Search

Duchenne muscular dystrophy is a severe genetic disease caused by mutations in the dystrophin gene (DMD), which lead to a significant decrease or complete absence of the protein of the same name in muscle fibers. The disease manifests itself in boys from the age of 2–5 years in the form of progressive muscular weakness, cardiomyopathy and respiratory failure. As a result of progression, patients lose the ability to move by adolescence and die in the third decade from cardiopulmonary complications. However, timely pathogenetic therapy for Duchenne muscular dystrophy can prolong the life of patients and improve its quality. In this regard, early diagnosis of the disease and early initiation of pathogenetic therapy are very important.The article describes two clinical cases of the disease in siblings with onset at 2 years of age and different ages of diagnosis. Pathogenetic therapy in the first case made it possible to prolong the patient’s outpatient stay and improve the quality of life, and early diagnosis and initiation of pathogenetic therapy in the second case avoided disease progression and contributed to the development of new motor skills. The presented clinical case demonstrates the need for early diagnosis of the disease even before the onset of clinical manifestations.

OBJECTIVE: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, international, multicenter registry of real-world ataluren use in individuals with nonsense mutation Duchenne muscular dystrophy (nmDMD) in clinical practice. This updated interim report (data cut-off: January 31, 2022), describes STRIDE patient characteristics and ataluren safety data, as well as the effectiveness of ataluren plus standard of care (SoC) in STRIDE versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS). METHODS: Patients are followed up from enrollment for at least 5 years or until study withdrawal. Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established predictors of disease progression. RESULTS: As of January 31, 2022, 307 patients were enrolled from 14 countries. Mean (standard deviation [SD]) ages at first symptoms and at genetic diagnosis were 2.9 (1.7) years and 4.5 (3.7) years, respectively. Mean (SD) duration of ataluren exposure was 1671 (56.8) days. Ataluren had a favorable safety profile; most treatment-emergent adverse events were mild or moderate and unrelated to ataluren. Kaplan-Meier analyses demonstrated that ataluren plus SoC significantly delayed age at loss of ambulation by 4 years (p

Abstract Background This paper details the results of an evaluation of the level of consensus amongst clinicians on the use of ataluren in both ambulatory and non-ambulatory patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). The consensus was derived using a modified Delphi methodology that involved an exploration phase and then an evaluation phase. Methods The exploration phase involved 90-minute virtual 1:1 interviews of 12 paediatric neurologists who cared for 30–120 DMD patients each and had patient contact every one or two weeks. The respondents managed one to ten nmDMD patients taking ataluren. The Discussion Guide for the interviews can be viewed as Appendix A. Following the exploration phase interviews, the interview transcripts were analysed by an independent party to identify common themes, views and opinions and developed 43 draft statements that the Steering Group (authors) reviewed, refined and endorsed a final list of 42 statements. Details of the recruitment of participants for the exploration and evaluation phases can be found under the Methods section. Results A consensus was agreed (> 66% of respondents agreeing) for 41 of the 42 statements using results from a consensus survey of healthcare professionals (n = 20) experienced in the treatment of nmDMD. Conclusions The statements with a high consensus suggest that treatment with ataluren should be initiated as soon as possible to delay disease progression and allow patients to remain ambulatory for as long as possible. Ataluren is indicated for the treatment of Duchenne muscular dystrophy that results from a nonsense mutation in the dystrophin gene, in ambulatory patients aged 2 years and older (see Summary of Product Characteristics for each country)

Background: This paper details the results of an evaluation of the level of consensus amongst clinicians on the use of ataluren in both ambulatory and non-ambulatory patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). The consensus was derived using a modified Delphi methodology that involved an exploration phase and then an evaluation phase. Methods: The exploration phase involved 90-minute virtual 1:1 interviews of 12 paediatric neurologists who cared for 30–120 DMD patients each and had patient contact every one or two weeks. The respondents managed one to ten nmDMD patients taking ataluren. The Discussion Guide for the interviews can be viewed as Appendix A. Following the exploration phase interviews, the interview transcripts were analysed by an independent party to identify common themes, views and opinions and developed 43 draft statements that the Steering Group (authors) reviewed, refined and endorsed a final list of 42 statements. Details of the recruitment of participants for the exploration and evaluation phases can be found under the Methods section. Results: A consensus was agreed (> 66% of respondents agreeing) for 41 of the 42 statements using results from a consensus survey of healthcare professionals (n = 20) experienced in the treatment of nmDMD. Conclusions: The statements with a high consensus suggest that treatment with ataluren should be initiated as soon as possible to delay disease progression and allow patients to remain ambulatory for as long as possible. Ataluren is indicated for the treatment of Duchenne muscular dystrophy that results from a nonsense mutation in the dystrophin gene, in ambulatory patients aged 2 years and older (see Summary of Product Characteristics for each country) [ABSTRACT FROM AUTHOR]

Summary: Shwachman–Diamond syndrome (SDS) is characterized by neutropenia, exocrine pancreatic insufficiency and skeletal abnormalities. SDS bone marrow haematopoietic progenitors show increased apoptosis and impairment in granulocytic differentiation. Loss of Shwachman–Bodian–Diamond syndrome (SBDS) expression results in reduced eukaryotic 80S ribosome maturation. Biallelic mutations in the SBDS gene are found in ~90% of SDS patients, ~55% of whom carry the c.183‐184TA>CT nonsense mutation. Several translational readthrough‐inducing drugs aimed at suppressing nonsense mutations have been developed. One of these, ataluren, has received approval in Europe for the treatment of Duchenne muscular dystrophy. We previously showed that ataluren can restore full‐length SBDS protein synthesis in SDS‐derived bone marrow cells. Here, we extend our preclinical study to assess the functional restoration of SBDS capabilities in vitro and ex vivo. Ataluren improved 80S ribosome assembly and total protein synthesis in SDS‐derived cells, restored myelopoiesis in myeloid progenitors, improved neutrophil chemotaxis in vitro and reduced neutrophil dysplastic markers ex vivo. Ataluren also restored full‐length SBDS synthesis in primary osteoblasts, suggesting that its beneficial role may go beyond the myeloid compartment. Altogether, our results strengthened the rationale for a Phase I/II clinical trial of ataluren in SDS patients who harbour the nonsense mutation. [ABSTRACT FROM AUTHOR]

Aim: We investigated the effect of ataluren plus standard of care (SoC) on age at loss of ambulation (LoA) and respiratory decline in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD) versus patients with DMD on SoC alone. Patients & methods: Study 019 was a long-term Phase III study of ataluren safety in nmDMD patients with a history of ataluren exposure. Propensity score matching identified Study 019 and CINRG DNHS patients similar in disease progression predictors. Results & conclusion: Ataluren plus SoC was associated with a 2.2-year delay in age at LoA (p = 0.0006), and a 3.0-year delay in decline of predicted forced vital capacity to

Duchenne muscular dystrophy (DMD) is an X-linked inherited neuromuscular disorder typically manifesting in boys aged 2–5 years, characterized by a progressive course. According to natural disease progression data, individuals with DMD typically lose the ability to walk independently by the age of 13. In most cases, the disease leads to cardiorespiratory complications, resulting in a lethal outcome between the ages of 20–30.In recent years, there have been therapeutic agents developed for the pathogenic treatment of this condition. One such medication is ataluren (Translarna®), used in patients with DMD caused by the formation of a “stop codon” (nonsense mutation) in the DMD gene, responsible for the development of the disease.This article presents the experience of applying ataluren (Translarna®) in boys residing in Moscow who suffer from Duchenne muscular dystrophy.

