascular death, myocardial infarction, or stroke. An additional outcome of interest was major adverse limb events defined as acute limb ischemia, major amputation, or urgent peripheral revascularization for ischemia. RESULTS:Three thousand six hundred forty-two patients (13.2%) had PAD (1505 with no prior myocardial infarction or stroke). Evolocumab significantly reduced the primary end point consistently in patients with PAD (hazard ratio [HR] 0.79; 95% confidence interval [CI], 0.66-0.94; =0.0098) and without PAD (HR 0.86; 95% CI, 0.80-0.93; =0.0003; =0.40). For the key secondary end point, the HRs were 0.73 (0.59-0.91; =0.0040) for those with PAD and 0.81 (0.73-0.90; <0.0001) for those without PAD (=0.41). Because of their higher risk, patients with PAD had larger absolute risk reductions for the primary end point (3.5% with PAD, 1.6% without PAD) and the key secondary end point (3.5% with PAD, 1.4% without PAD). Evolocumab reduced the risk of major adverse limb events in all patients (HR, 0.58; 95% CI, 0.38-0.88; =0.0093) with consistent effects in those with and without known PAD. There was a consistent relationship between lower achieved low-density lipoprotein cholesterol and lower risk of limb events (=0.026 for the beta coefficient) that extended down to <10 mg/dL. CONCLUSIONS:Patients with PAD are at high risk of cardiovascular events, and PCSK9 inhibition with evolocumab significantly reduced that risk with large absolute risk reductions. Moreover, lowering of low-density lipoprotein cholesterol with evolocumab reduced the risk of major adverse limb events. CLINICAL TRIAL REGISTRATION:URL: https://www.clinicaltrials.gov. Unique identifier: NCT01764633.
Effects of PCSK9 Inhibition With Alirocumab on Lipoprotein Metabolism in Healthy Humans.
Reyes-Soffer Gissette,Pavlyha Marianna,Ngai Colleen,Thomas Tiffany,Holleran Stephen,Ramakrishnan Rajasekhar,Karmally Wahida,Nandakumar Renu,Fontanez Nelson,Obunike Joseph,Marcovina Santica M,Lichtenstein Alice H,Matthan Nirupa R,Matta James,Maroccia Magali,Becue Frederic,Poitiers Franck,Swanson Brian,Cowan Lisa,Sasiela William J,Surks Howard K,Ginsberg Henry N
BACKGROUND:Alirocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9), lowers plasma low-density lipoprotein (LDL) cholesterol and apolipoprotein B100 (apoB). Although studies in mice and cells have identified increased hepatic LDL receptors as the basis for LDL lowering by PCSK9 inhibitors, there have been no human studies characterizing the effects of PCSK9 inhibitors on lipoprotein metabolism. In particular, it is not known whether inhibition of PCSK9 has any effects on very low-density lipoprotein or intermediate-density lipoprotein (IDL) metabolism. Inhibition of PCSK9 also results in reductions of plasma lipoprotein (a) levels. The regulation of plasma Lp(a) levels, including the role of LDL receptors in the clearance of Lp(a), is poorly defined, and no mechanistic studies of the Lp(a) lowering by alirocumab in humans have been published to date. METHODS:Eighteen (10 F, 8 mol/L) participants completed a placebo-controlled, 2-period study. They received 2 doses of placebo, 2 weeks apart, followed by 5 doses of 150 mg of alirocumab, 2 weeks apart. At the end of each period, fractional clearance rates (FCRs) and production rates (PRs) of apoB and apo(a) were determined. In 10 participants, postprandial triglycerides and apoB48 levels were measured. RESULTS:Alirocumab reduced ultracentrifugally isolated LDL-C by 55.1%, LDL-apoB by 56.3%, and plasma Lp(a) by 18.7%. The fall in LDL-apoB was caused by an 80.4% increase in LDL-apoB FCR and a 23.9% reduction in LDL-apoB PR. The latter was due to a 46.1% increase in IDL-apoB FCR coupled with a 27.2% decrease in conversion of IDL to LDL. The FCR of apo(a) tended to increase (24.6%) without any change in apo(a) PR. Alirocumab had no effects on FCRs or PRs of very low-density lipoproteins-apoB and very low-density lipoproteins triglycerides or on postprandial plasma triglycerides or apoB48 concentrations. CONCLUSIONS:Alirocumab decreased LDL-C and LDL-apoB by increasing IDL- and LDL-apoB FCRs and decreasing LDL-apoB PR. These results are consistent with increases in LDL receptors available to clear IDL and LDL from blood during PCSK9 inhibition. The increase in apo(a) FCR during alirocumab treatment suggests that increased LDL receptors may also play a role in the reduction of plasma Lp(a). CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01959971.
