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1.
Drugs Today (Barc) ; 55(10): 627-639, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31720560

RESUMO

Duchenne muscular dystrophy is the most common lethal X-linked genetic disorder, characterized by progressive muscle loss, with cardiac and respiratory complications. It is caused by a lack of dystrophin protein due to mutations in the DMD gene, which can disrupt the reading frame of the dystrophin primary transcript. Antisense oligonucleotides such as phosphorodiamidate morpholino oligomers (PMOs) can induce exon skipping during pre-mRNA splicing and restore the reading frame of the DMD primary transcript. The resulting dystrophin protein is internally deleted but partially functional. Viltolarsen, also known as NS-065/NCNP-01, is a PMO developed through comprehensive sequence optimization and is designed to skip exon 53 on the DMD primary transcript. Exclusion of exon 53 from the DMD primary transcript can treat 8-10% of DMD patients worldwide. This review paper summarizes the mechanism of action, pharmacokinetics and safety of viltolarsen from preclinical and clinical trials.


Assuntos
Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne , Oligonucleotídeos Antissenso/uso terapêutico , Oligonucleotídeos/uso terapêutico , Ensaios Clínicos como Assunto , Distrofina , Éxons , Humanos , Precursores de RNA
2.
Medicine (Baltimore) ; 98(26): e15858, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31261494

RESUMO

This analysis aims to describe the outcomes of two nonambulatory patients with Duchenne muscular dystrophy (DMD) who participated in two clinical studies. The two consecutive trials of eteplirsen (studies 201 and 202) were conducted in patients with DMD (N = 12) and confirmed genetic mutations amenable to exon 51 skipping.In study 201, 12 patients were randomized to receive once-weekly, double-blind intravenous infusions of eteplirsen 30 or 50 mg/kg or placebo for 24 weeks; patients then received open-label eteplirsen during weeks 25 through 28. All 12 patients continued onto open-label extension study 202 and received long-term treatment with eteplirsen. We compared cardiac, pulmonary, and upper limb function and dystrophin production in the nonambulatory twin patients versus the 10 ambulatory patients through 240 combined treatment weeks.Ten study patients remained ambulatory through both studies, while the identical twin patients both experienced early, rapid loss of ambulation. The twin patients had greater disease severity at baseline (6-minute walk test [6MWT], 330 and 256 m) versus the other patients (n = 10; 6MWT range, 341-418 m). They maintained cardiac and upper limb function through combined week 240, with outcomes similar to those of the patients who remained ambulatory. Dystrophin production was confirmed following eteplirsen treatment.Despite the loss of ambulation, other markers of disease progression remained relatively stable in the eteplirsen-treated twin patients and were similar to those of the ambulatory patients.


Assuntos
Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Criança , Progressão da Doença , Doenças em Gêmeos , Método Duplo-Cego , Distrofina/genética , Distrofina/metabolismo , Humanos , Masculino , Morfolinos/efeitos adversos , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Processamento Pós-Transcricional do RNA/efeitos dos fármacos , Índice de Gravidade de Doença , Resultado do Tratamento , Teste de Caminhada , Caminhada
3.
J Neuromuscul Dis ; 6(2): 213-225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30856119

RESUMO

BACKGROUND: Duchenne muscular dystrophy (DMD) patients experience skeletal muscle degeneration, including respiratory muscles. Respiratory decline in glucocorticoid-treated DMD patients, measured by percent predicted forced vital capacity (FVC% p), is typically 5% annually in patients aged 10 to 18 years. OBJECTIVE: Evaluate the effects of eteplirsen on FVC% p annual change in 3 trials versus matched Cooperative International Neuromuscular Research Group Duchenne Natural History Study (CINRG DNHS) controls. METHODS: Eteplirsen studies 201/202 evaluated eligible ambulatory DMD patients for at least 4 years, study 204 evaluated primarily non-ambulatory DMD patients for 2 years, and ongoing study 301 is evaluating ambulatory DMD patients for 2 years (interim analysis is included). Eteplirsen-treated patients (n = 74) were amenable to exon 51 skipping and were receiving glucocorticoids. Three CINRG DNHS cohorts included: glucocorticoid-treated patients amenable to exon 51 skipping (Exon 51 CINRG DNHS; n = 20), all glucocorticoid-treated CINRG patients (All CINRG DNHS; n = 172), and all glucocorticoid-treated genotyped CINRG DNHS patients (Genotyped CINRG DNHS; n = 148). FVC% p assessments between ages 10 and <18 years were included for all patients; mixed-model analyses characterized FVC% p annual change. RESULTS: FVC% p annual change was greater for CINRG DNHS Exon 51 controls (- 6.00) versus patients in studies 201/202, study 204, and study 301 (- 2.19, P < 0.001; - 3.66, P 0.004; and - 3.79, P 0.017, respectively). FVC% p annual change in all eteplirsen studies suggested treatment benefit compared with the Genotyped CINRG DNHS (- 5.67) and All CINRG DNHS (- 5.56) cohorts (P < 0.05, all comparisons). CONCLUSIONS: Significant, clinically meaningful attenuation of FVC%p decline was observed in eteplirsen-treated patients versus CINRG DNHS controls.


