Angiopoietin-like 8 (ANGPTL8) is a calorically responsive regulator of lipoprotein lipase (LPL). It does this by forming complexes with ANGPTL3 or ANGPTL4 that either inhibit LPL in oxidative tissues or preserve LPL activity in adipose tissue, respectively. Human heterozygous (reference allele/alternate allele, R/A) carriers of rs145464906/p.Q121X and rs760351239/p.Q131X ANGPTL8 protein truncating variants (PTVs) have favorable lipid profiles and decreased cardiovascular risk. Given the purported role of ANGPTL8 in redirecting circulating lipids in response to feeding, it is not clear why these PTVs should profile as they do. We elucidated this process by investigating these ANGPTL8 PTVs along with several novel ANGPTL8 putative loss of function (pLOF) variants, including a splice donor variant rs774984872/c.459 + 1G > T that was predicted to result in an ANGPTL8 truncation (p.K165X), in a consanguineous population from the Pakistan Genomic Resource (PGR). We observed lower TG, lower total cholesterol, and increased HDL-C in heterozygous carriers of these variants, consistent with previous reports for p.Q121X and p.Q131X and confirmed decreased ANGPTL3/8 and ANGPTL4/8 complex levels in serum samples from these carriers compared to non-carriers (R/R). Biochemically, the p.Q121X, p.Q131X and c.459 + 1G > T mutations showed dramatically reduced ANGPTL3/8 complex-mediated LPL inhibition while only modestly decreasing ANGPTL4/8-mediated preservation of LPL activity. Furthermore, a cohort of 14 participants that included 8 non-carriers, 5 heterozygous carriers and a single homozygous (A/A) individual of the c.459 + 1G > T pLOF variant were recruited for kinetic studies following standard mixed meal tolerance tests. Heterozygous carriers showed significantly reduced postprandial TG excursions compared to non-carriers. Together, these results support the concept that pLOF variants in ANGPTL8 result in favorable lipid profiles by selectively reducing ANGPTL3/8-mediated LPL inhibition while largely maintaining ANGPTL4/8-mediated preservation of LPL activity.

BACKGROUND:Lipoprotein(a) [Lp(a)] is a largely genetically determined causal risk factor for atherosclerotic cardiovascular disease and aortic stenosis, likely mediated in part by oxidized phospholipids (OxPL) bound to apolipoprotein(a) [apo(a)] and apolipoprotein B (apoB). Lepodisiran, an extended-duration small interfering RNA demonstrated large and durable reductions in Lp(a) in a phase 2 trial. OBJECTIVES:The purpose of this study was to assess effects of lepodisiran on OxPL-apo(a) and -apoB levels, their relationship to Lp(a) and apoB lowering, whether reductions are proportional to particle reduction, and whether changes correlate with biomarkers of systemic inflammation. METHODS:The randomized, placebo-controlled phase 2 trial enrolled 320 participants at 66 global centers. The current post hoc analysis included 213 of 320 participants who received placebo or lepodisiran 16, 96, or 400 mg at baseline and day 180 and had OxPL levels measured at baseline, day 240, and day 360. Placebo-adjusted percent change from baseline in OxPL-apo(a) and -apoB were assessed. Correlations between percent change in Lp(a), OxPL-apo(a), and -apoB were also determined. RESULTS:Median baseline OxPL-apo(a) and -apoB levels were 122.0 nmol/L (Q1, Q3: 105.1, 137.7 nmol/L) and 27.7 nmol/L (Q1, Q3: 22.5, 36.2 nmol/L) for all participants. Placebo-adjusted geometric mean percent changes in OxPL-apo(a) at day 240 were -21.9% (95% CI: -45.0% to 11.0%), -65.1% (95% CI: -73.8% to -53.6%), and -94.2% (95% CI: -95.7% to -92.2%) in the 16-, 96-, and 400-mg dose groups, respectively. Percent changes in OxPL-apoB at day 240 in these dose groups were -39.5% (95% CI: -51.2% to -25.0%), -76.9% (95% CI: -80.6% to -72.5%), and -88.5% (95% CI: -90.4% to -86.3%), respectively. The percent change in OxPL-apo(a) at day 360 were -23.7% (95% CI: -47.0% to 9.8%), -41.6% (95% CI: -56.4% to -21.6%), and -80.7% (95% CI: -85.7% to -73.9%) in the 16-, 96-, and 400-mg dose groups, respectively. The percent changes in OxPL-apoB at day 360 in these dose groups were -30.6% (95% CI: -46.4% to -10.2%), -57.1% (95% CI: -65.2% to -47.2%), and -79.9% (95% CI: -83.8% to -75.2%), respectively. Percent change in OxPL-apo(a) correlated more closely than OxPL-apoB with percent change in Lp(a) than did OxPL-apoB. There was no significant correlation between changes in high-sensitivity C-reactive protein and OxPL. CONCLUSIONS:Lepodisiran produced sustained reductions in OxPL-apoB and OxPL-apo(a) levels that correlated with Lp(a) lowering. These findings provide additional biological rationale for the ongoing lepodisiran phase 3 cardiovascular outcomes trial, but do not establish clinical benefit. (A Study of LY3819469 in Participants With Elevated Lipoprotein(a) [Lp(a)]; NCT05565742).

