Dsrna, use thereof and preparation method therefor

A double-stranded ribonucleic acid (dsRNA) comprising a sense strand and an antisense strand that comprise contiguous nucleotides in a direction from the 5′ end to the 3′ end, wherein:

• the nucleotides at positions 7, 8, and 9 of the sense strand are 2′-fluoro-modified nucleotides, the nucleotide at position 5 is independently a 2′-methoxy-modified nucleotide or 2′-fluoro-modified nucleotide, and the nucleotides at the other positions are 2′-methoxy-modified nucleotides;
• the nucleotides at positions 2 and 14 of the antisense strand are 2′-fluoro-modified nucleotides, the nucleotides at positions 4, 6, 8, 9, 10, 12, 16, and 18 are independently 2′-methoxy-modified or 2′-fluoro-modified nucleotides, and the nucleotides at the other positions are 2′-methoxy-modified nucleotides;
• the number of 2′-fluoro-modified nucleotides in the antisense strand is 2-7;
• the antisense strand comprises a chemical modification represented by formula (I), a tautomer thereof, or a pharmaceutically acceptable salt thereof at nucleotide position 7:
• the chemical modification represented by formula (I) is selected from the group consisting of any one of the following structures:
• wherein B is the base of the nucleotide at position 7 of the 5′ region of the antisense strand when unmodified;
• and
• the dsRNA inhibits the expression of apolipoprotein C3 (APOC3).