Assuntos
Ensaios Clínicos como Assunto , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Respiração/efeitos dos fármacos , Capacidade Vital/efeitos dos fármacos , Adolescente , Criança , Humanos , Masculino
5.
Hum Mol Genet ; 28(3): 396-406, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30281092

RESUMO

Duchenne muscular dystrophy (DMD) is caused by loss of dystrophin protein, leading to progressive muscle weakness and premature death due to respiratory and/or cardiac complications. Cardiac involvement is characterized by progressive dilated cardiomyopathy, decreased fractional shortening and metabolic dysfunction involving reduced metabolism of fatty acids-the major cardiac metabolic substrate. Several mouse models have been developed to study molecular and pathological consequences of dystrophin deficiency, but do not recapitulate all aspects of human disease pathology and exhibit a mild cardiac phenotype. Here we demonstrate that Cmah (cytidine monophosphate-sialic acid hydroxylase)-deficient mdx mice (Cmah-/-;mdx) have an accelerated cardiac phenotype compared to the established mdx model. Cmah-/-;mdx mice display earlier functional deterioration, specifically a reduction in right ventricle (RV) ejection fraction and stroke volume (SV) at 12 weeks of age and decreased left ventricle diastolic volume with subsequent reduced SV compared to mdx mice by 24 weeks. They further show earlier elevation of cardiac damage markers for fibrosis (Ctgf), oxidative damage (Nox4) and haemodynamic load (Nppa). Cardiac metabolic substrate requirement was assessed using hyperpolarized magnetic resonance spectroscopy indicating increased in vivo glycolytic flux in Cmah-/-;mdx mice. Early upregulation of mitochondrial genes (Ucp3 and Cpt1) and downregulation of key glycolytic genes (Pdk1, Pdk4, Ppara), also denote disturbed cardiac metabolism and shift towards glucose utilization in Cmah-/-;mdx mice. Moreover, we show long-term treatment with peptide-conjugated exon skipping antisense oligonucleotides (20-week regimen), resulted in 20% cardiac dystrophin protein restoration and significantly improved RV cardiac function. Therefore, Cmah-/-;mdx mice represent an appropriate model for evaluating cardiac benefit of novel DMD therapeutics.


Assuntos
Citidina Monofosfato/genética , Distrofina/deficiência , Morfolinos/uso terapêutico , Animais , Cardiomiopatia Dilatada/genética , Carnitina O-Palmitoiltransferase/genética , Fator de Crescimento do Tecido Conjuntivo/análise , Citidina Monofosfato/fisiologia , Modelos Animais de Doenças , Distrofina/genética , Distrofina/metabolismo , Éxons , Terapia Genética/métodos , Coração/fisiopatologia , Masculino , Camundongos , Camundongos Endogâmicos mdx , Oxigenases de Função Mista/metabolismo , Distrofia Muscular de Duchenne/genética , Miocárdio/metabolismo , NADPH Oxidase 4/análise , Oligonucleotídeos Antissenso/genética , Peptídeos/genética , Fenótipo , Volume Sistólico , Proteína Desacopladora 3/genética , Função Ventricular Direita
7.
Lancet Child Adolesc Health ; 2(8): 600-609, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30119719

RESUMO

Inherited neuromuscular disorders encompass a broad group of genetic conditions, and the discovery of these underlying genes has expanded greatly in the past three decades. The discovery of such genes has enabled more precise diagnosis of these disorders and the development of specific therapeutic approaches that target the genetic basis and pathophysiological pathways. Such translational research has led to the approval of two genetic therapies by the US Food and Drug Administration: eteplirsen for Duchenne muscular dystrophy and nusinersen for spinal muscular atrophy, which are both antisense oligonucleotides that modify pre-mRNA splicing. In this Review we aim to discuss new genetic therapies and ongoing clinical trials for Duchenne muscular dystrophy, spinal muscular atrophy, and other less common childhood neuromuscular disorders.


