Plozasiran, an RNA Interference Agent Targeting APOC3, for Mixed Hyperlipidemia.

BACKGROUND: Persons with mixed hyperlipidemia are at risk for atherosclerotic cardiovascular disease due to an elevated non-high-density lipoprotein (HDL) cholesterol level, which is driven by remnant cholesterol in triglyceride-rich lipoproteins. The metabolism and clearance of triglyceride-rich lipoproteins are down-regulated through apolipoprotein C3 (APOC3)-mediated inhibition of lipoprotein lipase. METHODS: We carried out a 48-week, phase 2b, double-blind, randomized, placebo-controlled trial evaluating the safety and efficacy of plozasiran, a hepatocyte-targeted APOC3 small interfering RNA, in patients with mixed hyperlipidemia (i.e., a triglyceride level of 150 to 499 mg per deciliter and either a low-density lipoprotein [LDL] cholesterol level of ≥70 mg per deciliter or a non-HDL cholesterol level of ≥100 mg per deciliter). The participants were assigned in a 3:1 ratio to receive plozasiran or placebo within each of four cohorts. In the first three cohorts, the participants received a subcutaneous injection of plozasiran (10 mg, 25 mg, or 50 mg) or placebo on day 1 and at week 12 (quarterly doses). In the fourth cohort, participants received 50 mg of plozasiran or placebo on day 1 and at week 24 (half-yearly dose). The data from the participants who received placebo were pooled. The primary end point was the percent change in fasting triglyceride level at week 24. RESULTS: A total of 353 participants underwent randomization. At week 24, significant reductions in the fasting triglyceride level were observed with plozasiran, with differences, as compared with placebo, in the least-squares mean percent change from baseline of -49.8 percentage points (95% confidence interval [CI], -59.0 to -40.6) with the 10-mg-quarterly dose, -56.0 percentage points (95% CI, -65.1 to -46.8) with the 25-mg-quarterly dose, -62.4 percentage points (95% CI, -71.5 to -53.2) with the 50-mg-quarterly dose, and -44.2 percentage points (95% CI, -53.4 to -35.0) with the 50-mg-half-yearly dose (P<0.001 for all comparisons). Worsening glycemic control was observed in 10% of the participants receiving placebo, 12% of those receiving the 10-mg-quarterly dose, 7% of those receiving the 25-mg-quarterly dose, 20% of those receiving the 50-mg-quarterly dose, and 21% of those receiving the 50-mg-half-yearly dose. CONCLUSIONS: In this randomized, controlled trial involving participants with mixed hyperlipidemia, plozasiran, as compared with placebo, significantly reduced triglyceride levels at 24 weeks. A clinical outcomes trial is warranted. (Funded by Arrowhead Pharmaceuticals; MUIR ClinicalTrials.gov number NCT04998201.).

Zodasiran, an RNAi Therapeutic Targeting ANGPTL3, for Mixed Hyperlipidemia.

BACKGROUND: Angiopoietin-like 3 (ANGPTL3) inhibits lipoprotein and endothelial lipases and hepatic uptake of triglyceride-rich lipoprotein remnants. ANGPTL3 loss-of-function carriers have lower levels of triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and non-HDL cholesterol and a lower risk of atherosclerotic cardiovascular disease than noncarriers. Zodasiran is an RNA interference (RNAi) therapy targeting expression of ANGPTL3 in the liver. METHODS: We conducted a double-blind, placebo-controlled, dose-ranging phase 2b trial to evaluate the safety and efficacy of zodasiran in adults with mixed hyperlipidemia (fasting triglyceride level of 150 to 499 mg per deciliter and either an LDL cholesterol level of ≥70 mg per deciliter or a non-HDL cholesterol level of ≥100 mg per deciliter). Eligible patients were randomly assigned in a 3:1 ratio to receive subcutaneous injections of zodasiran (50, 100, or 200 mg) or placebo on day 1 and week 12 and were followed through week 36. The primary end point was the percent change in the triglyceride level from baseline to week 24. RESULTS: A total of 204 patients underwent randomization. At week 24, substantial mean dose-dependent decreases from baseline in ANGPTL3 levels were observed with zodasiran (difference in change vs. placebo, -54 percentage points with 50 mg, -70 percentage points with 100 mg, and -74 percentage points with 200 mg), and significant dose-dependent decreases in triglyceride levels were observed (difference in change vs. placebo, -51 percentage points, -57 percentage points, and -63 percentage points, respectively) (P<0.001 for all comparisons). Other differences in change from baseline as compared with placebo included the following: for non-HDL cholesterol level, -29 percentage points with 50 mg, -29 percentage points with 100 mg, and -36 percentage points with 200 mg; for apolipoprotein B level, -19 percentage points, -15 percentage points, and -22 percentage points, respectively; and for LDL cholesterol level, -16 percentage points, -14 percentage points, and -20 percentage points, respectively. We observed a transient elevation in glycated hemoglobin levels in patients with preexisting diabetes who received the highest dose of zodasiran. CONCLUSIONS: In patients with mixed hyperlipidemia, zodasiran was associated with significant decreases in triglyceride levels at 24 weeks. (Funded by Arrowhead Pharmaceuticals; ARCHES-2 ClinicalTrials.gov number, NCT04832971.).