BACKGROUND:The residual cardiovascular risk associated with hypertriglyceridemia and remnant particles supports efforts to develop effective novel therapeutic approaches. Angiopoietin-like protein 3 (ANGPTL3) inhibits lipoprotein and endothelial lipases, and Mendelian randomization studies associate lower ANGPTL3 activity with lower triglycerides, and lower cardiovascular risk. OBJECTIVES:The aim of this study was to evaluate the impact of solbinsiran, an N-acetylgalactosamine-conjugated small interfering RNA developed to inhibit hepatic translation of ANGPTL3 messenger RNA (mRNA), on ANGPTL3 and lipid levels in preclinical models and humans. METHODS:In preclinical studies, the impact of solbinsiran on ANGPTL3 levels was assessed in mouse and nonhuman primate models. The phase 1 clinical study enrolled participants with mixed dyslipidemia. In the single-ascending-dose study, participants received single subcutaneous doses of solbinsiran (24-960 mg) or matching placebo. In the repeat-dose study, subcutaneous solbinsiran (208 or 480 mg) or matching placebo on days 1 and 29 was evaluated. Safety, pharmacokinetics, and effect on levels of ANGPTL3 and lipid parameters were evaluated over 169 days. RESULTS:In mice transiently expressing human ANGPTL3, a single dose of solbinsiran reduced hepatocyte ANGPTL3 mRNA expression by 65% vs vehicle-treated mice. In cynomolgus monkeys, mean ± SEM reductions in hepatic ANGPTL3 mRNA expression up to 73% ± 2% (P < 0.0001) and serum ANGPTL3 protein expression up to 69% ± 4% (P < 0.001) were seen vs vehicle-treated monkeys. In humans, a single dose of solbinsiran resulted in dose-dependent mean percentage reductions from baseline in ANGPTL3 up to 86% ± 4%, triglycerides up to 73% ± 7%, low-density lipoprotein (LDL) cholesterol up to 30% ± 16%, non-high-density lipoprotein cholesterol up to 41% ± 12%, and apolipoprotein B up to 30% ± 11%, with sustained effects at higher doses (P < 0.0001 for all). The repeat-dose study demonstrated reductions in ANGPTL3 of 89% ± 6%, triglycerides up to 70% ± 13%, LDL cholesterol up to 42% ± 14%, non-high-density lipoprotein cholesterol up to 46% ± 14%, and apolipoprotein B up to 36% ± 13% (P < 0.0001 for all). Nuclear magnetic resonance lipoprotein analysis demonstrated reductions in the total number of triglyceride-rich lipoprotein and LDL particles with solbinsiran. Adverse events were mostly mild in severity, with similar incidence in solbinsiran- and placebo-treated participants. CONCLUSIONS:Solbinsiran inhibits hepatic ANGPTL3 translation and results in significant reductions in all atherogenic lipoproteins in mixed dyslipidemia. The impact of this approach on cardiovascular outcomes remains to be determined. (A Study of LY3561774 in Participants With Dyslipidemia; NCT04644809).

ImportanceMuvalaplin inhibits lipoprotein(a) formation. A 14-day phase 1 study demonstrated that muvalaplin was well tolerated and reduced lipoprotein(a) levels up to 65%. The effect of longer administration of muvalaplin on lipoprotein(a) levels in individuals at high cardiovascular risk remains uncertain.ObjectivesTo determine the effect of muvalaplin on lipoprotein(a) levels and to assess safety and tolerability.Design, Setting, and ParticipantsPhase 2, placebo-controlled, randomized, double-blind trial enrolling 233 participants with lipoprotein(a) concentrations of 175 nmol/L or greater with atherosclerotic cardiovascular disease, diabetes, or familial hypercholesterolemia at 43 sites in Asia, Europe, Australia, Brazil, and the United States between December 10, 2022, and November 22, 2023.InterventionsParticipants were randomized to receive orally administered muvalaplin at dosages of 10 mg/d (n = 34), 60 mg/d (n = 64), or 240 mg/d (n = 68) or placebo (n = 67) for 12 weeks.Main Outcomes and MeasuresThe primary end point was the placebo-adjusted percentage change from baseline in lipoprotein(a) molar concentration at week 12, using an assay to measure intact lipoprotein(a) and a traditional apolipoprotein(a)-based assay. Secondary end points included the percentage change in apolipoprotein B and high-sensitivity C-reactive protein.ResultsThe median age of study participants was 66 years; 33% were female; and 27% identified as Asian, 4% as Black, and 66% as White. Muvalaplin resulted in placebo-adjusted reductions in lipoprotein(a) of 47.6% (95% CI, 35.1%-57.7%), 81.7% (95% CI, 78.1%-84.6%), and 85.8% (95% CI, 83.1%-88.0%) for the 10-mg/d, 60-mg/d, and 240-mg/d dosages, respectively, using an intact lipoprotein(a) assay and 40.4% (95% CI, 28.3%-50.5%), 70.0% (95% CI, 65.0%-74.2%), and 68.9% (95% CI, 63.8%-73.3%) using an apolipoprotein(a)-based assay. Dose-dependent reductions in apolipoprotein B were observed at 8.9% (95% CI, −2.2% to 18.8%), 13.1% (95% CI, 4.4%-20.9%), and 16.1% (95% CI, 7.8%-23.7%) at 10 mg/d, 60 mg/d, and 240 mg/d, respectively. No change in high-sensitivity C-reactive protein was observed. No safety or tolerability concerns were observed at any dosage.Conclusions and RelevanceMuvalaplin reduced lipoprotein(a) measured using intact lipoprotein(a) and apolipoprotein(a)-based assays and was well tolerated. The effect of muvalaplin on cardiovascular events requires further investigation.Trial RegistrationClinicalTrials.gov Identifier: NCT05563246

