Polymeric alpha-hydroxy aldehyde and ketone reagents and conjugation method

Patent metadata

Field	Value
Publication number	US-2020354518-A1
Application number	US-202016937378-A
Country	US
Kind code	A1
Filing date	Jul 23, 2020
Priority date	Sep 11, 2008
Publication date	Nov 12, 2020
Grant date	—

Abstract

Provided herein are polymeric α-hydroxy aldehyde or α-hydroxy ketone reagents which can be conjugated to amine-containing compounds to form stable conjugates in a single-step reaction. In selected embodiments, the polymeric reagent itself incorporates an internal proton-abstracting (basic) functional group, to promote more efficient reaction. The substituent is appropriately situated, via a linker if necessary, to position the group for proton abstraction, preferably providing a 4- or 5-bond spacing between the abstracting atom and the hydrogen atom on the α-carbon. Also provided are methods of using the reagents and stable, solubilized conjugates of the reagents with biologically active compounds. In preferred embodiments, the polymeric component of the reagent or conjugate is a polyethylene glycol.

First claim

1 . A polymeric reagent having the structure I:

where
R 1 is selected from H, lower alkyl, and alkoxyalkyl;
R 4 is a two- or three-carbon chain which may be substituted with one or more groups selected from alkyl, alkenyl, aryl, alkoxy, halo, cyano, hydroxy, and a water soluble polymer; wherein the carbon adjacent to Cα is not substituted with hydroxy, and wherein two substituents on R 4 may together form an aliphatic or aromatic ring; and
NR 5 is a secondary or tertiary amino group which is linked to a water soluble polymer POLY via an optional spacer group Z, where R 5 is hydrogen or an alkyl group, which may form a ring with spacer group Z.

2 . The reagent of claim 1 , having the structure Ia:

where
R 1 , NR 5 , Z and POLY are as defined above,
each of the substituents R c , R c′ , R d , and R d′ is independently selected from hydrogen, alkyl, alkenyl, aryl, alkoxy, halo, cyano, hydroxy, and a water soluble polymer, and each of the substituents R b and R b′ is independently selected from hydrogen, alkyl, alkenyl, aryl, alkoxy, halo, cyano, and a water soluble polymer,
wherein at most one of these substituents is a water soluble polymer, and wherein any two of these substituents can together form an aliphatic ring.

3 . The reagent of claim 1 , wherein R 1 is H or methyl.

4 . The reagent of claim 3 , wherein R 1 is H.

5 . The reagent of claim 2 , wherein said substituents R b , R b′ , R c , R c′ , R d , and R d′ are independently selected from hydrogen and alkyl, wherein any two such alkyl substituents can together form a 5- to 7-membered aliphatic ring.

6 . The reagent of claim 5 , wherein two such alkyl substituents on adjacent carbon atoms together form a 5- to 7-membered aliphatic ring.

7 . The reagent of claim 2 , wherein R 5 is lower alkyl.

8 . The reagent of claim 7 , wherein each of R b , R b′ , R c , R c′ , R d , and R d′ is hydrogen and R 5 is methyl.

9 . The reagent of claim 1 , wherein Z consists of bonds selected from alkylene, ether, thioether, amide, and amine.

10 . The reagent of claim 2 , wherein each of R b , R b′ , R c , R c′ , R d , and R d′ is hydrogen, and NR 5 together with Z forms a piperazine ring to which POLY is linked via a ring nitrogen atom.

11 . A polymeric reagent having the structure II:

where
POLY is a water soluble polymer;
R 1 is selected from H, alkyl, hydroxyalkyl, and alkoxyalkyl;
m is 0-12; and
each R 2 and R 3 is independently selected from H, alkyl, alkylene, hydroxy, amino, alkoxy, hydroxyalkyl, alkoxyalkyl, alkoxyalkylene, aminoalkyl, iminoalkyl, carboxylic acid, alkylcarboxylic acid, phosphate, alkylphosphate, and a further water soluble polymer,
wherein at most one R 2 or R 3 group is a water soluble polymer, and wherein two substituents R 2 and R 3 in —(CR 2 R 3 ) m — can together form a ring;
with the proviso that no R 2 or R 3 on the carbon adjacent to Cα is a hydroxyl group or a 1,2,3-trihydroxypropyl group.

12 . The reagent of claim 11 , wherein at most one group R 2 or R 3 is selected from aminoalkyl, iminoalkyl, carboxylic acid, alkylcarboxylic acid, phosphate, and alkylphosphate.

13 . The reagent of claim 11 , wherein m is 0 to 6.

14 . The reagent of claim 11 , where POLY is a polyethylene glycol.

