Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload promotes the expression or activity of a functional dystrophin protein. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide, e.g., an oligonucleotide that causes exon skipping in a mRNA expressed from a mutant DMD allele.

The present invention provides a composition and a method for efficiently delivering a nucleic acid agent to the central nervous system and/or the retina and bringing about antisense effects. Provided is a composition for reducing the expression level of a target transcription product in the central nervous system and/or retina of a subject, the composition including a nucleic acid complex that includes a first nucleic acid strand and a second nucleic acid strand, wherein: the first nucleic acid strand comprises a base sequence capable of hybridizing with at least part of the target transcription product and has an antisense effect on the target transcription product; the second nucleic acid strand comprises a base sequence complementary to the first nucleic acid strand and is conjugated to tocopherol, cholesterol, or an analog thereof; and the first nucleic acid strand is annealed to the second nucleic acid strand.

A chimeric molecule resulting from fusion of a first nucleic acid or a derivative thereof, which has an ability to bind to a target nucleic acid, with a second nucleic acid or a derivative thereof, which has an ability to bind to the target nucleic acid, and in which a main chain skeleton. is anionic, a pharmaceutical composition containing the chimeric molecule, a method for cleaving a target nucleic acid using the chimeric molecule, and a kit for target nucleic acid cleavage or diagnosis including the chimeric molecule.

Disclosed are methods for modulating splicing of Tau mRNA in an animal with Tau antisense compounds. Also disclosed herein are methods for reducing expression of Tau mRNA and protein in an animal with Tau antisense compounds. Such compounds and methods are useful to treat, prevent, or ameliorate neurodegenerative diseases in an individual in need thereof. Examples of neurodegenerative diseases that can be treated, prevented, and ameliorated with the administration Tau antisense oligonucleotides include Alzheimer's Disease, Fronto-temporal Dementia (FTD), FTDP-17, Progressive Supranuclear Palsy, Chronic Traumatic Encephalopathy, Epilepsy, and Dravet's Syndrome.

Novel oligonucleotides that are fully chemically stabilized are provided. Methods of using oligonucleotides that are fully chemically stabilized are also provided.

Aspects of the disclosure relate to complexes comprising a muscle-targeting agent covalently linked to a molecular payload. In some embodiments, the muscle-targeting agent specifically binds to an internalizing cell surface receptor on muscle cells. In some embodiments, the molecular payload promotes the expression or activity of a functional dystrophin protein. In some embodiments, the molecular payload is an oligonucleotide, such as an antisense oligonucleotide, e.g., an oligonucleotide that causes exon skipping in a mRNA expressed from a mutant DMD allele.

The present invention provides a technique capable of transferring an active ingredient, particularly, a nucleic acid, to a cell with excellent efficiency and a cationic lipid for use in this technique, etc. The cationic lipid of the present invention is a compound represented by the formula (I) or a salt thereof. n1 represents an integer of 2 to 6, n2 represents an integer of 0 to 2, n3 represents an integer of 0 to 2, L represents —C(O)O— or —NHC(O)O—, Ra represents a linear C.sub.5-13 alkyl group, a linear C.sub.13-17 alkenyl group or a linear C.sub.17 alkadienyl group, Rb represents a linear C.sub.2-9 alkyl group, Rc represents a hydrogen atom or a linear C.sub.2-9 alkyl group, Rd represents a hydrogen atom or a linear C.sub.2-9 alkyl group, Re represents a linear C.sub.2-9 alkyl group, and Rf represents a linear C.sub.2-9 alkyl group.

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Novel oligonucleotides that are fully chemically stabilized are provided. Methods of using oligonucleotides that are fully chemically stabilized are also provided.

Provided are compounds, methods, and pharmaceutical compositions for modulating SMN2 RNA and/or protein in a cell or subject. Such compounds, methods, and pharmaceutical compositions are useful to ameliorate at least one symptom of a neurodegenerative disorder. Such symptoms include reduced muscle strength; inability or reduced ability to sit upright, to stand, and/or walk; reduced neuromuscular activity; reduced electrical activity in one or more muscles; reduced respiration; inability or reduced ability to eat, drink, and/or breathe without assistance; loss of weight or reduced weight gain; and/or decreased survival.

Disclosed herein are antisense compounds and methods for decreasing Ataxin 2 mRNA and protein expression. Such methods, compounds, and compositions are useful to treat, prevent, or ameliorate Ataxin 2 associated diseases, disorders, and conditions. Such Ataxin 2 associated diseases include spinocerebellar ataxia type 2 (SCA2), amyotropic sclerosis (ALS), and parkinsonism.