The Role of Antisense Therapies Targeting Lipoprotein(a).

ABSTRACT: Atherosclerotic cardiovascular disease (ASCVD) continues to be the leading cause of preventable death in the United States. Elevated low-density lipoprotein cholesterol (LDL-C) is well known to result in cardiovascular disease. Mainstay therapy for reducing LDL-C and ASCVD risk is statin therapy. Despite achieving desired LDL-C levels with lipid-lowering therapy, cardiovascular residual risk often persists. Elevated lipoprotein(a) [Lp(a)] levels have been highlighted as an inherent independent predictor of ASCVD, and decreasing Lp(a) levels may result in a significant reduction in the residual risk in high-risk patients. To date, there are no approved medications to lower Lp(a) levels. Nicotinic acid, proprotein convertase subtilisin/kexin 9 inhibitors, and antisense oligonucleotide have demonstrated modest to potent Lp(a) reduction. Spotlight has been placed on antisense oligonucleotides and their role in Lp(a) lowering. APO(a)LRx is in the frontline for selectively decreasing Lp(a) concentrations and ongoing research may prove that this medication may lower Lp(a)-mediated residual risk, translating into cardiovascular benefit.

Nanomedicine-based delivery strategies for nucleic acid gene inhibitors in inflammatory diseases.

Thanks to their abilities to modulate the expression of virtually any genes, RNA therapeutics have attracted considerable research efforts. Among the strategies focusing on nucleic acid gene inhibitors, antisense oligonucleotides and small interfering RNAs have reached advanced clinical trial phases with several of them having recently been marketed. These successes were obtained by overcoming stability and cellular delivery issues using either chemically modified nucleic acids or nanoparticles. As nucleic acid gene inhibitors are promising strategies to treat inflammatory diseases, this review focuses on the barriers, from manufacturing issues to cellular/subcellular delivery, that still need to be overcome to deliver the nucleic acids to sites of inflammation other than the liver. Furthermore, key examples of applications in rheumatoid arthritis, inflammatory bowel, and lung diseases are presented as case studies of systemic, oral, and lung nucleic acid delivery.

Phase Ib Clinical Trial of IGV-001 for Patients with Newly Diagnosed Glioblastoma.

PURPOSE: Despite standard of care (SOC) established by Stupp, glioblastoma remains a uniformly poor prognosis. We evaluated IGV-001, which combines autologous glioblastoma tumor cells and an antisense oligonucleotide against IGF type 1 receptor (IMV-001), in newly diagnosed glioblastoma. PATIENTS AND METHODS: This open-label protocol was approved by the Institutional Review Board at Thomas Jefferson University. Tumor cells collected during resection were treated ex vivo with IMV-001, encapsulated in biodiffusion chambers with additional IMV-001, irradiated, then implanted in abdominal acceptor sites. Patients were randomized to four exposure levels, and SOC was initiated 4-6 weeks later. On the basis of clinical improvements, randomization was halted after patient 23, and subsequent patients received only the highest exposure. Safety and tumor progression were primary and secondary objectives, respectively. Time-to-event outcomes were compared with the SOC arms of published studies. RESULTS: Thirty-three patients were enrolled, and median follow-up was 3.1 years. Six patients had adverse events (grade ≤3) possibly related to IGV-001. Median progression-free survival (PFS) was 9.8 months in the intent-to-treat population (vs. SOC, 6.5 months; P = 0.0003). In IGV-001-treated patients who met Stupp-eligible criteria, PFS was 11.6 months overall (n = 22; P = 0.001) and 17.1 months at the highest exposure (n = 10; P = 0.0025). The greatest overall survival was observed in Stupp-eligible patients receiving the highest exposure (median, 38.2 months; P = 0.044). Stupp-eligible patients with methylated O6-methylguanine-DNA methyltransferase promoter (n = 10) demonstrated median PFS of 38.4 months (P = 0.0008). Evidence of immune activation was noted. CONCLUSIONS: IGV-001 was well tolerated, PFS compared favorably with SOC, and evidence suggested an immune-mediated mechanism (ClinicalTrials.gov: NCT02507583).

