RNAi inhibition of angiopoietin-like protein 3 (ANGPTL3) with ARO-ANG3 mimics the lipid and lipoprotein profile of familial combined hypolipidemia

Background

Elevated LDL-C and triglyceride rich lipoproteins (TRLs) are independent risk factors for cardiovascular disease (CVD). Genetic deficiency of angiopoietin-like protein 3 (ANGPTL3) is associated with reduced circulating levels of LDL-C, triglycerides (TGs), VLDL-C, HDL-C and reduced CVD risk, with no described adverse phenotype. ARO-ANG3 is a RNA interference drug designed to silence expression of ANGPTL3. Single doses of ARO-ANG3 have been shown to reduce ANGPTL3, TGs, VLDL-C and LDL-C in healthy volunteers (HVs, AHA 2019). We report the effects of multiple doses of ARO-ANG3 in HVs with a focus on the duration of action.

Methods

ARO-ANG3 was administered subcutaneously to HVs on days 1 and 29 at doses of 100, 200 or 300 mg (n=4 per group). Measured parameters included ANGPTL3, LDL-C, TGs, VLDL-C and HDL-C. Follow up is ongoing.

Results

All HVs have received both doses and follow-up is currently through week 16 (12 weeks after second dose). Mean nadir for ANGPTL3 levels occurred 2 weeks after the second dose (−83–93%) with minimal change for 200 and 300 mg but 16% recovery for 100 mg at week 16. Mean TGs and VLDL-C reached nadir earlier (3 wks, −61–65%) without apparent dose response and minimal change for any dose at wk 16. LDL-C nadir occurred 4–6 wks after the second dose (−45–54%), again with minimal evidence for dose response or change through wk 16. HDL-C was reduced 14–37% at wk 16. ARO-ANG3 was well tolerated without serious or severe adverse events or dropouts related to drug. The most common adverse events have been headache and upper respiratory infections.

Conclusions

Genetic deficiency of ANGPTL3 is a cause of familial combined hypolipemia and is associated with a decreased risk of CVD. Using RNAi to selectively suppress ANGPTL3 production reproduces these genetic effects with a duration of at least 12 weeks following a second dose and with good tolerability over 16 wks. ANGPTL3 inhibition results in lowering of LDL-C and TRLs which may confer protection against CVD in patients with atherogenic mixed dyslipidemia.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Arrowhead Pharmaceuticals

REDUCE-IT: outcomes by baseline statin type

Background

REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial) randomized 8,179 statin-treated patients with elevated triglycerides and increased cardiovascular (CV) risk to either icosapent ethyl (IPE), a pure, stable prescription form of eicosapentaenoic acid, 4g/day or placebo. IPE significantly reduced time to first occurrence of the primary composite endpoint of major adverse CV events (CV death, nonfatal myocardial infarction [MI], nonfatal stroke, coronary revascularization, or hospitalization for unstable angina) (HR 0.75, CI 0.68–0.83) and key secondary endpoint events (composite of CV death, nonfatal MI, or nonfatal stroke) (HR 0.74, CI 0.65–0.83) versus placebo (all p<0.0001). A modest reduction in placebo-corrected LDL-C was observed (−6.6%; p<0.0001). The mechanisms for the CV benefit of icosapent ethyl are not fully understood.

Purpose

Explore the impact of statin type and lipophilic/lipophobic category on outcomes, and on LDL-C, to further consider the possible relevance of LDL-C pathways to the observed CV benefit of icosapent ethyl.

Methods

Primary and key secondary endpoint analyses and LDL-C changes from baseline were explored by individual statin type (atorvastatin, simvastatin, rosuvastatin, or pravastatin) at baseline, and then by categorizing these statins into lipophilic (i.e., hydrophobic: atorvastatin, simvastatin) and lipophobic (i.e., hydrophilic: rosuvastatin, pravastatin) statin groups; 96.1% of patients fell within these individual statin groups.

Results

CV outcomes were similar across statin types (interaction p=0.61) and lipophilic/lipophobic categories (interaction p=0.51) (Figure). Statin type and category had a similar lack of meaningful impact on the modest placebo-corrected median LDL-C changes from baseline to one year, which ranged from −5.8 to −8.4% (all p≤0.0003).

