Adrenocorticotropic hormone analogs and related methods

Abstract

ACTH analog compounds of the present invention include compounds comprising an ACTH peptide sequence with one or more structural modifications that can have one or more of the following preferred ACTH analog biological functions: (1) reduction of corticosteroid secretion by adrenal membrane in the presence of the ACTH analog compared to unmodified ACTH, (2) reduction of corticosteroid secretion by adrenal membrane in the presence of endogenous ACTH and (3) increased MC-2R binding affinity with reduced activation of the MC-2R receptor compared to unmodified ACTH binding to the MC-2R melanocortin. The ACTH analog compounds of the present invention are therefore useful for treatment or prevention of diseases and disorders related to ACTH, ACTH receptors or corticosteroid secretion, such as premature labor and Cushing's Disease.

1 . A composition comprising an isolated ACTH analog peptide, the ACTH analog peptide comprising the peptide of SEQ ID NO:2 with at least one of the following amino acid substitutions:
 a. the substitution of the Pro residue at position 19 of SEQ ID NO:2 with the amino acid Trp; or   b. one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:2, such that
 i. the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg; and 
 ii. the one or more amino acid residues substituted at position 16, 17 or 18 of SEQ ID NO:2 are selected from the group consisting of: Lys, Arg, Ala, Gly, Val, Leu, Ile, an amino acid analog comprising an alkyl side chain, Gln, Asn, Glu, and Asp. 
   
     
     
         2 . The composition of  claim 1 , wherein the ACTH analog peptide comprises at least one Ala and at least one Arg residue substituted at any two of the amino acid positions 15, 16, 17 or 18 of SEQ ID NO:2. 
     
     
         3 . The composition of  claim 1 , wherein the ACTH analog consists essentially of the sequence of SEQ ID NO:2 with the following amino acid substitutions: the Pro residue at position 19 of SEQ ID NO:2 is substituted with the amino acid Trp; the amino acid at position 15 of SEQ ID NO:2 is selected from the group consisting of: Lys, Ala and Gln; and the ACTH analog peptide comprises one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:2, such that the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg. 
     
     
         4 . The composition of  claim 1 , wherein the ACTH analog peptide includes the amino acid sequence -His 6 -Phe 7 -Arg 8 -Trp 9 - at amino acid residues 6-9. 
     
     
         5 . The composition of  claim 1 , wherein the ACTH analog peptide includes the amino acid sequence -Lys 15 -Arg 16 -Ala 17 -Ala 18 -Trp 19 - at amino acid residues 15-19. 
     
     
         6 . The composition of  claim 1 , wherein the administration of the ACTH analog peptide in an in vivo Serum Corticosteroid Inhibition Assay reduces ACTH-induced corticosteroid secretion by at least 10%. 
     
     
         7 . The composition of  claim 1 , wherein the ACTH analog peptide binds to and displaces a peptide of SEQ ID NO:2 from adrenal membrane, where the peptide binding is measured by an in vitro Serum-free Adrenal Competitive Binding Assay. 
     
     
         8 . The composition of  claim 7 , wherein the ACTH analog peptide binds to the MC-2R adrenal membrane with at least a 2-fold greater affinity than the peptide of SEQ ID NO:2. 
     
     
         9 . The composition of  claim 1 , wherein the ACTH analog peptide reduces the ACTH induced production of corticosterone by adrenal membrane in an in vitro Serum-free Adrenal Inhibition Assay. 
     
     
         10 . A composition comprising an isolated ACTH analog peptide, the ACTH analog peptide comprising the peptide of SEQ ID NO:2 with at least one amino acid substitution, wherein the ACTH analog peptide binds to and displaces a peptide of SEQ ID NO:2 from adrenal membrane, where the peptide binding is measured by an in vitro Serum-free Adrenal Competitive Binding Assay. 
     
