Hemoglobin-based therapeutic agents

1. A hemoglobin-based therapeutic agent comprising a hemoglobin and a chemotherapeutic agent selected from the group consisting of maytansinoid, an auristatin, and a calicheamicin, wherein the chemotherapeutic agent is covalently attached to the hemoglobin via a linker, and wherein the linker has the Formula 1:

the linker has the Formula 2:

wherein A is the chemotherapeutic;

N* represents a nitrogen in a lysine side chain in the hemoglobin or a N-terminal amine in the hemoglobin;

S* represents a sulfur in a cysteine side chain in the hemoglobin; n is a whole number selected from 1-10; and

each R is hydrogen; or two R taken together with the carbons to which they are attached form a 3-7 membered cycloalkane and each remaining R is hydrogen.

2. The hemoglobin-based therapeutic agent of claim 1 , wherein the hemoglobin is selected from the group consisting of bovine hemoglobin, human hemoglobin, canine hemoglobin, porcine hemoglobin, equine hemoglobin, recombinant hemoglobin and a subunit thereof.

3. The hemoglobin-based therapeutic agent of claim 1 , wherein the hemoglobin comprises a di-alpha chain and two beta chains, wherein the di-alpha chain comprises a polypeptide sequence having at least 98.93% sequence homology with SEQ ID NO: 1, wherein the amino acids at position 1 and position 143 of SEQ ID NO: 1 must be methionine, the amino acids at position 29 and position 171 of SEQ ID NO: 1 must be phenylalanine, and the amino acids at position 58 and position 200 of SEQ ID NO: 1 must be glutamine; and the each of the two beta chains comprises a polypeptide sequence having at least 97.94% sequence homology with SEQ ID NO: 2, wherein the amino acid at position 1 must be methionine.

4. The hemoglobin-based therapeutic agent of claim 1 , wherein the molar drug ratio (MDR) of the hemoglobin-based therapeutic agent is between 1.0-5.0.

5. The hemoglobin-based therapeutic agent of claim 1 , wherein the chemotherapeutic agent is selected from the group consisting of mertansine (DM1), ravtansine (DM4), and monomethylauristatin E (MMAE).

6. The hemoglobin-based therapeutic agent of claim 1 , wherein n is a whole number between 2-6 and each R is hydrogen; or n is a whole number between 4-6; two R taken together with the carbons to which they are attached form a 4-6 membered cycloalkane and each remaining R is hydrogen.

7. The hemoglobin-based therapeutic agent of claim 1 , wherein the hemoglobin-based therapeutic agent is selected from the group consisting of:

wherein each N* independently represents a nitrogen in a lysine side chain in the hemoglobin or a N-terminal amine in the hemoglobin;

S* independently represents a sulfur in a cysteine side chain in the hemoglobin;

n is a whole number between 1-10;

each R is hydrogen; or two R taken together with the carbons to which they are attached form a 3-7 membered cycloalkane and each remaining R is hydrogen;

X is the MDR of the hemoglobin-based therapeutic agent, wherein X has a value between 1.0-5.0; and

Y is the MDR of the hemoglobin-based therapeutic agent, wherein Y has a value between 1.0-2.0.

8. The hemoglobin-based therapeutic agent of claim 1 , wherein the hemoglobin-based therapeutic agent is selected from the group consisting of:

wherein each N* independently represents a nitrogen in a lysine side chain in the hemoglobin or a N-terminal amine in the hemoglobin;

S* independently represents a sulfur in a cysteine side chain in the hemoglobin;

X is the MDR of the hemoglobin-based therapeutic agent, wherein X has a value between 1.0-5.0; and

Y is the MDR of the hemoglobin-based therapeutic agent, wherein Y has a value between 1.0-2.0.

9. The hemoglobin-based therapeutic agent of claim 1 , wherein the hemoglobin-based therapeutic agent has the formula:

wherein N* independently represents a nitrogen in a lysine side chain in the hemoglobin or a N-terminal amine in the hemoglobin; and

X is the MDR of the hemoglobin-based therapeutic agent, wherein X has a value between 2.0-5.0.

10. The hemoglobin-based therapeutic agent of claim 9 , wherein X has a value between 2.5-3.5.

11. The hemoglobin-based therapeutic agent of claim 1 further comprising a fluorescent dye.

12. A pharmaceutical composition comprising a hemoglobin-based therapeutic agent of claim 1 and at least one pharmaceutically acceptable carrier.

13. A method for preparing a hemoglobin-based therapeutic agent of Formula 3:

wherein A is DM1 or DM4;

X is the MDR of the hemoglobin-based therapeutic agent, wherein X has a value between 1.0-5.0;

N* independently represents a nitrogen in a lysine side chain in the hemoglobin or a N-terminal amine in the hemoglobin;

n is a whole number selected from 1-10; and

each R is hydrogen; or two R taken together with the carbons to which they are attached form a 3-7 membered cycloalkane and each remaining R is hydrogen, the method comprising:

contacting a hemoglobin with a compound of Formula 4:

wherein LG is a leaving group, thereby forming the hemoglobin-based therapeutic agent of Formula 3.

14. The method of claim 13 , wherein the molar ratio of hemoglobin to the compound of Formula 4 is between 1:4 to 1:6.

15. The method of claim 13 , wherein the compound of Formula 4 has the structure:

16. A method of treating cancer in a subject in need thereof, the method comprising administering a therapeutically effective amount of a hemoglobin-based therapeutic agent of claim 1 to the subject.

17. The method of claim 16 , wherein the cancer is selected from the group consisting of pancreatic cancer, leukemia, head and neck cancer, colorectal cancer, lung cancer, breast cancer, liver cancer, nasopharyngeal cancer, esophageal cancer, lymphoma, melanoma, and brain cancer.

18. The method of claim 16 , wherein said cancer is hepatocellular carcinoma, liver cancer progenitor cells-induced tumor, glioblastoma, or triple negative progenitor cells-induced tumor.

19. The method of claim 16 , wherein the hemoglobin-based therapeutic agent is administered intravenously, intraperitoneally, or subcutaneously.