Background. Duchenne muscular dystrophy is a hereditary, X-linked, progressive, disabling disease. One of the possible pathogenetic methods for treating this disease is the drug ataluren, which acts at the stage of protein translation in the ribosome and makes it possible to read information from mRNA, despite the presence of a premature stop codon in it, and, as a result, synthesize the dystrophin protein.Aim. To evaluate the dynamics of the course of Duchenne muscular dystrophy in patients receiving appropriate drug and non-drug therapy and patients receiving pathogenetic therapy with ataluren.Materials and methods. We examined 38 patients with genetically confirmed Duchenne muscular dystrophy. Of these, 11 patients with a genetically confirmed nonsense mutation receiving pathogenetic therapy with ataluren and 27 patients in the comparison group with other mutations in the dystrophin gene. 6‑minute walk test and timed function tests was done at baseline and during follow-up. Ataluren side effects were assessed.Results. Statistically significant positive dynamics were revealed during follow-up at 12 month when assessing the distance of a 6‑minute walk test and tests for getting up from the floor and running 10 meters in groups taking ataluren and receiving standard drug therapy with the initial initiation of a course of regular physical exercise. The control group was characterized by negative dynamics in speed tests.Conclusion. Thus, when taking ataluren in the standard recommended dosage, patients with Duchenne muscular dystrophy with a nonsense mutation shows a decrease in the rate of disease progression and an improvement in speed and endurance. The initial prescription of regular non-weightbearing aerobic exercise on the early ambulatory stage is also characterized by an increase in motor skills.

In a five-step procedure, 18 new esters (20a–i and 21a–i) of ataluren and its analogs with dihydroartemisinin and zerumbone were synthesized from methyl 3-cyanobenzoate. The screening for their cytotoxic activity against two cancer cell lines, HepG2 and MCF-7, showed that most esters exhibit activity against the tested cell lines, with IC50 values in the range of 1.61–36.52 µM. Among the tested compounds, ester 21f containing 4-methoxy in structure R did not show cytotoxic activity. The interactions of these new derivatives with the epidermal growth factor receptor protein were also investigated by molecular docking studies. The obtained binding conformation revealed several notable results, demonstrating similarities between molecular modeling theory and experiment. These results contributed to interpreting the in vitro cytotoxicity of esters and proposed the basis for predicting the mechanism of their cytotoxic action. [ABSTRACT FROM AUTHOR]

Ataluren and eteplirsen are orphan drugs that delay progression of Duchenne muscular dystrophy in mutation-specific subgroups. They have yet to be approved in Egypt but are expected to reach the market soon. This study describes 2 cost-utility models comparing the drugs with the standard of care. We used a partition-survival model with 5 states based on the ambulatory status to model a cohort of ambulatory patients at the age of 5 years. Baseline curves were obtained from a published model; then the ambulation loss curve was updated using the Kaplan-Meier curve of the standard of care from a study by McDonald et al. Other curves were updated by calibration to this curve. Costs and utilities were from a local study. Deterministic and probabilistic sensitivity analyses were conducted. Prices were estimated based on other orphan drugs' prices. In the base case, ataluren 1000 mg and eteplirsen 50 mg/mL resulted in an incremental cost-effectiveness ratio of EGP 51 745 605 and EGP 69 652 533/quality-adjusted life-year, respectively, at their hypothetical prices of EGP 308 600 for ataluren 30-sachet pack and EGP 62 800 for eteplirsen 10 mL vial. The incremental cost-effectiveness ratio was sensitive to health state utilities but not to state costs. At EGP 911 719/quality-adjusted life-year threshold, the value-based prices were EGP 4680 for ataluren 1000 mg and EGP 733 for eteplirsen 10 mL vial. Based on these models, there is a huge gap between the prices of orphan drugs and their value-based prices, which highlights the need for major policy reforms in the assessment and pricing of orphan drugs. • Studies assessing the cost-utility of novel Duchenne muscular dystrophy treatments in the literature are scarce, whereas in Egypt this is considered the first published study in the area of a rare disease. • New Duchenne muscular dystrophy medications (ataluren and eteplirsen) are expected to reach the market with list prices that are not cost-effective for the Egyptian society according to the results of this study. Based on the current models, the calculated value-based prices of these drugs are very low compared with the expected prices (as estimated from the prices of other orphan drugs in Egypt). • Despite the recent efforts to update the national cost-effectiveness threshold considering disease rarity and severity factors, more policy reforms are still required to allow access to orphan drugs at fair prices for both manufacturers and society. [ABSTRACT FROM AUTHOR]

Both estrogen deficiency and aging may lead to osteoporosis. Developing novel drugs for treating osteoporosis is a popular research direction. We screened several potential therapeutic agents through a new deep learning-based efficacy prediction system (DLEPS) using transcriptional profiles for osteoporosis. DLEPS screening led to a potential novel drug examinee, ataluren, for treating osteoporosis. Ataluren significantly reversed bone loss in ovariectomized mice. Next, ataluren significantly increased human bone marrow-derived mesenchymal stem cell (hBMMSC) osteogenic differentiation without cytotoxicity, indicated by the high expression index of osteogenic differentiation genes (OCN , BGLAP, ALP, COL1A, BMP2, RUNX2). Mechanistically, ataluren exerted its function through the BMP-SMAD pathway. Furthermore, it activated SMAD phosphorylation but osteogenic differentiation was attenuated by BMP2-SMAD inhibitors or small interfering RNA of BMP2. Finally, ataluren significantly reversed bone loss in aged mice. In summary, our findings suggest that the DLEPS-screened ataluren may be a therapeutic agent against osteoporosis by aiding hBMMSC osteogenic differentiation.

Aim: Strategic Targeting of Registries and International Database of Excellence (STRIDE) is an ongoing, multicenter registry providing real-world evidence regarding ataluren use in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD). We examined the effectiveness of ataluren + standard of care (SoC) in the registry versus SoC alone in the Cooperative International Neuromuscular Research Group (CINRG) Duchenne Natural History Study (DNHS), DMD genotype-phenotype/-ataluren benefit correlations and ataluren safety. Patients & methods: Propensity score matching was performed to identify STRIDE and CINRG DNHS patients who were comparable in established disease progression predictors (registry cut-off date, 9 July 2018). Results & conclusion: Kaplan-Meier analyses demonstrated that ataluren + SoC significantly delayed age at loss of ambulation and age at worsening performance in timed function tests versus SoC alone (p ≤ 0.05). There were no DMD genotype-phenotype/ataluren benefit correlations. Ataluren was well tolerated. These results indicate that ataluren + SoC delays functional milestones of DMD progression in patients with nmDMD in routine clinical practice. ClinicalTrials.gov identifier: NCT02369731. ClinicalTrials.gov identifier: NCT02369731.

Premature termination codons (PTCs) account for ~12% of all human disease mutations. Translation readthrough-inducing drugs (TRIDs) are prominent among the several therapeutic approaches being used to overcome PTCs. Ataluren is the only TRID that has been approved for treating patients suffering from a PTC disease, Duchenne muscular dystrophy, but it gives variable readthrough results in cells isolated from patients suffering from other PTC diseases. We recently elucidated ataluren's mechanism of action as a competitive inhibitor of release factor complex (RFC) catalysis of premature termination and identified ataluren's binding sites on the ribosome responsible for such an inhibition. These results suggest the possibility of discovering new TRIDs, which would retain ataluren's low toxicity while displaying greater potency and generality in stimulating readthrough via the inhibition of termination. Here we present a detailed description of a new in vitro plate reader assay that we are using both to screen small compound libraries for the inhibition of RFC-dependent peptide release and to better understand the influence of termination codon identity and sequence context on RFC activity. [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 1 (NF1) is a human genetic disorder caused by variants in the NF1 gene. Plexiform neurofibromas, one of many NF1 manifestations, are benign peripheral nerve sheath tumors occurring in up to 50% of NF1 patients. A substantial fraction of NF1 pathogenetic variants are nonsense mutations, which result in the synthesis of truncated non-functional NF1 protein (neurofibromin). To date, no therapeutics have restored neurofibromin expression or addressed the consequences of this protein's absence in NF1 nonsense mutation patients, but nonsense suppression is a potential approach to the problem. Ataluren is a small molecule drug that has been shown to stimulate functional nonsense codon readthrough in several models of nonsense mutation diseases, as well as in Duchenne muscular dystrophy patients. To test ataluren's potential applicability in nonsense mutation NF1 patients, we evaluated its therapeutic effects using three treatment regimens in a previously established NF1 patient-derived (c.2041C > T; p.Arg681X) nonsense mutation mouse model. Collectively, our experiments indicate that: i) ataluren appeared to slow the growth of neurofibromas and alleviate some paralysis phenotypes, ii) female Nf1 -nonsense mutation mice manifested more severe paralysis and neurofibroma phenotypes than male mice, iii) ataluren doses with apparent effectiveness were lower in female mice than in male mice, and iv) age factors also influenced ataluren's effectiveness. • Ataluren slowed neurofibroma development in an Nf1- nonsense mutation mouse model. • Phenotypic severity differed between female and male Nf1 -nonsense mutation mice. • Effective ataluren doses differed for female and male mice. • Age factors influenced ataluren's efficacy. [ABSTRACT FROM AUTHOR]