Conclusion

No meaningful treatment differences in the primary or key secondary endpoints across statin type or lipophilic/lipophobic category were observed. A similar lack of treatment difference was observed in LDL-C changes from baseline to one year. Therefore, the LDL-C changes and CV risk reduction in REDUCE-IT appear independent of the type of concomitant statin therapy. These data provide clinicians with additional insight regarding concomitant statin therapy considerations when prescribing icosapent ethyl and suggest there are important mechanisms of action for the substantial CV risk reduction observed with icosapent ethyl that are distinct from the LDL receptor pathway.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The study was funded by Amarin Pharma, Inc.

Long-term safety and efficacy of bempedoic acid in patients at high risk of atherosclerotic cardiovascular disease: results from the CLEAR Harmony open-label extension study

Background

Bempedoic acid (BA) is an oral first-in-class, ATP-citrate lyase inhibitor that lowers low-density lipoprotein cholesterol (LDL-C) levels in adults with hypercholesterolemia. In the phase 3 CLEAR Harmony study (NCT02666664, n=2230), BA 180 mg for 52 weeks significantly lowered LDL-C at week 12 compared with placebo and was maintained for 52 weeks in hypercholesterolemic patients with atherosclerotic cardiovascular disease (ASCVD) and/or heterozygous familial hypercholesterolemia (HeFH) on stable, maximally tolerated statins.

Purpose

To report long-term safety, tolerability, and efficacy of BA from the CLEAR Harmony open-label extension (OLE) study (NCT03067441).

Methods

After completing the 52-week placebo-controlled CLEAR Harmony study, patients immediately entered the OLE and received BA for 78 weeks, followed by a 4-week washout period; the potential cumulative exposure to BA was 2.5 years. The primary endpoint was long-term safety of BA in the OLE.

Results

A total of 1462 patients enrolled in the OLE (BA n=970; placebo n=492 from CLEAR Harmony). At OLE baseline, mean (SD) age was 66.9 (8.7) years, 73.9% were male, 96.3% had ASCVD, 3.7% had HeFH with or without ASCVD, and all were receiving statins (93.5% moderate or high intensity). At baseline of CLEAR Harmony, patients had mean (SD) LDL-C of 102.9 (29.9) mg/dL (BA) and 99.0 (24.2) mg/dL (placebo). The majority of OLE patients (86.2%, n=1260) completed 78 weeks of BA treatment. At week 12 and 78 of OLE treatment, respectively, mean LDL-C lowering from CLEAR Harmony baseline was –14.9% and –14.4%. A total of 1143 patients (78.2%) reported a treatment-emergent adverse event (TEAE), and 299 (20.5%) reported a serious TEAE. TEAEs of special interest, determined by the therapeutic area or prior observations in preclinical or early clinical studies, occurred at similar rates as CLEAR Harmony (creatine kinase elevations, 1.8%; gout, 2.6%; hepatic enzyme elevations, 2.0%; hypoglycemia, 1.2%; muscular disorders, 8.5%; neurocognitive disorders, 0.9%; new onset/worsening diabetes mellitus, 5.5%; renal disorders, 2.8%) with biochemical changes that were stable over the course of the study and approached baseline levels after treatment discontinuation. Overall, 114 patients (7.8%) reported a TEAE leading to discontinuation of BA (most common: myalgia [0.6%], muscle spasm [0.5%]).

Conclusion

Durable lipid lowering was observed through 78 weeks of BA treatment and patient adherence to BA therapy was high (86.2%). Overall safety during the OLE was similar to results reported in the 52-week-long CLEAR Harmony study and the overall BA phase 3 clinical program, with no new safety findings.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Esperion Therapeutics, Inc., funded the research for this study and provided writing support for this abstract. Medical writing assistance was provided by Agnella Izzo Matic, PhD, CMPP, and Kelly M Cameron, PhD, CMPP, of JB Ashtin.