Fazirsiran for Liver Disease Associated with Alpha1-Antitrypsin Deficiency.

BACKGROUND: Alpha1-antitrypsin (AAT) deficiency results from carriage of a homozygous SERPINA1 "Z" mutation (proteinase inhibitor [PI] ZZ). The Z allele produces a mutant AAT protein called Z-AAT, which accumulates in hepatocytes and can lead to progressive liver disease and fibrosis. This open-label, phase 2 trial investigated the safety and efficacy of fazirsiran, an RNA interference therapeutic, in patients with liver disease associated with AAT deficiency. METHODS: We assigned adults with the PI ZZ genotype and liver fibrosis to receive fazirsiran at a dose of 200 mg (cohorts 1 [4 patients] and 2 [8 patients]) or 100 mg (cohort 1b [4 patients]) subcutaneously on day 1 and week 4 and then every 12 weeks. The primary end point was the change from baseline to week 24 (cohorts 1 and 1b) or week 48 (cohort 2) in liver Z-AAT concentrations, which were measured by means of liquid chromatography-mass spectrometry. RESULTS: All the patients had reduced accumulation of Z-AAT in the liver (median reduction, 83% at week 24 or 48). The nadir in serum was a reduction of approximately 90%, and treatment was also associated with a reduction in histologic globule burden (from a mean score of 7.4 [scores range from 0 to 9, with higher scores indicating a greater globule burden] at baseline to 2.3 at week 24 or 48). All cohorts had reductions in liver enzyme concentrations. Fibrosis regression was observed in 7 of 15 patients and fibrosis progression in 2 of 15 patients after 24 or 48 weeks. There were no adverse events leading to trial or drug discontinuation. Four serious adverse events (viral myocarditis, diverticulitis, dyspnea, and vestibular neuronitis) resolved. CONCLUSIONS: In this small trial, fazirsiran was associated with a strong reduction of Z-AAT concentrations in the serum and liver and concurrent improvements in liver enzyme concentrations. (Funded by Arrowhead Pharmaceuticals; AROAAT-2002 ClinicalTrials.gov number, NCT03946449.).

Effects of Patisiran, an RNA Interference Therapeutic, on Cardiac Parameters in Patients With Hereditary Transthyretin-Mediated Amyloidosis.

