RNA-based therapy in the management of lipid disorders: a review.

This review focuses on antisense oligonucleotides and small interfering ribonucleic acid therapies approved or under development for the management of lipid disorders. Recent advances in RNA-based therapeutics allow tissue-specific targeting improving safety. Multiple potential target proteins have been identified and RNA-based therapeutics have the potential to significantly improve outcomes for patients with or at risk for atherosclerotic cardiovascular disease. The advantages of RNA-based lipid modifying therapies include the ability to reduce the concentration of almost any target protein highly selectively, allowing for more precise control of metabolic pathways than can often be achieved with small molecule-based drugs. RNA-based lipid modifying therapies also make it possible to reduce the expression of target proteins for which there are no small molecule inhibitors. RNA-based therapies can also reduce pill burden as their administration schedule typically varies from weekly to twice yearly injections. The safety profile of most current RNA-based lipid therapies is acceptable but adverse events associated with various therapies targeting lipid pathways have included injection site reactions, inflammatory reactions, hepatic steatosis and thrombocytopenia. While the body of evidence for these therapies is expanding, clinical experience with these therapies is currently limited in duration and the results of long-term studies are eagerly awaited.

The therapeutic management of South African dyslipidaemic patients at very high cardiovascular risk (CARDIO TRACK): a cross-sectional study.

BACKGROUND: Dyslipidaemia is a major modifiable risk factor for atherosclerotic cardiovascular disease. At the time the study was conducted, guidelines recommended a low-density lipoprotein cholesterol (LDL-C) target of less than 1.8 mmol/l and a reduction of at least 50% if the baseline LDL-C was between 1.8 and 3.5 mmol/l in patients with either very high cardiovascular risk or established atherosclerosis. In South Africa, there is a paucity of data on attainment of LDL-C goal in patients with very high cardiovascular risk who are on maximum tolerated statin with or without ezetimibe. OBJECTIVE: The aim was to assess the percentage of very high cardiovascular risk South African patients with dyslipidaemia not reaching an LDL-C goal of less than 1.8 mmol/l, despite maximum tolerated statin with or without ezetimibe. METHODS: This was a multi-centre, observational, cross-sectional study conducted at 15 private healthcare sector sites and one public sector site. Adults (> 18 years) with very high cardiovascular risk of familial hypercholesterolaemia receiving stable, maximum-tolerated statin therapy for at least four weeks prior to their latest lipid profile were enrolled into the study, and electronic case report forms were completed after written informed consent was provided. LDL-C goal attainment was modelled, first assuming an increase in the statin dose to the registered maximum, followed by the addition of ezetimibe or a PCSK9-inhibitor. RESULTS: In total, 507 patients were screened, of whom 492 were eligible for study participation. One patient was excluded from the analysis because of a missing LDL-C value. Most participants were male (male 329, 67%; female 162, 33%). Most patients were either obese (223, 46.0%) or overweight (176, 36.3%). Hypertension and diabetes mellitus were frequent co-morbidities and were found in 381 (77.6%) and 316 (64.4%) patients, respectively. Eighty (16.3%) patients reported current smoking. Only 68 (13.8%) patients were taking ezetimibe in addition to a statin. Reasons for not using ezetimibe included no requirement for ezetimibe in the opinion of the treating physician (229, 48.7%), cost (149, 31.7%), Physician's choice (39, 8.3%), or other (53, 11.3%). Only 161 (32.8%) of the patients attained their goal LDL-C level. In our modelling analysis, increasing the statin dose to the registered maximum and adding ezetimibe brought an additional 34.5% of patients to goal, while adding a PCSK9-inhibitor, irrespective of any other changes to lipid-lowering therapy brought over 90% of not-at-goal patients to goal. CONCLUSIONS: Most study participants were not at LDL-C goal despite maximum-tolerated statin, highlighting the need for treatment intensification in this high-risk population. Although intensifying treatment by adding a PCSK9-inhibitor brought more patients to goal, the initial addition of ezetimibe would be more reasonable, given the cost of PCSK9-inhibitors.

Medical Science Liaisons (MSL) in Africa: a perspective.

The role of a Medical Science Liaison (MSL) is of growing importance to pharmaceutical, biotechnology, diagnostic and medical device companies. Through scientific engagement MSLs add value to clinical practice, ultimately benefiting patients. The MSL role is dynamic and encompasses in-depth product and disease knowledge together with the ability to communicate relevant, unbiased scientific information concisely and timely. Tasks are focused on contributing towards the advancement of medical knowledge, scientific data generation and dissemination. Professional relationships are developed, fostering collaboration between external experts and typically the medical affairs departments of pharmaceutical companies through a credible liaison. Through such relationships, critical insights are shared that shape the development pipeline, promote successful clinical translation and guide the market deployment strategy of therapeutic interventions through-out their life cycle. Despite the rising number of MSLs in the field and the implicit medical value of the role, there remains a lack of understanding for what the roles of a MSL entails. In Africa, where exponential growth of the pharmaceutical industry is expected, the number of MSLs will increase rapidly. Given the complexities of the African continent, the MSLs in this burgeoning environment will face various challenges including remote locations, time-constraints, regulatory and bureaucratic hurdles and importantly physician misperception of the MSL role that collectively may thwart the goal of meaningful scientific engagement; but these challenges can be surmounted through astute proactive planning and utilization of opportunities including digital communication strategies.

