Therapeutic liposome composition and method of preparation

Abstract

Reagents for use in preparing a therapeutic liposome composition sensitized to a target cell are described. The reagents include a liposomal composition composed of pre-formed liposomes having an entrapped therapeutic agent and a plurality of targeting conjugates composed of a lipid, a hydrophilic polymer and a targeting ligand. The therapeutic, target-cell sensitized liposome composition is formed by incubating the liposomal composition with a selected conjugate.

1 . A micellar suspension comprising a plurality of conjugates for use in preparing a liposome composition, each conjugate consisting essentially of (i) a lipid having a polar head group and a hydrophobic tail, (ii) a hydrophilic polymer having a proximal end and a distal end, said polymer attached at its proximal end to the head group of the lipid, and (iii) a targeting ligand having binding affinity for a receptor expressed on a cell, said ligand attached to the distal end of the hydrophilic polymer.  
     
     
         2 . The micellar suspension of  claim 1 , wherein the lipid is selected from the group consisting of distearoyl phosphatidylethanolamine, distearoyl-phosphatidylcholine, monogalactosyl diacylglycerols and digalactosyl diacylglycerols.  
     
     
         3 . The micelilar suspension of  claim 2 , wherein the hydrophilic polymer is polyethylene glycol.  
     
     
         4 . The micellar suspension of  claim 3 , wherein the polyethylene glycol has a molecular weight between 500-5,000 daltons.  
     
     
         5 . The micellar suspension of  claim 1 , wherein the targeting ligand is an antibody or an antibody fragment.  
     
     
         6 . The micellar suspension of  claim 5 , wherein the antibody or antibody fragment is a humanized murine antibody.  
     
     
         7 . The micellar suspension of  claim 1 , wherein the targeting ligand specifically binds to an extracellular domain of a growth factor receptor.  
     
     
         8 . The micellar suspension of  claim 7 , wherein the receptors are selected from the group consisting of c-erbB-2 protein product of the HER2/neu oncogene, epidermal growth factor receptor, basic fibroblast growth factor receptor and vascular endothelial growth factor receptor.  
     
     
         9 . The micellar suspension of  claim 1 , wherein the targeting ligand binds a receptor selected from the group consisting of E-selectin receptor, L-selectin receptor, P-selectin receptor, folate receptor, CD4 receptor, CD19 receptor, αβ integrin receptors and chemokine receptors.  
     
     
         10 . The micellar suspension of  claim 1 , wherein the targeting ligand binds a receptor on a malignant B-cell or T-cell, said receptor selected from the group consisting of CD19, CD20, CD22, CD4, CD7 and CD8.  
     
     
         11 . The micellar suspension of  claim 1 , wherein the targeting ligand is selected from the group consisting of folic acid, pyridoxal phosphate, vitamin B12, sialyl Lewis x , transferrin, epidermal growth factor, basic fibroblast growth factor, vascular endothelial growth factor, VCAM-1, ICAM-1, PECAM-1, RGD peptides and NGR peptides.  
     
     
         12 . The micellar suspension of  claim 1 , wherein the targeting ligand is selected from the group consisting of water soluble vitamins, apolipoproteins, insulin, galactose, Mac-1, PECAM-1/CD31, fibronectin, osteopontin, RGD sequences of matrix proteins, HIV GP 120/41 domain peptomers, GP120 C4 domain peptomers, T cell tropic isolates, SDF-1 chemokines, Macrophage tropic isolates, anti-cell surface receptor antibodies or fragments thereof, pyridoxyl ligands, biotin, RGD peptide mimetics, YIGSRG protein, avB5, IL-8, anti-E-selectin Fab.  
     
     
         13 . The micellar suspension of  claim 12 , wherein the anti-cell surface receptor antibodies or fragments thereof is selected from the group consisting of anti-HER2/neu, anti-selectin and anti-VEGF pyridoxyl.  
     
     
         14 . The micellar suspension of  claim 12 , wherein the pyridoxyl ligand is selected from the group consisting of pyridoxal, pyridoxine, pyridoxamine, pyridoxal 5′-phosphate and N-(4′-pyridoxyl)amines.  
     
     
         15 . A conjugate consisting essentially of (i) a lipid having a polar head group and a hydrophobic tail, (ii) a polyethylene glycol polymer chain, said polymer having a proximal end, a distal end, and a molecular weight of between about 500-5000 Daltons, said polymer attached at its proximal end to the head group of the lipid, and (iii) a targeting ligand having binding affinity for a receptor expressed on a cell, said ligand attached to the distal end of the polymer.  
     
     
         16 . The conjugate of  claim 15 , wherein the targeting ligand is an antibody or an antibody fragment.  
     
     
         17 . The conjugate of  claim 16 , wherein the antibody or antibody fragment is a humanized murine antibody.  
     
     
         18 . The conjugate of  claim 15 , wherein the targeting ligand specifically binds to an extracellular domain of a growth factor receptor.  
     
     
         19 . The conjugate of  claim 18 , wherein the receptors are selected from the group consisting of c-erbB-2 protein product of the HER2/neu oncogene, epidermal growth factor receptor, basic fibroblast growth factor receptor and vascular endothelial growth factor receptor.  
     
     
         20 . The conjugate of  claim 15 , wherein the targeting ligand binds a receptor selected from the group consisting of E-selectin receptor, L-selectin receptor, P-selectin receptor, folate receptor, CD4 receptor, CD19 receptor, αβ integrin receptors and chemokine receptors.  
     
     
         21 . The conjugate of  claim 15 , wherein the targeting ligand binds a receptor on a malignant B-cell or T-cell, said receptor selected from the group consisting of CD19, CD20, CD22, CD4, CD7 and CD8.  
     
     
         22 . The conjugate of  claim 15 , wherein the targeting ligand is selected from the group consisting of folic acid, pyridoxal phosphate, vitamin B12, sialyl Lewisx, transferrin, epidermal growth factor, basic fibroblast growth factor, vascular endothelial growth factor, VCAM-1, ICAM-1, PECAM-1, RGD peptides and NGR peptides.  
     
     
         23 . The conjugate of  claim 15 , wherein the targeting ligand is selected from the group consisting of water soluble vitamins, apolipoproteins, insulin, galactose, Mac-1, PECAM-1/CD31, fibronectin, osteopontin, RGD sequences of matrix proteins, HIV GP 120/41 domain peptomers, GP120 C4 domain peptomers, T cell tropic isolates, SDF-1 chemokines, Macrophage tropic isolates, anti-cell surface receptor antibodies or fragments thereof, pyridoxyl ligands, biotin, RGD peptide mimetics, YIGSRG protein, avB5, IL-8, and anti-E-selectin Fab.  
     
     
         24 . The conjugate of  claim 23 , wherein the anti-cell surface receptor antibodies or fragments thereof is selected from the group consisting of anti-HER2/neu, anti-selectin and anti-VEGF pyridoxyl.  
     
     
         25 . The conjugate of  claim 23 , wherein the pyridoxyl ligand is selected from the group consisting of pyridoxal, pyridoxine, pyridoxamine, pyridoxal 5′-phosphate and N-(4′-pyridoxyl)amines.