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 composition comprising reagents for use in preparing a therapeutic liposome composition sensitized to a target cell, said reagents comprised of (a) a liposomal composition composed of pre-formed liposomes having an entrapped therapeutic agent; and (b) a plurality of conjugates, each conjugate composed 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 attached to the distal end of the polymer; 
 wherein said reagents are mixed to form the therapeutic, target-cell sensitized liposome composition.    
     
     
         2 . The composition of  claim 1 , wherein the targeting ligand is an antibody or an antibody fragment.  
     
     
         3 . The composition of  claim 2 , wherein the antibody or antibody fragment is a humanized murine antibody.  
     
     
         4 . The composition of  claim 2 , wherein the targeting ligand specifically binds to an extracellular domain of a growth factor receptor.  
     
     
         5 . The composition of  claim 4 , 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.  
     
     
         6 . The composition of  claim 2 , 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.  
     
     
         7 . The composition 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.  
     
     
         8 . The composition 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.  
     
     
         9 . The composition of  claim 1 , wherein the hydrophilic polymer is selected from the group consisting of polyvinylpyrrolidone, polyvinylmethylether, polymethyloxazoline, polyethyloxazoline, polyhydroxypropyloxazoline, polyhydroxypropylmethacrylamide, polymethacrylamide, polydimethylacrylamide, polyhydroxypropylmethacrylate, polyhydroxyethylacrylate, hydroxymethylcellulose, hydroxyethylcellulose, polyethyleneglycol, polyaspartamide and hydrophilic peptide sequences.  
     
     
         10 . The composition of  claim 1 , wherein the hydrophilic polymer is polyethylene glycol.  
     
     
         11 . The composition of  claim 10 , wherein the polyethylene glycol has a molecular weight between 500-5,000 daltons.  
     
     
         12 . The composition of  claim 1 , wherein the liposomes further contain a cationic lipid.  
     
     
         13 . The composition of  claim 1 , wherein the entrapped therapeutic agent is a cytotoxic drug.  
     
     
         14 . The composition of  claim 13 , wherein the cytotoxic drug is an anthracycline antibiotic selected from the group consisting of doxorubicin, daunorubicin, epirubicin and idarubicin and analogs thereof.  
     
     
         15 . The composition of  claim 13 , wherein the cytotoxic agent is a platinum compound selected from cisplatin, carboplatin, ormaplatin, oxaliplatin, zeniplatin, enloplatin, lobaplatin, spiroplatin, ((−)-(R)-2-aminomethylpyrrolidine (1,1-cyclobutane dicarboxylato)platinum), (SP-4-3(R)-1,1-cyclobutane-dicarboxylato(2-)-(2-methyl-1,4-butanediamine-N,N′)platinum), nedaplatin and (bis-acetato-ammine-dichloro-cyclohexylamine-platinum(IV)).  
     
     
         16 . The composition of  claim 13 , wherein the cytotoxic agent is a topoisomerase 1 inhibitor selected from the group consisting of topotecan, irinotecan, (7-(4-methylpiperazino-methylene)-10,11-ethylenedioxy-20(S)-camptothecin), 7-(2-(N-isopropylamino)ethyl)-(20S)-camptothecin, 9-aminocamptothecin and 9-nitrocamptothecin.  
     
     
         17 . The composition of  claim 13 , wherein the cytotoxic agent is a vinca alkaloid selected from the group consisting of vincristine, vinblastine, vinleurosine, vinrodisine, vinorelbine and vindesine.  
     
     
         18 . The composition of  claim 1 , wherein the entrapped agent is a nucleic acid.  
     
     
         19 . The composition of  claim 18 , wherein the nucleic acid is an antisense oligonucleotide or ribozyme.  
     
     
         20 . The composition of  claim 18 , wherein the nucleic acid is a plasmid containing a therapeutic gene which when internalized by the target cells achieves expression of the therapeutic gene to produce a therapeutic gene product.  
     
     
         21 - 56  (Canceled)  
     
     
         57 . A therapeutic liposome composition having sensitivity to a target cell, comprising 
 pre-formed liposomes having an entrapped therapeutic agent; and    one or more conjugates composed 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 attached to the distal end of the polymer;    wherein said pre-formed liposomes and said one or more conjugates are in individual containers prior to formation of the therapeutic liposome composition having sensitivity to a target cell.    
     
     
         58 . The composition of  claim 57 , wherein said conjugate is comprised of a vesicle-forming lipid, polyethylene glycol, and a targeting ligand having binding affinity for a cell surface receptor.  
     
     
         59 . The composition of  claim 57 , wherein said pre-formed liposomes include as the entrapped therapeutic agent doxorubicin.  
     
     
         60 . The composition of  claim 58 , wherein said pre-formed liposomes include as the entrapped therapeutic agent doxorubicin.