Lipoprotein(a) [Lp(a)] is a cardiovascular risk factor, and there is considerable interest in developing Lp(a)-lowering therapeutics for cardiovascular prevention. Current commercial Lp(a) assays measure total apolipoprotein(a) [apo(a)] and may be insufficient to accurately measure Lp(a) concentrations and determine Lp(a) lowering by a new class of small-molecule Lp(a) formation inhibitors such as muvalaplin. We developed a novel immunoassay that measures only Lp(a) particles. This intact Lp(a) assay demonstrated robust analytical performance, was insensitive to apo(a) isoform size, and correlated with a liquid chromatography-tandem mass spectrometry method. Muvalaplin phase I multiple ascending dose study samples and lepodisiran, a small-interfering RNA that lowers Lp(a), phase I single ascending dose study samples were analyzed using the intact Lp(a) assay and commercial assays. The Lp(a)-lowering efficacy of muvalaplin was underestimated by the commercial assay measuring total apo(a) compared with the intact Lp(a) assay specifically measuring Lp(a) particles. In contrast, the Lp(a)-lowering effect of lepodisiran was clinically comparable between the intact Lp(a) assay and commercial assay. This novel intact Lp(a) assay provides a more accurate approach for the assessment of Lp(a)-lowering agents and the study of Lp(a)-associated risk compared with currently available assays.

Purpose of review To review the development of oral agents to lower Lp(a) levels as an approach to reducing cardiovascular risk, with a focus on recent advances in the field. Recent findings Extensive evidence implicates Lp(a) in the causal pathway of atherosclerotic cardiovascular disease and calcific aortic stenosis. There are currently no therapies approved for lowering of Lp(a). The majority of recent therapeutic advances have focused on development of injectable agents that target RNA and inhibit synthesis of apo(a). Muvalaplin is the first, orally administered, small molecule inhibitor of Lp(a), which acts by disrupting binding of apo(a) and apoB, in clinical development. Nonhuman primate and early human studies have demonstrated the ability of muvalaplin to produce dose-dependent lowering of Lp(a). Ongoing clinical trials will evaluate the impact of muvalaplin in high cardiovascular risk and will ultimately need to determine whether this strategy lowers the rate of cardiovascular events. Summary Muvalaplin is the first oral agent, developed to lower Lp(a) levels. The ability of muvalaplin to reduce cardiovascular risk remains to be investigated, in order to determine whether it will be a useful agent for the prevention of cardiovascular disease.

IMPORTANCE Muvalaplin inhibits lipoprotein(a) formation. A 14-day phase 1 study demonstrated that muvalaplin was well tolerated and reduced lipoprotein(a) levels up to 65%. The effect of longer administration of muvalaplin on lipoprotein(a) levels in individuals at high cardiovascular risk remains uncertain. OBJECTIVES To determine the effect of muvalaplin on lipoprotein(a) levels and to assess safety and tolerability. DESIGN, SETTING, AND PARTICIPANTS Phase 2, placebo-controlled, randomized, double-blind trial enrolling 233 participants with lipoprotein(a) concentrations of 175 nmol/L or greater with atherosclerotic cardiovascular disease, diabetes, or familial hypercholesterolemia at 43 sites in Asia, Europe, Australia, Brazil, and the United States between December 10, 2022, and November 22, 2023. INTERVENTIONS Participants were randomized to receive orally administered muvalaplin at dosages of 10 mg/d (n = 34), 60 mg/d (n = 64), or 240 mg/d (n = 68) or placebo (n = 67) for 12 weeks. MAIN OUTCOMES AND MEASURES The primary end point was the placebo-adjusted percentage change from baseline in lipoprotein(a) molar concentration at week 12, using an assay to measure intact lipoprotein(a) and a traditional apolipoprotein(a)-based assay. Secondary end points included the percentage change in apolipoprotein B and high-sensitivity C-reactive protein. RESULTS The median age of study participants was 66 years; 33% were female; and 27% identified as Asian, 4% as Black, and 66% as White. Muvalaplin resulted in placebo-adjusted reductions in lipoprotein(a) of 47.6% (95% CI, 35.1%-57.7%), 81.7% (95% CI, 78.1%-84.6%), and 85.8% (95% CI, 83.1%-88.0%) for the 10-mg/d,60-mg/d, and 240-mg/d dosages, respectively, using an intact lipoprotein(a) assay and 40.4% (95% CI, 28.3%-50.5%), 70.0% (95% CI, 65.0%-74.2%), and 68.9% (95% CI, 63.8%-73.3%) using an apolipoprotein(a)based assay. Dose-dependent reductions in apolipoprotein B were observed at 8.9% (95% CI, -2.2% to 18.8%), 13.1% (95% CI, 4.4%-20.9%), and 16.1% (95% CI, 7.8%-23.7%) at 10 mg/d, 60 mg/d, and 240 mg/d, respectively. No change in high-sensitivity C-reactive protein was observed. No safety or tolerability concerns were observed at any dosage. CONCLUSIONS AND RELEVANCE Muvalaplin reduced lipoprotein(a) measured using intact lipoprotein(a) and apolipoprotein(a)-based assays and was well tolerated. The effect of muvalaplin on cardiovascular events requires further investigation. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT05563246

