RESUMEN
Duchenne muscular dystrophy (DMD) afflicts 1 in 5000 newborn males, leading to progressive muscle weakening and the loss of ambulation between the ages of 8 and 12. Typically, DMD patients pass away from heart failure or respiratory failure. Currently, there is no cure, though exon-skipping therapy including eteplirsen (brand name Exondys 51), a synthetic antisense oligonucleotide designed to skip exon 51 of the dystrophin gene, is considered especially promising. Applicable to approximately 14% of DMD patients, a phosphorodiamidate morpholino oligomer (PMO) antisense oligonucleotide eteplirsen received accelerated approval by the US Food and Drug Administration (FDA) in 2016. Throughout clinical trials, eteplirsen has been well tolerated by patients with no serious drug-related adverse events. The most common events observed are balance disorder, vomiting, and skin rash. Despite its safety and promise of functional benefits, eteplirsen remains controversial due to its low production of dystrophin. In addition, unmodified PMOs have limited efficacy in the heart. To address these concerns of efficacy, eteplirsen has been conjugated to a proprietary cell-penetrating peptide; the conjugate is called SRP-5051. Compared to eteplirsen, SRP-5051 aims to better prompt exon-skipping and dystrophin production but may have greater toxicity concerns. This paper reviews and discusses the available information on the efficacy, safety, and tolerability data of eteplirsen and SRP-5051 from preclinical and clinical trials. Issues faced by eteplirsen and SRP-5051, including efficacy and safety, are identified. Lastly, the current state of eteplirsen and exon-skipping therapy in general as a strategy for the treatment of DMD are discussed.
Asunto(s)
Distrofia Muscular de Duchenne , Niño , Exones , Humanos , Recién Nacido , Masculino , Morfolinos/efectos adversos , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/genética , Oligonucleótidos Antisentido/genética , Oligonucleótidos Antisentido/uso terapéuticoRESUMEN
BACKGROUND: AVI-7288 is a phosphorodiamidate morpholino oligomer with positive charges that targets the viral messenger RNA that encodes Marburg virus (MARV) nucleoprotein. Its safety in humans is undetermined. METHODS: We assessed the efficacy of AVI-7288 in a series of studies involving a lethal challenge with MARV in nonhuman primates. The safety of AVI-7288 was evaluated in a randomized, multiple-ascending-dose study in which 40 healthy humans (8 humans per dose group) received 14 once-daily infusions of AVI-7288 (1 mg, 4 mg, 8 mg, 12 mg, or 16 mg per kilogram of body weight) or placebo, in a 3:1 ratio. We estimated the protective dose in humans by comparing pharmacokinetic variables in infected nonhuman primates, uninfected nonhuman primates, and uninfected humans. RESULTS: Survival in infected nonhuman primates was dose-dependent, with survival rates of 0%, 30%, 59%, 87%, 100%, and 100% among monkeys treated with 0 mg, 3.75 mg, 7.5 mg, 15 mg, 20 mg, and 30 mg of AVI-7288 per kilogram, respectively (P<0.001 with the use of the log-rank test for the comparison of survival across groups). No safety concern was identified at doses up to 16 mg per kilogram per day in humans. No serious adverse events were reported. Drug exposure (the area under the curve) was dose-dependent in both nonhuman primates and humans; drug clearance was independent of dose but was higher in nonhuman primates than in humans. The protective dose in humans was initially estimated, on the basis of exposure, to be 9.6 mg per kilogram per day (95% confidence interval, 6.6 to 12.5) for 14 days. Monte Carlo simulations supported a dose of 11 mg per kilogram per day to match the geometric mean protective exposure in nonhuman primates. CONCLUSIONS: This study shows that, on the basis of efficacy in nonhuman primates and pharmacokinetic data in humans, AVI-7288 has potential as postexposure prophylaxis for MARV infection in humans. (Funded by the Department of Defense; ClinicalTrials.gov number, NCT01566877.).