REDUCE-IT: accumulation of data across prespecified interim analyses to final results

Background

REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial), an event-driven trial, randomized 8,179 statin-treated patients with elevated triglycerides (TGs) and increased cardiovascular (CV) risk to icosapent ethyl (IPE); pure, stable prescription eicosapentaenoic acid, 4g/day or placebo. 1,612 primary endpoint events (CV death, nonfatal myocardial infarction [MI], nonfatal stroke, coronary revascularization, or hospitalization for unstable angina) projected 90% power to detect 15% relative risk reduction (5% 2-sided alpha). The key secondary composite endpoint was CV death, nonfatal MI, or nonfatal stroke. An independent data and safety monitoring committee (DMC) performed prespecified interim analyses (IAs) at ∼60% (IA1 31 May 2016 data cutoff; 2.9 y median primary endpoint follow-up) and ∼80% (IA2 01 May 2017; 3.7 y) of events; final analysis included 1,606 events (06 Sep 2018; 4.9 y median study follow-up).

Purpose

Explore REDUCE-IT efficacy and safety across prespecified IAs for insight into progression of robustness and consistency of conclusions.

Methods

The interim statistical analysis plan guided study continuation decisions by a prespecified decision-making process, including assessment of safety, treatment arm performance, primary composite endpoint formal analyses, and informal robustness analyses, with no futility or efficacy stopping requirements. Prior to DMC IA study continuation decisions, the need for a mature dataset to support the robustness of final efficacy and safety findings was discussed. Sponsor, Steering Committee, and Clinical Endpoint Committee were blinded throughout.

Results

Primary and key secondary endpoints achieved statistical significance at IA1 and IA2 that persisted at final analyses (p-value below final adjusted 2-sided alpha of 0.0437); hazard ratios also remained consistent and similar robustness was observed across individual endpoint components; clarity of findings across endpoints and subgroups improved with more events. Stopping for overwhelming efficacy was discussed at each IA; prior to IA study continuation recommendations, the DMC considered historical examples of failed CV outcome studies for TG-lowering and mixed omega-3 therapies, reflected on the potential for overestimating final demonstrated benefit using incomplete data, and weighed societal impacts of fuller datasets relative to patient therapy access.

Conclusions

Consistent, potent efficacy emerged early and persisted across the two prespecified interim and final analyses. The mature dataset demonstrated highly statistically significant reductions in the primary (25%; p=0.00000001) and key secondary (26%; p=0.0000006) endpoints and allowed robust analyses to support overall efficacy and safety conclusions. Allowing the REDUCE-IT dataset to fully mature provided clinicians with robust, consistent, and reliable data upon which to base clinical decisions for IPE in CV risk reduction.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The study was funded by Amarin Pharma, Inc.

REDUCE-IT: total ischemic events reduced across the full range of baseline LDL cholesterol and other key subgroups

Background

REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial), a study of 8,179 randomized statin-treated patients with elevated triglycerides (TG) and increased cardiovascular (CV) risk followed for a median of 4.9 years, demonstrated robust results. Icosapent ethyl (IPE), a pure and stable prescription form of eicosapentaenoic acid, 4g/day reduced both time-to-first and total primary endpoint ischemic events (CV death, nonfatal myocardial infarction [MI], nonfatal stroke, coronary revascularization, or hospitalization for unstable angina) by 25% (HR 0.75; 95% CI 0.68–0.83; p<0.0001) and 30% (rate ratio 0.70; 95% CI 0.62–0.78; p<0.0001), respectively. Similar substantial reductions in first and total key secondary endpoint ischemic events (composite of CV death, nonfatal MI, or nonfatal stroke) were also observed. Demographic and baseline disease characteristics were generally balanced across treatment groups. Time-to-first event analyses showed robust and generally consistent benefit across subgroups. Previous total event analyses by baseline TG demonstrated large, consistent, statistically significant reductions across tertiles, suggesting the CV benefit of IPE is tied primarily to non-TG factors.

Purpose

Further explore the extent to which IPE reduced total primary and key secondary events across prespecified baseline demographic, disease, treatment, and lipid/lipoprotein/inflammatory biomarker subgroups.

Methods

Total events across subgroups were assessed with the prespecified negative binomial regression method. Main outcomes were total (first and subsequent) primary and key secondary composite endpoint events.

