Safety and efficacy of laropiprant and extended-release niacin combination in the management of mixed dyslipidemias and primary hypercholesterolemia

Niacin in the Treatment of Hyperlipidemias in Light of New Clinical Trials: Has Niacin Lost its Place?

Niacin is considered to be a powerful drug for the treatment of lipid and lipoprotein abnormalities connected with “residual cardiovascular risk”, which persist in high-risk patients even when the target goals of LDL-C are achieved with statin therapy. Recent large randomized clinical studies – AIM-HIGH (Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides) and HPS2-THRIVE (Heart Protection Study 2-Treatment of HDL to Reduce the Incidence of Vascular Events) – delivered some disappointing results, leading to the conclusion that no further benefit (decreased parameters of cardiovascular risk) is achieved by adding niacin to existing statin therapy in patients with high cardiovascular risk. Moreover, in these studies, several adverse effects of the treatment were observed; therefore, niacin treatment for hypolipidemias is not recommended. In this paper, we analyze the mechanisms underlying the hypolipidemic and antiatherogenic effects of niacin as well as some limitations of the designs of the AIM HIGH and HP2-THRIVE studies. We also provide the possibilities of rational usage of niacin for specific types of dyslipidemias.

Extended-release niacin/laropiprant for lipid management: observational study in clinical practice

AIMS

Patients with dyslipidaemia or hypercholesterolemia carry a substantially increased cardiovascular risk and need optimal treatment of this key risk factor. We aimed to investigate the utilisation, efficacy and tolerability of the single pill combination extended-release niacin/laropiprant 1000 mg/20 mg or 2000 mg /40 mg under conditions of primary care practice.

METHODS

The present study was a prospective, non-interventional, observational study involving 885 primary care physicians throughout Germany. Data on adult patients treated with niacin/laropiprant one or two tablets daily within the labelled indication were documented for an average of 23 ± 7 weeks. The study was registered in the Association of research-based pharmaceutical companies (VFA) database under no. 354.

RESULTS

A total of 2359 patients were analysed in the intent-to-treat population (mean age 61.1 years, 67% males) of whom 1917 could be followed up. Background statin therapy was often discontinued and only about 50% of patients received two tables niacin/laropiprant at the end of the study. Individual goal attainment rates as subjectively determined by the investigator were for LDL-C 59.4%, total cholesterol 59.5%, HDL-C 72.8% and TG 51.5%, respectively. Objective (laboratory) goal attainment rates according to NCEP ATP III criteria were lower: LDL-C <100 mg/dl goal was achieved in 17.8%, HDL-C >40 in males or >50 mg/dl in females in 37.9% and TG <150 mg/dl in 18.7%. Totally, 422 adverse events were noted in 231 patients (9.7%), of which 317 were considered drug-related. Flushing occurred in 15%.

CONCLUSION

Niacin/laropiprant resulted in beneficial effects on serum lipids and was generally well tolerated. The full potential of the drug combination was not explored by most physicians due to discontinuation of statins and lack of titration of the combination. Overall, treatment effects were consistent with those seen in controlled trials.

Large-scale gene-centric meta-analysis across 32 studies identifies multiple lipid loci

Genome-wide association studies (GWASs) have identified many SNPs underlying variations in plasma-lipid levels. We explore whether additional loci associated with plasma-lipid phenotypes, such as high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglycerides (TGs), can be identified by a dense gene-centric approach. Our meta-analysis of 32 studies in 66,240 individuals of European ancestry was based on the custom ∼50,000 SNP genotyping array (the ITMAT-Broad-CARe array) covering ∼2,000 candidate genes. SNP-lipid associations were replicated either in a cohort comprising an additional 24,736 samples or within the Global Lipid Genetic Consortium. We identified four, six, ten, and four unreported SNPs in established lipid genes for HDL-C, LDL-C, TC, and TGs, respectively. We also identified several lipid-related SNPs in previously unreported genes: DGAT2, HCAR2, GPIHBP1, PPARG, and FTO for HDL-C; SOCS3, APOH, SPTY2D1, BRCA2, and VLDLR for LDL-C; SOCS3, UGT1A1, BRCA2, UBE3B, FCGR2A, CHUK, and INSIG2 for TC; and SERPINF2, C4B, GCK, GATA4, INSR, and LPAL2 for TGs. The proportion of explained phenotypic variance in the subset of studies providing individual-level data was 9.9% for HDL-C, 9.5% for LDL-C, 10.3% for TC, and 8.0% for TGs. This large meta-analysis of lipid phenotypes with the use of a dense gene-centric approach identified multiple SNPs not previously described in established lipid genes and several previously unknown loci. The explained phenotypic variance from this approach was comparable to that from a meta-analysis of GWAS data, suggesting that a focused genotyping approach can further increase the understanding of heritability of plasma lipids.