The present disclosure belongs to the field of biomedicines, and specifically relates to a
nucleic acid capable of inhibiting the expression of a coagulation
factor XI (
factor XI), a pharmaceutical composition containing the
nucleic acid, and an siRNA conjugate. Specifically, provided in the present disclosure is a double-stranded
oligonucleotide capable of inhibiting the expression of FXI. The double-stranded
oligonucleotide comprises a
sense strand and an antisense strand, wherein the
sense strand and the antisense strand are at least partially reverse-complementary to form a double-stranded region, the antisense strand is at least partially complementary to a segment of nucleotides within FXI-transcribed mRNA, the length of the
sense strand does not exceed 21 nucleotides, the length of the antisense strand does not exceed 23 nucleotides, and the antisense strand comprises a sequence of at least 17 contiguous nucleotides that differs from any one of the
nucleotide sequences as set forth in SEQ ID NOs: 175-347 and 706-714 by no more than 4, 3, 2, or 1 nucleotides. The
oligonucleotide prepared in the present disclosure has a good
inhibitory effect on the expression of the coagulation
factor XI both
in vitro and
in vivo.