Possibility of exon skipping therapy for Duchenne muscular dystrophy in Russian patients: present and future

Background. Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy in children, that occurs between one and three years of age. DMD is caused by pathogenic and likely pathogenic variants in the DMD gene, which lead to a deficit of various isoforms of the dystrophin protein, the main protein of the muscle cytoskeleton. Drugs aimed at slowing the progression of the disease are being actively developed around the world. One of the perspective approaches to pathogenetic therapy is therapy using exon skipping. As a result of this treatment, the reading frame is restored due to the exon skipping enabling the production of truncated dystrophin.

Aim. To evaluate the applicability of exon skipping therapy in Russian patients with DMD.

Materials and methods. The applicability of therapy aimed at exon skipping was analyzed for a sample of 1519 patients admitted to the laboratory of DNA diagnostics of the Research Centre for Medical Genetics with a referral diagnosis of Duchenne/Becker muscular dystrophy from October 1, 2018 to September 1, 2023.

Results. As a result of the study and analysis of the spectrum of mutations in the DMD gene among patients with DMD in the Russian Federation, the theoretical applicability of exon skipping therapy was assessed: for 29.3 % of patients this approach to treatment is applicable. The proportions of patients for whom existing exon skipping therapies are available were also estimated. In total, skipping of frequent exons 51, 53, 45 is applicable for 14.6 % of patients. Conclusion. One of the effective and accessible types of therapy for DMD is exon skipping. This type of therapy is mutation-specific. In this regard, the assessment of applicability will allow us to estimate the proportion of patients for whom a particular exon skipping will be available.

1. Annexstad E.J., Lund-Petersen I., Rasmussen M. Duchenne muscular dystrophy. Tidsskr Nor Laegeforen 2014;134(14):1361–4. DOI: 10.4045/tidsskr.13.0836

2. Duan D., Goemans N., Takeda S. et al. Duchenne muscular dystrophy. Nat Rev Dis Primers 2021;7(1):13. DOI: 10.1038/s41572-021-00248-3

3. Wang L., Chen M., He R. et al. Serum creatinine distinguishes duchenne muscular dystrophy from becker muscular dystrophy in patients aged ≤3 years: A retrospective study. Front Neurol 2017;8:196. DOI: 10.3389/fneur.2017.00196

4. Porteous D., Davies B., English C. et al. An integrative review exploring psycho-social impacts and therapeutic interventions for parent caregivers of young people living with Duchenne’s muscular dystrophy. Children (Basel) 2021;8(3):212. DOI: 10.3390/children8030212

5. Tuffery-Giraud S., Saquet C., Thorel D. et al. Mutation spectrum leading to an attenuated phenotype in dystrophinopathies. Eur J Hum Genet 2005;13(12):1254–60. DOI: 10.1038/sj.ejhg.5201478

6. Fortunato F., Farnè M., Ferlini A. The DMD gene and therapeutic approaches to restore dystrophin. Neuromuscul Disord 2021;31(10):1013–20. DOI: 10.1016/j.nmd.2021.08.004

7. Gao Q.Q., McNally E.M. The dystrophin complex: Structure, function, and implications for therapy. Compr Physiol 2015;5(3):1223–39. DOI: 10.1002/cphy.c140048

8. Elangkovan N., Dickson G. Gene therapy for Duchenne muscular dystrophy. J Neuromuscul Dis 2021;8(s2):S303–16. DOI: 10.3233/JND-210678

9. Falzarano M.S., Scotton C., Passarelli C. et al. Duchenne muscular dystrophy: From diagnosis to therapy. Molecules 2015;20(10):18168–84. DOI: 10.3390/molecules201018168

10. Bladen C.L., Salgado D., Monges S. et al. The TREAT-NMD DMD Global Database: analysis of more than 7,000 Duchenne muscular dystrophy mutations. Hum Mutat 2015;36(4):395–402. DOI: 10.1002/humu.22758

11. Aartsma-Rus A., Ginjaar I.B., Bushby K. The importance of genetic diagnosis for Duchenne muscular dystrophy. J Med Genet 2016;53(3):145–51. DOI: 10.1136/jmedgenet-2015-103387

12. Aartsma-Rus A., Van Deutekom J.C., Fokkema I.F. et al. Entries in the Leiden Duchenne muscular dystrophy mutation database: An overview of mutation types and paradoxical cases that confirm the reading-frame rule. Muscle Nerve 2006;34(2):135–44. DOI: 10.1002/mus.20586

13. Neri M., Rossi R., Trabanelli C. et al. The genetic landscape of dystrophin mutations in Italy: A nationwide study. Front Genet 2020;11:131. DOI: 10.3389/fgene.2020.00131

14. Zinina E., Bulakh M., Chukhrova A. et al. Specificities of the DMD gene mutation spectrum in Russian patients. Int J Mol Sci 2022;23(21):12710. DOI: 10.3390/ijms232112710

15. Schneider A.E., Aartsma-Rus A. Developments in reading frame restoring therapy approaches for Duchenne muscular dystrophy. Expert Opin Biol Ther 2021;21(3):343–59. DOI: 10.1080/14712598.2021.1832462

16. Takeda S., Clemens P.R., Hoffman E.P. Exon-skipping in Duchenne muscular dystrophy. J Neuromuscul Dis 2021;8(s2):S343–58. DOI: 10.3233/JND-210682