BACKGROUND: Hereditary transthyretin-mediated (hATTR) amyloidosis is a rapidly progressive, multisystem disease that presents with cardiomyopathy or polyneuropathy. The APOLLO study assessed the efficacy and tolerability of patisiran in patients with hATTR amyloidosis. The effects of patisiran on cardiac structure and function in a prespecified subpopulation of patients with evidence of cardiac amyloid involvement at baseline were assessed. METHODS: APOLLO was an international, randomized, double-blind, placebo-controlled phase 3 trial in patients with hATTR amyloidosis. Patients were randomized 2:1 to receive 0.3 mg/kg patisiran or placebo via intravenous infusion once every 3 weeks for 18 months. The prespecified cardiac subpopulation comprised patients with a baseline left ventricular wall thickness ≥13 mm and no history of hypertension or aortic valve disease. Prespecified exploratory cardiac end points included mean left ventricular wall thickness, global longitudinal strain, and N-terminal prohormone of brain natriuretic peptide. Cardiac parameters in the overall APOLLO patient population were also evaluated. A composite end point of cardiac hospitalizations and all-cause mortality was assessed in a post hoc analysis. RESULTS: In the cardiac subpopulation (n=126; 56% of total population), patisiran reduced mean left ventricular wall thickness (least-squares mean difference ± SEM: -0.9±0.4 mm, P=0.017), interventricular septal wall thickness, posterior wall thickness, and relative wall thickness at month 18 compared with placebo. Patisiran also led to increased end-diastolic volume (8.3±3.9 mL, P=0.036), decreased global longitudinal strain (-1.4±0.6%, P=0.015), and increased cardiac output (0.38±0.19 L/min, P=0.044) compared with placebo at month 18. Patisiran lowered N-terminal prohormone of brain natriuretic peptide at 9 and 18 months (at 18 months, ratio of fold-change patisiran/placebo 0.45, P<0.001). A consistent effect on N-terminal prohormone of brain natriuretic peptide at 18 months was observed in the overall APOLLO patient population (n=225). Median follow-up duration was 18.7 months. The exposure-adjusted rates of cardiac hospitalizations and all-cause death were 18.7 and 10.1 per 100 patient-years in the placebo and patisiran groups, respectively (Andersen-Gill hazard ratio, 0.54; 95% CI, 0.28-1.01). CONCLUSIONS: Patisiran decreased mean left ventricular wall thickness, global longitudinal strain, N-terminal prohormone of brain natriuretic peptide, and adverse cardiac outcomes compared with placebo at month 18, suggesting that patisiran may halt or reverse the progression of the cardiac manifestations of hATTR amyloidosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01960348.

RNA Therapeutics in Cardiovascular Disease.

Noncoding RNAs have been shown to exert important physiological and pathophysiological functions. Various studies suggest that modulating noncoding RNAs may provide a therapeutic option. Noncoding RNAs comprise small RNAs, mainly microRNAs, and long noncoding RNAs. MicroRNAs postranscriptionally regulate gene expression pattern by binding to the 3'untranslated region of a given target mRNA, thereby blocking protein translation or inducing its degradation. Long noncoding RNAs on the contrary have more diverse functions acting as epigenetic regulators, molecular scaffolds, or decoys. In this article, we summarize examples of microRNAs and long noncoding RNAs, which might be promising novel targets for treatment of cardiovascular diseases, such as heart failure, acute myocardial infarction, fibrosis, as well as atherosclerosis. Furthermore, we give insights into the available tools to inhibit or overexpress noncoding RNAs and discuss the challenges for translation. Strategies for improving RNA therapeutics and reducing toxicity, for example, by augmenting tissue specificity or cellular uptake will be discussed.

Phase 3 Multicenter Study of Revusiran in Patients with Hereditary Transthyretin-Mediated (hATTR) Amyloidosis with Cardiomyopathy (ENDEAVOUR).

PURPOSE: The Phase 3 ENDEAVOUR study evaluated revusiran, an investigational RNA interference therapeutic targeting hepatic transthyretin (TTR) production, for treating cardiomyopathy caused by hereditary transthyretin-mediated (hATTR) amyloidosis. METHODS: Patients with hATTR amyloidosis with cardiomyopathy were randomized 2:1 to receive subcutaneous daily revusiran 500 mg (n = 140) or placebo (n = 66) for 5 days over a week followed by weekly doses. Co-primary endpoints were 6-min walk test distance and serum TTR reduction. RESULTS: Revusiran treatment was stopped after a median of 6.71 months; the study Sponsor prematurely discontinued dosing due to an observed mortality imbalance between treatment arms. Eighteen (12.9%) patients on revusiran and 2 (3.0%) on placebo died during the on-treatment period. Most deaths in both treatment arms were adjudicated as cardiovascular due to heart failure (HF), consistent with the natural history of the disease. A post hoc safety investigation of patients treated with revusiran found that, at baseline, a greater proportion of those who died were ≥ 75 years and showed clinical evidence of more advanced HF compared with those who were alive throughout treatment. Revusiran pharmacokinetic exposures and TTR lowering did not show meaningful differences between patients who died and who were alive. Revusiran did not deleteriously affect echocardiographic parameters, cardiac biomarkers, or frequency of cardiovascular and HF hospitalization events. CONCLUSIONS: Causes for the observed mortality imbalance associated with revusiran were thoroughly investigated and no clear causative mechanism could be identified. Although the results suggest similar progression of cardiac parameters in both treatment arms, a role for revusiran cannot be excluded. CLINICAL TRIAL REGISTRATION: NCT02319005.