Amyloidosis: diagnosis and new therapies for a misunderstood and misdiagnosed disease.

Amyloidosis is a group of diseases characterized by extracellular deposition of amyloid fibril complexes. Fibril deposition results in organ dysfunction and possible failure. Amyloidosis is regarded as a rare disease, but in general is underdiagnosed. The two main types of systemic amyloidosis are immunoglobulin light chain and transthyretin amyloidosis. The increased availability of noninvasive cardiac imaging, genetic testing and improved laboratory assays and protein identification methods have led to increased diagnosis. However, in many cases, the diagnosis is not made until the patient develops organ impairment. Earlier diagnosis is required to prevent irreversible organ failure. Novel treatments for immunoglobulin light chain and transthyretin amyloidosis that halt disease progression, prolong and increase quality of life have recently become available.

Novel RNA-targeted therapies for hereditary ATTR amyloidosis and their impact on the autonomic nervous system.

PURPOSE: Transthyretin-mediated hereditary amyloidosis (hATTR amyloidosis) is a multisystemic disease with heterogeneous clinical presentation. Hallmarks of the disease are sensory-motor and autonomic neuropathy and cardiomyopathy. Two disease-modifying drugs, inotersen (an antisense oligonucleotide) and patisiran (a small interfering RNA agent), were recently approved for the treatment of hATTR polyneuropathy. We here review the results of the RNA-targeted therapy clinical trials with special emphasis on the endpoints measuring autonomic symptoms and function. METHODS: Literature review. We used the terms "autonomic neuropathy", "dysautonomia", "autonomic symptoms", "oligonucleotides", "inotersen" and "patisiran" in patients with hATTR amyloidosis. RESULTS: In the NEURO-TTR (inotersen) clinical trial, the modified NIS+7 score (mNIS+7) remained stable in 36% of the patients in the inotersen arm (defined as a change of less than 2 points), and 50% of patients had improved quality of life (Norfolk-QOL-DN score) after 15 months. In the APOLLO patisiran trial, 74% of the patients showed stabilization of the neuropathy, defined as a < 10 points increase on mNIS+7, and 51% of patients showed an improvement of quality of life (Norfolk QOL-DN), favoring patisiran at 18 months. Patients on patisiran had a reduced burden of autonomic dysfunction as measured by the COMPASS-31, and a stabilization of nutritional status, suggesting an effect on gastrointestinal autonomic function. CONCLUSIONS: Clinical trials of inotersen and patisiran showed that these agents were able to halt the progression of the disease, with some patients even reducing the burden of polyneuropathy, and improving qualify of life. The information on their impact on autonomic parameters is limited, warranting further dedicated studies.

Inotersen for the treatment of adults with polyneuropathy caused by hereditary transthyretin-mediated amyloidosis.

Introduction: Hereditary transthyretin-mediated amyloidosis (ATTRv; v for variant) is an underdiagnosed, progressive, and fatal multisystemic disease with a heterogenous clinical phenotype that is caused by TTR gene mutations that destabilize the TTR protein, resulting in its misfolding, aggregation, and deposition in tissues throughout the body. Areas covered: Inotersen, an antisense oligonucleotide inhibitor, was recently approved in the United States and Europe for the treatment of the polyneuropathy of ATTRv based on the positive results obtained in the pivotal phase 3 trial, NEURO-TTR. This review will discuss the mechanism of action of inotersen and its pharmacology, clinical efficacy, and safety and tolerability. A PubMed search using the terms 'inotersen,' 'AG10,' 'antisense oligonucleotide,' 'hereditary transthyretin amyloidosis,' 'familial amyloid polyneuropathy,' and 'familial amyloid cardiomyopathy' was performed, and the results were screened for the most relevant English language publications. The bibliographies of all retrieved articles were manually searched to identify additional studies of relevance. Expert opinion: Inotersen targets the disease-forming protein, TTR, and has been shown to improve quality of life and neuropathy progression in patients with stage 1 or 2 ATTRv with polyneuropathy. Inotersen is well tolerated, with a manageable safety profile through regular monitoring for the development of glomerulonephritis or thrombocytopenia.

