Alirocumab in patients with heterozygous familial hypercholesterolemia undergoing lipoprotein apheresis: Rationale and design of the ODYSSEY ESCAPE trial

Efficacy and safety of PCSK9 inhibitors, potent statins, and their combinations for reducing low-density lipoprotein cholesterol in hyperlipidemia patients: a systematic network meta-analysis

Background

The objective of this study is to assess the relative efficacy of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, such as alirocumab, evolocumab, and inclisiran, in conjunction with potent statins like atorvastatin and rosuvastatin, in patients presenting with hyperlipidemia or heightened cardiovascular risk attributable to elevated low-density lipoprotein cholesterol (LDL-C).

Methods

A systematic search was conducted across databases including PubMed, Embase, and the Cochrane Library to explore lipid-lowering therapies in hyperlipidemia from their inception to 7 November 2023. A network meta-analysis (NMA) was conducted via Stata 17 software, with two authors independently conducting the search, screening, and data abstraction.

Results

A total of 68 clinical studies involving 21,288 patients with hyperlipidemia were incorporated into the NMA. PSCK9 inhibitors and potent statins significantly reduced LDL-C levels from baseline vs. placebo regardless of background therapy. Regarding the efficacy of lipid reduction, four principal medications were evaluated: evolocumab and atorvastatin [mean standard deviation (MD) -3.41, 95% CI -4.81 to -2.00] and evolocumab with rosuvastatin (MD -3.44, 95% CI -5.10 to -1.78) vs. placebo; alirocumab combined with rosuvastatin (MD -2.91, 95% CI -3.95 to -1.88) and alirocumab with atorvastatin (MD -2.90, 95% CI -3.97 to -1.84) vs. placebo. Meanwhile, compared with placebo, evolocumab (MD -1.89, 95% CI -2.27 to -1.50), alirocumab (MD -1.83, 95% CI -2.09 to -1.57), rosuvastatin (MD -1.93, 95% CI -2.30 to -1.56), inclisiran (MD -1.68, 95% CI -2.10 to -1.27), and atorvastatin (MD -1.68, 95% CI -2.04 to -1.31) could also play a role in the treatment of LDL-C reduction. Moreover, the incidence of adverse events (AEs) was similar to that observed in the control group, which included both placebo and potent statin groups, with no significant differences identified in our study (P > 0.05).

Conclusions

The combination of PCSK9 inhibitors with robust statins like rosuvastatin and atorvastatin markedly decreases LDL-C levels in patients with hyperlipidemia when compared to placebo or monotherapy. Notably, the pairing of evolocumab and atorvastatin exhibited exceptional efficacy in this investigation. In the interim, the combination of PCSK9 inhibitors and potent statins demonstrates a notable safety profile when contrasted with the control group.

Long-term lipoprotein apheresis reduces cardiovascular events in high-risk patients with isolated lipoprotein(a) elevation

BACKGROUND

Elevated lipoprotein(a) (Lp(a)) is an established risk factor for cardiovascular disease (CVD). To date, the only approved treatment to lower Lp(a) is lipoprotein apheresis (LA). Previous studies have demonstrated that LA is effective in reducing cardiovascular (CV) risk in patients with elevated low-density lipoprotein cholesterol (LDL-C) and/or Lp(a). Here we report our long-term experience with LA and its effectiveness in reducing CVD events in patients with elevated Lp(a).

METHODS

This retrospective open-label, single-center study included 25 individuals with Lp(a) elevation >60 mg/dL and LDL-C < 2.59 mmol/L who had indication for LA. The primary endpoint of this study was the incidence of any CV event (determined by medical records) after initiation of LA.

RESULTS

Mean LA treatment duration was 7.1 years (min-max: 1-19 years). Median Lp(a) was reduced from 95.0 to 31.1 mg/dL after LA (-67.3%, p < 0.0001). Mean LDL-C was reduced from 1.85 to 0.76 mmol/L after LA (-58.9%, p < 0.0001). Prior to LA, 81 CV events occurred in total (0.87 events/patient/year). During LA, 49 CV events occurred in total (0.24 events/patient/year; -0.63, p = 0.001). Yearly major adverse cardiac event (MACE) rate was reduced from 0.34 to 0.006 (-0.33, p = 0.0002). Similar results were obtained when considering only individuals with baseline LDL-C below 1.42 mmol/L.