Effect of an siRNA Therapeutic Targeting PCSK9 on Atherogenic Lipoproteins: Prespecified Secondary End Points in ORION 1.

BACKGROUND: The ORION-1 trial (Trial to Evaluate the Effect of ALN-PCSSC Treatment on Low Density Lipoprotein Cholesterol [LDL-C]) demonstrated that inclisiran, an siRNA therapeutic that targets protease proprotein convertase subtilisin/kexin type 9 mRNA within hepatocytes, produces significant low-density lipoprotein cholesterol reduction. The effects of inclisiran on other lipids are less well described. METHODS: ORION-1 was a phase 2 trial assessing 6 different inclisiran dosing regimens versus placebo. Participants with elevated low-density lipoprotein cholesterol despite receiving maximally tolerated statin therapy received a single-dose (200, 300, or 500 mg) or 2-dose starting regimen (100, 200, or 300 mg on days 1 and 90) of inclisiran or placebo. This prespecified analysis reports the percentage reductions in non-high-density lipoprotein cholesterol (non-HDL-C), apolipoprotein (apo) B, very-low-density lipoprotein cholesterol, lipoprotein(a), triglycerides, HDL-C, and apo A1 at the primary efficacy time point (day 180) with mixed-effect models for repeated measures. Additional prespecified analyses report time course of changes from baseline at each visit to day 210, interindividual variation in response, and lipid goal attainment. RESULTS: The mean age of the 501 participants was 63 years, 65% were male, 69% had atherosclerotic cardiovascular disease, 73% used statins, and mean low-density lipoprotein cholesterol was 128 mg/dL. A single dose of inclisiran reduced apo B, non-HDL-C, and very-low-density lipoprotein cholesterol over 210 days. A second dose of inclisiran provided additional lowering of these lipids. At day 180, non-HDL-C was lowered dose-dependently: by 25% from 148±43 to 110±45 mg/dL in the 200-mg single-dose group and by 46% from 161±58 to 91±58 mg/dL in the 2-dose 300-mg group. For the same dosing regimens, apo B was reduced by 23% from 101±23 to 78±29 mg/dL and by 41% from 106±31 to 65±33 mg/dL ( P<0.001 for all groups versus placebo). In the 300-mg 2-dose group, all individuals experienced apo B and non-HDL-C reductions. There was larger interindividual variation in very-low-density lipoprotein cholesterol, triglycerides, and lipoprotein(a) reductions. In the 300-mg 2-dose group, the percentages of patients achieving guideline-recommended apo B goals for high- and very-high-risk patients at day 180 were 78% and 90%; 68% and 83% of participants achieved non-HDL-C <100 and <130 mg/dL. CONCLUSIONS: Inclisiran produces significant and prolonged reductions in atherogenic lipoproteins, suggesting that inhibiting the synthesis of protease proprotein convertase subtilisin/kexin type 9 through siRNA may be a viable alternative to other approaches that target protease proprotein convertase subtilisin/kexin type 9. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02597127.

Time-dependent p53 inhibition determines senescence attenuation and long-term outcome after renal ischemia-reperfusion.

Inhibition of p53 has been shown to be an efficient strategy for ameliorating kidney ischemia-reperfusion (I/R) injury in experimental models. The therapeutic value of p53 siRNA-based inhibition for I/R in renal transplantation is currently being evaluated in clinical studies. While the major rationale for these studies is the suppression of proapoptotic properties, there are more equally important injury response pathways regulated by p53. A p53-dependent pathway shown to be crucial for renal long-term outcome is cellular senescence. In this study, we tested the hypothesis that p53 siRNA reduces I/R-induced senescence and thereby improves kidney outcome. By comparing the impact of different treatment durations in a mouse model of renal I/R, we found that repetitive administration of p53 siRNA during the first 14 days after I/R reduced the senescence load and ameliorated the postischemic phenotype. Prolonged application of p53 siRNA over a 26-day period after I/R, however, did not provide any additional benefit for senescence reduction but reversed some of the renoprotective effects of the early treatment. These data suggest a time-dependent role of p53 activity supporting the current therapeutic concept of a short-term inhibition, while advocating against a prolonged treatment after I/R.