Lipoprotein(a) (Lp(a)), an independent, causal cardiovascular risk factor, is a lipoprotein particle that is formed by the interaction of a low-density lipoprotein (LDL) particle and apolipoprotein(a) (apo(a))1,2. Apo(a) first binds to lysine residues of apolipoprotein B-100 (apoB-100) on LDL through the Kringle IV (KIV) 7 and 8 domains, before a disulfide bond forms between apo(a) and apoB-100 to create Lp(a) (refs. 3-7). Here we show that the first step of Lp(a) formation can be inhibited through small-molecule interactions with apo(a) KIV7-8. We identify compounds that bind to apo(a) KIV7-8, and, through chemical optimization and further application of multivalency, we create compounds with subnanomolar potency that inhibit the formation of Lp(a). Oral doses of prototype compounds and a potent, multivalent disruptor, LY3473329 (muvalaplin), reduced the levels of Lp(a) in transgenic mice and in cynomolgus monkeys. Although multivalent molecules bind to the Kringle domains of rat plasminogen and reduce plasmin activity, species-selective differences in plasminogen sequences suggest that inhibitor molecules will reduce the levels of Lp(a), but not those of plasminogen, in humans. These data support the clinical development of LY3473329-which is already in phase 2 studies-as a potent and specific orally administered agent for reducing the levels of Lp(a).

ImportanceEpidemiological and genetic data have implicated lipoprotein(a) as a potentially modifiable risk factor for atherosclerotic disease and aortic stenosis, but there are no approved pharmacological treatments.ObjectivesTo assess the safety, tolerability, pharmacokinetics, and effects of lepodisiran on lipoprotein(a) concentrations after single doses of the drug; lepodisiran is a short interfering RNA directed at hepatic synthesis of apolipoprotein(a), an essential component necessary for assembly of lipoprotein(a) particles.Design, Setting, and ParticipantsA single ascending-dose trial conducted at 5 clinical research sites in the US and Singapore that enrolled 48 adults without cardiovascular disease and with lipoprotein(a) serum concentrations of 75 nmol/L or greater (or ≥30 mg/dL) between November 18, 2020, and December 7, 2021; the last follow-up visit occurred on November 9, 2022.InterventionsParticipants were randomized to receive placebo or a single dose of lepodisiran (4 mg, 12 mg, 32 mg, 96 mg, 304 mg, or 608 mg) administered subcutaneously.Main Outcomes and MeasuresThe primary outcome was the safety and tolerability of the single ascending doses of lepodisiran. The secondary outcomes included plasma levels of lepodisiran for 168 days after dose administration and changes in fasting lipoprotein(a) serum concentrations through a maximum follow-up of 336 days (48 weeks).ResultsOf the 48 participants enrolled (mean age, 46.8 [SD, 11.6] years; 35% were women), 1 serious adverse event occurred. The plasma concentrations of lepodisiran reached peak levels within 10.5 hours and were undetectable by 48 hours. The median baseline lipoprotein(a) concentration was 111 nmol/L (IQR, 78 to 134 nmol/L) in the placebo group, 78 nmol/L (IQR, 50 to 152 nmol/L) in the 4 mg of lepodisiran group, 97 nmol/L (IQR, 86 to 107 nmol/L) in the 12-mg dose group, 120 nmol/L (IQR, 110 to 188 nmol/L) in the 32-mg dose group, 167 nmol/L (IQR, 124 to 189 nmol/L) in the 96-mg dose group, 96 nmol/L (IQR, 72 to 132 nmol/L) in the 304-mg dose group, and 130 nmol/L (IQR, 87 to 151 nmol/L) in the 608-mg dose group. The maximal median change in lipoprotein(a) concentration was −5% (IQR, −16% to 11%) in the placebo group, −41% (IQR, −47% to −20%) in the 4 mg of lepodisiran group, −59% (IQR, −66% to −53%) in the 12-mg dose group, −76% (IQR, −76% to −75%) in the 32-mg dose group, −90% (IQR, −94% to −85%) in the 96-mg dose group, −96% (IQR, −98% to −95%) in the 304-mg dose group, and −97% (IQR, −98% to −96%) in the 608-mg dose group. At day 337, the median change in lipoprotein(a) concentration was −94% (IQR, −94% to −85%) in the 608 mg of lepodisiran group.Conclusions and RelevanceIn this phase 1 study of 48 participants with elevated lipoprotein(a) levels, lepodisiran was well tolerated and produced dose-dependent, long-duration reductions in serum lipoprotein(a) concentrations. The findings support further study of lepodisiran.Trial RegistrationClinicalTrials.gov Identifier: NCT04914546

