Immunogenic compound

Abstract

The present application relates to an immunostimulatory compound comprising an immunostimulant portion and a peptide portion. The peptide portion is not a disease-associated immunogen. Furthermore, the peptide portion has an amino acid sequence in which 75% or less of the amino acid residues are hydrophobic and/or has an isoelectric point of 5 or greater. The compounds of the invention address the problem of systemic distribution of immunostimulants causing unwanted side effects. The inventors have found that the physicochemical properties of the immunostimulant can be controlled by covalent linkage to a peptide. Further physicochemical properties may be modified in a useful manner by incorporating additional features.

1 - 31 . (canceled) 
     
     
         32 . An immunostimulatory compound comprising (i) an immunostimulant portion covalently coupled to (ii) a peptide portion,
 wherein the immunostimulant portion is selected from a Toll-like receptor 7 (TLR7) or TLR8 agonist, or a NOD-like receptor (NLR) agonist (NOD1 or NOD2) and wherein the immunostimulant portion comprises at least one of an imidazopyridine moiety, an imidazoquinoline moiety, a muramyl dipeptide moiety, a muramyl tripeptide moiety, and a γ-D-glutamyl-meso-diaminopimelic acid moiety; and,   wherein the peptide portion is 17 to 45 amino acids in length and comprises an amino acid sequence of RRLLHALLALLAHLLRR (SEQ ID NO: 17).   
     
     
         33 . The compound of  claim 32 , further comprising a spacer portion between the immunostimulant portion and the peptide portion. 
     
     
         34 . The compound of  claim 33 , wherein the spacer portion comprises an acid-cleavable or an enzymatically cleavable linker. 
     
     
         35 . The compound of  claim 32 , wherein the immunostimulant portion has a structure according to any one of Formulae (I), (IIa), (IIb), (IIIa), (IIIb) or (IV): 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R1, R4 and R5 are each independently selected from H or C1-C6 branched or unbranched alkyl or alkenyl, or R4 and R5 together with the carbon atoms to which they are attached form a 4-, 5-, 6-, 7- or 8-membered cycloalkyl, cycloalkenyl, or aromatic hydrocarbon ring, 
         with up to two carbon atoms in each of R1, R4, and R5, or R4 and R5 in combination, being replaceable with heteroatoms selected from O, N and S; and 
         the wavy line indicates the point of attachment to the remainder of the compound. 
       
     
     
         36 . The compound of  claim 32 , wherein the immunostimulant portion has a structure according to Formula (VI): 
       
         
           
           
               
               
           
         
       
     
     
         37 . The compound of  claim 32 , wherein the peptide portion comprises a terminal lysine. 
     
     
         38 . The compound of  claim 32 , wherein the immunostimulant portion comprises a compound selected from N-acetylmuramyl-L-alanyl-D-isoglutamine, N-glycolylmuramyl-L-alanyl-D-isoglutamine, N-acetylmuramyl-L-alanyl-D-glutamine n-butyl ester (murabutide), N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-lysine, N-acetylmuramyl-L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, N-acetyl-D-glucosaminyl-(β-1,4)-N-acetylmuramyl-L-alanyl-D-isoglutamine, 6-O-stearoyl-N-acetylmuramyl-L-alanyl-D-isoglutamine, mifamurtide, N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine cholesterol ester, γ-D-glutamyl-meso-diaminopimelic acid, L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, N-acetylmuramyl-L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, lauroyl-γ-D-glutamyl-meso-diaminopimelic acid, 6-O—(N-acetylmuramyl-L-alanyl-D-isoglutamine)-yl, N-acetylmuramyl-L-alanyl-D-isoglutaminyl, N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanyl, or 6-O—(N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine)-yl. 
     
