Pegylated L-Asparaginase
Disclosed is a conjugate of a protein having substantial L-asparagine aminohydrolase activity and polyethylene glycol. In particular, the polyethylene glycol has a molecular weight less than or equal to about 5000 Da and the protein is an L-asparaginase from Erwinia . The conjugate of the invention has shown superior properties such as maintenance of a high level of in vitro activity and an unexpected increase in half-life in vivo. Also disclosed are methods of producing the conjugate and use of the conjugate in therapy. In particular, a method is disclosed for use of the conjugate in the treatment of cancer, particularly Acute Lymphoblastic Leukemia (ALL). More specifically, a method is disclosed for use of the conjugate as a second line therapy for patients who have developed hypersensitivity or have had a disease relapse after treatment with other L-asparaginase preparations.
1 . A conjugate comprising an L-asparaginase from Erwinia chrysanthemi having the amino acid of SEQ ID NO: 1 and polyethylene glycol (PEG), wherein the PEG has a molecular weight less than or equal to about 5000 Da.
2 - 30 . (canceled)
31 . The conjugate of claim 1 , wherein the PEG is covalently linked to one or more amino groups of said L-asparaginase.
32 . The conjugate of claim 31 , wherein the PEG is covalently linked to said one or more amino groups by an amide bond.
33 . (canceled)
34 . The conjugate of claim 31 , wherein the PEG is covalently linked to at least from about 40% to about 90% of total amino groups.
35 - 38 . (canceled)
39 . The conjugate of claim 1 , wherein said PEG is monomethoxy-polyethylene glycol.
40 - 49 . (canceled)
50 . A method of treating a disease treatable by L-asparagine depletion in a human patient, said method comprising administering to said patient an effective amount of the conjugate claim 1 .
51 . The method of claim 50 , wherein said disease treatable by L-asparagine depletion is a cancer.
52 . The method of claim 51 , wherein said cancer is selected from the group consisting of Acute Lymphoblastic Leukemia (ALL), acute myeloid leukemia (AML), non-Hodgkin's lymphoma, NK lymphoma, and pancreatic cancer.
53 . The method of claim 52 , wherein said cancer is ALL.
54 . The method of claim 53 , wherein said conjugate is administered at an amount of about 5 U/kg to about 25 U/kg.
55 . The method of claim 54 , wherein said conjugate is administered at an amount of about 25 U/kg.
56 - 59 . (canceled)
60 . The method of claim 50 , wherein said conjugate is administered intravenously.
61 . The method of claim 50 , wherein said conjugate is administered intramuscularly.
62 . The method of claim 50 , wherein said conjugate is administered once per week.
63 . The method of claim 50 , wherein. said conjugate is administered twice per week.
64 . The method of claim 50 , wherein said conjugate is administered less than once per week.
65 . The method of claim 50 , wherein said conjugate is administered as monotherapy.
66 . The method of claim 65 , wherein said conjugate is not administered with an asparagine synthetase inhibitor.
67 . The method of claim 50 , wherein said human patient has had a previous hypersensitivity to an E. coli L-asparaginase or PEGylated form thereof.
68 . (canceled)
69 . The method of claim 67 , wherein said hypersensitivity is selected from the group consisting of allergic reaction, anaphylactic shock, and silent hypersensitivity.
70 . The method of claim 50 , wherein said human patient has had a disease relapse.
71 . The method of claim 70 , wherein said disease relapse occurs after treatment with an E. coli L-asparaginase or PEGylated form thereof.
72 - 94 . (canceled)