Importance:Lipoprotein(a) (Lp[a]) is associated with atherosclerotic disease and aortic stenosis. Lp(a) forms by bonding between apolipoprotein(a) (apo[a]) and apo B100. Muvalaplin is an orally administered small molecule that inhibits Lp(a) formation by blocking the apo(a)-apo B100 interaction while avoiding interaction with a homologous protein, plasminogen.Objective:To determine the safety, tolerability, pharmacokinetics, and pharmacodynamic effects of muvalaplin.Design, Setting, and Participants:This phase 1 randomized, double-blind, parallel-design study enrolled 114 participants (55 assigned to a single-ascending dose; 59 assigned to a multiple-ascending dose group) at 1 site in the Netherlands.Interventions:The single ascending dose treatment evaluated the effect of a single dose of muvalaplin ranging from 1 mg to 800 mg or placebo taken by healthy participants with any Lp(a) level. The multiple ascending dose treatment evaluated the effect of taking daily doses of muvalaplin (30 mg to 800 mg) or placebo for 14 days in patients with Lp(a) levels of 30 mg/dL or higher.Main Outcomes and Measures:Outcomes included safety, tolerability, pharmacokinetics, and exploratory pharmacodynamic biomarkers.Results:Among 114 randomized (55 in the single ascending dose group: mean [SD] age, 29 [10] years, 35 females [64%], 2 American Indian or Alaska Native [4%], 50 White [91%], 3 multiracial [5%]; 59 in the multiple ascending dose group: mean [SD] age 32 [15] years; 34 females [58%]; 3 American Indian or Alaska Native [5%], 6 Black [10%], 47 White [80%], 3 multiracial [5%]), 105 completed the trial. Muvalaplin was not associated with tolerability concerns or clinically significant adverse effects. Oral doses of 30 mg to 800 mg for 14 days resulted in increasing muvalaplin plasma concentrations and half-life ranging from 70 to 414 hours. Muvalaplin lowered Lp(a) plasma levels within 24 hours after the first dose, with further Lp(a) reduction on repeated dosing. Maximum placebo-adjusted Lp(a) reduction was 63% to 65%, resulting in Lp(a) plasma levels less than 50 mg/dL in 93% of participants, with similar effects at daily doses of 100 mg or more. No clinically significant changes in plasminogen levels or activity were observed.Conclusion:Muvalaplin, a selective small molecule inhibitor of Lp(a) formation, was not associated with tolerability concerns and lowered Lp(a) levels up to 65% following daily administration for 14 days. Longer and larger trials will be required to further evaluate safety, tolerability, and effect of muvalaplin on Lp(a) levels and cardiovascular outcomes.Trial Registration:ClinicalTrials.gov Identifier: NCT04472676.

Importance:Epidemiological and genetic data have implicated lipoprotein(a) as a potentially modifiable risk factor for atherosclerotic disease and aortic stenosis, but there are no approved pharmacological treatments.Objectives:To assess the safety, tolerability, pharmacokinetics, and effects of lepodisiran on lipoprotein(a) concentrations after single doses of the drug; lepodisiran is a short interfering RNA directed at hepatic synthesis of apolipoprotein(a), an essential component necessary for assembly of lipoprotein(a) particles.Design, Setting, and Participants:A single ascending-dose trial conducted at 5 clinical research sites in the US and Singapore that enrolled 48 adults without cardiovascular disease and with lipoprotein(a) serum concentrations of 75 nmol/L or greater (or ≥30 mg/dL) between November 18, 2020, and December 7, 2021; the last follow-up visit occurred on November 9, 2022.Interventions:Participants were randomized to receive placebo or a single dose of lepodisiran (4 mg, 12 mg, 32 mg, 96 mg, 304 mg, or 608 mg) administered subcutaneously.Main Outcomes and Measures:The primary outcome was the safety and tolerability of the single ascending doses of lepodisiran. The secondary outcomes included plasma levels of lepodisiran for 168 days after dose administration and changes in fasting lipoprotein(a) serum concentrations through a maximum follow-up of 336 days (48 weeks).Results:Of the 48 participants enrolled (mean age, 46.8 [SD, 11.6] years; 35% were women), 1 serious adverse event occurred. The plasma concentrations of lepodisiran reached peak levels within 10.5 hours and were undetectable by 48 hours. The median baseline lipoprotein(a) concentration was 111 nmol/L (IQR, 78 to 134 nmol/L) in the placebo group, 78 nmol/L (IQR, 50 to 152 nmol/L) in the 4 mg of lepodisiran group, 97 nmol/L (IQR, 86 to 107 nmol/L) in the 12-mg dose group, 120 nmol/L (IQR, 110 to 188 nmol/L) in the 32-mg dose group, 167 nmol/L (IQR, 124 to 189 nmol/L) in the 96-mg dose group, 96 nmol/L (IQR, 72 to 132 nmol/L) in the 304-mg dose group, and 130 nmol/L (IQR, 87 to 151 nmol/L) in the 608-mg dose group. The maximal median change in lipoprotein(a) concentration was -5% (IQR, -16% to 11%) in the placebo group, -41% (IQR, -47% to -20%) in the 4 mg of lepodisiran group, -59% (IQR, -66% to -53%) in the 12-mg dose group, -76% (IQR, -76% to -75%) in the 32-mg dose group, -90% (IQR, -94% to -85%) in the 96-mg dose group, -96% (IQR, -98% to -95%) in the 304-mg dose group, and -97% (IQR, -98% to -96%) in the 608-mg dose group. At day 337, the median change in lipoprotein(a) concentration was -94% (IQR, -94% to -85%) in the 608 mg of lepodisiran group.Conclusions and Relevance:In this phase 1 study of 48 participants with elevated lipoprotein(a) levels, lepodisiran was well tolerated and produced dose-dependent, long-duration reductions in serum lipoprotein(a) concentrations. The findings support further study of lepodisiran.Trial Registration:ClinicalTrials.gov Identifier: NCT04914546.

