Novel trialkyl cationic lipids and methods of use thereof

Abstract

The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses. In addition, the compositions and methods of the present invention are less toxic and provide a greater therapeutic index compared to compositions and methods previously known in the art.

1 . A cationic lipid of Formula I having the following structure: 
       
         
           
           
               
               
           
         
         or salts and isomers thereof, wherein:
 R 1  and R 2  are independently selected from the group consisting of hydrogen (H), optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, and C 2 -C 6  alkynyl; 
 alternatively, R 1  and R 2  may join to form an optionally substituted heterocycloalkyl of 4 to 6 carbon atoms and 1 to 2 heteroatoms selected from the group consisting of nitrogen (N), oxygen (O), and mixtures thereof; 
 R 3  is absent or is hydrogen (H) or a C 1 -C 6  alkyl to provide a quaternary amine; 
 R 4  is absent or is selected from the group consisting of —CH 2 —, optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, C 10 -C 30  alkynyl, C 10 -C 30  acyl, and NR 4a R 4b , wherein R 4a  and R 4b  are independently selected from the group consisting of hydrogen (H), an optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, and C 2 -C 6  alkynyl; 
 R 5  is selected from the group consisting of hydrogen (H), oxygen (O), optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, C 10 -C 30  alkynyl, and OR 5a , wherein R 5a  is selected from the group consisting of hydrogen (H), an optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, and C 2 -C 6  alkynyl; 
 alternatively, R 4  and R 5  may join to form a C 3-10  heterocycloalkyl having from 1 to 3 heteroatoms each independently selected from the group consisting of nitrogen (N), oxygen (O), and sulfur (S), and optionally substituted with from 1 to 3 groups each independently selected from the group consisting of hydrogen (H) and C 1 -C 6  alkyl; 
 R 6  and R 7  are independently selected from the group consisting of optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, C 10 -C 30  alkynyl, and C 10 -C 30  acyl; 
 R 8  is selected from the group consisting of optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, C 10 -C 30  alkynyl, and C 10 -C 30  acyl; 
 R 13  and R 14  are independently selected from the group consisting of hydrogen (H), optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, and C 2 -C 6  alkynyl; 
 X is selected from the group consisting of —CH—, nitrogen (N), oxygen (O), sulfur (S), N(R 9 ), C(O), C(O)O, OC(O), C(O)N(R 9 ), N(R 9 )C(O), OC(O)N(R 9 ), N(R 9 )C(O)O, C(O)S, SC(O), C(S)O, OC(S), S(O), S(O)(O), and C(S), wherein R 9  is selected from the group consisting of hydrogen (H), optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, C 2 -C 6  alkynyl, and 
 
       
       
         
           
           
               
               
           
         
         
            wherein * represents the point of attachment to N; 
           Y is selected from the group consisting of —CR 11 R 12 — and oxygen (O), wherein R 11  and R 12  are independently selected from the group consisting of hydrogen (H), optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, and C 2 -C 6  alkynyl; 
           Z 1 , Z 2 , and Z 3  are independently selected from oxygen (O), C(O)O, or OC(O); 
           T 1 , T 2 , and T 3  are independently selected from hydrogen (H) or OR 10 , wherein R 10  is hydrogen (H) or optionally substituted C 1 -C 6  alkyl, C 2 -C 6  alkenyl, or C 2 -C 6  alkynyl; 
           subscripts a, b, c, d, e, f, and g are independently selected from the group consisting of 0, 1, 2, 3, 4, 5, 6, 7 and 8; 
           subscripts h, i, j, k, and m are independently selected from the group consisting of 0 and 1; 
         
         provided that when R 5  is an optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, C 10 -C 30  alkynyl, and C 10 -C 30  acyl, then either h is 0 or at least one of Z 1  and Z 2  is oxygen (O); and 
         provided that at least three of R 4 , R 5 , R 6 , R 7 , and R 8  are selected from the group consisting of optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, and C 10 -C 30  alkynyl. 
       