Residual Inflammatory Risk on Treatment With PCSK9 Inhibition and Statin Therapy.
Pradhan Aruna D,Aday Aaron W,Rose Lynda M,Ridker Paul M
BACKGROUND:The combination of statin therapy and PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibition markedly lowers low-density lipoprotein cholesterol (LDL-C) and reduces cardiovascular event rates. Whether residual inflammatory risk as measured by on-treatment high sensitivity C-reactive protein (hsCRP) remains an important clinical issue in such patients is uncertain. METHODS:We evaluated residual inflammatory risk among 9738 patients participating in the SPIRE-1 and SPIRE-2 cardiovascular outcomes trials (Studies of PCSK9 Inhibition and the Reduction in Vascular Events), who were receiving both statin therapy and bococizumab, according to on-treatment levels of hsCRP (hsCRP) and LDL-C measured 14 weeks after drug initiation. The primary end point was nonfatal myocardial infarction, nonfatal stroke, hospitalization for unstable angina requiring urgent revascularization, or cardiovascular death. RESULTS:At 14 weeks, the mean percentage change in LDL-C among statin-treated patients who additionally received bococizumab was -60.5% (95% confidence interval [CI], -61.2 to -59.8; <0.001; median change, -65.4%) as compared to 6.6% (95% CI, -1.0 to 14.1; =0.09; median change, 0.0%) for hsCRP. Incidence rates for future cardiovascular events for patients treated with both statin therapy and bococizumab according to hsCRP <1, 1 to 3, and >3 mg/L were 1.96, 2.50, and 3.59 events per 100 person-years, respectively, corresponding to multivariable adjusted hazard ratios of 1.0, 1.16 (95% CI, 0.81-1.66), and 1.62 (95% CI, 1.14-2.30) (-trend=0.001) after adjustment for traditional cardiovascular risk factors and LDL-C. Comparable adjusted hazard ratios for LDL-C (<30, 30-50, >50 mg/dL) were 1.0, 0.87, and 1.21, respectively (-trend=0.16). Relative risk reductions with bococizumab were similar across hsCRP groups (-interaction=0.87). CONCLUSIONS:In this post hoc analysis of the SPIRE trials of bococizumab in a stable outpatient population, evidence of residual inflammatory risk persisted among patients treated with both statin therapy and proprotein convertase subtilisin-kexin type 9 inhibition. CLINICAL TRIAL REGISTRATION:URL: https://www.clinicaltrials.gov. Unique identifiers: NCT01975376, NCT01975389.
Inhibition of PCSK9 potentiates immune checkpoint therapy for cancer.
Liu Xinjian,Bao Xuhui,Hu Mengjie,Chang Hanman,Jiao Meng,Cheng Jin,Xie Liyi,Huang Qian,Li Fang,Li Chuan-Yuan
Despite its success in achieving the long-term survival of 10-30% of treated individuals, immune therapy is still ineffective for most patients with cancer. Many efforts are therefore underway to identify new approaches that enhance such immune 'checkpoint' therapy (so called because its aim is to block proteins that inhibit checkpoint signalling pathways in T cells, thereby freeing those immune cells to target cancer cells). Here we show that inhibiting PCSK9-a key protein in the regulation of cholesterol metabolism-can boost the response of tumours to immune checkpoint therapy, through a mechanism that is independent of PCSK9's cholesterol-regulating functions. Deleting the PCSK9 gene in mouse cancer cells substantially attenuates or prevents their growth in mice in a manner that depends on cytotoxic T cells. It also enhances the efficacy of immune therapy that is targeted at the checkpoint protein PD1. Furthermore, clinically approved PCSK9-neutralizing antibodies synergize with anti-PD1 therapy in suppressing tumour growth in mouse models of cancer. Inhibiting PCSK9-either through genetic deletion or using PCSK9 antibodies-increases the expression of major histocompatibility protein class I (MHC I) proteins on the tumour cell surface, promoting robust intratumoral infiltration of cytotoxic T cells. Mechanistically, we find that PCSK9 can disrupt the recycling of MHC I to the cell surface by associating with it physically and promoting its relocation and degradation in the lysosome. Together, these results suggest that inhibiting PCSK9 is a promising way to enhance immune checkpoint therapy for cancer.