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.

Genetic pharmacology: progresses in siRNA delivery and therapeutic applications.

In the RNA interference process, the catalytic degradation of an endogenous mRNA results from the Watson-Crick complementary recognition by either a small silencing synthetic double-stranded ribonucleotide (siRNA) or by a small hairpin RNA (shRNA) produced in the cell by transcription from a DNA template. This interference process ideally results in an exquisitely specific mRNA suppression. The present review is dedicated to siRNAs. It describes the mechanism of RNA silencing and the main siRNA delivery techniques, with a focus on siRNA self-complexing to cationic lipids to form nanoparticles, which are called lipoplexes. The addition to lipoplexes of an anionic polymer leads to the ternary formulation APIRL (Anionic-Polymer-Interfering-RNA-Lipoplexes) with increased in vivo stability and biological efficacy. In terms of clinical development, the review focuses on therapeutic applications by intravenous delivery to the liver and inflammatory joints, and to localized siRNA delivery to the ocular sphere.

AAV5-miHTT gene therapy demonstrates suppression of mutant huntingtin aggregation and neuronal dysfunction in a rat model of Huntington's disease.

Huntington's disease (HD) is a fatal progressive neurodegenerative disorder caused by a mutation in the huntingtin (HTT) gene. To date, there is no treatment to halt or reverse the course of HD. Lowering of either total or only the mutant HTT expression is expected to have therapeutic benefit. This can be achieved by engineered micro (mi)RNAs targeting HTT transcripts and delivered by an adeno-associated viral (AAV) vector. We have previously showed a miHTT construct to induce total HTT knock-down in Hu128/21 HD mice, while miSNP50T and miSNP67T constructs induced allele-selective HTT knock-down in vitro. In the current preclinical study, the mechanistic efficacy and gene specificity of these selected constructs delivered by an AAV serotype 5 (AAV5) vector was addressed using an acute HD rat model. Our data demonstrated suppression of mutant HTT messenger RNA, which almost completely prevented mutant HTT aggregate formation, and ultimately resulted in suppression of DARPP-32-associated neuronal dysfunction. The AAV5-miHTT construct was found to be the most efficient, although AAV5-miSNP50T demonstrated the anticipated mutant HTT allele selectivity and no passenger strand expression. Ultimately, AAV5-delivered-miRNA-mediated HTT lowering did not cause activation of microglia or astrocytes suggesting no immune response to the AAV5 vector or therapeutic precursor sequences. These preclinical results suggest that using gene therapy to knock-down HTT may provide important therapeutic benefit for HD patients and raised no safety concerns, which supports our ongoing efforts for the development of an RNA interference-based gene therapy product for HD.

Experimental Treatment of Ebola Virus Disease with TKM-130803: A Single-Arm Phase 2 Clinical Trial.

BACKGROUND: TKM-130803, a small interfering RNA lipid nanoparticle product, has been developed for the treatment of Ebola virus disease (EVD), but its efficacy and safety in humans has not been evaluated. METHODS AND FINDINGS: In this single-arm phase 2 trial, adults with laboratory-confirmed EVD received 0.3 mg/kg of TKM-130803 by intravenous infusion once daily for up to 7 d. On days when trial enrolment capacity was reached, patients were enrolled into a concurrent observational cohort. The primary outcome was survival to day 14 after admission, excluding patients who died within 48 h of admission. After 14 adults with EVD had received TKM-130803, the pre-specified futility boundary was reached, indicating a probability of survival to day 14 of ≤0.55, and enrolment was stopped. Pre-treatment geometric mean Ebola virus load in the 14 TKM-130803 recipients was 2.24 × 109 RNA copies/ml plasma (95% CI 7.52 × 108, 6.66 × 109). Two of the TKM-130803 recipients died within 48 h of admission and were therefore excluded from the primary outcome analysis. Of the remaining 12 TKM-130803 recipients, nine died and three survived. The probability that a TKM-130803 recipient who survived for 48 h will subsequently survive to day 14 was estimated to be 0.27 (95% CI 0.06, 0.58). TKM-130803 infusions were well tolerated, with 56 doses administered and only one possible infusion-related reaction observed. Three patients were enrolled in the observational cohort, of whom two died. CONCLUSIONS: Administration of TKM-130803 at a dose of 0.3 mg/kg/d by intravenous infusion to adult patients with severe EVD was not shown to improve survival when compared to historic controls. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201501000997429.