Phosphorothioated antisense oligodeoxynucleotide suppressing interleukin-10 is a safe and potent vaccine adjuvant.

While vaccination is highly effective for the prevention of many infectious diseases, the number of adjuvants licensed for human use is currently very limited. The aim of this study was to evaluate the safety, efficacy, and to clarify the mechanism of a phosphorothioated interleukin (IL)-10-targeted antisense oligonucleotide (ASO) as an immune adjuvant in intradermal vaccination. The cytotoxicity of IL-10 ASO and its ability to promote T cell proliferation were assessed by Cell Counting Kit-8 (CCK-8) assay. The contents of IL-6, IL-8, TNF-α, IL-1ß, and IL-10 in inoculated local tissue and the antigen-specific antibody titers in mouse serum samples were determined by ELISA. The target cells of IL-10 ASO were observed using immunofluorescent staining. The results showed that the specific antibody titer of ovalbumin (OVA), a model antigen, was increased 100-fold upon addition of IL-10 ASO as an adjuvant compared to that of OVA alone. IL-10 ASO showed an immunopotentiation efficacy similar to that of Freund's incomplete adjuvant, with no detectable cell or tissue toxicity. In vitro and in vivo experiments confirmed that IL-10 ASO enhances immune responses by temporarily suppressing IL-10 expression from local dendritic cells and consequently promoting T cell proliferation. In conclusion, IL-10 ASO significantly enhances immune responses against co-delivered vaccine antigens with high efficacy and low toxicity. It has the potential to be developed into a safe and efficient immune adjuvant.

Antisense Oligonucleotides Targeting Lipoprotein(a).

PURPOSE OF REVIEW: High lipoprotein(a) levels are observationally and causally, from human genetics, associated with increased risk of cardiovascular disease including myocardial infarction and aortic valve stenosis. The European Atherosclerosis Society recommends screening for elevated lipoprotein(a) levels in high-risk patients. Different therapies have been suggested and some are used to treat elevated lipoprotein(a) levels such as niacin, PCSK9 inhibitors, and CETP inhibitors; however, to date, no randomized controlled trial has demonstrated that lowering of lipoprotein(a) leads to lower risk of cardiovascular disease. RECENT FINDINGS: Synthetic oligonucleotides can be used to inactivate genes involved in disease processes. To lower lipoprotein(a), two antisense oligonucleotides have been developed, one targeting apolipoprotein B and one targeting apolipoprotein(a). Mipomersen is an antisense oligonucleotide targeting apolipoprotein B and thereby reducing levels of all apolipoprotein B containing lipoproteins in the circulation. Mipomersen has been shown to lower lipoprotein(a) by 20-50% in phase 3 studies. AKCEA-APO(a)-LRx is the most recent antisense oligonucleotide targeting apolipoprotein(a) and thereby uniquely targeting lipoprotein(a). It has been tested in a phase 2 study and has shown to lower lipoprotein(a) levels by 50-80%. The treatment of elevated lipoprotein(a) levels with the newest antisense oligonucleotides seems promising; however, no improvement in cardiovascular disease risk has yet been shown. However, a phase 3 study of AKCEA-APO(a)-LRx is being planned with cardiovascular disease as outcome, and results are awaited with great anticipation.

Inotersen: new promise for the treatment of hereditary transthyretin amyloidosis.

