Nucleic acids for inhibiting expression of c3 in a cell

A double-stranded nucleic acid that is capable of inhibiting expression of complement component C3 for use as a medicament.

The nucleic acid of any of the preceding claims, wherein the first strand and the second strand form a duplex region from 17-25 nucleotides in length.

The nucleic acid of any of the preceding claims, wherein the nucleic acid mediates RNA interference.

The nucleic acid of any of the preceding claims, wherein at least one nucleotide of the first and/or second strand is a modified nucleotide, preferably a non-naturally occurring nucleotide such as a 2′-F modified nucleotide.

The nucleic acid of any of the preceding claims, wherein at least nucleotides 2 and 14 of the first strand are modified by a first modification, the nucleotides being numbered consecutively starting with nucleotide number 1 at the 5′ end of the first strand.

The nucleic acid of any of the previous claims, wherein the first strand has a terminal 5′ (E)-vinylphosphonate nucleotide at its 5′ end.

The nucleic acid of any of the preceding claims, wherein the nucleic acid comprises a phosphorothioate linkage between the terminal two or three 3′ nucleotides and/or 5′ nucleotides of the first and/or the second strand and preferably wherein the linkages between the remaining nucleotides are phosphodiester linkages.

The nucleic acid of any of the preceding claims, comprising a phosphorodithioate linkage between each of the two, three or four terminal nucleotides at the 3′ end of the first strand and/or comprising a phosphorodithioate linkage between each of the two, three or four terminal nucleotides at the 3′ end of the second strand and/or a phosphorodithioate linkage between each of the two, three or four terminal nucleotides at the 5′ end of the second strand and comprising a linkage other than a phosphorodithioate linkage between the two, three or four terminal nucleotides at the 5′ end of the first strand.

The nucleic acid of any of the preceding claims, wherein the nucleic acid is conjugated to a ligand.

A composition comprising a nucleic acid of any of the previous claims and a delivery vehicle and/or a physiologically acceptable excipient and/or a carrier and/or a diluent and/or a buffer and/or a preservative and/or a further therapeutic agent selected from the group comprising an oligonucleotide, a small molecule, a monoclonal antibody, a polyclonal antibody and a peptide.