Asunto(s)
Antivirales/administración & dosificación , Enfermedad del Virus de Marburg/tratamiento farmacológico , Marburgvirus , Morfolinos/administración & dosificación , Animales , Antivirales/efectos adversos , Antivirales/farmacocinética , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Humanos , Estimación de Kaplan-Meier , Macaca fascicularis , Enfermedad del Virus de Marburg/mortalidad , Marburgvirus/genética , Morfolinos/efectos adversos , Morfolinos/farmacocinética , ARN Mensajero , ARN ViralRESUMEN
Paired-like homeodomain transcription factor 1 (PITX1) was proposed to be part of the disease mechanisms of facioscapulohumeral muscular dystrophy (FSHD). We generated a tet-repressible muscle-specific Pitx1 transgenic mouse model which develops phenotypes of muscular dystrophy after the PITX1 expression is induced. In this study, we attempted to block the translation of PITX1 protein using morpholinos. Three groups of the transgenic mice received intravenous injections of phosphorodiamidate morpholino oligomers (PMO) (100 mg/kg), octaguanidinium dendrimer-conjugated morpholino (vivo-morpholino) (10 mg/kg), or phosphate-buffered saline (PBS) after the PITX1 expression was induced. Immunoblotting data showed that PITX1 expression in the triceps and quadriceps was significantly reduced 70% and 63% by the vivo-morpholino treatment, respectively. Muscle pathology of the mice treated with the vivo-morpholino was improved by showing 44% fewer angular-shaped atrophic myofibers. Muscle function determined by grip strength was significantly improved by the vivo-morpholino treatment. The study showed that systemic delivery of the vivo-morpholino reduced the PITX1 expression and improved the muscle phenotypes. Aberrant expression of DUX4 from the last unit of the D4Z4 array has been proposed to be the cause of FSHD. The findings of this study suggest that the same principle may be applied to suppress the aberrantly expressed DUX4 in FSHD.
Asunto(s)
Morfolinos/administración & dosificación , Morfolinos/genética , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Distrofia Muscular Facioescapulohumeral/genética , Distrofia Muscular Facioescapulohumeral/terapia , Factores de Transcripción Paired Box/genética , Animales , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica , Masculino , Ratones , Ratones Transgénicos , Morfolinos/efectos adversos , Fuerza Muscular/efectos de los fármacos , Fuerza Muscular/genética , Músculo Esquelético/patología , Distrofia Muscular Facioescapulohumeral/rehabilitación , Factores de Transcripción Paired Box/metabolismoRESUMEN
Two identical single-ascending-dose studies evaluated the safety and pharmacokinetics (PK) of AVI-6002 and AVI-6003, two experimental combinations of phosphorodiamidate morpholino oligomers with positive charges (PMOplus) that target viral mRNA encoding Ebola virus and Marburg virus proteins, respectively. Both AVI-6002 and AVI-6003 were found to suppress disease in virus-infected nonhuman primates in previous studies. AVI-6002 (a combination of AVI-7537 and AVI-7539) or AVI-6003 (a combination of AVI-7287 and AVI-7288) were administered as sequential intravenous (i.v.) infusions of a 1:1 fixed dose ratio of the two subcomponents. In each study, 30 healthy male and female subjects between 18 and 50 years of age were enrolled in six-dose escalation cohorts of five subjects each and received a single i.v. infusion of active study drug (0.005, 0.05, 0.5, 1.5, 3, and 4.5 mg/kg per component) or placebo in a 4:1 ratio. Both AVI-6002 and AVI-6003 were safe and well tolerated at the doses studied. A maximum tolerated dose was not observed in either study. The four chemically similar PMOplus components exhibited generally similar PK profiles. The mean peak plasma concentration and area under the concentration-time curve values of the four components exhibited dose-proportional PK. The estimated plasma half-life of all four components was 2 to 5 h. The safety of the two combinations and the PK of the four components were similar, regardless of the target RNA sequence.