Assuntos
Terapia Genética , Morfolinos/uso terapêutico , Atrofia Muscular Espinal/congênito , Atrofia Muscular Espinal/tratamento farmacológico , Distrofia Muscular de Duchenne/congênito , Distrofia Muscular de Duchenne/tratamento farmacológico , Oligonucleotídeos/uso terapêutico , Criança , Humanos , Doenças Neuromusculares/tratamento farmacológico
8.
Orphanet J Rare Dis ; 13(1): 93, 2018 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-29907124

RESUMO

BACKGROUND: Exon skipping has been considered a promising therapeutic approach for Duchenne muscular dystrophy (DMD). Eteplirsen received conditional approval in the United States in 2016. To date, no systematic reviews or meta-analyses of randomized controlled trials (RCTs) of exon skipping drugs have been published to determine the pooled estimates for the effect of exon skipping in treating DMD. METHODS: A systematic review and meta-analysis of double-blind RCTs comparing exon-skipping drugs with placebo in DMD was performed. Trials were identified by searching published and unpublished studies from electronically available databases and clinical trial registries through October 2017. The primary outcomes were changes in the 6-min walk test (6MWT) distance, North Star Ambulatory Assessment (NSAA) scores, and adverse events. Random-effects meta-analysis and assessment of risk of bias were performed. This systematic review was registered at PROSPERO (CRD42016037504). RESULTS: Five studies involving 322 participants were included, investigating eteplirsen in one and drisapersen in four studies. There were no changes in 6MWT distance (mean difference [MD] - 9.16, 95% confidence interval [CI] - 21.94 to 3.62) or NSAA scores (MD 1.20, 95% CI - 2.35 to 4.75) after 24 weeks of treatment in the exon-skipping group compared with placebo. Subgroup analysis for a 6 mg/kg weekly injection of drisapersen showed significant changes in the 6MWT, favoring drisapersen after 24 weeks (MD - 20.24; 95% CI - 39.59 to - 0.89). However, drisapersen resulted in a significant increase in injection site reactions (risk ratio [RR] 3.67, 95% CI 1.96 to 6.89, p < 0.0001) and renal toxicity (RR 1.81, 95% CI 1.11 to 2.94, p = 0.02). Risk of bias was high in two of the five studies, including the eteplirsen and one drisapersen study. CONCLUSIONS: Current available data do not show evidence that exon-skipping drugs are effective in DMD. Despite potential effectiveness when used at a specific dose, significant side effects were reported with drisapersen. The small number of RCTs with relatively small numbers of participants indicate the difficulty in conducting sufficiently powered studies of DMD. Prospectively planned meta-analysis and utilization of the real-world data may provide a more precise estimate of the effect of exon skipping in this disease.


Assuntos
Éxons/genética , Distrofia Muscular de Duchenne/diagnóstico , Método Duplo-Cego , Humanos , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/genética , Oligonucleotídeos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Teste de Caminhada
9.
PLoS One ; 13(6): e0198897, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29912990

