iRNA AGENTS WITH BIOCLEAVABLE TETHERS
The invention relates to iRNA agents, which preferably include a monomer in which the ribose moiety has been replaced by a moiety other than ribose that further includes a tether having one or more linking groups, in which at least one of the linking groups is a cleavable linking group. The tether in turn can be connected to a selected moiety, e.g., a ligand, e.g., a targeting or delivery moiety, or a moiety which alters a physical property. The cleavable linking group is one which is sufficiently stable outside the cell such that it allows targeting of a therapeutically beneficial amount of an iRNA agent (e.g., a single stranded or double stranded iRNA agent), coupled by way of the cleavable linking group to a targeting agent—to targets cells, but which upon entry into a target cell is cleaved to release the iRNA agent from the targeting agent.
1 . A modified RNA agent comprising a sense strand and an antisense strand, wherein one or more ribose replacement modification subunit (RRMS) comprising a cell-permeation peptide or a cell-targeting ligand is incorporated into at least one of said strands via a phosphatase-cleavable linking group, and wherein the RRMS is a cyclic or acyclic carrier.
2 . The modified RNA agent of claim 1 , wherein the RRMS is a cyclic carrier selected from the group consisting of hydroxyproline, piperidine, morpholine, piperazine, and decalin/indane.
3 . The modified RNA agent of claim 1 , wherein the RRMS is an acyclic carrier based on the backbones selected from the group consisting of serinol and bis(hydroxyalkyl)amine.
4 . The modified RNA agent of claim 1 , wherein the phosphatase-cleavable linking group is a phosphate-based linking group.
5 . The modified RNA agent of claim 4 , wherein the phosphate-based linking group is selected from the group consisting of —O—P(O)(OR k )—O—, —O—P(S)(OR k )—O—, —O—P(S)(SR k )—O—,
—S—P(O)(OR k )—O—, —O—P(O)(OR k )—S—, —S—P(O)(OR k )—S—, —O—P(S)(OR k )—S—,
—S—P(S)(OR k )—O—, —O—P(O)(R k )—O—, —O—P(S)(R k )—O—, —S—P(O)(R k )—O—, —S—P(S)(R k )—O—,
—S—P(O)(R k )—S—, and —O—P(S)(R k )—S—, wherein R k at each occurrence is, independently, H, C 1 -C 10 alkyl, C 1 -C 10 haloalkyl, C 6 -C 10 aryl, or C 7 -C 12 aralkyl.
6 . The modified RNA agent of claim 4 , wherein the phosphate-based linking group is selected from the group consisting of —O—P(O)(OH)—O—, —O—P(S)(OH)—O—, —O—P(S)(SH)—O—,
—S—P(O)(OH)—O—, —O—P(O)(OH)—S—, —S—P(O)(OH)—S—, —O—P(S)(OH)—S—, —S—P(S)(OH)—O—,
—O—P(O)(H)—O—, —O—P(S)(H)—O—, —S—P(O)(H)—O—, —S—P(S)(H)—O—, —S—P(O)(H)—S—, and
—O—P(S)(H)—S—.
7 . The modified RNA agent of claim 1 , wherein the RRMS is incorporated into the sense strand.
8 . The modified RNA agent of claim 7 , wherein the RRMS is incorporated into the 3′ end of the sense strand.
9 . The modified RNA agent of claim 8 , wherein the RRMS is placed within 1, 2, or 3 positions of the 3′ end of the sense strand.
10 . The modified RNA agent of claim 1 , wherein the RRMS is incorporated into the antisense strand.
11 . The modified RNA agent of claim 10 , wherein the RRMS is incorporated into the 3′ end of the antisense strand.
12 . The modified RNA agent of claim 1 , wherein the sense strand and the antisense strand are independently 17 to 25 nucleotides in length.
13 . The modified RNA agent of claim 1 , wherein the modified RNA agent includes a duplex region between 17 and 23 pairs in length.
14 . The modified RNA agent of claim 1 , wherein the modified RNA agent includes at least one 3′ overhang of 2-3 nucleotides in length.
15 . The modified RNA agent of claim 1 , wherein the cell-permeation peptide or cell-targeting ligand is selected from the group consisting of an α-helical linear peptide, a disulfide bond-containing peptide, a peptide containing only one or two dominating amino acids, and a bipartite amphipathic peptide.
16 . The modified RNA agent of claim 1 , wherein the cell-permeation peptide or cell-targeting ligand is an RGD peptide or its variants, or a ligand that targets an integrin.
17 . The modified RNA agent of claim 16 , wherein the cell-permeation peptide or cell-targeting ligand is an RGD peptide or a ligand that targets the alpha- V beta-3 integrin.
18 . The modified RNA agent of claim 1 , wherein at least two RRMS subunits are incorporated into at least one of said strands.
19 . The modified RNA agent of claim 18 , wherein at least two RRMS subunits are incorporated into the sense strand.
20 . The modified RNA agent of claim 18 , wherein at least two RRMS subunits are incorporated into the antisense strand.