Objectives: Duchenne Muscular Dystrophy (DMD) is a severe, progressive, X-linked disorder resulting in muscle wasting, progressive functional loss and cardiomyopathy. Therapeutic strategies feature glucocorticoid corticosteroids plus gene therapy/stop codon read-through, plus standards of care. Prolonged survival, delayed loss of ambulation (LoA), and innovative treatment prescriptions pose new clinical challenges, including identification of new outcome measures/targets and implementation of continuity of care., Methods: We report on the results of an Italian experts' meeting held in Rome, Italy on 20 th April 2022. We aimed to: discuss challenges linked to transitioning from the ambulatory to the non-ambulatory phase, and from pediatric to adult care; collect experience on the importance of ongoing care and treatment in advanced disease stages and on the need to measure clinically relevant outcomes during disease progression after LoA., Results: Following LoA the main management focus shifts to cardiac, respiratory, orthopaedics, nutrition and upper limbs function. More data on clinical needs, available treatments, standards of care, frequency of follow-up, and transition should be collected in order to facilitate management optimisation. Shared protocols should be developed, especially to improve patients' management in the acute setting., Conclusions: Transition from paediatric to adult services and from the ambulatory to the non-ambulatory phase require a multidisciplinary approach and the Identification of clinically meaningful outcome measures, which should be described in long-term longitudinal studies., (Copyright © 2024 Gaetano Conte Academy - Mediterranean Society of Myology.)

Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are neuromuscular disorders that affect muscular function. The most common causes of morbidity and mortality are respiratory complications, including restrictive lung disease, ineffective cough, and sleep-disordered breathing. The paradigm of care is changing as new disease-modifying therapies are altering disease trajectory, outcomes, expectations, as well as patient and caregiver experiences. This article provides an overview on therapeutic advances for SMA and DMD in the last 10 years, with a focus on the effects of disease-modifying therapies on respiratory function., Competing Interests: Disclosure Dr R. Amin is a committee member of the American College of Chest Physicians and a pediatrics committee member of the American Thoracic Society. R. Amin holds research grants from Canadian Institutes of Health Research, Canada, Cure SMA Canada, Canada, Muscular Dystrophy Canada, Canada, VHA Home Healthcare, Canada, Boehringer-Ingelheim, Germany, Medigas, Canada, ProResp, Canada, Baxter Corporation Endowment Fund for Home Care, United States, and Ontario Ministry of Health and Long-Term Care, Canada. Dr L. Xiao is a committee member of the American College of Chest Physicians. Dr. Xiao holds research grants from Muscular Dystrophy Canada, Baxter Corporation Endowment Fund for Home Care, International Pediatric Sleep Association, United States, and the Sleep Research Society Foundation, United States., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Abstarct: Suppressing translation termination at premature termination codons (PTCs), termed readthrough, is a potential therapy for genetic diseases caused by nonsense mutations. Ataluren is a compound that has shown promise for clinical use as a readthrough agent. However, some reports suggest that ataluren is ineffective at suppressing PTCs. To further evaluate the effectiveness of ataluren as a readthrough agent, we examined its ability to suppress PTCs in a variety of previously untested models. Using NanoLuc readthrough reporters expressed in two different cell types, we found that ataluren stimulated a significant level of readthrough. We also explored the ability of ataluren to suppress a nonsense mutation associated with Mucopolysaccharidosis I-Hurler (MPS I-H), a genetic disease that is caused by a deficiency of α-L-iduronidase that leads to lysosomal accumulation of glycosaminoglycans (GAGs). Using mouse embryonic fibroblasts (MEFs) derived from Idua-W402X mice, we found that ataluren partially rescued α-L-iduronidase function and significantly reduced GAG accumulation relative to controls. Two-week oral administration of ataluren to Idua-W402X mice led to significant GAG reductions in most tissues compared to controls. Together, these data reveal important details concerning the efficiency of ataluren as a readthrough agent and the mechanisms that govern its ability to suppress PTCs. Key messages: Ataluren promotes readthrough of PTCs in a wide variety of contexts. Ataluren reduces glycosaminoglyan storage in MPS I-H cell and mouse models. Ataluren has a bell-shaped dose–response curve and a narrow effective range. [ABSTRACT FROM AUTHOR]

Abstract Background Duchenne muscular dystrophy is a rare genetic neuromuscular disorder, which can result in early death due to disease progression. Ataluren is indicated for the treatment of nonsense mutation Duchenne muscular dystrophy, in ambulatory individuals aged two years and older. This study explored the impact of caring for an ambulatory individual with nonsense mutation Duchenne muscular dystrophy, as well as the impact of treatment with ataluren on the caregiver experience, using retrospective recall. Methods Qualitative interviews were conducted with caregivers in the UK. Interviews were conducted by telephone, were recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded. Results Ten interviews were conducted with parents of individuals aged 4–19 years. Caregivers reported proximal impacts (physical, emotional, time-related), and distal impacts (work, relationships, social life) of caring for their sons. The relationships between these impacts were illustrated in a conceptual model. Changes to the caregiver experience since initiation with their son’s treatment were discussed. Conclusion Caring for an ambulatory individual with nonsense mutation Duchenne muscular dystrophy has a substantial multifaceted impact on caregivers. Treatments which have the potential to improve symptoms or delay progression, may also have a positive impact on the quality of life of caregivers.

Abstract Background Duchenne muscular dystrophy is a rare genetic neuromuscular disorder, which can result in early death due to disease progression. Ataluren is indicated for the treatment of nonsense mutation Duchenne muscular dystrophy, in ambulatory individuals aged two years and older. This study explored the symptoms and impacts of nonsense mutation Duchenne muscular dystrophy and experience with ataluren. Methods Qualitative interviews were conducted with caregivers in the UK. Interviews were conducted by telephone, were recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded. Results Ten interviews were conducted with parents of individuals aged 4–19 years. Key symptoms included muscle weakness and muscle breakdown, which were associated with limitations in physical function and pain. These impacted individuals’ daily activities, social activities and emotional wellbeing. These concepts and relationships were illustrated in a conceptual model, along with positive and negative moderating factors. Experience with ataluren and changes since initiation with treatment were discussed. Conclusion Individuals with nonsense mutation Duchenne muscular dystrophy experience a range of interrelated symptoms and functional issues which impact their broader health-related quality of life. Treatments which address this high unmet need have the potential to improve the health-related quality of life of these individuals.