RESUMO

Cardiac failure is a major cause of mortality in patients with Duchenne muscular dystrophy (DMD). Antisense-mediated exon skipping has the ability to correct out-of-frame mutations in DMD to produce truncated but functional dystrophin. Traditional antisense approaches have however been limited by their poor uptake into cardiac muscle. The addition of cell-penetrating peptides to antisense molecules has increased their potency and improved their uptake into all muscles, including the heart. We have investigated the efficacy of the Peptide-conjugated phosphodiamidate morpholino oligomer (P-PMO) Pip6a-PMO, for restoration of cardiac dystrophin and functional rescue in DMD mice- the mdx mouse and the less well characterised Cmah-/-mdx mouse (which carry a human-like mutation in the mouse Cmah gene as well as a mutation in DMD). In our first study male mdx mice were administered Pip6a-PMO, i.v, fortnightly from 12 to 30 weeks of age alongside mock-injected age-matched mdx and C57BL10 controls. Mice received 4 doses of 18 mg/kg followed by 8 doses of 12.5 mg/kg. The cardiac function of the mice was analysed 2 weeks after their final injection by MRI followed by conductance catheter and their muscles were harvested for dystrophin quantification. In the second study, male Cmah-/-mdx mice, received 12.5 mg/kg Pip6a-PMO, i.v fortnightly from 8 to 26 weeks and assessed by MRI at 3 time points (12, 18 and 28 weeks) alongside mock-injected age-matched mdx, C57BL10 and Cmah-/-mdx controls. The mice also underwent MEMRI and conductance catheter at 28 weeks. This allowed us to characterise the cardiac phenotype of Cmah-/-mdx mice as well as assess the effects of P-PMO on cardiac function. Pip6a-PMO treatment resulted in significant restoration of dystrophin in mdx and Cmah-/-mdx mice (37.5% and 51.6%, respectively), which was sufficient to significantly improve cardiac function, ameliorating both right and left ventricular dysfunction. Cmah-/-mdx mice showed an abnormal response to dobutamine stress test and this was completely ameliorated by PIP6a-PMO treatment. These encouraging data suggest that total restoration of dystrophin may not be required to significantly improve cardiac outcome in DMD patients and that it may be realistic to expect functional improvements with modest levels of dystrophin restoration which may be very achievable in future clinical trials.


Assuntos
Peptídeos Penetradores de Células/uso terapêutico , Insuficiência Cardíaca/etiologia , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/complicações , Animais , Modelos Animais de Doenças , Distrofina/metabolismo , Éxons/genética , Mutação da Fase de Leitura/genética , Coração/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/prevenção & controle , Camundongos , Camundongos Endogâmicos mdx , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatologia , Miocárdio/metabolismo
10.
Neurology ; 90(24): e2146-e2154, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29752304

RESUMO

OBJECTIVE: To describe the quantification of novel dystrophin production in patients with Duchenne muscular dystrophy (DMD) after long-term treatment with eteplirsen. METHODS: Clinical study 202 was an observational, open-label extension of the randomized, controlled study 201 assessing the safety and efficacy of eteplirsen in patients with DMD with a confirmed mutation in the DMD gene amenable to correction by skipping of exon 51. Patients received once-weekly IV doses of eteplirsen 30 or 50 mg/kg. Upper extremity muscle biopsy samples were collected at combined study week 180, blinded, and assessed for dystrophin-related content by Western blot, Bioquant software measurement of dystrophin-associated immunofluorescence intensity, and percent dystrophin-positive fibers (PDPF). Results were contrasted with matched untreated biopsies from patients with DMD. Reverse transcription PCR followed by Sanger sequencing of newly formed slice junctions was used to confirm the mechanism of action of eteplirsen. RESULTS: Reverse transcription PCR analysis and sequencing of the newly formed splice junction confirmed that 100% of treated patients displayed the expected skipped exon 51 sequence. In treated patients vs untreated controls, Western blot analysis of dystrophin content demonstrated an 11.6-fold increase (p = 0.007), and PDPF analysis demonstrated a 7.4-fold increase (p < 0.001). The PDPF findings were confirmed in a re-examination of the sample (15.5-fold increase, p < 0.001). Dystrophin immunofluorescence intensity was 2.4-fold greater in treated patients than in untreated controls (p < 0.001). CONCLUSION: Taken together, the 4 assays, each based on unique evaluation mechanisms, provided evidence of eteplirsen muscle cell penetration, exon skipping, and induction of novel dystrophin expression. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence of the muscle cell penetration, exon skipping, and induction of novel dystrophin expression by eteplirsen, as confirmed by 4 assays.


