Modified erythropoietin polypeptides and uses thereof for treatment

1. A modified erythropoietin (EPO) polypeptide or an active fragment thereof, comprising the amino acid replacement K20Q or a replacement corresponding to K20Q in a mature EPO polypeptide set forth in SEQ ID NO:2 or 237, wherein:

if the polypeptide is an active fragment, the active fragment contains the modification;

the modified erythropoietin polypeptide or an active fragment thereof exhibits increased resistance to proteolysis compared to the unmodified erythropoietin polypeptide that does not contain the modification; and

the modified erythropoietin polypeptide or an active fragment thereof retains one or more activities of the unmodified EPO polypeptide.

2. The modified polypeptide of claim 1 that is an active fragment that includes the K20Q modification.

3. The EPO polypeptide of claim 1 that is 160, 161, 162, 163, 164, 165 or 166 amino acids in length.

4. The modified EPO polypeptide of claim 1 that has the sequence of amino acids set forth in SEQ ID NO. 2 or 237 with the amino acid replacement K20Q and also comprising the amino acid replacement R139H, wherein the amino acid replacements correspond to amino acid replacements in a mature erythropoietin cytokine having the sequence set forth in SEQ ID NO: 2 or SEQ ID NO: 237.

5. The modified EPO polypeptide of claim 1 that comprises the sequence of amino acids set forth in any of SEQ ID NOS: 202-213, 215, 217-222 and 224-226, wherein:

the amino acid in the modified erythropoietin polypeptide at the position corresponding to position 20 in the mature EPO polypeptide with the sequence of amino acids set forth in SEQ ID NO:2 or 237 is replaced with Q;

the amino acid in the modified erythropoietin polypeptide at the position corresponding to position 139 in the mature EPO polypeptide whose sequence is set forth in SEQ ID NO:2 or 237 is replaced with H; and

corresponding positions are determined by sequence alignment.

6. The EPO polypeptide of claim 1 that is 165 or 166 amino acids in length.

7. A pharmaceutical composition, comprising a polypeptide of claim 1 and a pharmaceutically acceptable carrier or excipient.

8. The modified Erythropoietin (EPO) polypeptide or active fragment thereof of claim 1 , comprising K20Q and R139H, wherein the amino acid replacements correspond to amino acid replacements in a mature erythropoietin polypeptide having the sequence of amino acids set forth in SEQ ID NO: 2 or SEQ ID NO: 237.

9. The modified polypeptide of claim 8 that is a precursor form of the EPO polypeptide.

10. The modified polypeptide of claim 8 that is a mature form of the EPO polypeptide.

11. The modified EPO polypeptide of claim 8 , that comprises the sequence of amino acids set forth in any of SEQ ID NOS: 2, 228, 309, 310 and 237 with the modifications K20Q and R139H or an EPO polypeptide that is an allelic or species variant thereof or is a variant that has 95% sequence identity with the sequence of amino acids set forth in any of SEQ ID NOS: 2, 228, 309, 310 and 237 and comprises the amino acid replacements Q and H at a position corresponding to K20 and R139, respectively.

12. The modified EPO polypeptide of claim 8 , comprising another amino acid replacement at an amino acid position selected from among 2, 3, 4, 5, 7, 8, 10, 12, 13, 14, 15, 16, 17, 18, 21, 23, 29, 31, 35, 37, 42, 43, 45, 48, 49, 51, 52, 53, 54, 55, 62, 64, 67, 69, 70, 72, 75, 76, 80, 81, 87, 88, 89, 90, 91, 93, 96, 97, 102, 103, 105, 108, 109, 110, 112, 116, 117, 121, 122, 123, 129, 130, 131, 136, 138, 140, 141, 142, 143, 145, 148, 149, 150, 152, 153, 154, 155, 156, 159, 162, 165, and 166, wherein said amino acid positions reference the positions in a mature human EPO polypeptide having the sequence set forth in SEQ ID NO: 2 or 237.

