title: 2'-O-Methyl RNA/Ethylene-Bridged Nucleic Acid Chimera Antisense Oligonucleotides to Induce Dystrophin Exon 45 Skipping.
abstract: Duchenne muscular dystrophy (DMD) is a fatal muscle-wasting disease characterized by dystrophin deficiency from mutations in thedystrophingene. Antisense oligonucleotide (AO)-mediated exon skipping targets restoration of thedystrophinreading frame to allow production of an internally deleted dystrophin protein with functional benefit for DMD patients who have out-of-frame deletions. After accelerated US approval of eteplirsen (Exondys 51), which targetsdystrophinexon 51 for skipping, efforts are now focused on targeting other exons. For improved clinical benefits, this strategy requires more studies of the delivery method and modification of nucleic acids. We studied a nucleotide with a 2'-O,4'-C-ethylene-bridged nucleic acid (ENA), which shows high nuclease resistance and high affinity for complementary RNA strands. Here, we describe the process of developing a 2'-O-methyl RNA(2'-OMeRNA)/ENA chimera AO to inducedystrophinexon 45 skipping. One 18-mer 2'-OMeRNA/ENA chimera (AO85) had the most potent activity for inducing exon 45 skipping in cultured myotubes. AO85 was administered tomdxmice without significant side effects. AO85 transfection into cultured myotubes from 13 DMD patients induced exon 45 skipping in all samples at different levels and dystrophin expression in 11 patients. These results suggest the possible efficacy of AO-mediated exon skipping changes in individual patients and highlight the 2'-OMeRNA/ENA chimera AO as a potential fundamental treatment for DMD.
authors.affiliation: Department of Pediatrics, Hyogo College of Medicine, Nishinomiya 6638501, Japan. leeleetomo@me.com.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 6500017, Japan. awahiro@med.kobe-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Awano
authors.affiliation: Nikoniko House Medical and Welfare Center, Kobe 6511102, Japan. marikoyagi.sgt@gmail.com.
authors.forename: Mariko
authors.initials: M
authors.lastname: Yagi
authors.affiliation: Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe 6500017, Japan. mmatsu@med.kobe-u.ac.jp.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Matsumoto
authors.affiliation: Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co., Ltd., Tokyo 1408710, Japan. watanabe.nobuaki.nc@daiichisankyo.co.jp.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co., Ltd., Tokyo 1408710, Japan. goda.ryoya.u4@daiichisankyo.co.jp.
authors.forename: Ryoya
authors.initials: R
authors.lastname: Goda
authors.affiliation: Modality Research Laboratories, Daiichi Sankyo Co., Ltd., Tokyo 1408710, Japan. koizumi.makoto.h7@daiichisankyo.co.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Koizumi
authors.affiliation: Department of Pediatrics, Hyogo College of Medicine, Nishinomiya 6638501, Japan. ytake@hyo-med.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takeshima
authors.affiliation: Department of Physical Therapy, Faculty of Rehabilitation, Kobe Gakuin University, Kobe 6512180, Japan. mmatsuo@reha.kobegakuin.ac.jp.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Matsuo
keywords: 2′-O,4′-C-ethylene-bridged nucleic acid; Duchenne muscular dystrophy; ENA; antisense oligonucleotide; exon skipping therapy