Pulmonary Delivery of siRNA via Polymeric Vectors as Therapies of Asthma.

Asthma is a chronic inflammatory disease. Despite the fact that current therapies, such as the combination of inhaled corticosteroids and ß2-agonists, can control the symptoms of asthma in most patients, there is still an urgent need for an alternative anti-inflammatory therapy for patients who suffer from severe asthma but lack acceptable response to conventional therapies. Many molecular factors are involved in the inflammatory process in asthma, and thus blocking the function of these factors could efficiently alleviate airway inflammation. RNA interference (RNAi) is often thought to be the answer in the search for more efficient and biocompatible treatments. However, difficulties of efficient delivery of small interference RNA (siRNA), the key factor in RNAi, to target cells and tissues have limited its clinical application. In this review, we summarize cytokines and chemokines, transcription factors, tyrosine kinases, and costimulatory factors that have been reported as targets of siRNA-mediated treatment in experimental asthma. Additionally, we conclude several targeted delivery systems of siRNA to specific cells such as T cells, macrophages, and dendritic cells, which could potentially be applied in asthma therapy.

siRNA Design and GalNAc-Empowered Hepatic Targeted Delivery.

Small interfering RNA (siRNA) is a clinically approved therapeutic modality, which has attracted widespread attention not only from basic research but also from pharmaceutical industry. As siRNA can theoretically modulate any disease-related gene's expression, plenty of siRNA therapeutic pipelines have been established by tens of biotechnology companies. The drug performance of siRNA heavily depends on the sequence, the chemical modification, and the delivery of siRNA. Here, we describe the rational design protocol of siRNA, and provide some modification patterns that can enhance siRNA's stability and reduce its off-target effect. Also, the delivery method based on N-acetylgalactosamine (GalNAc)-siRNA conjugate that is widely employed to develop therapeutic regimens for liver-related diseases is also recapitulated.

Kidney Allograft Fibrosis: Diagnostic and Therapeutic Strategies.

Interstitial fibrosis with tubule atrophy (IF/TA) is the response to virtually any sustained kidney injury and correlates inversely with kidney function and allograft survival. IF/TA is driven by various pathways that include hypoxia, renin-angiotensin-aldosterone system, transforming growth factor-ß signaling, cellular rejection, inflammation, and others. In this review, we will focus on key pathways in the progress of renal fibrosis, diagnosis and therapy of allograft fibrosis. This review discusses the role and origin of myofibroblasts as matrix producing cells and therapeutic targets in renal fibrosis with a particular focus on renal allografts. We summarize current trends to use multiomic approaches to identify new biomarkers for IF/TA detection and to predict allograft survival. Furthermore, we review current imaging strategies that might help to identify and follow-up IF/TA complementary or as alternative to invasive biopsies. We further discuss current clinical trials and therapeutic strategies to treat kidney fibrosis.

Effect of inclisiran, the small-interfering RNA against proprotein convertase subtilisin/kexin type 9, on platelets, immune cells, and immunological biomarkers: a pre-specified analysis from ORION-1.

