Cyclic-dinucleotides and its conjugates as adjuvants and their uses in pharmaceutical compositions

1. A method of enhancing an immune response in a subject in need thereof for eliciting a balanced Th1/Th2 response, comprising the step of administering, as an adjuvant with one or more different antigens, to the subject at least one compound according to formula (I)

wherein

A is independently S or O;

X is independently S, N, O, CH2;

Y, Y′ is independently NH, CH2, O;

Z, Z′ is independently NH, CH2, O;

R1 is H;

R2 is H or absent;

R3 is independently NH2, O, OH, H, or a halogen;

R4 is independently H, halogen, or straight or branched C1-C6 alkyl group which may optionally be substituted;

R5 is independently H, OH or a straight or branched C1-C6 alkyl group or a straight or branched C1-C6 alkoxy group which may optionally be substituted;

is a single or double bond;

and salts or solvates thereof, wherein said enhanced immune response is to said one or more different antigens.

2. The method according to claim 1 wherein in the compound according to formula (I) the purine residue is selected from the group consisting of an adenine, an inosine, a xanthine, and a hypoxanthine residue.

3. The method according to claim 1 wherein in the compound according to formula (I) R5 is OH, X is O, and Y,Y′, Z, and Z′ are O.

4. The method according to claim 1 wherein the compound according to formula (I) is a cyclic bis(3′-5′)diadenylic acid or a salt or a solvate thereof.

5. The method according to claim 1 wherein the compound of formula (I) is administered in combination with at least one of a pharmaceutically active ingredient, a pharmaceutically acceptable carrier, diluent, preservative, adjuvants other than the compound of formula (I), immunomodulators, or excipient.

6. The method according to claim 1 wherein the adjuvant is provided in a form admixed or co-formulated with an antigen.

7. The method according to claim 1 wherein said adjuvant is in a form suitable for mucosal administration.

8. The method according to claim 7 wherein said adjuvant is administered by a route selected from intranasal, intranasal-associated lymphoid tissue (intra NALT), oral, intra-rectal, intrapulmonary, intrabronchial, intrathecal, conjunctival, intra-vaginal, intra-urethral, administration into the milk ducts of the breast, and inhalation.

9. The method according to claim 1 wherein said adjuvant is in a form suitable for parenteral administration.

10. The method according to claim 9 wherein said adjuvant is administered by a route selected from subcutaneous, intravenous, intradermal, and intra muscular administration.

11. The method according to claim 2 wherein in the compound according to formula (I) the purine residue is selected from the group consisting of an adenine and an inosine.

12. A method of activating the antigen presenting function of antigen presenting cells and eliciting a balanced Th1/Th2 response, comprising the step of administering, as an adjuvant with one or more different antigens, to the subject at least one compound according to formula (I)

wherein

A is independently S or O;

X is independently S, N, O, CH2;

Y, Y′ is independently NH, CH2, O;

Z, Z′ is independently NH, CH2, O;

R1 is H;

R2 is H or absent;

R3 is independently NH2, O, OH, H, or a halogen;

R4 is independently H, halogen, or straight or branched C1-C6 alkyl group which may optionally be substituted;

R5 is independently H, OH or a straight or branched C1-C6 alkyl group or a straight or branched C1-C6 alkoxy group which may optionally be substituted;

is a single or double bond;

and salts or solvates thereof, wherein said at least one compound according to formula (I) activates the antigen presenting function of antigen presenting cells and said one or more different antigens elicits a balanced Th1/Th2 response.