Biallelic mutations in the dysferlin gene cause limb-girdle muscular dystrophy 2B or Miyoshi distal myopathy. We found that nonsense mutations are the most common mutation type among Korean patients with dysferlinopathy; more than half of the patients have at least one nonsense allele, which may be amenable to readthrough therapy. We generated a knockin mouse, dqx, harboring DYSF p.Q832∗ mutation. Homozygous dqx mice lacked dysferlin in skeletal muscle, while 2 weeks of oral ataluren restored dysferlin expression and ameliorated skeletal muscle pathology. Their physical performance improved, and protection against eccentric contractions was noted. The improvement was most evident in mice treated with oral ataluren of 0.9 mg/mL. These improvements were sustained for 8 weeks in ataluren-treated dqx mice, while the parameters of A/J mice treated with ataluren over the same period did not improve. These results support that readthrough therapy by oral ataluren may also be applicable to dysferlinopathy patients with nonsense mutation.

Въведение: ПМД тип Дюшен е Х-свързано рядко генетично заболяване, чиито клинични прояви започват преди 3-годишна възраст с предимно проксимална мускулна слабост, с промяна в походката, затруднено изкачване на стълби и изправяне от клекнало положение. Болните губят самостоятелна походка преди 13-годишна възраст. Въвеждането на стандарти на грижи и нови етиопатогенетични терапевтични възможности променят естествения ход на заболяването и подобряват качеството на живот на болните. Цел: Да се оцени ефекта на Аtaluren по отношение на двигателните и дихателните функции при четири пациента с ДМД с доказани безсмислени мутации, лекувани и проследявани в Експертния център по наследствени неврологични и метаболитни заболявания, Клиника по нервни болести, УМБАЛ „Александровска”, както и да се представят критериите и резултатите от скриниговата програма за ранна диагностика на момчета с ПМД тип Дюшен. Материал и методи: В изследването са включени 4 пациента с доказани безсмислени мутация в DMD-гена, при които е проведено лечение с Аtaluren за период от 6 мес. до 3 г., като са проследени моторните им функции чрез използване на тестовете 6 minutes walking test (6MWT) и Gowers sign и дихателните функции чрез функционално изследване на дишането (ФИД). Резултати: При пациентите, при които лечението е започнато по-късно (11-годишна възраст) е налице стабилизиране на оценките от 6MWT и Gowers sign, докато при тези с по-ранно иницииране на лечението се установява продобрение на моторните и дихателни функции в рамките на периода на проследяване. Заключение: Своевременната диагноза и лечение са свързани с по-добри резултати при болните, което се опосредства и от въвеждането на селективни скринингови програми сред високорискови популации.

Abstract Background 1,2,4-oxadiazole derivatives exhibited significant anti-cancer activity when they were evaluated, against human cancer cell lines. They also showed anti-inflammatory, analgesic, diabetic, immunosuppressive, α,β3-receptor antagonist, antimicrobial, anti-helminthic, histamine-H3 and antiparasitic properties. A pyrimidine analog, 5 fluoro-uracil is a chemotherapeutic drug used for treating multiple solid malignant tumors. But its application is limited, as it has side effects like low bioavailability and high toxicity. Molecular docking is an exemplary tool, helps in identifying target and designing a drug containing high bio-availability and minimum toxicity. Results A set of 1,2,4-oxadiazole linked 5-fluoruracil derivatives (7a–j) were synthesized and their structures were confirmed by 1HNMR, 13CNMR and Mass spectral analysis. Further, these compounds were investigated for their anticancer activity towards a panel of four human cancer cell lines such as (MCF-7, MDA MB-231), lung cancer (A549) and prostate cancer (DU-145) by using MTT method. Among them, compounds 7a, 7b, 7c, 7d and 7i demonstrated more promising anticancer activity than standard. Conclusion Synthesized derivatives (7a–j) of 1,2,4-oxadiazole linked 5-fluorouracil and investigated for their anticancer activity towards a panel of four human cancer cell lines.

Ataluren and Gentamicin are translational readthrough drugs (TRIDs) that induce premature termination codon (PTC) readthrough, resulting in the production of full-length proteins that usually harbor a single missense substitution. FAM161A is a ciliary protein which is expressed in photoreceptors, and pathogenic variants in this gene cause retinitis pigmentosa (RP). Applying TRIDs on fibroblasts from RP patients due to PTC in the FAM161A (p.Arg523*) gene may uncover whether TRIDs can restore expression, localization and function of this protein. Fibroblasts from six patients and five age-matched controls were starved prior to treatment with ataluren or gentamicin, and later FAM161A expression, ciliogenesis and cilia length were analyzed. In contrast to control cells, fibroblasts of patients did not express the FAM161A protein, showed a lower percentage of ciliated cells and grew shorter cilia after starvation. Ataluren and Gentamicin treatment were able to restore FAM161A expression, localization and co-localization with α-tubulin. Ciliogenesis and cilia length were restored following Ataluren treatment almost up to a level which was observed in control cells. Gentamicin was less efficient in ciliogenesis compared to Ataluren. Our results provide a proof-of-concept that PTCs in FAM161A can be effectively suppressed by Ataluren or Gentamicin, resulting in a full-length functional protein. [ABSTRACT FROM AUTHOR]

Shwachman-Diamond syndrome (SDS) is one of the most commonly inherited bone marrow failure syndromes (IBMFS). In SDS, bone marrow is hypocellular, with marked neutropenia. Moreover, SDS patients have a high risk of developing myelodysplastic syndrome (MDS), which in turn increases the risk of acute myeloid leukemia (AML) from an early age. Most SDS patients are heterozygous for the c.183-184TA>CT (K62X) SBDS nonsense mutation. Fortunately, a plethora of translational read-through inducing drugs (TRIDs) have been developed and tested for several rare inherited diseases due to nonsense mutations so far. The authors previously demonstrated that ataluren (PTC124) can restore full-length SBDS protein expression in bone marrow stem cells isolated from SDS patients carrying the nonsense mutation K62X. In this study, the authors evaluated the effect of a panel of ataluren analogues in restoring SBDS protein resynthesis and function both in hematological and non-hematological SDS cells. Besides confirming that ataluren can efficiently induce SBDS protein re-expression in SDS cells, the authors found that another analogue, namely NV848, can restore full-length SBDS protein synthesis as well, showing very low toxicity in zebrafish. Furthermore, NV848 can improve myeloid differentiation in bone marrow hematopoietic progenitors, enhancing neutrophil maturation and reducing the number of dysplastic granulocytes in vitro. Therefore, these findings broaden the possibilities of developing novel therapeutic options in terms of nonsense mutation suppression for SDS. Eventually, this study may act as a proof of concept for the development of similar approaches for other IBMFS caused by nonsense mutations. [ABSTRACT FROM AUTHOR]

The objective of this study was to apply molecular docking and molecular dynamics (MDs) simulation approaches to investigate the host–guest interactions between natural Cyclodextrins (CDs) (Alpha, Beta and Gamma Cyclodextrins) and some modified CDs (hydroxypropyl, sulfobutylether and randomly substituted methyl Beta Cyclodextrins) with Ataluren as a small molecule drug designed for diseases attributable to a nonsense mutation. Molecular docking results presented that randomly substituted methyl beta Cyclodextrin (RMBCD) has the highest binding affinity and Alpha Cyclodextrin (ACD) has the lowest binding affinity to Ataluren. According to the MDs simulation results, ACD and hydroxypropyl Cyclodextrin have not proper cavity for encapsulation of Ataluren. In contrast, Ataluren was totally included into the Beta Cyclodextrin (BCD), Gamma Cyclodextrin, sulfobutylether Beta Cyclodextrin (SBECD) and RMBCD due to appropriate interior capability. Moreover, MDs results showed that SBECD has the most conformational flexibility and BCD has the most conformational stability during simulation time. The results of this paper may open new paths to use this formulation for further researches in the delivery mechanism of hydrophobic pharmaceutical molecules. [ABSTRACT FROM AUTHOR]

Premature termination codons (PTCs) account for ~12% of all human disease mutations. Translation readthrough-inducing drugs (TRIDs) are prominent among the several therapeutic approaches being used to overcome PTCs. Ataluren is the only TRID that has been approved for treating patients suffering from a PTC disease, Duchenne muscular dystrophy, but it gives variable readthrough results in cells isolated from patients suffering from other PTC diseases. We recently elucidated ataluren’s mechanism of action as a competitive inhibitor of release factor complex (RFC) catalysis of premature termination and identified ataluren’s binding sites on the ribosome responsible for such an inhibition. These results suggest the possibility of discovering new TRIDs, which would retain ataluren’s low toxicity while displaying greater potency and generality in stimulating readthrough via the inhibition of termination. Here we present a detailed description of a new in vitro plate reader assay that we are using both to screen small compound libraries for the inhibition of RFC-dependent peptide release and to better understand the influence of termination codon identity and sequence context on RFC activity.