     
         11 . The composition of  claim 10 , wherein the ACTH analog peptide comprises with at least one of the following amino acid substitutions:
 (a) the substitution of the Pro residue at position 19 of SEQ ID NO:2 with the amino acid Trp; or   (b) one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:2, such that the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg; and the one or more amino acid residues substituted at position 16, 17 or 18 of SEQ ID NO:2 are selected from the group consisting of: Lys, Arg, Ala, Gly, Val, Leu, Ile, an amino acid analog comprising an alkyl side chain, Gin, Asn, Glu, and Asp.   
     
     
         12 . The composition of  claim 10 , wherein the ACTH analog peptide includes the amino acid sequence -Lys 15 -Arg 16 -Ala 17 -Ala 18 -Trp 19 - at amino acid residues 15-19. 
     
     
         13 . The composition of  claim 10 , wherein the ACTH analog peptide reduces the ACTH induced production of corticosterone by adrenal membrane in an in vitro Serum-free Adrenal Inhibition Assay. 
     
     
         14 . The composition of  claim 10 , wherein the administration of the ACTH analog peptide reduces ACTH-induced corticosteroid induction by at least 10%, wherein corticosterone induction is measured by an in vivo Serum Corticosteroid Inhibition Assay. 
     
     
         15 . The composition of  claim 10 , wherein the ACTH analog peptide reduces the ACTH induced production of corticosterone by adrenal membrane in an in vitro Serum Corticosteroid Induction Assay by at least 10% compared to the peptide of SEQ ID NO:2. 
     
     
         16 . A composition comprising an isolated ACTH analog peptide comprising the peptide of SEQ ID NO:1 with at least one amino acid substitution, wherein the ACTH analog peptide reduces the ACTH-induced production of corticosterone by adrenal membrane in an in vitro Serum Corticosteroid Induction Assay by at least 10% compared to the peptide of SEQ ID NO:2, wherein the at least one amino acid substitution includes substitution of an amino acid residue at position 19, 26, 30 or 36 of SEQ ID NO:1. 
     
     
         17 . The composition of  claim 16 , wherein the ACTH analog peptide with at least one of the following amino acid substitutions:
 (a) the substitution of the Pro residue at position 19 of SEQ ID NO:1 with the amino acid Trp; or   (b) one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:1, such that the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg; and the one or more amino acid residues substituted at position 16, 17 or 18 of SEQ ID NO:2 is selected from the group consisting of: Lys, Arg, Ala, Gly, Val, Leu, Ile, an amino acid analog comprising an alkyl side chain, Gln, Asn, Glu, and Asp.   
     
     
         18 . The composition of  claim 16 , wherein the ACTH analog peptide includes the amino acid sequence -Lys 15 -Arg 16 -Ala 17 -Ala 18 -Trp 19 - at amino acid residues 15-19. 
     
     
         19 . The composition of  claim 16 , wherein the ACTH analog further comprises truncation of amino acid residues 25-39 of SEQ ID NO:1. 
     
     
         20 . The composition of  claim 16 , wherein the ACTH analog peptide comprises the peptide of SEQ ID NO:20. 
     
     
         21 . A method of manufacturing a medicament for treating an ACTH-related condition, comprising the step of combining an ACTH analog with a suitable carrier, the ACTH analog comprising the peptide of SEQ ID NO:2 with at least one of the following amino acid substitutions:
 a. the substitution of the Pro residue at position 19 of SEQ ID NO:2 with the amino acid Trp; or   b. one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:2, such that
 i. the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg; and 
 ii. the one or more amino acid residues substituted at position 16, 17, or 18 of SEQ ID NO:2 are selected from the group consisting of: Lys, Arg, Ala, Gly, Val, Leu, Ile, an amino acid analog comprising an alkyl side chain, Gln, Asn, Glu, and Asp. 
   
     
     
         22 . The method of  claim 21 , wherein elevated blood corticosteroid concentration is a symptom of the ACTH-related condition. 
     
     
         23 . The method of  claim 21 , wherein the ACTH-related condition is selected from the group consisting of: Cushing's Disease, premature labor, a pituitary tumor, and a pathology of the hypothalamus/pituitary/interrenal (HPI) axis. 
     
     
         24 . The method of  claim 21 , wherein the medicament is formulated for administration by injection, inhalation or transdermal absorption. 
     
