Claims for Patent: 8,133,707

Summary for Patent: 8,133,707

Title:	Methods of preparing activated polymers having alpha nitrogen groups
Abstract:	Methods for preparing substantially non-antigenic polymers having lone electron pair-containing moieties in high purity are disclosed. The polymers are useful as intermediates for synthesis of amine-based polymers and in the formation of activated polymers for conjugation with nucleophiles. Conjugates and methods of preparation and treatment with the conjugates are also disclosed. The resultant polymer-amines are of sufficient purity so that expensive and time consuming purification steps required for pharmaceutical grade polymers are avoided.
Inventor(s):	Zhao; Hong (Edison, NJ), Wu; Dechun (Bridgewater, NJ)
Assignee:	Enzon Pharmaceuticals, Inc. (Piscataway, NJ)
Application Number:	11/333,072
Patent Claims:	1. A method of preparing a polymer having a lone electron pair-containing moiety thereon, comprising: reacting a polymer of formula (I) R.sub.2-R.sub.1-(L.sub.1).sub.n-LG (I) wherein R.sub.1 is a substantially non-antigenic polymer; R.sub.2 is a capping group, LG or LG-(L.sub.1).sub.n-; L.sub.1 is a bifunctional linker; LG is a leaving group selected from the group consisting of ##STR00020## wherein R.sub.3 is methyl, halogen, nitro, fluoromethyl, difluoromethyl, trifluoromethyl, or substituted carboxyl; a multi-halogen substituted benzenesulfonyl; mesylate; brosylate; tresylate, and nosylate; and n is 0 or positive integer, with a compound of Formula (III) in an aqueous base at a temperature of from about 45 to about 50.degree. C. and for a reaction time of less than about 18 hours, wherein the compound of Formula (III) is ##STR00021## wherein Z is NR.sub.7; X is O, S or NR.sub.8; m is a positive integer; R.sub.4 is H; R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are independently selected from the group consisting of H, C.sub.1-6 alkyls, C.sub.3-12 branched alkyls, C.sub.3-8 cycloalkyls, C.sub.1-6 substituted alkyls, C.sub.3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C.sub.1-6 heteroalkyls, substituted C.sub.1-6 heteroalkyls, C.sub.1-6 alkoxy, phenoxy and C.sub.1-6 heteroalkoxy, provided that R.sub.4 and R.sub.7 are both not H; and the aqueous base is selected from the group consisting of NaOH, KOH, LiOH, Mg(OH).sub.2, Ca(OH).sub.2 and mixtures thereof, wherein 10 molar equivalent of compound of Formula (III) is employed for each equivalent of LG; and the purity of the polymer having the lone electron pair-containing moiety thereon formed by said method is greater than 95%. 2. The method of claim 1, wherein the reaction time is less than about 12 hours. 3. The method of claim 1, wherein R.sub.2 is methoxy. 4. The method of claim 3, wherein LG is ##STR00022## 5. The method of claim 1, wherein X is O, m is 1, R.sub.5 and R.sub.6 are each H, and R.sub.7 is methyl. 6. The method of claim 1, wherein the compound of formula (III) is N-methyl-glycine (sarcosine). 7. The method of claim 1, wherein R.sub.1 is a polyalkylene oxide. 8. The method of claim 1, wherein the polymer of Formula (I) is selected from the group consisting of ##STR00023## wherein j is an integer from about 10 to about 340; x is an integer from about 10 to about 2,300; L.sub.1, L.sub.2 and L.sub.3 are bifunctional linkers; and z is an integer from 1 to about 120. 9. The method of claim 7, wherein said polyalkylene oxide is a polyethylene glycol of the formula: --CH.sub.2CH.sub.2--O--(CH.sub.2CH.sub.2O).sub.x--CH.sub.2CH.sub.2 wherein x is an integer from about 10 to about 2,300. 10. The method of claim 1, wherein the substantially non-antigenic polymer has a weight average molecular weight from about 200 to about 100,000 Daltons. 11. The method of claim 10, wherein the substantially non-antigenic polymer has a weight average molecular weight from about 2,000 to about 48,000 Daltons. 12. The method of claim 1, wherein the polymer of formula (I) is: ##STR00024## wherein R.sub.2 is methoxy; and R.sub.1 is a polyalkylene oxide. 13. The method of claim 12, wherein R.sub.1 is a polyethylene glycol. 14. The method of claim 1, wherein the aqueous base is NaOH. 15. The method of claim 1, wherein the polymer having the lone electron pair-containing moiety thereon is ##STR00025## wherein X is O or S; m is 1; n is 0 or 1; R.sub.5 and R.sub.6 are independently selected from the group consisting of H, C.sub.1-6 alkyls, C.sub.3-12 branched alkyls, C.sub.3-8 cycloalkyls, C.sub.1-6 substituted alkyls, C.sub.3-8 substituted cycloalkyls, aryls, substituted aryls, aralkyls, C.sub.1-6 alkoxy, and phenoxy; and R.sub.7 is selected from the group consisting of C.sub.1-6 alkyls, C.sub.3-12 branchedalkyls, C.sub.3-8 cycloalkyls, C.sub.1-6 substituted alkyls, C.sub.3-8 substituted cycloalkyls, aryls, and substituted aryls. 16. The method of claim 1, further comprising reacting the polymer having the lone electron pair-containing moiety thereon with a compound having an activating group thereon to form an activated polymer having a lone electron pair-containing moiety thereon. 17. The method of claim 16, wherein the activated polymer having the lone electron pair-containing moiety thereon is ##STR00026## 18. The method of claim 16, wherein the compound having the activating group thereon has a functional group capable of reacting with a nucleophile. 19. The method of claim 1, wherein the purity of the polymer the polymer having the lone electron pair-containing moiety thereon formed by said method is greater than 98%. 20. The method of claim 17, further comprising reacting ##STR00027## with asparaginase under conditions sufficient to form conjugates. 21. The method of claim 20, wherein said asparaginase is derived from a recombinant source. 22. The method of claim 1, wherein R.sub.1 is a linear, branched or multi-armed polymer.

Details for Patent 8,133,707

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Recordati Rare Diseases, Inc.	ELSPAR	asparaginase	For Injection	101063	01/10/1978		2039-02-26