Copyright of Neurologie Pro Praxi is the property of SOLEN sro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Ciliary dysfunction underlies a range of genetic disorders collectively termed ciliopathies, for which there are no treatments available. Bardet-Biedl syndrome (BBS) is characterised by multisystemic involvement, including rod-cone dystrophy and renal abnormalities. Together with Alström syndrome (AS), they are known as the ‘obesity ciliopathies’ due to their common phenotype. Nonsense mutations are responsible for approximately 11% and 40% of BBS and AS cases, respectively. Translational readthrough inducing drugs (TRIDs) can restore full-length protein bypassing in-frame premature termination codons, and are a potential therapeutic approach for nonsense-mediated ciliopathies. Methods: Patient fibroblasts harbouring nonsense mutations from two different ciliopathies (Bardet-Biedl Syndrome and Alström Syndrome) were treated with PTC124 (ataluren) or amlexanox. Following treatment, gene expression, protein levels and ciliogenesis were evaluated. The expression of intraflagellar transport protein IFT88 and G-protein coupled receptor SSTR3 was investigated as a readout of ciliary function. Findings: mRNA expression was significantly increased in amlexanox-treated patient fibroblasts, and full-length BBS2 or ALMS1 protein expression was restored in PTC124- and amlexanox-treated fibroblasts. Treatment with TRIDs significantly improved ciliogenesis defects in BBS2Y24*/R275* fibroblasts. Treatment recovered IFT88 expression and corrected SSTR3 mislocalisation in BBS2Y24*/R275* and ALMS1S1645*/S1645* fibroblasts, suggesting rescue of ciliary function. Interpretation: The recovery of full-length BBS2 and ALMS1 expression and correction of anatomical and functional ciliary defects in BBS2Y24*/R275* and ALMS1S1645*/S1645* fibroblasts suggest TRIDs are a potential therapeutic option for the treatment of nonsense-mediated ciliopathies.

Background: Duchenne muscular dystrophy is a rare genetic neuromuscular disorder, which can result in early death due to disease progression. Ataluren is indicated for the treatment of nonsense mutation Duchenne muscular dystrophy, in ambulatory individuals aged two years and older. This study explored the symptoms and impacts of nonsense mutation Duchenne muscular dystrophy and experience with ataluren. Methods: Qualitative interviews were conducted with caregivers in the UK. Interviews were conducted by telephone, were recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded. Results: Ten interviews were conducted with parents of individuals aged 4–19 years. Key symptoms included muscle weakness and muscle breakdown, which were associated with limitations in physical function and pain. These impacted individuals' daily activities, social activities and emotional wellbeing. These concepts and relationships were illustrated in a conceptual model, along with positive and negative moderating factors. Experience with ataluren and changes since initiation with treatment were discussed. Conclusion: Individuals with nonsense mutation Duchenne muscular dystrophy experience a range of interrelated symptoms and functional issues which impact their broader health-related quality of life. Treatments which address this high unmet need have the potential to improve the health-related quality of life of these individuals. [ABSTRACT FROM AUTHOR]

Background: Duchenne muscular dystrophy is a rare genetic neuromuscular disorder, which can result in early death due to disease progression. Ataluren is indicated for the treatment of nonsense mutation Duchenne muscular dystrophy, in ambulatory individuals aged two years and older. This study explored the impact of caring for an ambulatory individual with nonsense mutation Duchenne muscular dystrophy, as well as the impact of treatment with ataluren on the caregiver experience, using retrospective recall. Methods: Qualitative interviews were conducted with caregivers in the UK. Interviews were conducted by telephone, were recorded and transcribed. Data were analysed using thematic analysis and saturation was recorded. Results: Ten interviews were conducted with parents of individuals aged 4–19 years. Caregivers reported proximal impacts (physical, emotional, time-related), and distal impacts (work, relationships, social life) of caring for their sons. The relationships between these impacts were illustrated in a conceptual model. Changes to the caregiver experience since initiation with their son's treatment were discussed. Conclusion: Caring for an ambulatory individual with nonsense mutation Duchenne muscular dystrophy has a substantial multifaceted impact on caregivers. Treatments which have the potential to improve symptoms or delay progression, may also have a positive impact on the quality of life of caregivers. [ABSTRACT FROM AUTHOR]

Background: 1,2,4-oxadiazole derivatives exhibited significant anti-cancer activity when they were evaluated, against human cancer cell lines. They also showed anti-inflammatory, analgesic, diabetic, immunosuppressive, α,β3-receptor antagonist, antimicrobial, anti-helminthic, histamine-H3 and antiparasitic properties. A pyrimidine analog, 5 fluoro-uracil is a chemotherapeutic drug used for treating multiple solid malignant tumors. But its application is limited, as it has side effects like low bioavailability and high toxicity. Molecular docking is an exemplary tool, helps in identifying target and designing a drug containing high bio-availability and minimum toxicity. Results: A set of 1,2,4-oxadiazole linked 5-fluoruracil derivatives (7a–j) were synthesized and their structures were confirmed by 1HNMR, 13CNMR and Mass spectral analysis. Further, these compounds were investigated for their anticancer activity towards a panel of four human cancer cell lines such as (MCF-7, MDA MB-231), lung cancer (A549) and prostate cancer (DU-145) by using MTT method. Among them, compounds 7a, 7b, 7c, 7d and 7i demonstrated more promising anticancer activity than standard. Conclusion: Synthesized derivatives (7a–j) of 1,2,4-oxadiazole linked 5-fluorouracil and investigated for their anticancer activity towards a panel of four human cancer cell lines. [ABSTRACT FROM AUTHOR]

Background: Duchenne muscular dystrophy (DMD) is the most frequent genetic neuromuscular disease in childhood with loss of ambulation usually occurring around the age of 9–11 years. Objective, material and methods: Based on current guidelines and clinical trials, neuropediatric and neurological experts developed recommendations for the treatment of nonambulatory DMD patients focusing on drug treatment of adults. This advisory board was sponsored by PTC Therapeutics, the distributers of the substance ataluren. Results and conclusion: Loss of ambulation is heterogeneously defined across clinical trials. Among others, the need of a wheelchair, ambulation without mobility aids or maximum walking distance can be suitable parameters for assessment. Treatment of DMD patients at any stage of the disease is based on supportive and symptomatic measures, which should be continued after loss of ambulation. In addition, disease-modifying drugs are available for the treatment of DMD and glucocorticoids are the usual standard of care treatment even beyond the loss of ambulation. Ataluren, a potentially dystrophin restorative, disease-modifying treatment, has been approved for patients with DMD due to a nonsense mutation (nmDMD), which applies to approximately 13% of DMD patients and is usually combined with steroids. Clinical data from the STRIDE registry demonstrated a delayed disease progression even after loss of ambulation. Currently, no reliable data are available for exon skipping approaches in adult DMD patients. The antioxidant idebenone could be an option in nonambulant adolescent patients not treated with glucocorticoids and without other therapeutic options. A combination treatment of idebenone and glucocorticoids is currently being investigated in a clinical trial. Add-on treatment with idebenone in addition to ataluren may be considered for nonambulant nmDMD patients. Some of the discussed treatment options are still in clinical trials or there are not enough data for older DMD patients; therefore, these expert recommendations correspond to evidence class IV. [ABSTRACT FROM AUTHOR]