13. The modified EPO polypeptide of claim 12 , wherein the amino acid replacement(s) is/are selected from among P2S, P2A, P3S, P3A, R4H, R4Q, L5I, L5V, C7S, C7V, C7A, C7I, C7T, D8Q, D8H, D8N, R10H, R10Q, L12V, L12I, E13Q, E13H, E13N, R14H, R14Q, Y15H, Y15I, L16I, L16V, L17I, L17V, E18Q, E18H, E18N, E21Q, E21H, E21N, E23Q, E23H, E23N, C29S, C29V, C29A, C29I, C29T, E31Q, E31H, E31N, L35V, L35I, E37Q, E37H, E37N, P42S, P42A, D43Q, D43H, D43N, K45Q, K45T, K45N, F48I, F48V, Y49H, Y49I, W51S, W51H, K52Q, K52T, K52N, R53H, R53Q, M54V, M54I, E55Q, E55H, E55N, E62Q, E62H, E62N, W64S, W64H, L67I, L67V, L69V, L69I, L70I, L70V, E72Q, E72H, E72N, L75V, L75I, R76H, R76Q, L80V, L80I, L81I, L81V, P87S, P87A, W88S, W88H, E89Q, E89H, E89N, P90S, P90A, L91I, L91V, L93V, L93I, D96Q, D96H, D96N, K97Q, K97T, K97N, L102V, L102I, R103H, R103Q, L105I, L105V, L108I, L108V, L109I, L109V, R110H, R110Q, L112V, L112I, K116Q, K116T, K116N, E117Q, E117H, E117N, P121S, P121A, P122S, P122A, D123Q, D123H, D123N, P129S, P129A, L130V, L130I, R131H, R131Q, D136Q, D136H, D136N, F138I, F138V, K140N, K140Q, L141I, L141V, F142I, F142V, R143H, R143Q, Y145H, Y145I, F148I, F148V, L149I, L149V, R150H, R150Q, K152Q, K152T, K152N, L153I, L153V, K154Q, K154T, K154N, L155V, L155I, Y156H, Y156I, E159Q, E159H, E159N, R162H, R162Q, D165Q, D165H, D165N, R166H, and R166Q.

14. The modified EPO polypeptide of claim 13 , wherein the amino acid replacements in the modified EPO are selected from among R139H/K20Q, K20Q/L80I/R139H, K20Q/L93I/R139H, K20Q/L93V/R139H, R4H/K20Q/R139H/L80I, E159N/K20Q/R139H/L93I, K20Q/R139H/L153V, L153V/K20Q/R139H/L80I and E159N/K20Q/R139H/L80I.

15. The modified EPO polypeptide of claim 8 that comprises one or more further amino acid replacement(s) selected from among A30N, H32T, P87V, W88N, and P90T.

16. A modified EPO polypeptide of claim 8 , further comprising one or more additional amino acid modification(s) that eliminates one up to all glycosylation sites.

17. The modified EPO polypeptide of claim 16 , wherein the glycosylation site is an O-glycosylation site or is an N-glycosylation site.

18. The modified EPO polypeptide of claim 17 , wherein the glycosylation site is an O-glycosylation site and is S126.

19. The modified EPO polypeptide of claim 17 , wherein the glycosylation site is an N-glycosylation site and is selected from among N24, N38 and N83.

20. The modified EPO polypeptide of claim 19 , wherein the amino acid replacement is selected from among N24H, N38H, N83H, N24K, N38K, N83K, N38H/N83H and N24H/N38H/N83H.

21. The modified EPO polypeptide of claim 16 , wherein the one or more additional amino acid modifications are selected from natural amino acids, non-natural amino acids and a combination of natural and non-natural amino acids.

22. The modified EPO polypeptide of claim 8 that is a mature form of an EPO polypeptide or that is a precursor form of an EPO polypeptide.

23. A pharmaceutical composition, comprising a polypeptide of claim 8 and a pharmaceutically acceptable carrier or excipient.

24. The pharmaceutical composition of claim 23 that is formulated as a liquid, a pill, a tablet, a lozenge or a capsule for oral administration.

25. The EPO polypeptide of claim 8 that is 165 or 166 amino acids in length.

26. A modified erythropoietin (EPO) polypeptide or an active fragment thereof, comprising the amino acid replacement K20Q or a replacement corresponding to K20Q in a mature EPO polypeptide set forth in SEQ ID NO:2 or 237, wherein:

the modified erythropoietin polypeptide or an active fragment thereof retains one or more activities of the unmodified EPO polypeptide;

if the polypeptide is an active fragment, the active fragment contains the modification; and

the modified EPO polypeptide comprises amino acid replacements selected from among N38H/R139H/K20Q, K20Q/N38H/N83H/R139H, K20Q/N38H/L80I/N83H/R139H, K20Q/N38H/N83H/L93I/R139H, K20Q/N38H/N83H/L93V/R139H, K20Q/N24H/N38H/N83H/R139H/L80I, K20Q/N24H/N38H/N83H/R139H/L93I, K20Q/N24H/N38H/N83H/R139H/L93V, R4H/K20Q/N24H/N38H/N83H/R139H/L80I, E159N/K20Q/N24H/N38H/N83H/R139H/L93I, K20Q/N24H/N38H/N83H/R139H/L153V, L153V/K20Q/N24H/N38H/N83H/R139H/L80 I and E159N/K20Q/N24H/N38H/N83H/R139H/L80I.

27. The modified EPO polypeptide of claim 26 that comprises one or more further amino acid replacement(s) selected from among A30N, H32T, P87V, W88N, and P90T.