CONCLUSION

In this observational study of a heterogeneous CV high-risk cohort with elevated Lp(a), LA reduced Lp(a) levels and was paralleled by a decrease in CV events and MACE. We recommend LA for patients with high Lp(a) who still have CV events despite optimal lipid-lowering medication and lifestyle changes.

Is Liver Transplant Curative in Homozygous Familial Hypercholesterolemia? A Review of Nine Global Cases

INTRODUCTION

Homozygous familial hypercholesterolemia (HoFH) is a rare, life-threatening, inherited condition characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C). Patients are at high risk of atherosclerotic cardiovascular disease, adverse cardiovascular events, and associated early mortality. Liver transplant is sometimes used with curative intent. The objective of the current case series was to evaluate the follow-up of a range of patients who have undergone liver transplant for the treatment of HoFH.

METHODS

Patients with clinical and/or genetic diagnoses of HoFH were treated according to local practices in four units in Europe and the Middle East. All patients underwent liver transplantation. Baseline and long-term follow-up data were collected, including LDL-C levels, DNA mutations, lipid-lowering medications, and complications due to surgery and immunosuppressive therapy.

RESULTS

Nine patients were included with up to 22 years' follow-up (mean ± SD 11.7 ± 11.7 years; range 0.5-28 years). Three of the patients died as a result of complications of transplant surgery (mortality rate 33%). Among the surviving six patients, four required continued lipid-lowering therapy (LLT) to maintain LDL-C levels and two patients show signs of increasing LDL-C levels that require management. One case (11%) required two consecutive transplants to achieve a viable graft and is awaiting a third transplant because of graft failure.

CONCLUSIONS

Liver transplant did not enable attainment of recommended LDL-C targets in most patients with HoFH, and the majority of patients still required post-transplant LLT. Liver transplant was not curative in most of the patients with HoFH followed. Guidelines suggest that transplant is a treatment of last resort if contemporary treatments are not available or possible.

Cardiovascular events in patients with familial hypercholesterolemia and hyperlipoproteinaemia (a): Indications for lipoprotein apheresis in Poland

BACKGROUND

Lipoprotein apheresis (LA) is a safe method of reducing atherogenic lipoproteins and improving cardiovascular (CV) outcomes. We aimed to assess the reductions in low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] levels in patients undergoing regular LA therapy and to evaluate its influence on the incidence rate of adverse cardiac and vascular events (ACVE) and major adverse cardiac events (MACE).

METHODS

A longitudinal study in Poland evaluated the prospective and retrospective observational data of 23 patients with hyperlipoproteinaemia (a) [hyper-Lp(a)] and familial hypercholesterolemia (FH), undergoing 1014 LA sessions between 2013 and 2020. Their pre- and post-apheresis LDL-C and Lp(a) levels were assessed to calculate the acute percent reductions. The time period used to evaluate annual rates of ACVE and MACE before and after initiation of LA was matched in each patient.

RESULTS

The pre-apheresis LDL-C and Lp(a) concentrations were 155 (107-228) (mg/dL) (median and interquartile range) and 0.56 (0.14-1.37) (g/L), respectively. LA therapy resulted in a reduction of LDL-C to 50 (30-73.5) (mg/dL) and of Lp(a) to 0.13 (0.05-0.34) (g/L), representing a percent reduction of 70.0% and 72.7% for LDL-C and Lp(a), respectively. We found a significant reduction in the annual rate of ACVE (0.365[0.0-0.585] vs (0.0[0.0-0.265]; P = .047) and MACE (0.365[0.0-0.585] vs 0.0[0.0-0.265]; P = .031).

CONCLUSIONS

The findings of our study indicate that LA treatment in patients with hyperlipoproteinaemia (a) and FH on maximally tolerated lipid lowering therapies leads to a substantial reduction in LDL-C and Lp(a) concentrations and lowers CV event rates in Polish patients.