Metabolomic consequences of genetic inhibition of PCSK9 compared with statin treatment.
Sliz Eeva,Kettunen Johannes,Holmes Michael V,Williams Clare Oliver,Boachie Charles,Wang Qin,Männikkö Minna,Sebert Sylvain,Walters Robin,Lin Kuang,Millwood Iona Y,Clarke Robert,Li Liming,Rankin Naomi,Welsh Paul,Delles Christian,Jukema J Wouter,Trompet Stella,Ford Ian,Perola Markus,Salomaa Veikko,Järvelin Marjo-Riitta,Chen Zhengming,Lawlor Debbie A,Ala-Korpela Mika,Danesh John,Davey Smith George,Sattar Naveed,Butterworth Adam,Würtz Peter
Background:Both statins and PCSK9 inhibitors lower blood low-density lipoprotein cholesterol (LDL-C) levels to reduce risk of cardiovascular events. To assess potential differences between metabolic effects of these two lipid-lowering therapies, we performed detailed lipid and metabolite profiling of a large randomized statin trial and compared the results with the effects of genetic inhibition of PCSK9, acting as a naturally occurring trial. Methods:228 circulating metabolic measures were quantified by nuclear magnetic resonance spectroscopy, including lipoprotein subclass concentrations and their lipid composition, fatty acids, and amino acids, for 5,359 individuals (2,659 on treatment) in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) trial at 6-months post-randomization. The corresponding metabolic measures were analyzed in eight population cohorts (N=72,185) using rs11591147 as an unconfounded proxy to mimic the therapeutic effects of PCSK9 inhibitors. Results:Scaled to an equivalent lowering of LDL-C, the effects of genetic inhibition of PCSK9 on 228 metabolic markers were generally consistent with those of statin therapy ( =0.88). Alterations in lipoprotein lipid composition and fatty acid distribution were similar. However, discrepancies were observed for very-low-density lipoprotein (VLDL) lipid measures. For instance, genetic inhibition of PCSK9 had weaker effects on lowering of VLDL-cholesterol compared with statin therapy (54% vs. 77% reduction, relative to the lowering effect on LDL-C; =2x10 for heterogeneity). Genetic inhibition of PCSK9 showed no significant effects on amino acids, ketones, or a marker of inflammation (GlycA) whereas statin treatment weakly lowered GlycA levels. Conclusions:Genetic inhibition of PCSK9 had similar metabolic effects to statin therapy on detailed lipid and metabolite profiles. However, PCSK9 inhibitors are predicted to have weaker effects on VLDL lipids compared with statins for an equivalent lowering of LDL-C, which potentially translate into smaller reductions in cardiovascular disease risk.
Association of Baseline Low-Density Lipoprotein Cholesterol and Percentage Low-Density Lipoprotein Cholesterol Reduction With Statins, Ezetimibe, and PCSK9 Inhibition.