Hereditary transthyretin amyloidosis is a fatal autosomal dominant disorder characterized by deposition of transthyretin amyloid into the peripheral nervous system, heart, kidney, and gastrointestinal tract. Previous treatments using liver transplantation and small molecule stabilizers were not effective in stopping disease progression. Inotersen, a 2'-O-methyoxyethyl-modified antisense oligonucleotide, which acts by reducing the production of transthyretin, was recently demonstrated to improve disease course and quality of life in early hereditary transthyretin amyloidosis polyneuropathy in a 15-month Phase III study.

Safety and efficacy of mipomersen in patients with heterozygous familial hypercholesterolemia.

BACKGROUND AND AIMS: Heterozygous familial hypercholesterolemia (HeFH) is a common genetic disorder characterized by elevated low-density lipoprotein cholesterol (LDL-C) and increased cardiovascular disease risk. Despite multiple LDL-C-lowering therapies, many HeFH patients do not reach LDL-C targets. Mipomersen, an antisense oligonucleotide against apolipoprotein B (apoB), might further lower LDL-C in HeFH patients. We assessed the efficacy and safety of two mipomersen dosing regimens in HeFH patients and explored whether thrice-weekly dosing improves the benefit-risk profile. METHODS: In this double-blind trial, HeFH patients (LDL-C >160 mg/dL) on maximal tolerated LDL-lowering therapy were randomized to mipomersen 200 mg once weekly (n = 104), mipomersen 70 mg thrice weekly (n = 102), or placebo in matching frequency (n = 103) for 60 weeks. Main outcomes were LDL-C, apoB, and lipoprotein(a) levels after 60 weeks of treatment. RESULTS: Mipomersen 200 mg once weekly and mipomersen 70 mg thrice weekly significantly lowered LDL-C compared with placebo by 21.0% and 18.8%, respectively, and apoB by 22.1% and 21.7% (all p < 0.001). Lipoprotein(a) was significantly lowered by 27.7% (p < 0.001) with thrice-weekly dosing. Injection-site reactions and flu-like symptoms led to discontinuation in 21.2% (200 mg), 17.6% (70 mg), and 5.8% (placebo) of participants. Alanine transaminase was elevated (≥3× upper limit of normal at least once) in 21.2%, 21.6%, and 1.0% of subjects, respectively. CONCLUSIONS: Mipomersen 200 mg once weekly and 70 mg thrice weekly are effective in lowering apoB-containing lipoproteins in HeFH patients. This is counterbalanced by limited tolerability and increased hepatic transaminase levels in about 21% of patients. The thrice-weekly dosing regimen was associated with lower frequency of flu-like symptoms, which might help avert discontinuation in some patients, but otherwise had no major benefits.

The Effectiveness and Value of Patisiran and Inotersen for Hereditary Transthyretin Amyloidosis.

DISCLOSURES: Funding for this summary was contributed by the Laura and John Arnold Foundation, Blue Shield of California, and California Health Care Foundation to the Institute for Clinical and Economic Review (ICER), an independent organization that evaluates the evidence on the value of health care interventions. ICER's annual policy summit is supported by dues from Aetna, AHIP, Anthem, Blue Shield of California, CVS Caremark, Express Scripts, Harvard Pilgrim Health Care, Cambia Health Solutions, United Healthcare, Kaiser Permanente, Premera Blue Cross, AstraZeneca, Genentech, GlaxoSmithKline, Johnson & Johnson, Merck, National Pharmaceutical Council, Prime Therapeutics, Sanofi, Spark Therapeutics, Health Care Service Corporation, Editas, Alnylam, Regeneron, Mallinkrodt, Biogen, HealthPartners, and Novartis. Mickle, Dreitlein, and Pearson are ICER employees. Lasser, Cipriano, and Hoch have nothing to disclose.

TTR Gene Silencers for Hereditary ATTR Amyloidosis: More than ICER Recognized.

DISCLOSURES: No funding support was received for the writing of this commentary. The author ser ves as a consultant for Akcea Therapeutics, Alnylam Phar maceuticals, Corino Therapeutics, Intellia Therapeutics, and Ionis Pharmaceuticals.