Assuntos
Distrofina/biossíntese , Éxons/genética , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Biópsia , Criança , Humanos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Resultado do Tratamento
11.
Sci Transl Med ; 10(437)2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29669851

RESUMO

Duchenne muscular dystrophy (DMD) is a lethal hereditary muscle disease caused by mutations in the gene encoding the muscle protein dystrophin. These mutations result in a shift in the open reading frame leading to loss of the dystrophin protein. Antisense oligonucleotides (ASOs) that induce exon skipping correct this frame shift during pre-mRNA splicing and partially restore dystrophin expression in mouse and dog models. We conducted a phase 1, open-label, dose-escalation clinical trial to determine the safety, pharmacokinetics, and activity of NS-065/NCNP-01, a morpholino ASO that enables skipping of exon 53. Ten patients with DMD (6 to 16 years old), carrying mutations in the dystrophin gene whose reading frame would be restored by exon 53 skipping, were administered NS-065/NCNP-01 at doses of 1.25, 5, or 20 mg/kg weekly for 12 weeks. The primary endpoint was safety; the secondary endpoints were pharmacokinetics and successful exon skipping. No severe adverse drug reactions were observed, and no treatment discontinuation occurred. Muscle biopsy samples were taken before and after treatment and compared by reverse transcription polymerase chain reaction (RT-PCR), immunofluorescence, and Western blotting to assess the amount of exon 53 skipping and dystrophin expression. NS-065/NCNP-01 induced exon 53 skipping in dystrophin-encoding mRNA in a dose-dependent manner and increased the dystrophin/spectrin ratio in 7 of 10 patients. Furthermore, the amount of exon skipping correlated with the maximum drug concentration in plasma (Cmax) and the area under the concentration-time curve in plasma (AUC0-t ). These results indicate that NS-065/NCNP-01 has a favorable safety profile and promising pharmacokinetics warranting further study in a phase 2 clinical trial.


Assuntos
Éxons/genética , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/genética , Oligonucleotídeos Antissenso/uso terapêutico , Administração Intravenosa , Adolescente , Criança , Pré-Escolar , Distrofina/genética , Humanos , Masculino , Morfolinos/administração & dosagem , Morfolinos/uso terapêutico , Oligonucleotídeos Antissenso/administração & dosagem , Reação em Cadeia da Polimerase Via Transcriptase Reversa
12.
Handb Clin Neurol ; 148: 591-601, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29478602

RESUMO

Autosomal-recessive proximal spinal muscular atrophy (Werdnig-Hoffmann, Kugelberg-Welander) is caused by mutation of the SMN1 gene, and the clinical severity correlates with the number of copies of a nearly identical gene, SMN2. The SMN protein plays a critical role in spliceosome assembly and may have other cellular functions, such as mRNA transport. Cell culture and animal models have helped to define the disease mechanism and to identify targets for therapeutic intervention. The main focus for developing treatment has been to increase SMN levels, and accomplishing this with small molecules, oligonucleotides, and gene replacement has been quite. An oligonucleotide, nusinersen, was recently approved for treatment in patients, and confirmatory studies of other agents are now under way.


Assuntos
Atrofia Muscular Espinal , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Animais , Humanos , Morfolinos/uso terapêutico , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/metabolismo , Atrofia Muscular Espinal/terapia , Mutação/genética , Oligonucleotídeos/uso terapêutico , Proteína 2 de Sobrevivência do Neurônio Motor/genética
13.
Methods Mol Biol ; 1687: 3-17, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29067652

RESUMO

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in childhood. Mutations of the DMD gene destabilize the dystrophin associated glycoprotein complex in the sarcolemma. Ongoing mechanical stress leads to unregulated influx of calcium ions into the sarcoplasm, with activation of proteases, release of proinflammatory cytokines, and mitochondrial dysfunction. Cumulative damage and reparative failure leads to progressive muscle necrosis, fibrosis, and fatty replacement. Although there is presently no cure for DMD, scientific advances have led to many potential disease-modifying treatments, including dystrophin replacement therapies, upregulation of compensatory proteins, anti-inflammatory agents, and other cellular targets. Recently approved therapies include ataluren for stop codon read-through and eteplirsen for exon 51 skipping of eligible individuals. The purpose of this chapter is to summarize the clinical features of DMD, to describe current outcome measures used in clinical studies, and to highlight new emerging therapies for affected individuals.