AIMS: Small-interfering RNA (siRNA)-based targeting of proprotein convertase subtilisin/kexin type 9 (PCSK9) represents a novel therapeutic approach that may provide a convenient, infrequent, and safe dosing schedule to robustly lower low-density lipoprotein cholesterol (LDL-C). Given the long duration of action, however, establishing safety in particular with respect to immunogenicity is of paramount importance. In earlier clinical studies of other RNA-targeted treatment approaches (antisense oligonucleotide therapy) immunological and haematological adverse effects, in particular thrombocytopenia and pro-inflammatory effects, have been reported. Here, we present the pre-specified safety analysis from ORION-1 evaluating platelets, immune cells, immunological markers, antidrug antibodies, and clinical immunogenicity adverse events (AEs) under PCSK9 siRNA treatment with inclisiran. METHODS AND RESULTS: The pre-specified safety analysis from ORION-1 was performed in six different inclisiran dosing regimens in patients at high risk of cardiovascular disease with elevated LDL-C levels. Patients received either a single dose (SD: 200 mg, n = 60; 300 mg, n = 62 or 500 mg, n = 66) or double-dose starting regimen (DD: 100 mg, n = 62; 200 mg, n = 63; or 300 mg, n = 61 on days 1 and 90) of inclisiran or placebo (SD: n = 65; DD: n = 62). The effects of inclisiran on haematological parameters including platelet counts, lymphocytes, and monocytes as well as on the immune markers interleukin 6 (IL-6) and tumour necrosis factor-α (TNF-α) were examined after 180 days. Immunogenicity was further evaluated by analysis of anti-drug-antibodies (ADAs) towards inclisiran in 6068 study samples and by careful analysis of immunogenicity AEs as part of the pharmacovigilance strategy. At day 180, no significant alterations of platelet counts were observed in any of the dosing groups (change from baseline, SD: 200 mg: 0.8%; 300 mg: -0.5%; 500 mg: -1.8%; DD: 100 mg: 1.3%; 200 mg: -0.5%; 300 mg: 1.0%; no significant difference for any group as compared with placebo). No significant effects on other immune cells, including leucocytes, monocytes, or neutrophils were detected. Notably, no significant increase of inflammatory biomarkers (IL-6 or TNF-α) with either the SD or DD regimen became evident. There was no evidence for immunogenicity based on ADA level analysis and careful review of clinical immunogenicity AEs in none of the treatment regimens. CONCLUSION: In this pre-specified safety analysis of ORION-1 for the siRNA therapeutic inclisiran, no adverse effects on measures of inflammation or immune activation nor adverse effects on platelets or clinical immunogenicity AEs were observed over at least 6-month treatment. These safety findings in the largest analysis of an RNAi study in humans to date provide strong reassurance about the safety of inclisiran and the potential of cardiovascular RNA-targeted therapies.

Advances in lipid-lowering therapy through gene-silencing technologies.

New treatment opportunities are emerging in the field of lipid-lowering therapy through gene-silencing approaches. Both antisense oligonucleotide inhibition and small interfering RNA technology aim to degrade gene mRNA transcripts to reduce protein production and plasma lipoprotein levels. Elevated levels of LDL, remnant lipoproteins, and lipoprotein(a) all cause cardiovascular disease, whereas elevated levels of triglyceride-rich lipoproteins in some patients can cause acute pancreatitis. The levels of each of these lipoproteins can be reduced using gene-silencing therapies by targeting proteins that have an important role in lipoprotein production or removal (for example, the protein products of ANGPTL3, APOB, APOC3, LPA, and PCSK9). Using this technology, plasma levels of these lipoproteins can be reduced by 50-90% with 2-12 injections per year; such dramatic reductions are likely to reduce the incidence of cardiovascular disease or acute pancreatitis in at-risk patients. The reported adverse effects of these new therapies include injection-site reactions, flu-like symptoms, and low blood platelet counts. However, newer-generation drugs are more efficiently delivered to liver cells, requiring lower drug doses, which leads to fewer adverse effects. Although these findings are promising, robust evidence of cardiovascular disease reduction and long-term safety is needed before these gene-silencing technologies can have widespread implementation. Before the availability of such evidence, these drugs might have roles in patients with unmet medical needs through orphan indications.

Control the intracellular NF-κB activity by a sensor consisting of miRNA and decoy.