DMD genotype correlations from the Duchenne Registry: Endogenous exon skipping is a factor in prolonged ambulation for individuals with a defined mutation subtype.

Antisense oligonucleotide (AON)-mediated exon skipping is an emerging therapeutic for individuals with Duchenne muscular dystrophy (DMD). Skipping of exons adjacent to common exon deletions in DMD using AONs can produce in-frame transcripts and functional protein. Targeted skipping of DMD exons 8, 44, 45, 50, 51, 52, 53, and 55 is predicted to benefit 47% of affected individuals. We observed a correlation between mutation subgroups and age at loss of ambulation in the Duchenne Registry, a large database of phenotypic and genetic data for DMD (N = 765). Males amenable to exon 44 (N = 74) and exon 8 skipping (N = 18) showed prolonged ambulation compared to other exon skip groups and nonsense mutations (P = 0.035 and P < 0.01, respectively). In particular, exon 45 deletions were associated with prolonged age at loss of ambulation relative to the rest of the exon 44 skip amenable cohort and other DMD mutations. Exon 3-7 deletions also showed prolonged ambulation relative to all other exon 8 skippable mutations. Cultured myotubes from DMD patients with deletions of exons 3-7 or exon 45 showed higher endogenous skipping than other mutations, providing a potential biological rationale for our observations. These results highlight the utility of aggregating phenotypic and genotypic data for rare pediatric diseases to reveal progression differences, identify potentially confounding factors, and probe molecular mechanisms that may affect disease severity.

Antisense oligonucleotides and other genetic therapies made simple.

Many genetic neurological diseases result from the dysfunction of single proteins. Genetic therapies aim to modify these disease-associated proteins by targeting the RNA and DNA precursors. This review provides a brief overview of the main types of genetic therapies, with a focus on antisense oligonucleotides (ASOs) and RNA interference (RNAi). We use examples of new genetic therapies for spinal muscular atrophy, Duchenne muscular dystrophy and familial amyloid polyneuropathy to highlight the different mechanisms of action of ASOs and RNAi.

Antisense Inhibition of Protein Tyrosine Phosphatase 1B With IONIS-PTP-1BRx Improves Insulin Sensitivity and Reduces Weight in Overweight Patients With Type 2 Diabetes.

OBJECTIVE: To evaluate safety and efficacy of IONIS-PTP-1BRx, a second-generation 2'-O-methoxyethyl antisense inhibitor of protein tyrosine phosphatase 1B, as add-on therapy in overweight patients with type 2 diabetes inadequately controlled with metformin with or without sulfonylurea therapy. RESEARCH DESIGN AND METHODS: In this phase II, double-blind, randomized, placebo-controlled, multicenter trial, overweight and obese patients (BMI ≥27 kg/m2) with type 2 diabetes (HbA1c ≥7.5% [58 mmol/mol] and ≤10.5% [91 mmol/mol]) on a stable dose of metformin alone or with sulfonylurea were randomized 2:1 to IONIS-PTP-1BRx 200 mg (n = 62) or placebo (n = 30) once weekly for 26 weeks. RESULTS: Mean baseline HbA1c was 8.6% (70 mmol/mol) and 8.7% (72 mmol/mol) in placebo and active treatment, respectively. At week 27, IONIS-PTP-1BRx reduced mean HbA1c levels by -0.44% (-4.8 mmol/mol; P = 0.074) from baseline and improved leptin (-4.4 ng/mL; P = 0.007) and adiponectin (0.99 µg/mL; P = 0.026) levels compared with placebo. By week 36, mean HbA1c was significantly reduced (-0.69% [-7.5 mmol/mol]; P = 0.034) and accompanied by reductions in fructosamine (-33.2 µmol/L; P = 0.005) and glycated albumin (-1.6%; P = 0.031) versus placebo. Despite both treatment groups receiving similar lifestyle counseling, mean body weight significantly decreased from baseline to week 27 with IONIS-PTP-1BRx versus placebo (-2.6 kg; P = 0.002) independent of HbA1c reduction (R2 = 0.0020). No safety concerns were identified in the study. CONCLUSIONS: Compared with placebo, IONIS-PTP-1BRx treatment for 26 weeks produced prolonged reductions in HbA1c, improved medium-term glycemic parameters, reduced leptin and increased adiponectin levels, and resulted in a distinct body weight-reducing effect.