Assuntos
Distrofina/genética , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/terapia , Oxidiazóis/uso terapêutico , Códon de Terminação/genética , Bases de Dados Genéticas , Distrofina/uso terapêutico , Éxons/genética , Humanos , Morfolinos/toxicidade , Células Musculares/metabolismo , Distrofia Muscular de Duchenne/genética , Mutação
14.
Methods Mol Biol ; 1687: 123-141, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29067660

RESUMO

Exon skipping therapy using synthetic DNA-like molecules called antisense oligonucleotides (ASOs) is a promising therapeutic candidate for overcoming the dystrophin mutation that causes Duchenne muscular dystrophy (DMD). This treatment involves splicing out the frame-disrupting segment of the dystrophin mRNA, which restores the reading frame and produces a truncated yet functional dystrophin protein. Phosphorodiamidate morpholino oligomer (PMO) is the safest ASO for patients among ASOs and has recently been approved under the accelerated approval pathway by the U.S. Food and Drug Administration (FDA) as the first drug for DMD. Here, we describe the methodology and protocol of PMO transfection and evaluation of the exon skipping efficacy in the mdx52 mouse, an exon 52 deletion model of DMD produced by gene targeting. The mdx52 mouse model offers advantages over the mdx mouse, a spontaneous DMD model with a nonsense mutation in exon 23, in terms of the deletion in a hotspot of deletion mutations in DMD patients, the analysis of caveolae and also Dp140 and Dp260, shorter dystrophin isoforms.


Assuntos
Distrofina/genética , Terapia Genética/métodos , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/terapia , Processamento Alternativo/genética , Animais , Modelos Animais de Doenças , Distrofina/antagonistas & inibidores , Éxons/genética , Humanos , Camundongos , Camundongos Endogâmicos mdx , Morfolinos/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/uso terapêutico , Transfecção
15.
Methods Mol Biol ; 1687: 143-155, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29067661

RESUMO

During the past 10 years, antisense oligonucleotide-mediated exon skipping and splice modulation have proven to be powerful tools for correction of mRNA splicing in genetic diseases. In 2016, the US Food and Drug Administration (FDA)-approved Exondys 51 (eteplirsen) and Spinraza (nusinersen), the first exon skipping and exon inclusion drugs, to treat patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), respectively. The exon skipping of DMD mRNA aims to restore the disrupted reading frame using antisense oligonucleotides (AONs), allowing the production of truncated but partly functional dystrophin proteins, and slow down the progression of the disease. This approach has also been explored in several other genetic disorders, including laminin α2 chain-deficient congenital muscular dystrophy, dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy and limb-girdle muscular dystrophy type 2B), sarcoglycanopathy (limb-girdle muscular dystrophy type 2C), and Fukuyama congenital muscular dystrophy. Antisense-mediated exon skipping is also a powerful tool to examine the function of genes and exons. A significant challenge in exon skipping is how to design effective AONs. The mechanism of mRNA splicing is highly complex with many factors involved. The selection of target sites, the length of AONs, the AON chemistry, and the melting temperature versus the RNA strand play important roles. A cocktail of AONs can be employed to skip multiples exons. In this chapter, we discuss the design of effective AONs for exon skipping.


Assuntos
Terapia Genética/métodos , Atrofia Muscular Espinal/terapia , Distrofia Muscular do Cíngulo dos Membros/terapia , Distrofia Muscular de Duchenne/terapia , Distrofina/genética , Distrofina/uso terapêutico , Éxons/genética , Humanos , Morfolinos/uso terapêutico , Atrofia Muscular Espinal/genética , Atrofia Muscular Espinal/patologia , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Oligonucleotídeos/uso terapêutico , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/uso terapêutico , Processamento de RNA/genética
16.
Methods Mol Biol ; 1687: 185-192, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29067664

RESUMO

Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration, caused by nonsense or frameshift mutations in the dystrophin (DMD) gene. Antisense oligonucleotides can be used to induce specific exon skipping; recently, a phosphorodiamidate morpholino oligomer (PMO) has been approved for clinical use in DMD. However, an efficient PMO delivery strategy is required to improve the therapeutic efficacy in DMD patients. We previously developed polyethylene glycol (PEG)-modified liposomes containing ultrasound contrast gas, "Bubble liposomes" (BLs), and found that the combination of BLs with ultrasound exposure is a useful gene delivery tool. Here, we describe an efficient PMO delivery strategy using the combination of BLs and ultrasound exposure to treat muscles in a DMD mouse model (mdx). This ultrasound-mediated BL technique can increase the PMO-mediated exon-skipping efficiency, leading to significantly increased dystrophin expression. Thus, the combination of BLs and ultrasound exposure may be a feasible PMO delivery method to improve therapeutic efficacy and reduce the PMO dosage for DMD treatment.


