Glycemic Control Using Intrinsic Factor Bound to A Vitamin B12 Conjugate of a Glucagon-Like Peptide-1 Receptor Agonist

Abstract

The present invention provides compositions and methods for lowering blood glucose. More specifically, the present invention provides compositions comprising a complex comprising IF and B12 conjugated to a peptide comprising a GLP-1 agonist. Advantageously, the composition may be delivered subcutaneously.

What is claimed is: 
     
         1 . A subcutaneous delivery mechanism for a drug, comprising:
 a) a molecule of B 12  conjugated to a target peptide; and   b) intrinsic factor bound to the conjugate of the molecule of B 12  and the target peptide.   
     
     
         2 . The delivery mechanism of  claim 1 , wherein the conjugate of the molecule of B 12  and the target peptide includes a spacer having between three and six carbon atoms positioned between the molecule of B 12  and the target peptide. 
     
     
         3 . The mechanism of  claim 2 , wherein the target peptide comprises exendin-4. 
     
     
         4 . The mechanism of  claim 3 , wherein the peptide is conjugated to a 5′ hydroxyl group of the molecule of B 12  that has been oxidized to a carboxylic acid. 
     
     
         5 . A method of enhancing a subcutaneously delivered target peptide, comprising the steps of:
 a) conjugating a molecule of B 12  to the target peptide; and   b) binding intrinsic factor to the conjugate of the molecule of B 12  and the target peptide.   
     
     
         6 . The method of  claim 5 , wherein the steps of conjugating the molecule of B 12  to the target peptide and binding intrinsic fact to the conjugate are performed prior to subcutaneous administration of the target peptide. 
     
     
         7 . The method of  claim 6 , wherein the conjugate of the molecule of B 12  and the target peptide includes a spacer having between three and six carbon atoms positioned between the molecule of B 12  and the target peptide. 
     
     
         8 . The method of  claim 7 , wherein the target peptide comprises exendin-4. 
     
     
         9 . The method of  claim 8 , wherein the peptide is conjugated to a 5′ hydroxyl group of the molecule of B 12  that has been oxidized to a carboxylic acid. 
     
     
         10 . A pharmaceutical composition for subcutaneous or intraperitoneal administration, the pharmaceutical composition comprising a pharmaceutically acceptable intrinsic factor complexed with B 12  or an analog thereof, wherein the B 12  or analog thereof is conjugated to a peptide comprising a glucagon-like peptide-1 (GLP-1) receptor agonist. 
     
     
         11 . The pharmaceutical composition of  claim 10 , further comprising one or more pharmaceutically acceptable diluents, excipients, and/or carriers. 
     
     
         12 . The pharmaceutical composition of  claim 10 , wherein the peptide is conjugated to B 12  at the 5′ hydroxyl residue of the ribosyl group. 
     
     
         13 . The pharmaceutical composition of  claim 12 , wherein the 5′-hydroxyl of the ribose is oxidized to a carboxylic acid prior to conjugation to the peptide. 
     
     
         14 . The pharmaceutical composition of  claim 10 , further comprising a linker. 
     
     
         15 . The pharmaceutical composition of  claim 14 , wherein the linker comprises between three and six carbon atoms. 
     
     
         16 . The pharmaceutical composition of  claim 10 , wherein the linker comprises 4 carbon atoms. 
     
     
         17 . The pharmaceutical composition of  claim 10 , wherein the peptide comprises EX-4. 
     
     
         18 . The pharmaceutical composition of  claim 10 , wherein the peptide comprises the sequence set forth in SEQ ID NO:1 or SEQ ID NO:2. 
     
     
         19 . The pharmaceutical composition of  claim 18 , wherein the peptide comprising SEQ ID NO:1 is conjugated to the 5′-hydroxyl group of the ribose of B 12  via the azido group at lysine 12 of the peptide. 
     
     
         20 . The pharmaceutical composition of  claim 10 , wherein the IF is purified from a transgenic plant. 
     
     
         21 . A method to lower blood glucose in a subject, the method comprising subcutaneously or intraperitoneally administering to the subject an effective amount of a pharmaceutical composition comprising intrinsic factor complexed with B 12  or an analog thereof, wherein the B 12  or analog thereof is conjugated to a peptide comprising a glucagon-like peptide-1 (GLP-1) receptor agonist. 
     
     
         22 . A method for treating diabetes mellitus in a subject, the method comprising subcutaneously or intraperitoneally administering to the subject an effective amount of a pharmaceutical composition comprising intrinsic factor complexed with B 12  or an analog thereof, wherein the B 12  or analog thereof is conjugated to a peptide comprising a glucagon-like peptide-1 (GLP-1) receptor agonist. 
     
     
         23 . The method of  claim 21 , wherein the lowering of blood glucose is increased relative to the lowering of blood glucose with the peptide conjugated to B 12 . 
     
     
         24 . The method of  claim 21  or  22 , wherein the pharmaceutical composition further comprises one or more pharmaceutically acceptable diluents, excipients, and/or carriers. 
     
     
         25 . The method of  claim 21  or  22 , wherein the peptide is conjugated to B 12  at the 5′ hydroxyl residue of the ribosyl group. 
     
     
         26 . The method of  claim 25 , wherein the 5′-hydroxyl of the ribose is oxidized to a carboxylic acid prior to conjugation to the peptide. 
     
     
         27 . The method of  claim 21  or  22 , wherein the B 12  or analog thereof is conjugated to the peptide via a linker. 
     
     
         28 . The method of  claim 27 , wherein the linker comprises between three and six carbon atoms. 
     
     
         29 . The method of  claim 27 , wherein the linker comprises 4 carbon atoms. 
     
     
         30 . The method of  claim 21  or  22 , wherein the peptide comprises EX-4. 
     
     
         31 . The method of  claim 21  or  22 , wherein the peptide comprises the sequence set forth in SEQ ID NO:1 or SEQ ID NO:2. 
     
     
         32 . The method of  claim 31 , wherein the peptide comprising SEQ ID NO:1 is conjugated to the 5′-hydroxyl group of the ribose of B 12  via the azido group at lysine 12 of the peptide. 
     
     
         33 . The method of  claim 21  or  22 , wherein the IF is purified from a transgenic plant. 
     
     
         34 . A pharmaceutical composition for subcutaneous or intraperitoneal administration, the pharmaceutical composition comprising an intrinsic factor complexed with B 12  or an analog thereof, wherein the B 12  or analog thereof is conjugated to a peptide comprising a glucagon-like peptide-1 (GLP-1) receptor agonist. 
     
     
         35 . A method of mitigating the effect of TCII sequestration of a B 12  conjugate after administration of the conjugate to a subject, the method comprising complexing the B 12  conjugate with IF before administering the complex to the subject. 
     
     
         36 . The method of  claim 35 , wherein the complex is administered subcutaneously or intraperitonealy. 
     
     
         37 . The method of  claim 35 , wherein the complex is administered parenterally.