Toll-like receptor 9 antagonist suppresses humoral immunity in experimental autoimmune myasthenia gravis.

Recent studies have demonstrated the important role of toll-like receptor 9 (TLR9) signalling in autoimmune diseases, but its role in myasthenia gravis (MG) has not been fully established. We show herein that blocking TLR9 signalling via the suppressive oligodeoxynucleotide (ODN) H154 alleviated the symptoms of experimental autoimmune myasthenia gravis (EAMG). With the downregulation of dendritic cells (DCs), TLR9 interruption reduced follicular helper T cells (Tfh) and germinal centre (GC) B cells, leading to decreased antibody production. In addition, TLR9+ B cells as well as total B cells in the spleen were inhibited by H154. These findings highlight the critical role of TLR9 in EAMG and suggest that the inhibition of the TLR9 pathway might be a potential pharmacological strategy for the treatment of myasthenia gravis.

Spinal muscular atrophy: antisense oligonucleotide therapy opens the door to an integrated therapeutic landscape.

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of spinal cord motor neurons, muscle atrophy and infantile death or severe disability. It is caused by severe reduction of the ubiquitously expressed survival motor neuron (SMN) protein, owing to loss of the SMN1 gene. This would be completely incompatible with survival without the presence of a quasi-identical duplicated gene, SMN2, specific to humans. SMN2 harbours a silent point mutation that favours the production of transcripts lacking exon 7 and a rapidly degraded non-functional SMNΔ7 protein, but from which functional full length SMN protein is produced at very low levels (∼10%). Since the seminal discovery of the SMA-causing gene in 1995, research has focused on the development of various SMN replacement strategies culminating, in December 2016, in the approval of the first precise molecularly targeted therapy for SMA (nusinersen), and a pivotal proof of principle that therapeutic antisense oligonucleotide (ASO) treatment can effectively target the central nervous system (CNS) to treat neurological and neuromuscular disease. Nusinersen is a steric block ASO that binds the SMN2 messenger RNA and promotes exon 7 inclusion and thus increases full length SMN expression. Here, we consider the implications of this therapeutic landmark for SMA therapeutics and discuss how future developments will need to address the challenges of delivering ASO therapies to the CNS, with appropriate efficiency and activity, and how SMN-based therapy should be used in combination with complementary strategies to provide an integrated approach to treat CNS and peripheral pathologies in SMA.

In vitro and in vivo inhibition of proangiogenic retinal phenotype by an antisense oligonucleotide downregulating uPAR expression.

Neoangiogenesis is the main pathogenic event involved in a variety of retinal diseases. It has been recently demonstrated that inhibiting the urokinase-type plasminogen activator receptor (uPAR) results in reduced angiogenesis in a mouse model of oxygen-induced retinopathy (OIR), establishing uPAR as a therapeutic target in proliferative retinopathies. Here, we evaluated in cultured human retinal endothelial cells (HRECs) and in OIR mice the potential of a specific antisense oligodeoxyribonucleotide (ASO) in blocking the synthesis of uPAR and in providing antiangiogenic effects. uPAR expression in HRECs was inhibited by lipofection with the phosphorotioated 5'-CGGCGGGTGACCCATGTG-3' ASO-uPAR, complementary to the initial translation site of uPAR mRNA. Inhibition of uPAR expression via ASO-uPAR was evaluated in HRECs by analyzing VEGF-induced tube formation and migration. In addition, the well-established and reproducible murine OIR model was used to induce retinal neovascularization in vivo. OIR mice were injected intraperitoneally with ASO-uPAR and retinopathy was evaluated considering the extent of the avascular area in the central retina and neovascular tuft formation. The ASO-uPAR specifically decreased uPAR mRNA and protein levels in HRECs and mitigated VEGF-induced tube formation and cell migration. Noteworthy, in OIR mice ASO-uPAR administration reduced both the avascular area and the formation of neovascular tufts. In conclusion, although the extrapolation of these experimental findings to the clinic is not straightforward, ASO-uPAR may be considered a potential therapeutic tool for treatment of proliferative retinal diseases.