15 . The reagent of claim 11 , wherein one group R 2 or R 3 is selected from hydroxy, alkoxy, hydroxyalkyl, alkoxyalkyl, alkoxyalkylene, amino, aminoalkyl, iminoalkyl, carboxylic acid, alkylcarboxylic acid, phosphate, and alkylphosphate; and said group R 2 or R 3 and the value of m are selected such that an oxygen or nitrogen atom on R 2 or R 3 is separated from Cα by a four-bond path.

16 . The reagent of claim 15 , wherein one group R 2 or R 3 is selected from amino, aminoalkyl, iminoalkyl, carboxylic acid, and alkylcarboxylic acid.

17 . The reagent of claim 14 , wherein R 1 is H or methyl.

18 . The reagent of claim 17 , wherein POLY is mPEG.

19 . The reagent of claim 18 , wherein R 1 is H, m is 3, and —(CR 2 R 3 ) m — is selected from —(CH 2 ) 3 — and —CH 2 —CH(OH)—CH 2 —.

20 . The reagent of claim 19 , wherein —(CR 2 R 3 ) m — is —(CH 2 ) 3 —.

21 . The reagent of claim 20 , wherein —(CR 2 R 3 ) m — is —CH 2 —CH(OH)—CH 2 —.

22 . The reagent of claim 18 , wherein m is 1, R 1 is H, R 2 is H, and R 3 is iminoalkyl.

23 . The reagent of claim 22 , wherein R 3 is (4-imidazolyl)methyl.

24 . The reagent of claim 18 , wherein —(CR 2 R 3 ) m — is —CH 2 —CHR x —C(NH 2 )R y —, and R x and R y form a 5- to 7-membered ring to which POLY is linked.

24 . A polymeric reagent having the structure III:

where
POLY is a water soluble polymer; and
(i) R 7 is CH(OH)—C(═O)—R 1 , and R 8 is selected from —C(═O)OH, —CH 2 OH, —C(═O)N(R 1 ) 2 , —CH 2 N(R 1 ) 2 , —OH, and —N(R 1 ) 2 ; or
(ii) R 7 is CHR 1 CH(OH)—C(═O)—R 1 , and R 8 is OH or —N(R 1 ) 2 ;
where each R 1 is independently selected from H, lower alkyl, and alkoxyalkyl.

25 . The reagent of claim 24 , where R 7 is CH(OH)—C(═O)—R 1 and R 8 is selected from —C(═O)OH, —CH 2 OH, —C(═O)N(R 1 ) 2 , and —CH 2 N(R 1 ) 2 .

26 . The reagent of claim 24 , where each R 1 is independently H or methyl.

27 . The reagent of claim 24 , wherein R 1 in the moiety —C(═O)—R 1 is H, such that the reagent comprises an α-hydroxy aldehyde.

28 . The reagent of claim 27 , where R 7 is —CH(OH)—C(═O)—H and R 8 is —C(═O)OH or —CH 2 NH 2 .

29 . The reagent of claim 27 , where R 7 is —CH(OH)—C(═O)—H and R 8 is —OH or —NH 2 .

30 . The reagent of claim 27 , where R 7 is —CH 2 CH(OH)—C(═O)—H and R 8 is —OH or —NH 2 .

31 . A method of conjugating a water soluble polymer with a compound B—NH 2 having a reactive amine group, the method comprising
contacting the compound B—NH 2 with a water soluble polymeric reagent comprising a water soluble polymer and an α-hydroxy aldehyde or α-hydroxy ketone end group, respectively,
thereby forming a conjugate in which said water soluble polymer is linked to a moiety having the structure —C(═O)—CHR 1 —NH—B, where R 1 is hydrogen or methyl, respectively, and NH—B represents the residue of the amine-containing compound.

32 . The method of claim 31 , wherein said polymeric reagent further comprises a proton-abstracting functional group containing a proton-abstracting atom selected from oxygen and nitrogen, situated such there is a 3- or 4-bond spacing between the proton-abstracting atom and the α-carbon of said α-hydroxy aldehyde or α-hydroxy ketone.

33 . The method of claim 32 , wherein said spacing in said reagent is a 4-bond spacing.

34 . The method of claim 31 , wherein said polymeric reagent has the structure I:

where
R 1 is selected from H, lower al

Assignees

• Nektar Therapeutics

Inventors

• Culbertson Sean M
• Shen Xiaoming
• Kozlowski Antoni
• Mcmanus Samuel P

Classifications

• C07K1/003 Primary

  by transforming the C-terminal amino acid to amides · CPC title

• C08G65/3315

  aromatic · CPC title

• C08G65/26

  from cyclic ethers and other compounds · CPC title

• C08G65/33327

  cyclic · CPC title

• C08G65/2606 Primary

  containing hydroxyl groups · CPC title