Long-term safety and efficacy of alirocumab in South African patients with heterozygous familial hypercholesterolaemia: the ODYSSEY Open-Label Extension study.

BACKGROUND: Alirocumab reduces low-density lipoprotein cholesterol (LDL-C) levels by up to 61%. The ODYSSEY Open-Label Extension study investigated the effect of alirocumab in patients with heterozygous familial hypercholesterolaemia (HeFH) over 144 weeks. METHODS: Eligible patients with HeFH had completed an earlier double-blind, randomised, placebo-controlled parent study. Patients were initiated on 75 mg alirocumab Q2W subcutaneous (SC) unless baseline LDL-C was > 8.9 mmol/l, in which case they received 150 mg alirocumab Q2W. Dose titration to 150 mg Q2W was at the investigator's discretion. RESULTS: The study enrolled 167 patients and the parent study mean (± SD) baseline LDL-C level was 3.65 ± 1.9 mmol/l. Mean LDL-C level was reduced by 48.7% at week 144; mean on-treatment LDL-C was 2.30 ± 1.24 mmol/l. Eight patients reported injection-site reactions, with one treatment discontinuation. Treatment emergent anti-drug antibodies were identified in five patients but these did not affect the efficacy. CONCLUSIONS: Alirocumab effectively and safely reduced LDL-C in these patients.

Incidence of hypoglycaemia in the South African population with diabetes: results from the IDMPS Wave 7 study

Objectives: Management of diabetes is a balancing act of preventing a state of hyperglycaemia while avoiding episodes of hypoglycaemia. Limited information is currently available on the incidence of hypoglycaemia in South African people diagnosed with diabetes. Data regarding the management of diabetes and incidence of hypoglycaemia in the South African population was collected as part of Wave 7 of the International Diabetes Management Practices Study (IDMPS). Design and methods: During this observational study the first 10 adult individuals with type 2 diabetes and the first five adult individuals with type 1 diabetes presenting to a study site during the two-week study period were enrolled. Setting:Patients were enrolled from the private healthcare sector in South Africa only. Subjects:A total of 445 individuals (49 diagnosed with T1D, 396 diagnosed with T2D) were included. Outcome measures:Glycated haemoglobin and hypoglycaemia data were recorded for each patient. Results:Of the patients who reported experiencing hypoglycaemia, 48.6% (17/35) among T1D individuals and 67.8% (40/71) among T2D individuals experienced hypoglycaemia over a four-week period. Furthermore, in patients who discontinued insulin treatment (n= 11), fear of hypoglycaemia was reported to influence adherence to insulin treatment by 27.3% in T1D and T2D individuals. Of the 148 patients not achieving their HbA1c target, 23.0% reported fear of hypoglycaemia as a reason. Conclusions: This report demonstrates the need to address hypoglycaemia and fear of hypoglycaemia in the South African diabetes population

Limitations of the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay when compared to three commonly used cell enumeration assays.

BACKGROUND: The tetrazolium-based MTT assay has long been regarded as the gold standard of cytotoxicity assays as it is highly sensitive and has been miniaturised for use as a high-throughput screening assay. However, various reports refer to interference by different test compounds, including the glycolysis inhibitor 3-bromopyruvate, with the conversion of the dye to coloured formazan crystals. This study assessed the linear range and reproducibility of three commonly used cell enumeration assays; the neutral red uptake (NRU), resazurin reduction (RES) and sulforhodamine B (SRB) assays, in comparison to the MTT assay. Interference between the MTT assay and three glycolysis inhibitors, 2-deoxyglucose, 3-bromopyruvate and lonidamine, was investigated. RESULTS: Data indicate that the NRU, RES and SRB assays showed the smallest variability across the linear range, while the largest variation was observed for the MTT assay. This implies that these assays would more accurately detect small changes in cell number than the MTT assay. The SRB assay provided the most reproducible results as indicated by the coefficient of determination after a limited number of experiments. The SRB assay also produced the lowest variance in the derived 50% inhibitory concentration (IC50), while IC50 concentrations of 3-bromopyruvate could not be detected using either the MTT or RES assays after 24 hours incubation. Interference in the MTT assay was observed for all three tested glycolysis inhibitors in a cell-free environment. No interferences were observed for the NRU, SRB or RES assays. CONCLUSIONS: This study demonstrated that the MTT assay was not the best assay in a number of parameters that must be considered when a cell enumeration assay is selected: the MTT assay was less accurate in detecting changes in cell number as indicated by the variation observed in the linear range, had the highest variation when the IC50 concentrations of the glycolysis inhibitors were determined, and interference between the MTT assay and all the glycolysis inhibitors tested were observed. The SRB assay performed best overall considering all of the parameters, suggesting that it is the most suitable assay for use in preclinical screening of novel therapeutic compounds with oxido-reductive potential.