Many diseases are associated with the abnormal activation of NF-κB and its signaling pathway. NF-κB has become an important target for disease treatment and development of new drugs. Many various NF-κB inhibitors were therefore developed; however, they have difficulties to become clinical drugs due to their adverse side effects resulted from the affected normal physiological functions of this transcription factor. To overcome this limitation, this study construct a transgenic vector that can express an artificial miRNA targeting NF-κB RelA under the control of a NF-κB-specific promoter. The promoter consists of a NF-κB decoy and a minimal promoter. The vector was named as decoy minimal promoter-artificial microRNA (DMP-amiRNA). This study verified that this vector can sense and control the intracellular NF-κB activity upon transfection. Working of the vector forms a perfect feedback loop that realizes the NF-κB self-control. With the vector in cells, the higher NF-κB activity, the higher DMP transcriptional activity, and the more amiR533 expression. DMP-amiRNA can moderately inhibit the intracellular NF-κB activity but exert no significant effect on cell viability. This study therefore develops a new strategy for inhibiting over activity of NF-κB, which should has great potential in clinical application.

Cationic liquid crystalline nanoparticles for the delivery of synthetic RNAi-based therapeutics.

RNA interference (RNAi)-based therapeutics have been used to silence the expression of targeted pathological genes. Small interfering RNA (siRNAs) and microRNA (miRNAs) inhibitor have performed this function. However, short half-life, poor cellular uptake, and nonspecific distribution of small RNAs call for the development of novel delivery systems to facilitate the use of RNAi. We developed a novel cationic liquid crystalline nanoparticle (CLCN) to efficiently deliver synthetic siRNAs and miRNAs. CLCNs were prepared by using high-speed homogenization and assembled with synthetic siRNA or miRNA molecules in nuclease-free water to create CLCN/siRNA or miRNA complexes. The homogeneous and stable CLCNs and CLCN-siRNA complexes were about 100 nm in diameter, with positively charged surfaces. CLCNs are nontoxic and are taken up by human cells though endocytosis. Significant inhibition of gene expression was detected in transiently transfected lung cancer H1299 cells treated with CLCNs/anti-GFP complexes 24 hours after transfection. Biodistribution analysis showed that the CLCNs and CLCNs-RNAi complexes were successfully delivered to various organs and into the subcutaneous human lung cancer H1299 tumor xenografts in mice 24 hours after systemic administration. These results suggest that CLCNs are a unique and advanced delivery system capable of protecting RNAi from degradation and of efficiently delivering RNAi in vitro and in vivo.

Therapeutic Targeting of Protein Kinase CK2 Gene Expression in Feline Oral Squamous Cell Carcinoma: A Naturally Occurring Large-Animal Model of Head and Neck Cancer.

Protein kinase CK2 (CK2) is a highly promising target for cancer therapy, and anti-CK2 gene expression therapy has shown effectiveness in rodent models of human head and neck cancer (HNC). To date, there has been no large-animal model of cancer in which to further explore anti-CK2 therapies. Feline oral squamous cell carcinoma (FOSCC) has been proposed as a large-animal model for human HNC, and we have previously shown that CK2 is a rational target in FOSCC. Here we have tested the hypothesis that a novel tenfibgen-coated tumor-specific nanocapsule carrying RNA interference (RNAi) oligonucleotides targeting feline CK2α and CK2α' (TBG-RNAi-fCK2αα') would be safe in cats with FOSCC; assessment of target inhibition and tumor response were secondary aims. Nine cats were enrolled and treated at two dose levels in a 3+3 escalation. Cats received a total of six treatments with TBG-RNAi-fCK2αα'. Pre- and posttreatment, tumor and normal oral mucosa biopsies were collected to assess CK2 expression, using immunohistochemistry (IHC) preparations evaluated by light microscopy. Toxicity and tumor response were assessed on the basis of standard criteria. The most common adverse events were grade 1 or 2 weight loss and anorexia. Grade 3 tissue necrosis was seen in association with tumor response in one cat, asymptomatic grade 4 elevations in aspartate transaminase and creatine phosphokinase in one cat, and asymptomatic grade 3 hypokalemia in one cat. Of six cats with evaluable biopsies, two had a reduction in CK2 IHC score in tumors after treatment. Four cats had progressive disease during the study period, three had stable disease, one had partial response, and response could not be evaluated in one cat. We conclude that the drug appeared safe and that there is some evidence of efficacy in FOSCC. Further investigation regarding dosing, schedule, target modulation, toxicity, and efficacy in a larger group of cats is warranted and may inform future clinical studies in human head and neck cancer.