Method for enhancing specific immunotherapies in cancer treatment

1. A method for treating cancer comprising:

a) obtaining a composition for parenteral or enteral administration comprising:

(i) a galactoarabino-rhamnogalacturonate comprising a 1,4-linked galacturonic acid (GalA) comprising methyl galacturonate (MeGalA) residues backbone linked to branched heteropolymers of alternating oligomers of α-1,2 linked rhamnose and α-1,4-linked GalA residues, the rhamnose residues carrying a primary branching of oligomers of 1,4-β-D-galactose residues, 1,5-α-L-arabinose residues, or combinations thereof,

wherein the 1,4-β-D-galactose and 1,5-α-L-arabinose residues are present in a 2:1 to a 3:1 ratio, and wherein the galactoarabino-rhamnogalacturonate has a methyl galacturonate to galacturonic acid ratio ranging from 2:1 to 1:2, and

(ii) a therapeutically effective amount of an immune modulatory agent in an acceptable pharmaceutical carrier, wherein the immune modulatory agent comprises a monoclonal antibody, a peptide, or an agent capable of binding to lymphocyte co-stimulatory ligands or receptors, to lymphocyte inhibitory ligands or receptors, to the tumor necrosis factor receptor (TNFR) superfamily of receptors or to the tumor necrosis factor receptor (TNFR) superfamily of ligands; and

b) administering to a subject in need thereof an effective dose of the composition, wherein the subject in need thereof has a malignant tumor, and wherein the effective dose of the composition increases by at least 10% the activation of CD8+ T-cells, resulting in at least one of:

at least 10% increase of tumor-antigen specific CD8+ T-cells,

at least 10% decrease in the malignant tumor size,

at least 10% decrease in size of metastases,

at least a 10% decrease in number of metastases,

an increase in survival of the subject, or

a reduction of total tumor burden,

when compared to a control subject treated with the therapeutically effective amount of the immune modulatory agent alone, and

wherein the malignant tumor is one of gastrointestinal cancer, pancreatic cancer, bile duct cancer, sarcoma, myosarcoma, breast cancer, lung cancer, head and neck cancer, mouth cancer, skin cancer, melanoma, kidney cancer, urinary tract cancer, prostate cancer, testicular cancer, ovarian cancer, endometrial cancer, neurological cancer, endocrine gland cancer, bone cancer, hematological cancers, multiple myeloma, and myelofibrosis.

2. The method of claim 1 wherein the step of administering results in at least a 50% reduction of the total tumor burden in the subject so as to treat cancer.

3. The method of claim 1 wherein in the step of obtaining the galactoarabino-rhamnogalacturonate, the 1,4-linked galacturonic acid comprising methyl galacturonate residues backbone represents between 55 to 85 molar percent of a total carbohydrate molar content, the branched heteropolymer of alternating α-1,2 linked rhamnose and α-1,4-linked GalA residues represents between 1 and 6 molar percent of the total carbohydrate molar content, the oligomer 1,4-β-D-galactose of the primary branching represents between 6 to 15 molar percent of the total carbohydrate molar content and the oligomer 1,5-α-L-arabinose of the primary branching represents between 2 to 8 molar percent of the total carbohydrate molar content, as characterized by gas chromatography/mass spectrometry.

4. The method of claim 1 , wherein the galactoarabino-rhamnogalacturonate has an average molecular weight ranging from 20 kDa to 70 kDa.

5. The method of claim 1 wherein the immune modulatory agent comprises an anti-OX40, anti-CTLA-4, anti-PD-1 anti-PD-L1, anti PD-L2, antibody to 4-1BB/4-1BBL, antibody to LAG-3, or a combination thereof.

6. The method of claim 1 wherein the immune modulatory agent comprises a monoclonal antibody, peptide, or agent capable of binding to CD80, CD86, ICOS ligand or a combination thereof or a monoclonal antibody, peptide, agent capable of binding to CTLA-4, LAG-3 or combination thereof.

7. The method of claim 1 wherein the immune modulatory agent comprises a monoclonal antibody, peptide or other agent capable of binding to CD134, CD27, 4-1BB or combination thereof or capable of binding to OX40L, CD70, 4-1BBL or combination thereof.

8. The method of claim 1 wherein the immune modulatory agent comprises a recombinant OX40L or agonists of OX40.

9. The method of claim 1 wherein the immune modulatory agent comprises a monoclonal antibody capable of binding to PD-ligands.

10. The method of claim 1 wherein the immune modulatory agent comprises a monoclonal antibody, peptide or agent capable of modifying the activation or function of dendritic cells.

11. The method of claim 1 wherein the immune modulatory agent comprises a cancer vaccine, tumor-antigen directed vaccine or a vaccine capable of treating or preventing an infectious disease.

12. The method of claim 1 wherein the effective dose of the composition results in at least 10% increase of activation of CD8+ as measured by granzyme B expression.

13. The method of claim 1 wherein the effective dose of the composition results in at least 10% increase of activation of CD4+ as measured by Ki-67 expression.

14. The method of claim 1 wherein the effective dose of the composition results in at least 10% increase of GR-1 negative/CD11b positive cells.

15. The method of claim 1 wherein the effective dose of the composition results in at least 10% decrease of GR-1 intermediate/CD11b positive cells.

16. The method of claim 1 wherein the galactoarabino-rhamnogalacturonate inhibits galectin-3 function and augments CD8+ T cell expansion and effector function.

17. The method of claim 1 wherein when the composition is administered, the composition provides for a synergistic reduction of tumor size and/or increase in survival when compared to the reduction of the tumor size and/or increase in survival provided by the administration of the immune modulatory agent without the galactoarabino-rhamnogalacturonate.