Effects of hTERT antisense oligodeoxynucleotide on cell apoptosis and expression of hTERT and bcl-2 mRNA in keloid fibroblasts.

OBJECTIVE: This study was purposed to investigate the effects of hTERT antisense oligodeoxynucleotide (ASODN) on cell apoptosis and expression of hTERT and bcl-2 mRNA in keloid fibroblasts and to explore its anti-keloid effect. MATERIALS AND METHODS: Primary cultures of dermal fibroblasts derived from 12 keloid samples were established, strains of fibroblasts at passages 3 to 4 were used in this study. After treated by hTERT ASODN the proliferation of the fibroblasts was measured by cell count and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay method, the apoptosis was analyzed by flow cytometry (FCM), and the expression of hTERT and bcl-2 mRNA were observed by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The data was analyzed by statistical software (SPSS11.5). RESULTS: The results showed that after sealing hTERT gene with ASODN for 72 h, the fibroblasts growth was repressed and the ability of proliferation decreased as the fibroblasts were treated with 1.0 mol/L ASODN for 72 h, the fibroblasts apoptosis was induced and the expression of hTERT and bcl-2 mRNA was lower than that of controlled group. The result was significantly different between control group and treatment group and was related to the treatment time of ASODN (p<0.01), but the difference was no significant when compared 1.0 µmol/L SODN group with untreated group (p>0.05). CONCLUSIONS: As a negative modutory factor, hTERT-ASODN can suppress growth and proliferation of keloid fibroblasts. Decreasing the telomerase activity of keloid fibroblasts may be one of the most important mechanisms. That hTERT-ASODN inhibited telomerase activity in keloid fibroblasts is an important pathway that may play a key role in the anti- keloid therapy.

The Race of 10 Synthetic RNAi-Based Drugs to the Pharmaceutical Market.

Ten years after Fire and Melo's Nobel Prize for discovery of gene silencing by double-stranded RNA, a remarkable progress was achieved in RNA interference (RNAi). Changes in the chemical structure of synthetic oligonucleotides make them more stable and specific, and new delivery strategies became progressively available. The attention of pharmaceutical industry rapidly turned to RNAi, as an opportunity to explore new drug targets. This review addresses nine small-interfering RNAs (siRNAs) and one unique microRNA (miRNA) inhibitor, which entered the phase 2-3 clinical trials. The siRNAs in focus are PF-04523655, TKM-080301, Atu027, SYL040012, SYL1001, siG12D-LODER (phase 2), QPI-1002, QPI-1007, and patisiran (phase 3). Regarding miRNAs, their content can be down- or up-regulated, by using miRNA inhibitors (AntimiRs) or miRNA mimics. Miravirsen is an AntimiR-122 for hepatitis C virus infection. The flexibility of RNAi technology is easily understood taking into account: (i) the different drug targets (i.e. p53, caspase 2, PKN3, ß2-adrenergic receptor, mutated KRAS, microRNAs); (ii) therapeutic conditions, including ophthalmic diseases, kidney injury, amyloidosis, pancreatic cancer, viral hepatitis; and (iii) routes of administration (ocular, intravenous, subcutaneous, intratumoral). Although some issues are still matters of concern (delivery, toxicity, cost, and biological barriers), RNAi definitively opens a wide avenue for drug development.