Claims for Patent: 10,537,620

Summary for Patent: 10,537,620

Title:	Site-specific polyethylene glycolylated (pegylated) asparaginase, preparation method therefor and use thereof
Abstract:	The present application discloses a PEGylated asparaginase and use thereof. In this application, the polyethylene glycol (PEG) is coupled to the N-terminal amino of 1 or 2 subunits of L-asparaginase, and the molecular weight of the PEG is 30-40 KDa. The PEG is preferably branched and has an aldehyde group serving as an activating group. The PEGylated asparaginase is useful in the preparation of anti-tumor drugs.
Inventor(s):	Ma; Bruce Yong (Changzhou, CN), Wang; Jun (Changzhou, CN), Wang; He (Changzhou, CN), Xu; Chunlin (Changzhou, CN), Chen; Yifei (Changzhou, CN), Wang; Yaofang (Changzhou, CN)
Assignee:	ZONHON BIOPHARMA INSTITUTE INC. (Changzhou, CN) GENSUN INSTITUTE OF BIOMEDICINE CO., LTD. (Changzhou, CN)
Application Number:	15/522,445
Patent Claims:	1. A site-specific di-polyethylene glycolylated (diPEGylated) L-asparaginase or a pharmaceutically acceptable salt or complex thereof, wherein each of N-terminal aminos of 2 out of 4 subunits of the diPEGylated L-asparaginase is coupled to one polyethylene glycol (PEG) molecule separately, wherein the PEG molecule prior to coupling to the L-asparaginase is branched and has a molecular weight of 30-40 KDa, and wherein the diPEGylated L-asparaginase has the general structural formula below: ##STR00004## wherein R is H or a C1-C4 alkyl, n is an integer from 320 to 455, P is an integer from 1 to 4, AA is an N-terminal L-amino acid residue, m is an integer from 0 to 5, S is 2, and ASP is L-asparaginase. 2. The site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 1, wherein R is methyl, n is an integer from 320 to 455, P is 2, and m is 0. 3. The site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 1, wherein the PEG prior to coupling to the L-asparaginase has an aldehyde group serving as an activating group. 4. The site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 3, wherein the aldehyde group is acetaldehyde, propionaldehyde, butyraldehyde, or valeraldehyde. 5. A pharmaceutical composition, comprising the site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 1, and a pharmaceutically acceptable adjuvant. 6. The pharmaceutical composition according to claim 5, which is in the dosage form of a freeze-dried powder injection. 7. A method for preparing the site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 1, comprising: step 1: formulating a 15-20 mg/mL L-asparaginase solution in 40 mM acetic acid-sodium acetate buffer pH 5.0; step 2: reacting for 12-24 hours at 4.degree. C. at a molar ratio of L-asparaginase:PEG:reducing agent=1:(4-5):(100-200); and step 3: purifying by ion exchange chromatography after reaction, to finally obtain the diPEGylated L-asparaginase according to claim 1, wherein the reducing agent of step 2 is sodium cyanoborohydride, and wherein the PEG of step 2 has the general structural formula below: ##STR00005## wherein R is H or a C1-C4 alkyl, n is an integer from 320 to 455, and P is an integer from 1 to 4. 8. A method for treating tumors in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of the site-specific diPEGylated L-asparaginase or pharmaceutically acceptable salt or complex thereof according to claim 1. 9. The method according to claim 8, wherein the tumors include acute lymphoblastic leukemia (ALL) tumors, NK/T cell lymphoma tumors, Hodgkin's disease tumors, acute myeloid leukemia tumors, acute myelomonocytic leukemia tumors, chronic lymphocytic leukemia tumors, lymphosarcoma tumors, reticulum cell sarcoma tumors, or melanotic sarcoma tumors. 10. A method for treating tumors in a patient in need thereof which comprises administering to said patient a therapeutically effective amount of the pharmaceutical composition according to claim 5. 11. The method according to claim 10, wherein the tumors include acute lymphoblastic leukemia (ALL) tumors, NK/T cell lymphoma tumors, Hodgkin's disease tumors, acute myeloid leukemia tumors, acute myelomonocytic leukemia tumors, chronic lymphocytic leukemia tumors, lymphosarcoma tumors, reticulum cell sarcoma tumors, or melanotic sarcoma tumors.

Details for Patent 10,537,620

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Recordati Rare Diseases, Inc.	ELSPAR	asparaginase	For Injection	101063	01/10/1978		2034-12-29