Abstract Background Lipoprotein(a) [Lp(a)] is a lipoprotein particle consisting of a low-density lipoprotein (LDL) particle and apolipoprotein(a) [apo(a)]. Lp(a) is a causal risk factor for cardiovascular disease. The formation of Lp(a) requires an initial interaction of apo(a) Kringle IV Domains 7 and 8 (KIV7, KIV8) with apoB-100 on LDL, followed by formation of a disulfide bond between apo(a) and apoB-100. Blocking the initial apo(a)-apoB interaction is a viable therapeutic approach to reduce circulating levels of Lp(a). The apo(a) protein is encoded by the LPA gene that arose from the plasminogen gene through an evolutionary gene duplication event. Because of sequence conservation between apo(a) and plasminogen, compound selectivity for apo(a) is imperative for clinical development. Purpose We report the discovery and preclinical characterization of LY3473329, a novel selective small molecule inhibitor of Lp(a) formation. Methods Computational and synthetic chemistry approaches coupled with multiple biochemical and biophysical assays were used to create apo(a) KIV7,8 binders. Chemical optimization led to molecules with potent inhibition of in vitro Lp(a) formation. Both apo(a) and plasminogen binding assays were conducted to evaluate compound selectivity. The potential for LY3473329 to lower steady state Lp(a) levels was assessed in human Lp(a) transgenic mice and in cynomolgus monkeys, and its effect on plasminogen activity was assessed in rat and monkey. Results Computational modeling, synthetic chemistry and small molecule library screens identified compounds that bind apo(a) KIV7 and KIV8 domains, and subsequent chemical optimization yielded compounds with sub-micromolar Lp(a) inhibition potency. Exploration of compound multivalency created inhibitors with sub-nanomolar potency, including LY3473329. LY3473329 engages multiple apo(a) KIV motifs, allowing it to potently inhibit Lp(a) formation in vitro. Oral doses of LY3473329 given to human Lp(a) transgenic mice and cynomolgus monkeys caused dose-dependent decreases in plasma Lp(a). The key binding motif for LY3473329 is shared by two KIV domains in rat and monkey plasminogen, but only one KIV domain in human plasminogen. LY3473329 was non-selective for rat and monkey plasminogen, but showed ∼ 50-fold selectivity for human plasminogen in in vitro binding assays. In cynomolgus monkeys and rats, LY3473329 significantly reduced plasminogen activity levels without adverse effects. Given its selectivity against human plasminogen, LY3473329 is expected to lower Lp(a) in human without affecting plasminogen. LY3473329 has been evaluated in a human Phase 1 study and is currently in Phase 2 clinical development. Conclusions LY3473329 is a potent and selective small molecule inhibitor of Lp(a) formation and is the only orally administered Lp(a) investigational therapeutic in clinical development.

