CPC C12N 15/113 (2013.01) [C12N 2310/14 (2013.01); C12N 2310/313 (2013.01); C12N 2310/321 (2013.01); C12N 2310/322 (2013.01); C12N 2310/351 (2013.01)] | 14 Claims |
1. A nucleic acid for inhibiting expression of a target gene in a cell, comprising at least one duplex region that comprises at least a portion of a first strand and at least a portion of a second strand that is at least partially complementary to the first strand, wherein said first strand is at least partially complementary to at least a portion of RNA transcribed from said target gene, wherein said first strand includes modified nucleotides at a plurality of positions,
wherein the nucleotides at positions 2 and 14 from the 5′ end of the first strand are modified with a 2′ fluoro modification, and the nucleotides on the second strand which correspond to position 11, or 13, or 11 and 13, or 11-13 of the first strand are modified with a 2′ fluoro modification; wherein the nucleic acid is conjugated with a ligand, wherein the ligand is conjugated to the nucleic acid by a bivalent or trivalent branched linker and wherein the ligand comprises the formula I:
[S-X1-P-X2]3-A-X3- (I)
wherein:
S represents a saccharide, wherein the saccharide is N-acetyl galactosamine;
X1 represents C3-C6 alkylene or (—CH2—CH2—O)m(—CH2)2— wherein m is 1, 2, or 3;
P is a phosphate or modified phosphate;
X2 is alkylene or an alkylene ether of the formula (—CH2)n—O—CH2— where n=1-6;
A is a branching unit;
X3 represents a bridging unit; and
wherein the nucleic acid is conjugated to X3 via a phosphate or modified phosphate.
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