     
     
         2 - 6 . (canceled) 
     
     
         7 . The cationic lipid of  claim 1 , wherein R 6 , R 7 , and R 8  independently comprise at least one site of unsaturation. 
     
     
         8 . The cationic lipid of  claim 7 , wherein R 6 , R 7 , and R 8  are independently selected from the group consisting of a dodecenyl moiety, a tetradecenyl moiety, a hexadecenyl moiety, an octadecenyl moiety, and an icosadecenyl moiety. 
     
     
         9 - 11 . (canceled) 
     
     
         12 . The cationic lipid of  claim 1 , wherein R 6 , R 7 , and R 8  independently comprise at least two sites of unsaturation. 
     
     
         13 . The cationic lipid of  claim 12 , wherein R 6 , R 7 , and R 8  are independently selected from the group consisting of a dodecadienyl moiety, a tetradecadienyl moiety, a hexadecadienyl moiety, an octadecadienyl moiety, and an icosadienyl moiety. 
     
     
         14 - 16 . (canceled) 
     
     
         17 . The cationic lipid of  claim 1 , wherein R 6 , R 7 , and R 8  independently comprise at least three sites of unsaturation. 
     
     
         18 . The cationic lipid of  claim 17 , wherein R 6 , R 7 , and R 8  are independently selected from the group consisting of a dodecatrienyl moiety, a tetradectrienyl moiety, a hexadecatrienyl moiety, an octadecatrienyl moiety, and an icosatrienyl moiety. 
     
     
         19 - 21 . (canceled) 
     
     
         22 . The cationic lipid of  claim 1 , wherein R 6 , R 7 , and R 8  are independently selected from the group consisting of oleyl moieties, linoleyl moieties, linolenyl moieties, γ-linolenyl moieties, and phytanyl moieties. 
     
     
         23 - 27 . (canceled) 
     
     
         28 . The cationic lipid of  claim 1 , wherein R 6 , R 7 , and R 8  independently comprise at least one optionally substituted cyclic alkyl group. 
     
     
         29 - 33 . (canceled) 
     
     
         34 . The cationic lipid of  claim 1 , wherein subscripts g, k, and m are all 0. 
     
     
         35 . The cationic lipid of  claim 34 , wherein R 5 , R 6 , and R 7  are independently selected from the group consisting of an optionally substituted C 10 -C 30  alkyl, C 10 -C 30  alkenyl, and C 10 -C 30  alkynyl. 
     
     
         36 . The cationic lipid of  claim 35 , wherein R 5 , R 6 , and R 7  are independently selected from the group consisting of oleyl moieties, linoleyl moieties, linolenyl moieties, γ-linolenyl moieties, and phytanyl moieties. 
     
     
         37 - 39 . (canceled) 
     
     
         40 . The cationic lipid of  claim 1 , wherein X is selected from the group consisting of C(O)O and OC(O). 
     
     
         41 . The cationic lipid of  claim 1 , wherein X is N(R 9 )C(O)O or OC(O)N(R 9 ). 
     
     
         42 - 79 . (canceled) 
     
     
         80 . A lipid particle comprising a cationic lipid of  claim 1 . 
     
     
         81 - 87 . (canceled) 
     
     
         88 . The lipid particle of  claim 80 , wherein the particle further comprises a therapeutic agent. 
     
     
         89 . The lipid particle of  claim 88 , wherein the therapeutic agent is a nucleic acid. 
     
     
         90 . The lipid particle of  claim 89 , wherein the nucleic acid is an interfering RNA. 
     
     
         91 - 96 . (canceled) 
     
     
         97 . A pharmaceutical composition comprising a lipid particle of  claim 80  and a pharmaceutically acceptable carrier. 
     
     
         98 - 102 . (canceled) 
     
     
         103 . A method for treating a disease or disorder in a mammal in need thereof, the method comprising: administering to the mammal a therapeutically effective amount of a lipid particle of  claim 88 . 
     
     
         104 - 105 . (canceled)