Compositions and Methods for Inhibiting Expression of Transthyretin

Abstract

The invention relates to a double-stranded ribonucleic acid (dsRNA) targeting a transthyretin (TTR) gene, and methods of using the dsRNA to inhibit expression of TTR.

1 . A double-stranded ribonucleic acid (dsRNA) for inhibiting expression of transthyretin (TTR), wherein the dsRNA comprises a sense strand and an antisense strand, the antisense strand comprising a region complementary to a part of a mRNA encoding transthyretin (TTR), wherein the region of complementarity is less than 30 nucleotides in length and the antisense strand comprises 15 or more contiguous nucleotides of an antisense strand selected from Tables 3A, 3B, 4, 6A, 6B, 7, and 16 or SEQ ID NO:170, SEQ ID NO:450, SEQ ID NO:730, or SEQ ID NO:1010. 
     
     
         2 . The dsRNA of  claim 1 , wherein the region of complementarity is 19 nucleotides in length. 
     
     
         3 . The dsRNA of  claim 1 , wherein each strand of the dsRNA is 19, 20, 21, 22, 23, or 24 nucleotides in length. 
     
     
         4 . The dsRNA of  claim 1 , wherein the dsRNA comprises at least one modified nucleotide. 
     
     
         5 . The dsRNA of  claim 1 , wherein the dsRNA comprises at least one modified nucleotide selected from the group consisting of: a 2′-O-methyl modified nucleotide, a nucleotide comprising a 5′-phosphorothioate group, a terminal nucleotide linked to a cholesteryl derivative or dodecanoic acid bisdecylamide group, a 2′-deoxy-2′-fluoro modified nucleotide, a 2′-deoxy-modified nucleotide, a locked nucleotide, an abasic nucleotide, a 2′-amino-modified nucleotide, a 2′-alkyl-modified nucleotide, a morpholino nucleotide, a phosphoramidate, and a non-natural base comprising nucleotide. 
     
     
         6 . The dsRNA of  claim 1 , wherein the dsRNA is conjugated to a ligand. 
     
     
         7 . The dsRNA of  claim 1 , wherein the dsRNA is formulated in a lipid formulation. 
     
     
         8 . The dsRNA of  claim 1 , wherein administration of the dsRNA to a cell results in about 95% inhibition of TTR mRNA expression as measured by a real time PCR assay, wherein the cell is a HepG2 cell or a Hep3B cell, and wherein the concentration of the dsRNA is 10 nM. 
     
     
         9 . The dsRNA of  claim 1 , wherein the dsRNA has an IC 50  of less than 10 pM in a HepG2 cell, and wherein the concentration of the dsRNA is 10 nM. 
     
     
         10 . The dsRNA of  claim 1 , wherein the dsRNA has an ED 50  of about 1 mg/kg. 
     
     
         11 . The dsRNA of  claim 1 , wherein administration of the dsRNA does not result in immunostimulatory activity in human peripheral blood mononuclear cells (PBMCs) as measured by IFN-alpha and TNF-alpha ELISA assays. 
     
     
         12 . A cell containing the dsRNA of  claim 1 . 
     
     
         13 . A pharmaceutical composition for inhibiting expression of a TTR gene comprising the dsRNA of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         14 . A method of inhibiting TTR expression in a cell, the method comprising:
 (a) contacting the cell with the dsRNA of  claim 1 ; and   (b) maintaining the cell produced in step (a) for a time sufficient to obtain degradation of the mRNA transcript of a TTR gene, thereby inhibiting expression of the TTR gene in the cell.   
     
     
         15 . A method of treating a disorder mediated by TTR expression comprising administering to a human in need of such treatment a therapeutically effective amount of the dsRNA of  claim 1 . 
     
     
         16 . The method of  claim 15 , wherein the human has transthyretin amyloidosis, a liver disorder, or is further provided a liver transplant.