Results

Median baseline LDL-C levels in ascending tertiles were 58, 76, and 96 mg/dL; there were large, significant relative reductions in total primary endpoint events with IPE across tertiles (35%, 28%, and 27%, respectively; interaction p=0.62), with parallel substantial absolute risk reductions. Similar, significant relative reductions of 33%, 28%, and 24% in total key secondary endpoint events were observed, along with substantial absolute risk reductions. Total events analyses of prespecified subgroups also demonstrated robust and generally consistent findings for the primary and key secondary composite endpoints.

Conclusion

REDUCE-IT demonstrated substantial reductions in first and total primary and key secondary endpoint ischemic events, with robust and generally consistent results across baseline TG and LDL-C levels, as well as other prespecified baseline biomarker, demographic, disease, and treatment subgroups. These analyses provide useful insights for clinicians considering the range of patients who may benefit from IPE therapy and suggest that mechanisms beyond the lipid/lipoprotein/inflammatory pathways tested, including mechanisms beyond the LDL receptor pathways, may contribute to the observed substantial reductions in total ischemic burden with IPE therapy.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The study was funded by Amarin Pharma, Inc.

RNA interference targeting apolipoprotein C-III with ARO-APOC3 in healthy volunteers mimics lipid and lipoprotein findings seen in subjects with inherited apolipoprotein C-III deficiency

Background

Individuals with triglycerides (TGs) ≥1,000 mg/dL (11.1 mmol/L) are at increased risk of acute pancreatitis. Genetic studies indicate that individuals with apolipoprotein C-3 (APOC3) loss-of-function mutations have low TGs, reduced cardiovascular risk and no observed adverse phenotype. RNA interference (RNAi) with ARO-APOC3 has shown deep and durable knockdown (KD) of APOC3 after single doses in healthy volunteers (HVs, presented at AHA 2019) with good tolerability. We report here initial results using multiple doses of ARO-APOC3 to silence APOC3 expression in HVs.

Methods

ARO-APOC3 was administered subcutaneously to HVs on days 1 and 29 at doses of 10, 25 or 50 mg (n=4 per group). Measured parameters included plasma concentrations of APOC3, LDL-C, TGs, VLDL-C and HDL-C.

Results

All HVs have received both doses and follow-up for most parameters is available through week (wk) 14 (10 wks after second dose) for the 10 and 25 mg doses and through wk 10 for 50 mg. Mean nadir for APOC3 levels occurred at wk 3 for 10 mg (−73%) and remained similar at wk 10 (−66%), at wk 6 for 25 mg (−90%) with no change at wk 10 and at wk 2 for 50 mg (−94%) unchanged at wk 8. TGs fell faster in the 50 mg group (wk 1: 10 mg −41%; 25 mg −47%; 50 mg −72%). By wk 6 the 25 and 50 mg results were similar (−68% and −74%, respectively) and remained similar through wk 14. 10 mg was less active with a nadir of −56% and mean reductions between 42% and 56% post-nadir. VLDL-C values mirrored TGs. LDL-C reductions were more modest and did not manifest a dose response. Mean nadirs (−23–26%) occurred 4–6 wks after the first dose, again with minimal change through 10–14 wks of follow-up. Consistent with genetic studies, HDL-C increased to a maximum at approximately wk 8 (10 mg +42%, 25 mg +48%, 50 mg +84%). ARO-APOC3 was well tolerated without serious or severe adverse events or dropouts related to drug. The most common adverse events were mild injection site AEs and headache.

Conclusions

Genetic deficiency of APOC3 is associated with substantial reductions in TGs, VLDL-C and increases in HDL-C without an adverse phenotype. Using RNAi to selectively suppress APOC3 production mimics these lipid and lipoprotein effects, with a duration of at least 10 weeks following a second dose and with good tolerability over 16 wks using doses ranging from 10 to 50 mg. Investigation of optimal dosing regimen is ongoing, especially with respect to dosing interval. This therapeutic approach has potential for treating patients with chylomicronemia at risk of pancreatitis.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Arrowhead Pharmaceuticals

Collaborative meta-analysis of individual participant data from observational studies of Lp-PLA2 and cardiovascular diseases

BACKGROUND

A large number of observational epidemiological studies have reported generally positive associations between circulating mass and activity levels of lipoprotein-associated phospholipase A2 (Lp-PLA2) and the risk of cardiovascular diseases. Few studies have been large enough to provide reliable estimates in different circumstances, such as in different subgroups (e.g., by age group, sex, or smoking status) or at different Lp-PLA2 levels. Moreover, most published studies have related disease risk only to baseline values of Lp-PLA2 markers (which can lead to substantial underestimation of any risk relationships because of within-person variability over time) and have used different approaches to adjustment for possible confounding factors.

