Patent ID: 8188060

Claim:
A method for inhibiting expression of a target mRNA in a cell, the method comprising delivering to said cell a duplex oligonucleotide complex comprising: a. a sense strand that is 19 nucleotide in length, wherein nucleotides 1 and 2 and all C nucleotides and all U nucleotides on said sense strand are 2′O- methyl modified; b. an antisense strand that is 21 nucleotides in length, wherein: i. all C nucleotides and all U nucleotides on said antisense strand are 2′ F modified; ii. the antisense strand has 100% complementarity with a target mRNA; iii. the sense strand and the antisense strand form a duplex having a 2 nucleotide overhang at the 3′ end of the antisense strand, said 2 nucleotide overhang comprising phosphorothioate linkages; c. a cholesterol molecule attached to the 3′ end of the sense strand via a C5 linker molecule wherein the cholesterol- linker-sense strand has the structure: d. a phosphate group at the 5′ end of the antisense strand; and e. three mismatches on the sense strand with the corresponding nucleotides on the antisense strand, wherein the mismatches are between nucleotide 6 on the sense strand and the opposite nucleotide 14 on the antisense strand, nucleotide 13 on the sense strand and the opposite nucleotide 7 on the antisense strand, and nucleotide 19 on the sense strand and the opposite nucleotide 1 on the antisense strand, wherein said mismatches enhance silencing activity of the complex; wherein the duplex oligonucleotide complex is capable of entry into a cell by passive delivery and wherein each nucleotide number refers to the nucleotide's position in an identified strand as counted from the identified strand's 5′ end and at all positions other than positions 6, 13 and 19 on the sense strand, there is a nucleotide that is complementary to the nucleotide on the opposite position on the antisense strand.