Assuntos
Distrofina/genética , Terapia Genética/métodos , Distrofia Muscular de Duchenne/terapia , Oligonucleotídeos Antissenso/uso terapêutico , Animais , Códon sem Sentido/genética , Modelos Animais de Doenças , Distrofina/uso terapêutico , Éxons/genética , Humanos , Lipossomos/uso terapêutico , Camundongos , Camundongos Endogâmicos mdx , Morfolinos/genética , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/genética , Oligonucleotídeos Antissenso/genética , Ultrassonografia/métodos
17.
Br J Clin Pharmacol ; 84(1): 25-34, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28929521

RESUMO

AIMS: The aims of the present study were to assess the safety, tolerability and pharmacokinetics of radavirsen following single ascending doses and multiple doses given as intravenous infusions in healthy adults. METHODS: A phase I safety and pharmacokinetic study of radavirsen was performed in healthy volunteers. The study was divided into two parts. The first was a single-ascending-dose study of five cohorts of eight subjects each, randomized 6:2 to receive single intravenous doses of radavirsen ranging from 0.5 mg kg-1 to 8 mg kg-1 or placebo. The second was a multiple-dose study of 16 subjects randomized 12:4 to receive 8 mg kg-1 or placebo once daily for 5 days. RESULTS: A total of 66 subjects were screened, and 56 subjects were dosed between 2013 and 2015. At least one adverse event occurred in 31/42 (74%) who received radavirsen, and 13/14 (93%) receiving placebo. The most common adverse events were headache and proteinuria, and were similar in incidence and severity among those receiving radavirsen or placebo. Single-dose pharmacokinetics demonstrated relatively linear and dose-proportional increases in maximal concentration and in area under the concentration-time curve from zero to 24 h (AUC0-24 ). At 8 mg kg-1 in the multiple-dose cohort, the day 4 geometric mean AUC0-24 was 57.9 µg*h ml-1 . CONCLUSION: Single infusions of radavirsen up to 8 mg kg-1 , and multi-dosing at 8 mg kg-1 once daily for 5 days, appear to be safe and well tolerated in healthy subjects. The multi-dose day 4 AUC0-24 in the present study was comparable with that associated with protection from viral infection in a preclinical ferret influenza model. Further evaluation of radavirsen for the treatment of influenza infections is warranted.


Assuntos
Antivirais/farmacologia , Influenza Humana/tratamento farmacológico , Morfolinos/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Adulto , Antivirais/uso terapêutico , Método Duplo-Cego , Esquema de Medicação , Feminino , Cefaleia/induzido quimicamente , Cefaleia/epidemiologia , Voluntários Saudáveis , Humanos , Incidência , Vírus da Influenza A/genética , Influenza Humana/virologia , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Morfolinos/genética , Morfolinos/uso terapêutico , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/uso terapêutico , Placebos , Biossíntese de Proteínas/genética , Proteinúria/induzido quimicamente , Proteinúria/epidemiologia , Proteínas da Matriz Viral/genética , Adulto Jovem
18.
J Neuromuscul Dis ; 5(1): 47-58, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29278896