17. Yokota T., Duddy W., Partridge T. Optimizing exon skipping therapies for DMD. Acta Myol 2007;26(3):179–84.

18. Lim K.R., Maruyama R., Yokota T. Eteplirsen in the treatment of Duchenne muscular dystrophy. Drug Des Devel Ther 2017;11:533–45. DOI: 10.2147/DDDT.S97635

19. Eser G., Topaloğlu H. Current Outline of exon skipping trials in Duchenne muscular dystrophy. Genes (Basel) 2022;13(7):1241. DOI: 10.3390/genes13071241

20. Aartsma-Rus A., Fokkema I., Verschuuren J. et al. Theoretic applicability of antisense-mediated exon skipping for Duchenne muscular dystrophy mutations. Hum Mutat 2009;30(3):293–9. DOI: 10.1002/humu.20918

21. Brolin C., Shiraishi T. Antisense mediated exon skipping therapy for Duchenne muscular dystrophy (DMD). Artif DNA PNA XNA 2011;2(1):6–15. DOI: 10.4161/adna.2.1.15425

22. Wood M.J., Gait M.J., Yin H. RNA-targeted splice-correction therapy for neuromuscular disease. Brain 2010;133(Pt 4):957–72. DOI: 10.1093/brain/awq002

23. Wizard Genomic DNA Purification Kit Quick Protocol. Available at: https://worldwide.promega.com/-/media/files/resources/protcards/wizard-genomic-dna-purification-kit-quick-protocol.pdf?rev=4cc2e14ff84c4281a97eb50b32755c33&sc_lang=en.

24. MRC Holland. Available at: https://www.mrcholland.com.

25. Variant-specific Therapies. Available at: https://www.parentprojectmd.org/about-duchenne/what-is-duchenne/types-ofmutations/mutation-specific-therapies/.

26. Happi Mbakam C., Roustant J., Rousseau J. et al. Prime editing strategies to mediate exon skipping in DMD gene. Front Med (Lausanne) 2023;10:1128557. DOI: 10.3389/fmed.2023

27. Aartsma-Rus A., de Waele L., Houwen-Opstal S. et al. The dilemma of choice for Duchenne patients eligible for exon 51 skipping: The European experience. J Neuromuscul Dis 2023;10(3):315–25. DOI: 10.3233/JND-221648

28. Dominski Z., Kole R. Restoration of correct splicing in thalassemic pre-mRNA by antisense oligonucleotides. Proc Natl Acad Sci USA 1993;90(18):8673–7. DOI: 10.1073/pnas.90.18.8673

29. Aartsma-Rus A., van Ommen G.J. Antisense-mediated exon skipping: A versatile tool with therapeutic and research applications. RNA 2007;13(10):1609–24. DOI: 10.1261/rna.653607

30. Niks E.H., Aartsma-Rus A. Exon skipping: A first in class strategy for Duchenne muscular dystrophy. Expert Opin Biol Ther 2017;17(2):225–36. DOI: 10.1080/14712598.2017.1271872

31. Juan-Mateu J., Gonzalez-Quereda L., Rodriguez M.J. et al. DMD mutations in 576 dystrophinopathy families: A step forward in genotype-phenotype correlations. PLoS One 2015;10(8):e0135189. DOI: 10.1371/journal.pone.0135189

32. Ishizuka T., Komaki H., Asahina Y. et al. Systemic administration of the antisense oligonucleotide NS-089/NCNP-02 for skipping of exon 44 in patients with Duchenne muscular dystrophy: Study protocol for a phase I/II clinical trial. Neuropsychopharmacol Rep 2023;43(2):277–86. DOI: 10.1002/npr2.12335

33. Barthélémy F., Wang R.T., Hsu C. et al. Targeting RyR Activity boosts antisense exon 44 and 45 skipping in human DMD skeletal or cardiac muscle culture models. Mol Ther Nucleic Acids 2019;18:580–9. DOI: 10.1016/j.omtn.2019.09.020

34. Luce L., Carcione M., Mazzanti C. et al. Theragnosis for Duchenne muscular dystrophy. Front Pharmacol 2021;12:648390. DOI: 10.3389/fphar.2021.648390

35. Flanigan K.M., Dunn D.M., von Niederhausern A. et al. Mutational spectrum of DMD mutations in dystrophinopathy patients: Application of modern diagnostic techniques to a large cohort. Hum Mutat 2009;30(12):1657–66. DOI: 10.1002/humu.21114

36. Waldrop M.A., Yaou R.B., Lucas K.K. et al. Clinical phenotypes of DMD exon 51 Skip equivalent deletions: A systematic review. J Neuromuscul Dis 2020;7(3):217–29. DOI: 10.3233/JND-200483

37. Lim K.R., Maruyama R., Yokota T. Eteplirsen in the treatment of Duchenne muscular dystrophy. Drug Des Devel Ther 2017;11:533–45. DOI: 10.2147/DDDT.S97635

38. Frank D.E., Schnell F.J., Akana C. et al. Increased dystrophin production with golodirsen in patients with Duchenne muscular dystrophy. Neurology 2020;94(21):e2270–82. DOI: 10.1212/WNL.0000000000009233

39. Happi Mbakam C., Lamothe G., Tremblay J.P. Therapeutic strategies for dystrophin replacement in Duchenne muscular dystrophy. Front Med (Lausanne) 2022;9:859930. DOI: 10.3389/fmed.2022.859930