Shwachman-Diamond syndrome (SDS) is one of the most commonly inherited bone marrow failure syndromes (IBMFS). In SDS, bone marrow is hypocellular, with marked neutropenia. Moreover, SDS patients have a high risk of developing myelodysplastic syndrome (MDS), which in turn increases the risk of acute myeloid leukemia (AML) from an early age. Most SDS patients are heterozygous for the c.183-184TA>CT (K62X) SBDS nonsense mutation. Fortunately, a plethora of translational read-through inducing drugs (TRIDs) have been developed and tested for several rare inherited diseases due to nonsense mutations so far. The authors previously demonstrated that ataluren (PTC124) can restore full-length SBDS protein expression in bone marrow stem cells isolated from SDS patients carrying the nonsense mutation K62X. In this study, the authors evaluated the effect of a panel of ataluren analogues in restoring SBDS protein resynthesis and function both in hematological and non-hematological SDS cells. Besides confirming that ataluren can efficiently induce SBDS protein re-expression in SDS cells, the authors found that another analogue, namely NV848, can restore full-length SBDS protein synthesis as well, showing very low toxicity in zebrafish. Furthermore, NV848 can improve myeloid differentiation in bone marrow hematopoietic progenitors, enhancing neutrophil maturation and reducing the number of dysplastic granulocytes in vitro. Therefore, these findings broaden the possibilities of developing novel therapeutic options in terms of nonsense mutation suppression for SDS. Eventually, this study may act as a proof of concept for the development of similar approaches for other IBMFS caused by nonsense mutations.

Ataluren and Gentamicin are translational readthrough drugs (TRIDs) that induce premature termination codon (PTC) readthrough, resulting in the production of full-length proteins that usually harbor a single missense substitution. FAM161A is a ciliary protein which is expressed in photoreceptors, and pathogenic variants in this gene cause retinitis pigmentosa (RP). Applying TRIDs on fibroblasts from RP patients due to PTC in the FAM161A (p.Arg523*) gene may uncover whether TRIDs can restore expression, localization and function of this protein. Fibroblasts from six patients and five age-matched controls were starved prior to treatment with ataluren or gentamicin, and later FAM161A expression, ciliogenesis and cilia length were analyzed. In contrast to control cells, fibroblasts of patients did not express the FAM161A protein, showed a lower percentage of ciliated cells and grew shorter cilia after starvation. Ataluren and Gentamicin treatment were able to restore FAM161A expression, localization and co-localization with α-tubulin. Ciliogenesis and cilia length were restored following Ataluren treatment almost up to a level which was observed in control cells. Gentamicin was less efficient in ciliogenesis compared to Ataluren. Our results provide a proof-of-concept that PTCs in FAM161A can be effectively suppressed by Ataluren or Gentamicin, resulting in a full-length functional protein.

The aim of the study was to assess timely recognition of clinical characteristics and implementation of a multidisciplinary approach according to the latest guidelines, and to analyse clinical course in patients on gene therapy. The research was designed as a crosssectional and retrospective study. Patients with dystrophinopathies and their contacts were singled out by retrospective analysis of medical documentation. Data on current age, age at diagnosis, type of mutations, methods of confirming the diagnosis, clinical picture and therapy administered were extracted. Nine subjects were included in the study, eight with the diagnosis of Duchenne muscular dystrophy (DMD) and one with the diagnosis of Becker muscular dystrophy (BDM). The age at diagnosis of DMD ranged between two and six and a half years, while in the subject with BMD it was set at the age of eleven. Considering types of mutations, four patients had deletions, three of them duplications and two of them point mutations. Six subjects were mobile independently, while three subjects were dependent on wheelchair use. Pulmonary function was normal in seven subjects, while two developed chronic pulmonary insufficiency and used non-invasive ventilation methods. Six subjects were on glucocorticoid therapy and all were using deflazacort. In conclusion, patients with DMD, in addition to basic progressive muscle weakness, also develop complications of other organ systems, which requires multidisciplinary care. The advent of gene therapy as a causal therapy for DMD has placed additional emphasis on diagnosing the disease as early as possible. This achieves an additional prolongation of life expectancy and increase in the quality of life in patients with DMD. [ABSTRACT FROM AUTHOR]

Ataluren was developed for potential treatment of nonsense-mutation cystic fibrosis (CF). A previous phase 3 ataluren study failed to meet its primary efficacy endpoint, but post-hoc analyses suggested that aminoglycosides may have interfered with ataluren's action. Thus, this subsequent trial (NCT02139306) was designed to assess the efficacy and safety of ataluren in patients with nonsense-mutation CF not receiving aminoglycosides. Eligible subjects with nonsense-mutation CF (aged ≥6 years; percent predicted (pp) FEV 1 ≥40 and ≤90) from 75 sites in 16 countries were randomly assigned in double-blinded fashion to receive oral ataluren or matching placebo thrice daily for 48 weeks. The primary endpoint was absolute change in average ppFEV 1 from baseline to the average of Weeks 40 and 48. 279 subjects were enrolled; 138 subjects in the ataluren arm and 136 in the placebo arm were evaluable for efficacy. Absolute ppFEV 1 change from baseline did not differ significantly between the ataluren and placebo groups at Week 40 (–0.8 vs –1.8) or Week 48 (–1.7 vs –2.4). Average ppFEV 1 treatment difference from baseline to Weeks 40 and 48 was 0.6 (95% CI –1.3, 2.5; p = 0.54). Pulmonary exacerbation rate per 48 weeks was not significantly different (ataluren 0.95 vs placebo 1.13; rate ratio p = 0.40). Safety was similar between groups. No life-threatening adverse events or deaths were reported. Neither ppFEV 1 change nor pulmonary exacerbation rate over 48 weeks were statistically different between ataluren and placebo groups. Development of a nonsense-mutation CF therapy remains elusive. [ABSTRACT FROM AUTHOR]

Duchenne muscular dystrophy is a severe muscle wasting disease caused by mutations in the dystrophin gene (dmd). Ataluren has been approved by the European Medicines Agency for treatment of Duchenne muscular dystrophy. Ataluren has been reported to promote ribosomal read‐through of premature stop codons, leading to restoration of full‐length dystrophin protein. However, the mechanism of Ataluren action has not been fully described. To evaluate the efficacy of Ataluren on all three premature stop codons featuring different termination strengths (UAA > UAG > UGA), novel dystrophin‐deficient zebrafish were generated. Pathological assessment of the muscle by birefringence quantification, a tool to directly measure muscle integrity, did not reveal a significant effect of Ataluren on any of the analysed dystrophin‐deficient mutants at 3 days after fertilization. Functional analysis of the musculature at 6 days after fertilization by direct measurement of the generated force revealed a significant improvement by Ataluren only for the UAA‐carrying mutant dmdta222a. Interestingly however, all other analysed dystrophin‐deficient mutants were not affected by Ataluren, including the dmdpc3 and dmdpc2 mutants that harbour weaker premature stop codons UAG and UGA, respectively. These in vivo results contradict reported in vitro data on Ataluren efficacy, suggesting that Ataluren might not promote read‐through of premature stop codons. In addition, Ataluren had no effect on dystrophin transcript levels, but mild adverse effects on wild‐type larvae were identified. Further assessment of N‐terminally truncated dystrophin opened the possibility of Ataluren promoting alternative translation codons within dystrophin, thereby potentially shifting the patient cohort applicable for Ataluren. [ABSTRACT FROM AUTHOR]

Around 12% of hereditary disease-causing mutations are in-frame nonsense mutations. The expression of genes containing nonsense mutations potentially leads to the production of truncated proteins with residual or virtually no function. However, the translation of transcripts containing premature stop codons resulting in full-length protein expression can be achieved using readthrough agents. Among them, only ataluren was approved in several countries to treat nonsense mutation Duchenne muscular dystrophy (DMD) patients. This review summarizes ataluren’s journey from its identification, via first in vitro activity experiments, to clinical trials in DMD, cystic fibrosis, and aniridia. Additionally, data on its pharmacokinetics and mechanism of action are presented. The range of diseases with underlying nonsense mutations is described for which ataluren therapy seems to be promising. What is more, experiments in which ataluren did not show its readthrough activity are also included, and reasons for their failures are discussed.