Asunto(s)
Fiebre Hemorrágica Ebola/tratamiento farmacológico , Enfermedad del Virus de Marburg/tratamiento farmacológico , Morfolinos/farmacocinética , Adulto , Animales , Área Bajo la Curva , Método Doble Ciego , Ebolavirus/efectos de los fármacos , Ebolavirus/genética , Femenino , Fiebre Hemorrágica Ebola/virología , Humanos , Infusiones Intravenosas , Masculino , Enfermedad del Virus de Marburg/virología , Marburgvirus/efectos de los fármacos , Marburgvirus/genética , Persona de Mediana Edad , Morfolinos/efectos adversos , Morfolinos/sangre , Placebos , Adulto JovenAsunto(s)
Distrofina/genética , Morfolinos/uso terapéutico , Distrofia Muscular de Duchenne/terapia , Mutación , Reparación del Gen Blanco/métodos , Investigación Biomédica Traslacional , Animales , Distrofina/metabolismo , Predisposición Genética a la Enfermedad , Humanos , Morfolinos/efectos adversos , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatología , Fenotipo , Recuperación de la Función , Reparación del Gen Blanco/efectos adversos , Resultado del TratamientoRESUMEN
AIM: The purpose of this study is to evaluate the safety and pharmacokinetics of the novel morpholino oligomer NS-089/NCNP-02 which can induce exon 44 skipping, in patients with DMD. Additionally, we aimed to identify markers predictive of therapeutic efficacy and determine the optimal dosing for future studies. METHODS: This is an open-label, dose-escalation, two-center phase I/II trial in ambulant patients with DMD, presence of an out-of-frame deletion, and a mutation amenable to exon 44 skipping. Part 1 is a stepwise dose-finding stage (4 weeks) during which NS-089/NCNP-02 will be administered intravenously at four dose levels once weekly (1.62, 10, 40, and 80 mg/kg); Part 2 is a 24-week evaluation period based on the dosages determined during Part 1. The primary (safety) endpoints are the results of physical examinations, vital signs, 12-lead electrocardiogram and echocardiography tests, and adverse event reporting. Secondary endpoints include expression of dystrophin protein, motor function assessment, exon 44 skipping efficiency, plasma and urinary NS-089/NCNP-02 concentrations, and changes in blood creatine kinase levels. DISCUSSION: Exon-skipping therapy using ASOs shows promise in selected patients, and this first-in-human study is expected to provide critical information for subsequent clinical development of NS-089/NCNP-02.
Asunto(s)
Distrofia Muscular de Duchenne , Humanos , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Oligonucleótidos Antisentido/efectos adversos , Morfolinos/efectos adversos , Exones , Mutación , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase I como AsuntoRESUMEN
Treacher Collins Syndrome (TCS) is a congenital disease characterized by defects in the craniofacial skeleton and absence of mental alterations. Recently we modelled TCS in zebrafish (Danio rerio) embryos through the microinjection of Morpholino® oligonucleotides blocking the translation of the ortholog of the main causative gene (TCOF1). We showed that Cnbp, a key cytoprotective protein involved in normal rostral head development, was detected in lower levels (without changes in its mRNA expression) in TCS-like embryos. As previous reports suggested that Cnbp is degraded through the proteasomal pathway, we tested whether proteasome inhibitors (MG132 and Bortezomib (Velcade®, Millennium laboratories)) were able to ameliorate cranial skeleton malformations in TCS. Here we show that treatment with both proteasome inhibitors produced a robust craniofacial cartilage phenotype recovery. This recovery seems to be consequence of a decreased degradation of Cnbp in TCS-like embryos. Critical TCS manifestations, such as neuroepithelial cell death and cell redox imbalance were attenuated. Thus, proteasome inhibitors may offer an opportunity for TCS molecular and phenotypic manifestation's prevention. Although further development of new safe inhibitors compatible with administration during pregnancy is required, our results encourage this therapeutic approach.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Disostosis Mandibulofacial/metabolismo , Morfolinos/efectos adversos , Fosfoproteínas/metabolismo , Proteínas de Unión al ARN/metabolismo , Proteínas de Pez Cebra/metabolismo , Animales , Embrión no Mamífero/anomalías , Embrión no Mamífero/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Disostosis Mandibulofacial/patología , Fosfoproteínas/genética , Pez Cebra , Proteínas de Pez Cebra/genéticaRESUMEN
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 (Nâ=â12) 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 50âmg/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 256âm) versus the other patients (nâ=â10; 6MWT range, 341-418âm). 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.