     
         39 . A pharmaceutical composition comprising an immunostimulatory compound and a pharmaceutically acceptable carrier or diluent, wherein the immunostimulatory compound comprises (i) an immunostimulant portion covalently coupled to (ii) a peptide portion,
 wherein the immunostimulant portion is selected from a Toll-like receptor 7 (TLR7) or TLR8 agonist, or a NOD-like receptor (NLR) agonist (NOD1 or NOD2) and wherein the immunostimulant portion comprises at least one of an imidazopyridine moiety, an imidazoquinoline moiety, a muramyl dipeptide moiety, a muramyl tripeptide moiety, and a γ-D-glutamyl-meso-diaminopimelic acid moiety; and,   wherein the peptide portion is 17 to 45 amino acids in length and comprises an amino acid sequence of RRLLHALLALLAHLLRR (SEQ ID NO: 17).   
     
     
         40 . The composition of  claim 39 , wherein the composition is present as a liquid, aerosol, solid, injectable solution, spray, suspension or emulsion. 
     
     
         41 . The composition of  claim 39 , wherein the immunostimulatory compound further comprises a spacer portion between the immunostimulant portion and the peptide portion. 
     
     
         42 . The composition of  claim 41 , wherein the spacer portion comprises an acid-cleavable or an enzymatically cleavable linker. 
     
     
         43 . The composition of  claim 39 , wherein the immunostimulant portion has a structure according to any one of Formulae (I), (IIa), (IIb), (IIIa), (IIIb) or (IV): 
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         wherein R1, R4 and R5 are each independently selected from H or C1-C6 branched or unbranched alkyl or alkenyl, or R4 and R5 together with the carbon atoms to which they are attached form a 4-, 5-, 6-, 7- or 8-membered cycloalkyl, cycloalkenyl, or aromatic hydrocarbon ring, 
         with up to two carbon atoms in each of R1, R4, and R5, or R4 and R5 in combination, being replaceable with heteroatoms selected from O, N and S; and 
         the wavy line indicates the point of attachment to the remainder of the compound. 
       
     
     
         44 . The composition of  claim 39 , wherein the immunostimulant portion has a structure according to Formula (VI): 
       
         
           
           
               
               
           
         
       
     
     
         45 . The composition of  claim 39 , wherein the peptide portion comprises a terminal lysine. 
     
     
         46 . The composition of  claim 39 , wherein the immunostimulant portion comprises a compound selected from N-acetylmuramyl-L-alanyl-D-isoglutamine, N-glycolylmuramyl-L-alanyl-D-isoglutamine, N-acetylmuramyl-L-alanyl-D-glutamine n-butyl ester (murabutide), N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-lysine, N-acetylmuramyl-L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, N-acetyl-D-glucosaminyl-(β-1,4)-N-acetylmuramyl-L-alanyl-D-isoglutamine, 6-O-stearoyl-N-acetylmuramyl-L-alanyl-D-isoglutamine, mifamurtide, N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine cholesterol ester, γ-D-glutamyl-meso-diaminopimelic acid, L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, N-acetylmuramyl-L-alanyl-γ-D-glutamyl-meso-diaminopimelic acid, lauroyl-γ-D-glutamyl-meso-diaminopimelic acid, 6-O—(N-acetylmuramyl-L-alanyl-D-isoglutamine)-yl, N-acetylmuramyl-L-alanyl-D-isoglutaminyl, N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanyl, or 6-O—(N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-alanine)-yl. 
     
     
         47 . A method of stimulating an immune response, comprising:
 administering intratumorally an immunostimulatory compound of  claim 32  to a subject in need thereof.   
     
     
         48 . The method of  claim 47 , wherein the immunostimulatory compound is present as a liquid, injectable solution, suspension or emulsion. 
     
     
         49 . A method of stimulating an anti-tumor immune response, comprising administering an immunostimulatory compound of  claim 32  to a subject in need thereof. 
     
     
         50 . The method of  claim 49 , wherein administering is via parenteral, subcutaneous, oral, epidermal, intradermal, intramuscular, intraarterial, intraperitoneal, intratumoral, intravesical or intravenous injection; or topically to skin or mucosa. 
     
     
         51 . The method of  claim 49 , wherein the immunostimulatory compound is present as a liquid, aerosol, solid, injectable solution, spray, suspension or emulsion.