Introduction Cardiovascular disease (CVD) is the leading cause of mortality worldwide and is the leading cause of death in the US. Lipid dysregulation is a well-known precursor to metabolic diseases, including CVD. There is a growing body of literature that suggests MRI-derived epicardial fat volume, or epicardial adipose tissue (EAT) volume, is linked to the development of coronary artery disease. Interestingly, epicardial fat is also actively involved in lipid and energy homeostasis, with epicardial adipose tissue having a greater capacity for release and uptake of free fatty acids. However, there is a scarcity of knowledge on the influence of plasma lipids on EAT volume. Aim The focus of this study is on the identification of novel lipidomic species associated with CMRI-derived measures of epicardial fat in Mexican American individuals. Methods We performed lipidomic profiling on 200 Mexican American individuals. High-throughput mass spectrometry enabled rapid capture of precise lipidomic profiles, providing measures of 799 unique species from circulating plasma samples. Because of our extended pedigree design, we utilized a standard quantitative genetic linear mixed model analysis to determine whether lipids were correlated with EAT by formally testing for association between each lipid species and the CMRI epicardial fat phenotype. Results After correction for multiple testing using the FDR approach, we identified 135 lipid species showing significant association with epicardial fat. Of those, 131 lipid species were positively correlated with EAT, where increased circulating lipid levels were correlated with increased epicardial fat. Interestingly, the top 10 lipid species associated with an increased epicardial fat volume were from the deoxyceramide (Cer(m)) and triacylglycerol (TG) families. Deoxyceramides are atypical and neurotoxic sphingolipids. Triacylglycerols are an abundant lipid class and comprise the bulk of storage fat in tissues. Pathologically elevated TG and Cer(m) levels are related to CVD risk and, in our study, to EAT volume. Conclusion Our results indicate that specific lipid abnormalities such as enriched saturated triacylglycerols and the presence of toxic ceramides Cer(m) in plasma of our individuals could precede CVD with increased EAT volume.

Supplemental Digital Content is available in the text. Background: The identification and understanding of therapeutic targets for atherosclerotic cardiovascular disease is of fundamental importance given its global health and economic burden. Inhibition of ANGPTL3 (angiopoietin-like 3) has demonstrated a cardioprotective effect, showing promise for atherosclerotic cardiovascular disease treatment, and is currently the focus of ongoing clinical trials. Here, we assessed the genetic basis of variation in ANGPTL3 levels in the San Antonio Family Heart Study. Methods: We assayed ANGPTL3 protein levels in ≈1000 Mexican Americans from extended pedigrees. By drawing upon existing plasma lipidome profiles and genomic data we conducted analyses to understand the genetic basis to variation in ANGPTL3 protein levels, and accordingly the correlation with the plasma lipidome. Results: In a variance components framework, we identified that variation in ANGPTL3 was significantly heritable (h2=0.33, P=1.31×10−16). To explore the genetic basis of this heritability, we conducted a genome-wide linkage scan and identified significant linkage (logarithm of odds =6.18) to a locus on chromosome 1 at 90 centimorgans, corresponding to the ANGPTL3 gene location. In the genomes of 23 individuals from a single pedigree, we identified a loss-of-function variant, rs398122988 (N121Kfs*2), in ANGPTL3, that was significantly associated with lower ANGPTL3 levels (β=−1.69 SD units, P=3.367×10−13), and accounted for the linkage signal at this locus. Given the known role of ANGPTL3 as an inhibitor of endothelial and lipoprotein lipase, we explored the association of ANGPTL3 protein levels and rs398122988 with the plasma lipidome and related phenotypes, identifying novel associations with phosphatidylinositols. Conclusions: Variation in ANGPTL3 protein levels is heritable and under significant genetic control. Both ANGPTL3 levels and loss-of-function variants in ANGPTL3 have significant associations with the plasma lipidome. These findings further our understanding of ANGPTL3 as a therapeutic target for atherosclerotic cardiovascular disease.

Lipoprotein lipase (LPL) is the key enzyme that hydrolyzes triglycerides from triglyceride-rich lipoproteins. Angiopoietin-like proteins (ANGPTL) 3, 4, and 8 are well-characterized protein inhibitors of LPL. ANGPTL8 forms a complex with ANGPTL3, and the complex is a potent endogenous inhibitor of LPL. However, the nature of the structural interaction between ANGPTL3/8 and LPL is unknown. To probe the conformational changes in LPL induced by ANGPTL3/8, we found that HDX-MS detected significantly altered deuteration in the lid region, ApoC2 binding site, and furin cleavage region of LPL in the presence of ANGPTL3/8. Supporting this HDX structural evidence, we found that ANGPTL3/8 inhibits LPL enzymatic activities and increases LPL cleavage. ANGPTL3/8-induced effects on LPL activity and LPL cleavage are much stronger than those of ANGPTL3 or ANGPTL8 alone. ANGPTL3/8-mediated LPL cleavage is blocked by both an ANGPTL3 antibody and a furin inhibitor. Knock-down of furin expression by siRNA significantly reduced ANGPT3/8-induced cleavage of LPL. Our data suggest ANGPTL3/8 promotes furin-mediated LPL cleavage.

Full CSV data export of the HDX experiment results analyzed by the software HDX Workbench for the manuscript The Complex of Angiopoietin-Like Protein 3 and 8 Interacts with Lipoprotein Lipase and Induces LPL Inhibition. The dataset includes % deuteration values for each sample/peptide/replicate, as well as experiment metadata.

