Novel lipid formulations for delivery of therapeutic agents to solid tumors

Abstract

The present invention provides novel, serum-stable lipid particles comprising one or more active agents or therapeutic agents, methods of making the lipid particles, and methods of delivering and/or administering the lipid particles. More particularly, the present invention provides serum-stable nucleic acid-lipid particles (SNALP) comprising a nucleic acid (e.g., one or more interfering RNA molecules), methods of making the SNALP, and methods of delivering and/or administering the SNALP (e.g., for the treatment of cancer). In particular embodiments, the present invention provides tumor-directed lipid particles that preferentially target solid tumors. The tumor-directed formulations of the present invention are capable of preferentially delivering a payload such as a nucleic acid to cells of solid tumors compared to non-cancerous cells.

1 . A nucleic acid-lipid particle comprising:
 (a) a nucleic acid;   (b) a cationic lipid comprising from about 50 mol % to about 65 mol % of the total lipid present in the particle;   (c) a non-cationic lipid comprising from about 25 mol % to about 45 mol % of the total lipid present in the particle; and   (d) a conjugated lipid that inhibits aggregation of particles comprising from about 5 mol % to about 10 mol % of the total lipid present in the particle, wherein the conjugated lipid comprises a polyethyleneglycol (PEG)-lipid conjugate, and wherein the PEG has an average molecular weight of from about 550 daltons to about 1000 daltons.   
     
     
         2 . The nucleic acid-lipid particle of  claim 1 , wherein the nucleic acid comprises an interfering RNA. 
     
     
         3 . The nucleic acid-lipid particle of  claim 2 , wherein the interfering RNA comprises an siRNA. 
     
     
         4 - 26 . (canceled) 
     
     
         27 . The nucleic acid-lipid particle of  claim 1 , wherein the cationic lipid comprises 1,2-dilinoleyloxy-N,N-dimethylaminopropane (DLinDMA), 1,2-dilinolenyloxy-N,N-dimethylaminopropane (DLenDMA), 1,2-di-γ-linolenyloxy-N,N-dimethylaminopropane (γ-DLenDMA), 2,2-dilinoleyl-4-(2-dimethylaminoethyl)-[1,3]-dioxolane (DLin-K-C2-DMA), 2,2-dilinoleyl-4-dimethylaminomethyl-[1,3]-dioxolane (DLin-K-DMA), or a mixture thereof. 
     
     
         28 . The nucleic acid-lipid particle of  claim 1 , wherein the cationic lipid comprises from about 50 mol % to about 60 mol % of the total lipid present in the particle. 
     
     
         29 . (canceled) 
     
     
         30 . The nucleic acid-lipid particle of  claim 1 , wherein the non-cationic lipid comprises a mixture of a phospholipid and cholesterol or a cholesterol derivative. 
     
     
         31 . The nucleic acid-lipid particle of  claim 30 , wherein the phospholipid is selected from the group consisting of dipalmitoylphosphatidylcholine (DPPC), distearoylphosphatidylcholine (DSPC), and a mixture thereof. 
     
     
         32 . The nucleic acid-lipid particle of  claim 30 , wherein the phospholipid comprises from about 5 mol % to about 10 mol % of the total lipid present in the particle. 
     
     
         33 . The nucleic acid-lipid particle of  claim 30 , wherein the cholesterol comprises from about 25 mol % to about 35 mol % of the total lipid present in the particle. 
     
     
         34 . The nucleic acid-lipid particle of  claim 1 , wherein the non-cationic lipid is a mixture of DPPC and cholesterol. 
     
     
         35 - 38 . (canceled) 
     
     
         39 . The nucleic acid-lipid particle of  claim 1 , wherein the PEG has an average molecular weight of about 750 daltons. 
     
     
         40 . The nucleic acid-lipid particle of  claim 1 , wherein the PEG-lipid conjugate is member selected from the group consisting of a PEG-diacylglycerol (PEG-DAG) conjugate, a PEG dialkyloxypropyl (PEG-DAA) conjugate, a PEG-phospholipid conjugate, a PEG-ceramide (PEG-Cer) conjugate, and a mixture thereof. 
     
     
         41 . (canceled) 
     
     
         42 . The nucleic acid-lipid particle of  claim 40 , wherein the PEG-DAA conjugate comprises a PEG-dimyristyloxypropyl (PEG-DMA) conjugate. 
     
     
         43 . The nucleic acid-lipid particle of  claim 1 , wherein the conjugated lipid that inhibits aggregation of particles comprises from about 6 mol % to about 8 mol % of the total lipid present in the particle. 
     
     
         44 . The nucleic acid-lipid particle of  claim 30 , wherein the nucleic acid-lipid particle comprises about 54 mol % cationic lipid, about 7 mol % phospholipid, about 32 mol % cholesterol or a derivative thereof, and about 7 mol % PEG-lipid conjugate. 
     
     
         45 . (canceled) 
     
     
         46 . The nucleic acid-lipid particle of  claim 1 , wherein the nucleic acid is fully encapsulated in the nucleic acid-lipid particle. 
     
     
         47 . A pharmaceutical composition comprising a nucleic acid-lipid particle of  claim 1  and a pharmaceutically acceptable carrier. 
     
     
         48 . A method for introducing a nucleic acid into a cell, the method comprising:
 contacting the cell with a nucleic acid-lipid particle of  claim 1 .   
     
     
         49 - 51 . (canceled) 
     
     
         52 . A method for the in vivo delivery of a nucleic acid to a solid tumor, the method comprising:
 administering to a mammal a nucleic acid-lipid particle of  claim 1 .   
     
     
         53 - 61 . (canceled) 
     
     
         62 . A method for treating a cell proliferative disorder in a mammal in need thereof, the method comprising:
 administering to the mammal a therapeutically effective amount of a nucleic acid-lipid particle of  claim 1 .   
     
     
         63 . (canceled) 
     
     
         64 . (canceled)