Targeted liposomal gemcitabine compositions and methods thereof

1. A targeted PEGylated liposomal gemcitabine (PLG) composition, comprising:

a unilamellar anionic PEGylated liposome encapsulating one or more agents, wherein the PEGylated liposome has a diameter in the range 80 nm to 130 nm wherein the one or more agents comprises gemcitabine and Beta 1, 6-glucan; wherein the PLG comprises one or more targeting moiety comprising an antibody, a fragment of an antibody or a component of an antibody having a specific affinity for at least one type of folate receptor, the one or more targeting moiety conjugated to one or more maleimide moieties attached to-one or both of a PEG and an exterior of the liposome.

2. The targeted PLG composition of claim 1 , wherein the PEGylated liposome further comprises one or more of an immunostimulatory agent, a detectable marker and a maleimide moiety disposed on at least one of the PEG and the exterior of the liposome.

3. The targeted PLG composition of claim 1 , wherein the specific affinity has an equilibrium dissociation constant (Kd) between 0.5×10 −10 to 10×10 −6 moles for at least one type of folate receptor.

4. The targeted PLG composition of claim 1 , wherein at least one targeting moiety has specific affinity for one or more selected from the group consisting of folate receptor alpha, folate receptor beta and folate receptor delta.

5. The targeted PLG composition of claim 4 , wherein at least one targeting moiety has specific affinity for folate receptor alpha and folate receptor beta.

6. The targeted PLG composition of claim 1 , wherein at least one targeting moiety has specific affinity for an epitope on a tumor cell surface antigen that is present on a tumor cell but absent or inaccessible on a non-tumor cell.

7. The targeted PLG composition of claim 6 , wherein the epitope on the tumor cell surface antigen is part of the ligand binding site of a folate receptor.

8. The targeted PLG composition of claim 6 , wherein the tumor cell surface antigen comprises one or more selected from the group consisting of: folate receptor alpha, folate receptor beta, and folate receptor delta.

9. The targeted PLG composition of claim 1 , wherein the one or more targeting moiety comprises one or more selected from the group consisting of: an antibody, a humanized antibody, an antigen binding fragment of an antibody, a single chain antibody, a single-domain antibody, a mono-specific antibody, a bi-specific antibody, a synthetic antibody, a pegylated antibody, and a multimeric antibody.

10. The targeted PLG composition of claim 1 , wherein the targeted PLG composition has an encapsulation efficiency of at least 10% or an encapsulation capacity of at least 5%.

11. The targeted PLG composition of claim 1 , wherein the liposome does not contain encapsulated cytidine deaminase.

12. The targeted PLG composition of claim 11 , wherein the cytidine deaminase is one or more of the enzymes that converts gemcitabine and other nucleotide analogues into inactive forms in patient plasma, produced in tumor microenvironment by tumor associated macrophages (TAMs), and/or associated with hypoxic tumor microenvironment.

13. The targeted PEGylated liposomal gemcitabine (PLG) composition of claim 1 , wherein the targeted PEGylated liposome further comprises one or more agents selected from the group consisting of: platinum; platinum derivative; taxane; taxane derivative; camptothecin; and camptothecin derivative.

14. The targeted PEGylated liposomal gemcitabine (PLG) composition of claim 13 , which further comprises one or more platinums or platinum derivatives selected from the group consisting of cisplatin, carboplatin and oxaliplatin.

15. The targeted PEGylated liposomal gemcitabine (PLG) composition of claim 13 which, when administered to a patient, results in a molar ratio of gemcitabine to platinum or gemcitabine to platinum derivative in the tumor micro-environment in a range of about 16:1 to about 1:64, or about 1:2.

16. The targeted PEGylated liposomal gemcitabine (PLG) composition of claim 13 , which further comprises one or more platinums or platinum derivatives, one or more taxanes or taxane derivatives, and one or more camptothecins or camptothecin derivatives, wherein the PLG, when administered, results in a molar ratio of [gemcitabine] to [platinum or platinum derivative] to [taxane or taxane derivative] to [camptothecin or camptothecin derivative] in the tumor micro-environment in a range of about 16:1:1:1 to about 1:64:64:64 or with a ratio of about 1:2:2:2.

17. A pharmaceutical composition comprising the targeted PEGylated liposomal gemcitabine (PLG) composition of claim 1 .