Marcusa Daniel P,Giugliano Robert P,Park Jeong-Gun,de Lemos James A,Cannon Christopher P,Sabatine Marc S
Importance:Low-density lipoprotein cholesterol (LDL-C) is an important modifiable risk factor for atherosclerotic cardiovascular disease. It is unclear whether the percentage LDL-C lowering with pharmacotherapies differs on the basis of baseline LDL-C levels. Objective:To evaluate the association between baseline LDL-C levels and the percentage LDL-C reduction with a statin, ezetimibe, and a PCSK9 inhibitor. Design, Setting, and Participants:This secondary exploratory study analyzed data from 3 randomized placebo-controlled clinical trials (Aggrastat to Zocor-Thrombolysis in Myocardial Infarction 21 [A to Z-TIMI 21], Improved Reduction of Outcomes: Vytorin Efficacy International Trial [IMPROVE-IT], and Further Cardiovascular Outcomes Research With PCSK9 Inhibition in Subjects With Elevated Risk [FOURIER]) of lipid-lowering therapies (statin, ezetimibe, and a PCSK9 inhibitor) and included participants with atherosclerotic cardiovascular disease. Analyses took place form April to October 2020. Interventions:In A to Z-TIMI 21, 1:1 randomization to simvastatin, 40 mg, daily for 30 days followed by 80 mg daily thereafter vs placebo for 4 months followed by simvastatin, 20 mg, daily thereafter. In IMPROVE-IT, 1:1 randomization to ezetimibe, 10 mg, daily plus simvastatin, 40 mg, daily vs placebo plus simvastatin, 40 mg, daily. In FOURIER, 1:1 randomization to evolocumab, 140 mg, every 2 weeks or 420 mg monthly vs matching placebo. Main Outcomes and Measures:The percentage LDL-C reduction at either 1 month (A to Z-TIMI 21, IMPROVE-IT) or 3 months (FOURIER) as a function of baseline LDL-C level. Data were modeled using a generalized linear regression model. Results:A total of 3187 patients from A to Z-TIMI 21, 10 680 patients from IMPROVE-IT, and 25 847 patients from FOURIER were analyzed. There was a higher percentage reduction in LDL-C levels with evolocumab in patients with lower baseline LDL-C levels, ranging from 59.4% (95% CI, 59.1%-59.8%) in patients with a baseline LDL-C level of 130 mg/dL to 66.1% (95% CI, 65.6%-66.6%) in patients with a baseline LDL-C level of 70 mg/dL (P < .001). In contrast, across the same range of baseline LDL-C level, there was a more modest difference for simvastatin (44.6% [95% CI, 43.9%-45.2%] vs 47.8% [95% CI, 46.4%-49.2%]; P < .001) and minimal difference with ezetimibe (25.0% [95% CI, 23.3%-26.6%] vs 26.2% [95% CI, 24.2%-28.1%]; P = .007). Conclusions and Relevance:The percentage LDL-C reduction with statins, ezetimibe, and PCSK9 inhibition is not attenuated in patients starting with lower baseline LDL-C levels and is 6.6% greater for PCSK9 inhibition. These data are encouraging for the use of intensive LDL-C-lowering therapy even for patients with lower LDL-C levels.
An oral antisense oligonucleotide for PCSK9 inhibition.
Science translational medicine
Inhibitors of proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein (LDL) cholesterol and are used for treatment of dyslipidemia. Current PCSK9 inhibitors are administered via subcutaneous injection. We present a highly potent, chemically modified PCSK9 antisense oligonucleotide (ASO) with potential for oral delivery. Past attempts at oral delivery using earlier-generation ASO chemistries and transient permeation enhancers provided encouraging data, suggesting that improving potency of the ASO could make oral delivery a reality. The constrained ethyl chemistry and liver targeting enabled by -acetylgalactosamine conjugation make this ASO highly potent. A single subcutaneous dose of 90 mg reduced PCSK9 by >90% in humans with elevated LDL cholesterol and a monthly subcutaneous dose of around 25 mg is predicted to reduce PCSK9 by 80% at steady state. To investigate the feasibility of oral administration, the ASO was coformulated in a tablet with sodium caprate as permeation enhancer. Repeated oral daily dosing in dogs resulted in a bioavailability of 7% in the liver (target organ), about fivefold greater than the plasma bioavailability. Target engagement after oral administration was confirmed by intrajejunal administration of a rat-specific surrogate ASO in solution with the enhancer to rats and by plasma PCSK9 and LDL cholesterol lowering in cynomolgus monkey after tablet administration. On the basis of an assumption of 5% liver bioavailability after oral administration in humans, a daily dose of 15 mg is predicted to reduce circulating PCSK9 by 80% at steady state, supporting the development of the compound for oral administration to treat dyslipidemia.