Nonsense mutations leading to premature stop codons are common occurring in approximately 12% of all human genetic diseases. Thus, pharmacological nonsense mutation suppression strategies would be beneficial to a large number of patients if the drugs could be targeted to the affected tissues at the appropriate time. Here, we used nonsense suppression to manipulate Pax6 dosage at different developmental times in the eye of the small eye (Pax6Sey/+; G194X) mouse model of aniridia. Efficacy was assessed by functional assays for visual capacity, including electroretinography and optokinetic tracking (OKT), in addition to histological and biochemical studies. Malformation defects in the Pax6Sey/+ postnatal eye responded to topically delivered nonsense suppression in a dose- and time-dependent manner. Elevated levels of Mmp9, a direct downstream target of Pax6 in the cornea, were observed with the different treatment regimens. The lens capsule was particularly sensitive to Pax6 dosage, revealing a potential new role for Pax6 in lens capsule maintenance and development. The remarkable capacity of malformed ocular tissue to respond postnatally to Pax6 dosage in vivo demonstrates that the use of nonsense suppression could be a valuable therapeutic approach for blinding diseases caused by nonsense mutations.

Duchenne muscular dystrophy (DMD) is a devastating X-linked neuromuscular disorder caused by dystrophin gene deletions (75%), duplications (15-20%) and point mutations (5-10%), a small portion of which are nonsense mutations. Women carrying dystrophin gene mutations are commonly unaffected because the wild X allele may produce a sufficient amount of the dystrophin protein. However, approximately 8-10% of them may experience muscle symptoms and 50% of those over 40 years develop cardiomyopathy. The presence of symptoms defines the individual as an affected " symptomatic or manifesting carrier". Though there is no effective cure for DMD, therapies are available to slow the decline of muscle strength and delay the onset and progression of cardiac and respiratory impairment. These include ataluren for patients with nonsense mutations, and antisense oligonucleotides therapies, for patients with specific deletions. Symptomatic DMD female carriers are not included in these indications and little data documenting their management, often entrusted to the discretion of individual doctors, is present in the literature. In this article, we report the clinical and instrumental outcomes of four symptomatic DMD carriers, aged between 26 and 45 years, who were treated with ataluren for 21 to 73 months (average 47.3), and annually evaluated for muscle strength, respiratory and cardiological function. Two patients retain independent ambulation at ages 33 and 45, respectively. None of them developed respiratory involvement or cardiomyopathy. No clinical adverse effects or relevant abnormalities in routine laboratory values, were observed., Competing Interests: The Authors have no conflicts of interest to declare that are relevant to the content of this article., (©2024 Gaetano Conte Academy - Mediterranean Society of Myology, Naples, Italy.)

Duchenne Muscular Dystrophy (DMD) includes predictable phases requiring dedicated standard treatments. Therapeutic strategies feature corticosteroids or the more recent gene therapy/stop codon read-through. Ataluren (Translarna ® ) is an oral drug promoting the readthrough of premature stop codons caused by nonsense mutation (nm) in order to produce full-length dystrophin. It was licensed by EMA in 2014 for ambulatory patients with nmDMD aged ≥ 5 years. Our aim is to report data on long-term ataluren use in Italian patients with nmDMD, with emphasis on continuity of the treatment after loss of ambulation (LoA). Four DMD patients aged between 16 and 24 years who lost ambulation between 12 and 14 years continued to take ataluren after LoA. The oldest patient, aged 24 years, is still taking a few steps. Even in those experiencing motor decline, PUL-test performances were stable and respiratory function satisfactory in all; two patients developed severe cardiomyopathy, stable in one. Therapeutic continuity with ataluren should be offered to all nmDMD patients after LoA given its favourable safety and efficacy profile. However, further research is recommended to identify additional clinically meaningful outcomes and treatment goals following LoA., Competing Interests: Luca Bello reports honoraria (speaker, consultancy) for PTC Therapeutics, Sarepta Therapeutics, Epirium Bio, Edgewise Therapeutics; research funding from PTC Therapeutics, Santhera Pharmaceuticals. Carlotta Spagnoli, Rachele Adorisio, Adele D’Amico, Maria Grazia D’Angelo, Marika Pane, Valeria Sansone, Andrea Vianello, and Carlo Fusco report no conflicts of interest to disclose., (©2023 Gaetano Conte Academy - Mediterranean Society of Myology, Naples, Italy.)

A series of novel 1,2,4-thiadiazole derivatives bearing 1,2,4-oxadiazole is synthesized. Structures of the synthesized compounds are confirmed by 1H and 13C NMR, and mass spectra. All products are evaluated for their anticancer activity towards human cancer cell lines: MCF-7 (breast), A549 (lung), Colo-205 (colon), and A2780 (ovarian), and demonstrate good to moderate anticancer activity. Four synthesized compounds are characterised by potent activity. [ABSTRACT FROM AUTHOR]

This is the second part of a two-part document intended to discuss recent therapeutic progresses in genetic neuromuscular disorders. The present review is for diseases of motor neuron and skeletal muscle, some of which reached recently the most innovative therapeutic approaches. Nusinersen, an SMN2 mRNA splicing modifier, was approved as first-ever therapy of spinal muscular atrophy (SMA) by FDA in 2016 and by EMA in 2017. The orally administered small-molecule risdiplam, which increases SMN protein levels similarly but also in peripheral organs, is tested in ongoing phase 2 and 3 trials. After positive results with phase 1 treatment with AAV9-SMN, the first gene therapy for SMA, a phase 3 clinical trial is ongoing. Ataluren is the first approved drug for Duchenne muscular dystrophy (DMD) patients with premature stop codon mutations and its indication has been recently extended since the age of 2 years. Exon skipping technology was and is currently tested in many phase 3 trials, and eteplirsen received a conditional approval by FDA for patients amenable to exon 51 skipping, but not by EMA. Many other compounds with different mechanisms of action are now tested in DMD by phase 2 and 3 trials, including phase 1 gene therapy. Other innovative approaches are under investigation, i.e., gene therapy in X-linked myotubular myopathy and Pompe disease, and antisense oligonucleotides in myotonic dystrophy type 1. Positive evidences are discussed about lamotrigine and ranolazine in non-dystrophic myotonias, chaperons in Pompe disease, and nucleosides in mitochondrial DNA depletion induced by thymidine kinase 2 deficiency. [ABSTRACT FROM AUTHOR]

To evaluate the potential for ethnicity‐related differences in ataluren pharmacokinetics (PK) and safety, a phase 1 single‐dose study was conducted in 48 healthy (24 Japanese and 24 Caucasian subjects), nonsmoking male volunteers who were equally divided into 3 cohorts of oral doses at 5, 10, and 20 mg/kg. Blood samples were collected until 48 hours postdose. PK results demonstrated rapid absorption of ataluren, with peak plasma levels (Cmax) being attained between 0.875 and 2.5 hours after dosing. The mean Cmax and area under the concentration‐time curve (AUC(0‐last)) increased with each increasing dose level in both Japanese and Caucasian subjects. Although the Cmax was similar across all subjects at each dose regardless of ethnicity, Japanese subjects had a mean AUC(0‐last) approximately 14% to 34% lower than that of Caucasian subjects across the 3 dose levels. This difference was likely due to the higher variability of AUC values in Caucasian subjects and the relatively small study population. In conclusion, similar ataluren PK profiles were observed in healthy Japanese and Caucasian subjects following single oral administration of ataluren at all dose levels. [ABSTRACT FROM AUTHOR]