RESUMO

BACKGROUND: Duchenne muscular dystrophy (DMD) is a rare, degenerative, X-linked genetic disease that results in progressive muscle loss and premature death, most commonly from respiratory or cardiac failure. DMD is primarily caused by whole exon deletions, resulting in a shift of the dystrophin mRNA reading frame that prevents production of functional dystrophin protein. Eteplirsen, a phosphorodiamidate morpholino oligomer (PMO), is designed to skip exon 51, restore the reading frame, and induce production of internally shortened dystrophin in patients with mutations amenable to such treatment. OBJECTIVE: Describe lung function assessed throughout eteplirsen studies 201/202. METHODS: Studies 201/202 included 12 patients treated with eteplirsen over 5 years. Pulmonary function tests included forced vital capacity (FVC), maximum expiratory pressure (MEP), and maximum inspiratory pressure (MIP). With no long-term placebo control, FVC results were compared with data from the United Dystrophinopathy Project (UDP). MIP and MEP were compared to published natural history. RESULTS: Age-adjusted mixed-model repeated-measures analysis showed decreases of 2.3% and 2.6% annually for FVC% p and MEP% p, and an annual increase of 0.6% for MIP% p for the eteplirsen-treated cohort. Data from the UDP demonstrated a 4.1% decline in FVC% p. The published natural history reports annual declines of at least 2.7% and 3.8% for MEP% p and MIP% p, respectively, in patients with DMD. CONCLUSIONS: With eteplirsen treatment, deterioration of respiratory muscle function based on FVC% p was half of that seen in the UDP; MEP% p and MIP% p compared favorably with natural history.


Assuntos
Pulmão/fisiopatologia , Pressões Respiratórias Máximas , Distrofia Muscular de Duchenne/fisiopatologia , Capacidade Vital , Adolescente , Estudos de Casos e Controles , Criança , Progressão da Doença , Método Duplo-Cego , Humanos , Masculino , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Testes de Função Respiratória
19.
J Clin Neurosci ; 49: 1-6, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29254734

RESUMO

BACKGROUND: Duchenne Muscular Dystrophy is a paediatric disorder resulting from a defective dystrophin gene. It causes progressive loss of muscle fibres, muscle weakness, and eventually loss of ambulation during adolescence, with death due to respiratory or cardiovascular complications soon afterwards. The drug eteplirsen has received support from medical experts and parents of affected children, but the FDA has delayed their decision for approval of this drug. OBJECTIVE: This study analysed the results of previous studies to assess the safety and efficacy of the eteplirsen, and is the first pooled-analysis of its kind. METHODS: A literature search of electronic databases was performed. Only human studies using eteplirsen were eligible. RESULTS: A total of four relevant clinical studies were identified. A pooled-analysis was performed using data relating to percentage dystrophin-positive fibres obtained from muscle biopsy, and the six-minute walk test (6 MWT). The average increase in percentage dystrophin-positive fibres after treatment with eteplirsen was 24.23% (range -4 to 78; SD 24.44%). The average rate of decline in distance walked was 65metres (range -335 to 83; SD 100.08 m). CONCLUSIONS: Whether or not this increase in percentage dystrophin-positive fibres and distance walked is clinically significant is unclear, and there is therefore a need for more clinical trials.


Assuntos
Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/tratamento farmacológico , Adolescente , Criança , Ensaios Clínicos como Assunto/métodos , Humanos , Masculino , Morfolinos/farmacologia , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/patologia , Debilidade Muscular/diagnóstico , Debilidade Muscular/tratamento farmacológico , Caminhada/fisiologia
20.
Rev Neurol ; 65(8): 373-380, 2017 10 16.
Artigo em Espanhol | MEDLINE | ID: mdl-28990648

RESUMO

INTRODUCTION: In 2016 the US Food and Drug Administration (FDA) granted the marketing authorization for eteplirsen for Duchenne muscular dystrophy. This has been a very controversial decision since it happened after a negative assessment from both the Advisory Committee and the technical FDA evaluation team. The FDA's Center for Drug Evaluation and Research (CDER) director was who ultimately approved the product, while the FDA Commissioner did not overrule that decision. AIM: To report about the most relevant events regarding the approval of eteplirsen by the US FDA. DEVELOPMENT: All relevant facts that occurred during the clinical development and evaluation phase following 'accelerated approval' procedure of eteplirsen are discussed in detail. The technical FDA evaluation team reasons supporting that the drug has not proven clinical benefit, the attitude of patient advocacy groups and the post-approval FDA requirements to the marketing authorization holder are discussed. Finally, we reflect on what is the situation Spanish patients face once eteplirsen is on the US market. CONCLUSIONS: This is a unique case in the history of drug authorizations in western countries, that shows the difficulties that current regulations on accelerated approval of new medicines could have when interpreting scarce and low quality clinical development data, when dealing with rare diseases with no available therapies.


Assuntos
Aprovação de Drogas , Morfolinos/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Grupos de Autoajuda , Humanos , Produção de Droga sem Interesse Comercial , Estados Unidos
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