     
         25 . The method of  claim 21 , wherein the medicament comprises the ACTH analog of SEQ ID NO:20. 
     
     
         26 . A method of treating an ACTH-related condition comprising the administration of a pharmaceutical composition comprising an ACTH analog to a subject, the ACTH analog comprising the peptide of SEQ ID NO:2 with at least one of the following amino acid substitutions:
 a. the substitution of the Pro residue at position 19 of SEQ ID NO:2 with the amino acid Trp; or   b. one or more amino acid substitutions of residues selected from amino acid residues 16 to 18 of SEQ ID NO:2, such that
 i. the amino acid residues 16, 17 and 18 of the ACTH analog do not include any two adjacent amino acid residues selected from the group consisting of: Lys and Arg; and 
 ii. the one or more amino acid residues substituted at position 16, 17 or 18 of SEQ ID NO:2 are selected from the group consisting of: Lys, Arg, Ala, Gly, Val, Leu, Ile, an amino acid analog comprising an alkyl side chain, Gln, Asn, Glu, and Asp. 
   
     
     
         27 . The method of  claim 26 , wherein the pharmaceutical composition is formulated for formulated for administration by injection, inhalation or transdermal absorption into a subject. 
     
     
         28 . The method of  claim 27 , wherein the pharmaceutical composition is formulated for injection, wherein the method further comprises the step of injecting the pharmaceutical composition into the subject. 
     
     
         29 . The method of  claim 26 , further comprising the step of measuring the blood corticosteroid level of the subject before administering the pharmaceutical composition. 
     
     
         30 . The method of  claim 28 , wherein the pharmaceutical composition is injected subcutaneously or intravenously. 
     
     
         31 . The method of  claim 28 , further comprising the step of administering a pharmaceutical agent to lower the corticosteroid blood level of the subject before injecting the pharmaceutical composition into the subject. 
     
     
         32 . The method of  claim 31 , wherein the pharmaceutical agent to lower the corticosteroid blood level comprises dexamethasone. 
     
     
         33 . The method of  claim 26 , wherein the subject is a human. 
     
     
         34 . The method of  claim 26 , wherein the pharmaceutical composition comprises a sustained release composition. 
     
     
         35 . The method of  claim 26 , wherein the pharmaceutical composition comprises the ACTH analog of SEQ ID NO:20. 
     
     
         36 . A method of screening ACTH analog compounds to identify ACTH analog compounds that induce less corticosteroid secretion by adrenal membrane than by unmodified ACTH of SEQ ID NO:2, comprising the step of contacting an adrenal membrane with an ACTH analog. 
     
     
         37 . The method of  claim 36 , wherein the method of screening further comprises the steps of:
 a. providing a first adrenal membrane and a second adrenal membrane;   b. contacting the first adrenal membrane a first composition comprising an unmodified peptide comprising SEQ ID NO:2, and subsequently measuring a first concentration of corticosteroid secreted by the first adrenal membrane after contact with the unmodified peptide comprising SEQ ID NO:2; and   c. contacting the second adrenal membrane with a second composition comprising the ACTH analog, and subsequently measuring a second concentration of corticosteroid secreted by the second adrenal membrane after contacting the ACTH analog.   
     
     
         38 . The method of  claim 37 , further comprising the step of: comparing the first concentration of corticosteroid secreted with the second concentration of corticosteroid secreted. 
     
     
         39 . The method of  claim 38 , further comprising the step of: determining whether the second compound induces less corticosteroid secretion than the first compound. 
     
     
         40 . The method of  claim 36 , wherein the ACTH analog is an ACTH analog of SEQ ID NO:20. 
     
     
         41 . The method of  claim 36 , wherein the first adrenal membrane and the second adrenal membrane are positioned within a subject and wherein the concentration of corticosteroid is measured in the blood of the subject. 
     
     
         42 . The method of  claim 36 , wherein the first adrenal membrane and the second adrenal membrane are explanted from the subject and wherein the concentration of corticosteroid is measured in serum-free media.