Aim: Ataluren has been approved for treating nonsense mutation Duchenne muscular dystrophy (nmDMD), and there are currently discussions concerning drug access and applications beyond the development programme. This study provides an overview of nmDMD and ataluren, stipulates clinical rules for treatment initiation and discontinuation and proposes a model for the implementation of orphan drugs in clinical practice in Sweden.Methods: This was a targeted mini-review of the literature from 1995 to 2018, which included cohort studies, guidelines, randomised clinical trials, clinical commentaries and reviews. The review covered the pathophysiology, epidemiology and burden of nmDMD and the clinical programme for ataluren.Results: Based on the current evidence, and our experiences, we recommend that patients with nmDMD should be given ataluren as soon as possible after diagnosis and this treatment should continue until they reach a forced vital capacity of <30%, and, or, a score of at least six on the Brooke upper extremity scale. We propose an implementation model that comprises a coordinating specialist physician and a national expert committee responsible for providing clinical intelligence to ensure appropriate use.Conclusion: Our clinical recommendations and proposed implementation model will inform the optimum medical management of nmDMD in Sweden and help ensure timely, equal access to ataluren and similar orphan drugs. [ABSTRACT FROM AUTHOR]

Background and objectives: Choroideremia (CHM) is an X-linked recessive chorioretinal dystrophy caused by mutations involving the CHM gene. Gene therapy has entered late-phase clinical trials, although there have been variable results. This review gives a summary on the outcomes of phase I/II CHM gene therapy trials and describes other potential experimental therapies. Materials and Methods: A Medline (National Library of Medicine, Bethesda, MD, USA) search was performed to identify all articles describing gene therapy treatments available for CHM. Results: Five phase I/II clinical trials that reported subretinal injection of adeno-associated virus Rab escort protein 1 (AAV2.REP1) vector in CHM patients were included. The Oxford study (NCT01461213) included 14 patients; a median gain of 5.5 ± 6.8 SD (−6 min, 18 max) early treatment diabetic retinopathy study (ETDRS) letters was reported. The Tubingen study (NCT02671539) included six patients; only one patient had an improvement of 17 ETDRS letters. The Alberta study (NCT02077361) enrolled six patients, and it reported a minimal vision change, except for one patient who gained 15 ETDRS letters. Six patients were enrolled in the Miami trial (NCT02553135), which reported a median gain of 2 ± 4 SD (−1 min, 10 max) ETDRS letters. The Philadelphia study (NCT02341807) included 10 patients; best corrected visual acuity (BCVA) returned to baseline in all by one-year follow-up, but one patient had −17 ETDRS letters from baseline. Overall, 40 patients were enrolled in trials, and 34 had 2 years of follow-up, with a median gain of 1.5 ± 7.2 SD (−14 min, 18 max) in ETDRS letters. Conclusions: The primary endpoint, BCVA following gene therapy in CHM, showed a marginal improvement with variability between trials. Optimizing surgical technique and pre-, peri-, and post-operative management with immunosuppressants to minimize any adverse ocular inflammatory events could lead to reduced incidence of complications. The ideal therapeutic window needs to be addressed to ensure that the necessary cell types are adequately transduced, minimizing viral toxicity, to prolong long-term transgenic potential. Long-term efficacy will be addressed by ongoing studies.

Congenital aniridia is a rare and severe panocular disease characterized by a complete or partial iris defect clinically detectable at birth. The most common form of aniridia occurring in around 90% of cases is caused by PAX6 haploinsufficiency. The phenotype includes ptosis, nystagmus, corneal limbal insufficiency, glaucoma, cataract, optic nerve, and foveal hypoplasia. Ataluren eye drops aim to restore ocular surface PAX6 haploinsufficiency in aniridia-related keratopathy (ARK). However, there are currently no available forms of the ophthalmic solution. The objective of this study was to assess the physicochemical and microbiological stability of ataluren 1% eye drop in preservative-free low-density polyethylene (LDPE) bottle with an innovative insert that maintains sterility after opening. Because ataluren is a strongly lipophilic compound, the formulation is complex and involves a strategy based on co-solvents in an aqueous phase or an oily formulation capable of totally dissolving the active ingredient. The visual aspect, ataluren quantification by a stability-indicating chromatographic method, and microbiological sterility were analyzed. The oily formulation in castor oil and DMSO (10%) better protects ataluren hydrolysis and oxidative degradation and permits its complete solubilization. Throughout the 60 days period, the oily solution in the LDPE bottle remained clear without any precipitation or color modification, and no drug loss and no microbial development were detected. The demonstrated physical and microbiological stability of ataluren 1% eye drop formulation at 22–25 °C might facilitate clinical research in aniridia.

Both estrogen deficiency and aging may lead to osteoporosis. Developing novel drugs for treating osteoporosis is a popular research direction. We screened several potential therapeutic agents through a new deep learning-based efficacy prediction system (DLEPS) using transcriptional profiles for osteoporosis. DLEPS screening led to a potential novel drug examinee, ataluren, for treating osteoporosis. Ataluren significantly reversed bone loss in ovariectomized mice. Next, ataluren significantly increased human bone marrow-derived mesenchymal stem cell (hBMMSC) osteogenic differentiation without cytotoxicity, indicated by the high expression index of osteogenic differentiation genes (OCN , BGLAP , ALP , COL1A , BMP2 , RUNX2). Mechanistically, ataluren exerted its function through the BMP-SMAD pathway. Furthermore, it activated SMAD phosphorylation but osteogenic differentiation was attenuated by BMP2-SMAD inhibitors or small interfering RNA of BMP2. Finally, ataluren significantly reversed bone loss in aged mice. In summary, our findings suggest that the DLEPS-screened ataluren may be a therapeutic agent against osteoporosis by aiding hBMMSC osteogenic differentiation. [Display omitted] • Ataluren, a potential novel anti-osteoporotic drug examinee, was screened by DLEPS. • Ataluren prevented bone loss triggered by ovariectomy and aging in mice. • Ataluren promoted osteogenesis by activating the BMP-SMAD pathway. [ABSTRACT FROM AUTHOR]

Inherited bone marrow failure syndromes (IBMFS) are a group of cancer-prone genetic diseases characterized by hypocellular bone marrow with impairment in one or more hematopoietic lineages. The pathogenesis of IBMFS involves mutations in several genes which encode for proteins involved in DNA repair, telomere biology and ribosome biogenesis. The classical IBMFS include Shwachman–Diamond syndrome (SDS), Diamond–Blackfan anemia (DBA), Fanconi anemia (FA), dyskeratosis congenita (DC), and severe congenital neutropenia (SCN). IBMFS are associated with high risk of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), and solid tumors. Unfortunately, no specific pharmacological therapies have been highly effective for IBMFS. Hematopoietic stem cell transplantation provides a cure for aplastic or myeloid neoplastic complications. However, it does not affect the risk of solid tumors. Since approximately 28% of FA, 24% of SCN, 21% of DBA, 20% of SDS, and 17% of DC patients harbor nonsense mutations in the respective IBMFS-related genes, we discuss the use of the nonsense suppression therapy in these diseases. We recently described the beneficial effect of ataluren, a nonsense suppressor drug, in SDS bone marrow hematopoietic cells ex vivo. A similar approach could be therefore designed for treating other IBMFS. In this review we explain in detail the new generation of nonsense suppressor molecules and their mechanistic roles. Furthermore, we will discuss strengths and limitations of these molecules which are emerging from preclinical and clinical studies. Finally we discuss the state-of-the-art of preclinical and clinical therapeutic studies carried out for IBMFS.