Lipoprotein(a) Lowering-From Lipoprotein Apheresis to Antisense Oligonucleotide Approach

It is well-known that elevated lipoprotein(a)—Lp(a)—levels are associated with a higher risk of cardiovascular (CV) mortality and all-cause mortality, although a standard pharmacotherapeutic approach is still undefined for patients with high CV risk dependent on hyperlipoproteinemia(a). Combined with high Lp(a) levels, familial hypercholesterolemia (FH) leads to a greater CVD risk. In suspected FH patients, the proportion of cases explained by a rise of Lp(a) levels ranges between 5% and 20%. In the absence of a specific pharmacological approach able to lower Lp(a) to the extent required to achieve CV benefits, the most effective strategy today is lipoprotein apheresis (LA). Although limited, a clear effect on Lp(a) is exerted by PCSK9 antagonists, with apparently different mechanisms when given with statins (raised catabolism) or as monotherapy (reduced production). In the era of RNA-based therapies, a new dawn is represented by the use of antisense oligonucleotides APO(a)L_rx, able to reduce Lp(a) from 35% to over 80%, with generally modest injection site reactions. The improved knowledge of Lp(a) atherogenicity and possible prevention will be of benefit for patients with residual CV risk remaining after the most effective available lipid-lowering agents.

Actual situation of lipoprotein apheresis in patients with elevated lipoprotein(a) levels

An elevation of lipoprotein(a) (Lp(a)) is an internationally recognized atherogenic risk factor, documented in epidemiological studies, in studies with Mendelian randomization and in genome-wide association studies (GWAS). At present, no drug is available to effectively reduce its concentration. In Germany, an elevation of Lp(a) associated with progressive cardiovascular diseases is officially recognized as an indication for a lipoprotein apheresis (LA). The number of patients who were treated with LA with this abnormality was steadily increasing in the years 2013-2016 - the official data are reported. In all new patients, who started to be treated at our LA center in 2017 (n = 20) the increased Lp(a) was a main indication for extracorporeal therapy, though some of them also showed clearly elevated LDL cholesterol (LDL-C) concentrations despite being treated with a maximal tolerated lipid-lowering drug therapy. A diabetes mellitus was seen in 5 patients. The higher was the Lp(a) level before the first LA session, the higher was the cardiovascular risk. Lp(a) concentrations measured before LA sessions were usually about 20% lower than those before the start of the LA therapy. Acutely, Lp(a) levels were reduced by about 70%. Following LA sessions the Lp(a) levels increased and in the majority reach pre-session concentrations after one week. Thus a weekly interval is best for the patients, but a few may need two sessions per week to stop the progress of atherosclerosis. The interval mean values were about 39% lower than previous levels. Several papers had been published showing a higher efficiency of LA therapy on the incidence of cardiovascular events in patients with high Lp(a) values when comparing with hypercholesterolemic patients with normal Lp(a) concentrations. Russian specific anti-Lp(a) columns positively affected coronary atherosclerosis. PCSK9 inhibitors reduce Lp(a) concentrations in many patients and in this way have a positive impact on cardiovascular outcomes. In the future, an antisense oligonucleotide against apolipoprotein(a) may be an alternative therapeutic option, provided a clear-cut reduction of cardiovascular events will be demonstrated.

PCSK9 Inhibition: New Treatment Options and Perspectives to Lower Atherogenic Lipoprotein Particles and Cardiovascular Risk

PURPOSE OF REVIEW

To summarize latest clinical studies and to put them into perspectives for clinical relevant subgroups and new therapeutic options.

RECENT FINDINGS

Have investigated PCSK9 inhibitors in patients with very high cardiovascular risk and insufficient LDL cholesterol lowering under current maximal tolerated lipid-lowering therapy, patients with statin intolerance, or genetic forms of familiar hypercholesterolemia, and patients on LDL apheresis. Purpose of recent cardiovascular endpoint trials has proven cardiovascular benefit of this new approach. PCSK9 inhibition with fully humanized antibodies has proven to be effective, safe, and well-tolerated in reducing cardiovascular risk by LDL cholesterol lowering. Therefore, research interests are to elucidate additional roles and effects of PCSK9 modulation on inflammation and cellular processes of the atherosclerotic plaque and to develop alternative therapeutic strategies addressing PCSK9 as a proven and therefore promising drug target.