OBJECTIVES

By combination of data from individual participants from all relevant observational studies in a systematic 'meta-analysis', with correction for regression dilution (using available data on serial measurements of Lp-PLA2), the Lp-PLA2 Studies Collaboration will aim to characterize more precisely than has previously been possible the strength and shape of the age and sex-specific associations of plasma Lp-PLA2 with coronary heart disease (and, where data are sufficient, with other vascular diseases, such as ischaemic stroke). It will also help to determine to what extent such associations are independent of possible confounding factors and to explore potential sources of heterogeneity among studies, such as those related to assay methods and study design. It is anticipated that the present collaboration will serve as a framework to investigate related questions on Lp-PLA2 and cardiovascular outcomes.

METHODS

A central database is being established containing data on circulating Lp-PLA2 values, sex and other potential confounding factors, age at baseline Lp-PLA2 measurement, age at event or at last follow-up, major vascular morbidity and cause-specific mortality. Information about any repeat measurements of Lp-PLA2 and potential confounding factors has been sought to allow adjustment for possible confounding and correction for regression dilution. The analyses will involve age-specific regression models. Synthesis of the available observational studies of Lp-PLA2 will yield information on a total of about 15 000 cardiovascular disease endpoints.

LFA-1 (CD11a/CD18) triggers hydrogen peroxide production by canine neutrophils

The respiratory burst of neutrophils stimulated by chemotactic factors is markedly augmented by Mac-1-dependent adhesion such as the interaction of Mac-1 (CD11b/CD18) with intercellular adhesion molecule-1 (ICAM-1; CD54) expressed on the surface of parenchymal cells (e.g., cardiac myocytes). In the current study, we evaluate the hypothesis that lymphocyte function-associated antigen-1 (LFA-1; CD11a/CD18) can also trigger the respiratory burst in neutrophils. To isolate LFA-1/ICAM-1 interactions from Mac-1/ ICAM-1 interactions, full-length chimeric ICAM-1 was developed and expressed in L cells with domains 1 and 2 from canine ICAM-1 and domains 3-5 from human ICAM-1 (C1,2;H3-5). We have shown that canine neutrophils do not bind to human ICAM-1. We demonstrated that chimeric ICAM-1 C1,2;H3-5 supported only LFA-1-dependent adhesion of canine neutrophils and that such adhesion triggered rapid onset of H2O2 production from canine neutrophils. The following seven experimental conditions distinguished LFA-1-dependent H2O2 production from Mac-1-dependent production: It did not require exogenous chemotactic stimulation; H2O2 release was more rapid, but the amount released was <40% of that mediated by Mac-1 adhesion; it was inhibited by anti-CD11a and anti-ICAM-1 antibodies; in contrast to that mediated by Mac-1, it was not inhibited by anti-CD11b antibody, neutrophil inhibitory factor (NIF), or cytochalasin B or H7. Thus, canine neutrophils seem to be able to utilize two members of the beta2 integrin family to interact with ICAM-1 and signal H2O2 production, with LFA-1 at an early stage without prior chemotactic stimulation and Mac-1 at a later stage requiring chemotactic stimulation.