The de novo ceramide synthesis pathway is essential to human biology and health, but genetic influences remain unexplored. The core function of this pathway is the generation of biologically active ceramide from its precursor, dihydroceramide. Dihydroceramides have diverse, often protective, biological roles; conversely, increased ceramide levels are biomarkers of complex disease. To explore the genetics of the ceramide synthesis pathway, we searched for deleterious nonsynonymous variants in the genomes of 1,020 Mexican Americans from extended pedigrees. We identified a Hispanic ancestry-specific rare functional variant, L175Q, in delta 4-desaturase, sphingolipid 1 (DEGS1), a key enzyme in the pathway that converts dihydroceramide to ceramide. This amino acid change was significantly associated with large increases in plasma dihydroceramides. Indexes of DEGS1 enzymatic activity were dramatically reduced in heterozygotes. CRISPR/Cas9 genome editing of HepG2 cells confirmed that the L175Q variant results in a partial loss of function for the DEGS1 enzyme. Understanding the biological role of DEGS1 variants, such as L175Q, in ceramide synthesis may improve the understanding of metabolic-related disorders and spur ongoing research of drug targets along this pathway.

Suicide is major public health concern; one million individuals worldwide die by suicide each year of which there are many more attempts. Thus, it is imperative that robust and reliable indicators, or biomarkers, of suicide risk be identified so that individuals at risk can be identified and provided appropriate interventions as quickly as possible. Previous work has revealed a relationship between low levels of circulating cholesterol and suicide risk, implicating cholesterol level as one such potential biomarker, but the factors underlying this relationship remain unknown. In the present study, we applied a combination of bivariate polygenic and coefficient-of-relatedness analysis, followed by mediation analysis, in a large sample of Mexican-American individuals from extended pedigrees [N = 1897; 96 pedigrees (average size = 19.17 individuals, range = 2–189) 60% female; mean age = 42.58 years, range = 18–97 years, sd = 15.75 years] with no exclusion criteria for any given psychiatric disorder. We observed that total esterified cholesterol measured at the time of psychiatric assessment shared a significant genetic overlap with risk for suicide attempt (ρg = −0.64, p = 1.24 × 10−04). We also found that total unesterified cholesterol measured around 20 years prior to assessment varied as a function of genetic proximity to an affected individual (h2 = 0.21, se = 0.10, p = 8.73 × 10−04; βsuicide = −0.70, se = 0.25, p = 8.90 × 10−03). Finally, we found that the relationship between total unesterified cholesterol and suicide risk was significantly mediated by ABCA-1-specific cholesterol efflux capacity (βsuicide-efflux = −0.45, p = 0.039; βefflux-cholexterol = −0.34, p < 0.0001; βindirect = −0.15, p = 0.044). These findings suggest that the relatively well-delineated process of cholesterol metabolism and associated molecular pathways will be informative for understanding the neurobiological underpinnings of risk for suicide attempt.

Introduction: The genomic regulatory networks underlying the pathogenesis of acute coronary syndrome (ACS) are incompletely understood. As intermediate traits, circulating protein biomarkers report on underlying disease severity and are powerfully prognostic in ACS. We hypothesized that integration of dense microRNA (miRNA) profiling with measurement of biomarkers would highlight potential regulatory pathways. Methods: We studied 186 patients enrolled in the biomarker substudy of the TRILOGY clinical trial of ACS. MiRNA sequencing was performed on RNA extracted from whole blood, and seven known prognostic protein biomarkers were measured from plasma (N-terminal pro B-type natriuretic peptide [NT-proBNP], C-reactive protein, osteopontin [OPN], myeloperoxidase, growth differentiation factor 15, monocyte chemoattractant protein 1, and neopterin). MiRNAs were tested for association with these biomarkers using generalized linear models. Target genes putatively regulated by the associated miRNAs were examined using pathway analysis. Results: Fourteen miRNAs, including cardiac-related miRs 20b-5p and 320a,b and d, were associated with OPN levels (min. p=1.1x10 -4 ), and five miRNAs, including cardiac-related miRs 25-3p and 423-3p, were associated with NT-proBNP levels (min. p=3.4x10 -4 ); no other biomarkers showed significant associations. Sixty-three KEGG pathways were enriched in the target genes of either NT-proBNP- or OPN-associated miRNAs, with five pathways found in the top ten for both biomarkers: prion diseases, fatty acid biosynthesis, lysine degradation, protein processing in endoplasmic reticulum, and viral carcinogenesis. Conclusions: By integrating large-scale microRNA profiling with circulating biomarkers as intermediate traits, we identified associations of known cardiac-related and novel miRs with two prognostic biomarkers (OPN and NT-proBNP), and identified potential genomic regulatory networks underlying these biomarkers. We further identified novel non-cardiac genomic pathways associated with these biomarkers. These results may inform future studies delineating genomic pathways underlying ACS outcomes.

Objectives: Cardiovascular disease (CVD) is the leading cause of death in the US, and prevention of CVD focuses on improving the lipid profile of patients at risk. The human plasma lipidome consists of thousands of lipid species. We have previously measured 315 such lipid species in the San Antonio Family Heart Study (SAFHS) cohort. These lipid species represent valuable endophenotypes for identifying genes involved in lipid metabolism related to CVD. Recent evidence has implicated microRNAs (miRNAs) in CVD pathogenesis. An expanded understanding of the function of miRNAs in gene networks associated with CVD will enable identification of novel mechanisms and biomarkers of disease. We conducted an analysis of circulating miRNAs associated with the human lipidome.