PCSK9 in context: A contemporary review of an important biological target for the prevention and treatment of atherosclerotic cardiovascular disease

The identification of the critical role of proprotein convertase subtilisin/kexin type 9 (PCSK9) has rapidly led to the development of PCSK9 inhibition with monoclonal antibodies (mAbs). PCSK9 mAbs are already in limited clinical use and are the subject of major cardiovascular outcomes trials, which, if universally positive, could see much wider clinical application of these agents. Patients with familial hypercholesterolaemia are the most obvious candidates for these drugs, but other patients with elevated cardiovascular risk, statin intolerance or hyperlipoproteinaemia(a) may also benefit. PCSK9 mAbs, administered once or twice monthly, reduce LDL cholesterol levels by 50% to 70%, and appear to be safe and acceptable to patients over at least 2 years of treatment; however, treatment-emergent adverse effects are not always identified in clinical trials, as well-evidenced by statin myopathy. Inclisiran is a promising RNA-based therapy that promotes the degradation of PCSK9 mRNA transcripts and has similar efficacy to mAbs, but with a much longer duration of action. The cost-effectiveness and long-term safety of therapies targeted at inhibiting PCSK9 remain to be demonstrated if they are to be used widely in coronary prevention.

PCSK9 Inhibitors: Mechanisms of Action, Metabolic Effects, and Clinical Outcomes

Atherosclerotic cardiovascular disease (ASCVD) is associated with significant morbidity and mortality worldwide. Increased serum levels of low-density lipoprotein cholesterol (LDL-C) are an independent risk factor for ASCVD, and clinical trial data have shown that lowering LDL-C generally reduces cardiovascular risk. Until recently, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) have been the main therapy for lowering LDL-C. However, some statin-treated patients have persistently elevated residual cardiovascular risk due to inadequate lowering of LDL-C levels or non-LDL-related dyslipidemia. In addition, adverse effects of statins may limit their tolerability and therefore the ability to attain effective doses in some patients. A new class of drugs that inhibit proprotein convertase subtilisin-kexin type 9 (PCSK9) has been developed to treat hyperlipidemia. This review discusses the history and mechanism of action of PCSK9 inhibitors, their metabolic effects, and clinical outcomes associated with these medications, highlighting recent large cardiovascular outcome trials investigating these therapies.

Alirocumab in patients with heterozygous familial hypercholesterolaemia undergoing lipoprotein apheresis: the ODYSSEY ESCAPE trial

AIM

To evaluate the effect of alirocumab on frequency of standard apheresis treatments [weekly or every 2 weeks (Q2W)] in heterozygous familial hypercholesterolaemia (HeFH).

METHODS AND RESULTS

ODYSSEY ESCAPE (NCT02326220) was a double-blind study in 62 HeFH patients undergoing regular weekly or Q2W lipoprotein apheresis. Patients were randomly assigned (2:1, respectively) to receive alirocumab 150 mg (n = 41) or placebo (n = 21) Q2W subcutaneously for 18 weeks. From day 1 to week 6, apheresis rate was fixed according to the patient's established schedule; from weeks 7 to 18, apheresis rate was adjusted based on the patient's low-density lipoprotein cholesterol (LDL-C) response in a blinded fashion. Apheresis was not performed when the LDL-C value was ≥30% lower than the baseline (pre-apheresis) value. The primary efficacy endpoint was the rate of apheresis treatments over 12 weeks (weeks 7-18), standardized to number of planned treatments. In the alirocumab group the least square (LS) mean ± SE (95% confidence interval [CI]) per cent change in pre-apheresis LDL-C from baseline at week 6 was -53.7 ± 2.3 (-58.2 to - 49.2) compared with 1.6 ± 3.1 (-4.7 to 7.9) in the placebo group. The primary efficacy endpoint showed statistically significant benefit in favour of alirocumab (Hodges-Lehmann median estimate of treatment difference: 0.75; 95% CI 0.67-0.83; P < 0.0001). Therefore, alirocumab-treated patients had a 0.75 (75%) additional reduction in the standardized rate of apheresis treatments vs. placebo-treated patients. During this period, 63.4% of patients on alirocumab avoided all and 92.7% avoided at least half of the apheresis treatments. Adverse event rates were similar (75.6% of patients on alirocumab vs. 76.2% on placebo).

CONCLUSIONS

Lipoprotein apheresis was discontinued in 63.4% of patients on alirocumab who were previously undergoing regular apheresis, and the rate was at least halved in 92.7% of patients. Alirocumab was generally safe and well tolerated.