Hydrogen peroxide induces LFA-1-dependent neutrophil adherence to cardiac myocytes

Adult cardiac myocytes express intercellular adhesion molecule (ICAM)-1 in response to cytokine stimulation. This allows stable adhesion of chemotactically stimulated but not unstimulated neutrophils. In the current study, we demonstrated that brief exposure of ICAM-1-expressing cardiac myocytes to H(2)O(2) promoted transient adhesive interactions between myocytes and neutrophils without added chemotactic factors. This transient adhesion differed in two ways from the stable adhesion promoted by exogenous chemotactic factors. It occurred more rapidly, peaking within 15 min, and it was dependent on leukocyte function-associated antigen (LFA)-1 (CD11a/CD18) on the neutrophil interacting with ICAM-1 on the myocyte. In contrast, chemotactic factor-induced adhesion peaked at 60 min and was dependent on Mac-1 (CD11b/CD18). The transient adhesion could be completely inhibited by platelet-activating factor (PAF)-receptor antagonists WEB-2086 and SDZ-64-412. These results indicate that canine neutrophils may utilize both LFA-1 and Mac-1 to adhere to adult cardiac myocytes, with LFA-1 triggered by a PAF-like activity induced in myocytes by H(2)O(2).

A controlled clinical trial of dorzolamide: a single-centre subset of a multicentre study

PURPOSE

To assess the safety and intraocular pressure (IOP)-lowering activity of 2% dorzolamide (topical carbonic anhydrase inhibitor), compared to 0.5% timolol and 0.5% betaxolol eyedrops.

METHODS

A parallel, masked, randomised one-year clinical trial was conducted in 16 patients with open-angle glaucoma or ocular hypertension, being a subset of a multicentre study which enrolled 523 subjects. Patients had IOP > 22 mmHg in one eye at baseline following washout of ocular hypotensive medications and were then randomised in a 3:1:1 ratio to receive 2% dorzolamide thrice daily, 0.5% timolol twice daily or 0.5% betaxolol twice daily respectively. IOP was measured at Hour 2 (morning peak), Hour 5 and Hour 8 (afternoon trough for dorzolamide) at baseline, Weeks 2 and 4 and Months 2, 3, 6, 9 and 12.

RESULTS

Topical dorzolamide 2% solution was well tolerated and safe. Mean IOP for dorzolamide at Hour 2 was 29.1 mmHg at baseline and 20.8 mmHg on treatment at one year, a 28.5% change. Mean IOP for dorzolamide at Hour 8 was 24.5 mmHg at baseline and 20.2 mmHg on treatment at one year, a 17.6% change. Comparable percent changes for timolol and betaxolol were 43.2/25.7 mmHg at Hour 2 and 21.9/13.5 mmHg at Hour 8 respectively.

CONCLUSIONS

Dozolamide 2% given thrice daily was well tolerated and safe, with a clinically significant effect on IOP comparable to betaxolol 0.5% twice daily, but not as great as timolol 0.5% twice daily.

Baseline characteristics of subjects in the Lipoprotein and Coronary Atherosclerosis Study (LCAS) with fluvastatin

A total of 429 subjects (79 women and 350 men), aged 35-75 years, have been enrolled in a randomized clinical trial of fluvastatin therapy for hypercholesterolemia. The progression and regression of atherosclerotic lesions will be assessed by quantitative angiography and positron emission tomography (PET) after 2.5 years of treatment. Patients were included in the trial if they had angiographically documented lesions that occluded 30-75% of the diameter of a major coronary vessel. Of the 429 subjects, 99 were also studied by PET at rest and during static exercise of sustained handgrip combined with administration of dipyridamole. All subjects were instructed in an American Heart Association/National Cholesterol Education Program (AHA/NCEP) Step I or Step II diet. Of the total, 107 subjects (25%) had low density lipoprotein cholesterol (LDL-C) > or = 160 mg/dL and were given cholestyramine, 8 g/day. All subjects were randomized to placebo or fluvastatin, the newest 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor to be introduced into the U.S. market. Fluvastatin is entirely synthetic and is similar in efficacy to the other available HMG-CoA reductase inhibitors. Its pharmaceutical profile (i.e., low systemic exposure) makes fluvastatin a good candidate for use in combination lipid-lowering therapy. The majority of subjects were recruited through a community campaign and the remainder through cardiac catheterization laboratories and the medical records of hospitals in the Texas Medical Center. Approximately 8,500 prospects from the community campaign were screened and 272 were randomized, a conversion rate of approximately 3%.(ABSTRACT TRUNCATED AT 250 WORDS)