Asunto(s)
Morfolinos/uso terapéutico , Distrofia Muscular de Duchenne/tratamiento farmacológico , Niño , Progresión de la Enfermedad , Enfermedades en Gemelos , Método Doble Ciego , Distrofina/genética , Distrofina/metabolismo , Humanos , Masculino , Morfolinos/efectos adversos , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatología , Procesamiento Postranscripcional del ARN/efectos de los fármacos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Prueba de Paso , CaminataRESUMEN
AIM: AVI-7100 (Radavirsen) is a 20-mer phosphorodiamidate morpholino oligomer (PMOplus®) for the treatment of influenza. Results/methodology: An automated solid-phase extraction method was used to extract plasma samples (200 µl). The extracts were analyzed using liquid chromatography coupled with tandem mass spectrometry under the positive ionization mode. This method was fully validated over the calibration curve range of 5.00-1000 ng/ml. The between-run precision and accuracy ranged from 0.0 to 5.2% relative standard deviation and 91.6 to 100.0% of nominal for all quality control concentrations, including the lower limit of quantitation. DISCUSSION/CONCLUSION: This is the first liquid chromatography coupled with tandem mass spectrometry method for the measurement of AVI-7100 concentrations in human plasma. It has been used to support regulated bioanalysis.
Asunto(s)
Análisis Químico de la Sangre/métodos , Cromatografía Liquida/métodos , Morfolinos/sangre , Espectrometría de Masas en Tándem/métodos , Calibración , Ensayos Clínicos como Asunto , Humanos , Morfolinos/efectos adversos , Morfolinos/aislamiento & purificación , Morfolinos/farmacocinética , Seguridad , Extracción en Fase SólidaRESUMEN
PURPOSE: The cornea is one of the most commonly transplanted tissues. The morpholino-oligomer antisense compound AVI-5126 suppresses expression of proto-oncogene c-myc, a key factor in transplant rejection. AVI-5126 was evaluated in a rat cornea transplant model. METHODS: Donor corneas obtained from August x Copenhagen Irish rats were stored in Optisol™ containing 1.0 or 0.5 mg/mL AVI-5126 or Optisol alone for 24 h before transplant. Recipient Lewis rats were treated topically 3x/d with TobraDex™ and with 1.0 or 0.5 mg/mL of AVI-5126 or saline with daily monitoring for rejection using a modified McDonald-Shadduck Slit Lamp Scale. Using the high-performance liquid chromatography technique, the stability of AVI-5126 (0.5 mg/mL) in Optisol was evaluated for 30 days. AVI-5126 corneal transport was measured using Ussing chamber mounted rabbit corneas. The potential ocular toxicity of AVI-5126 (0.5 mg/mL) was evaluated after 8 days of 3x/d topical application in rats and in-vitro by incubation of human corneas for 8 days. RESULTS: Cornea storage in Optisol containing 1.0 mg/mL AVI-5126 plus post-transplant topical tid AVI-5126 (1.0 mg/mL) application significantly increased graft survival (7.0±1.6 days) versus 5.0±0.8 days for Optisol alone storage plus post-transplant topical tid saline application (P<0.001). After 30 days of storage, no significant degradation of AVI-5126 in Optisol was noted by high-performance liquid chromatography analysis. After 24 h, 5 µg/mL (1% of total dose) crossed the corneas mounted in Ussing chambers. Neither extended topical application of AVI-5126 to rats nor incubation of human corneas in AVI-5126 decreased endothelial cell density. CONCLUSIONS: Graft rejection was significantly delayed after pretransplantation storage of graft corneas in Optisol containing AVI-5126 followed by topical application of AVI-5126 post-transplantation. AVI-5126 was well tolerated, stable, and effectively penetrated the cornea.