CA2191726A1 - Non-antigenic amine derived polymers and polymer conjugates - Google Patents

Abstract

Substantially non-antigenic polymers containing pI and/or pH optimum modulating moieties 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.

Description

W0 96100080 2 1 9 1 ~ 2 ~ s ,~

NON-ANTTI'.I.NIC AMTl~ DFR~ POLYMF~C
ANI) pOT.YMFR CONJU(~.~T~.~

Crocc-rPfPr~nrP to I ' This application is a c in part of U.S. Patent Application Serial No.
081265,593 filed June 24, 1994.

B~('Rt 11NDOFT~TF.lNVhNTlON

I . FiPIrl nf thP TnvPntinn The present invention relates to polymers which are useful in extending the in vivo circulating life of biologically active materials. The invention also relates to conjugates made with the polymers.

2. DPCt rU?tinn nf Prinr Art Some of the initial concepts of coupling peptides or pc)l~ A;~o to poly(ethylene glycol) PEG and sirnilar water-soluble poly(alkylene oxides) are 2 0 disclosed in U. S. Patent No. 4,179,33 7, the disclosure of which is ~,v. ~L~.l herein by reference. Pol~ "fid~.~ modrfied with these polymers exhibit reduced ~ ~~ or antigenicity and circulate in the I ' ~: longer than unmodified versions.
To conjugate poly(alkylene oxides), one of the hydroxyl end-groups is 2 5 converted into a reactive functional group. This process is frequently referred to as "activation" and the product is called an "activated poly(alkylene oxide)". Other '1~ non-antigenic polymers are similarly "activated" or r - ~-The activated polymers are reacted with a therapeutic agent having fimctional group(s) that serve as attachment site(s). One 1~

WO 96/00080 ;; P~,l/-J.,,~,.'(,, ~
2 ~

functional group commonly used as an attachment site is the epsilon-amino group of Iysines. Free carboxylic acid groups, suitably activated carbonyl groups, oxidized ~boh~ moieties, hydroxyl and mercapto groups have also been used as attachment sites.
Over the years, one ' : " observed with polymer, ; g ~ is that the conjugate has a different pl tham the unmodified p}otein, enzyme, etc. For example, pegylation, i.e. attachment of the polymer, of Iysine amino groups result in a decrease in the isoelectric point and changes the pH optimum, i.e .the pH at which maximum bioactivity is observed. In some cases, it would be beneficial to restore the original pl or even alter the pl value of the polymer conjugate in order to optimize bioactivity at physiologic pH.
The present invention provides solutions to this problern.
SUMM~RY OF T~li', INVENTION
In one aspect of the invention, there are provided amine-based polymer ' having the formula:
(I) R-B
wherein (R) is a water-soluble, ! ' ' ' ~ "~' non-antigenic polymer residue and (B) is preferably a secondary amine or a tertiary amine. Suitable secondary amines are of the formula:
(II) -NH(CH2)nX
wherein:
(n) is an integer from 1-12, inclusive; and X is selected from the group consisting of H, OH; CO2RI, where R, is H or a C~-6 alkyl; halogen, aryl moieties and h~,t~ , moieties.
Suitable tertiary amines can be selected from:

~) Z
--N(CH2)mX

~ W0 96100080 ~ 7 2 6 r~

--N y--(CH2)mX

r\
--N

(cH2)mx (Vl) /--\
--N
\1--(CH2)mX

wberein (m) is an integer from 0-12, inclusive;
2 0 : (X) is selected from the group consisting of H, OH, CO2R" where R, is H or a Cl.6 alkyl, halogen, aryl moieties and 1.. ~ ,~, moieties;
(Y) is N or CH; and (Z) is a C,.6 alkyl.
The polymer is preferably a poly(alkylene oxide) residue such as a poly(ethylene glycol) having a molecular weight between about 200 and about - 100,000. In ad&tion, the polymer is preferably capped with a C,., alkyl group on the end opposite (i.e. distal to) the B moiety.
In another aspect of the inventior.~, there are provided ' ".~ non-antigenic polymers of the formula:

wo s6/onoso 2191~26 (V~) R-B'-W-L
wherein (R) is as defned above; (B~ is NY, where Y is H or a Cl4 alkyl or cycloalkyl;
(W) is a spacer group, such as a C, ~ alkyl and ~L) is a functional group capable of bonding with ' , ' ' Other aspects of the invention include polymer conjugates containing bi~lo~. U~ active materials, described as le I ' ' herein as well as methods of conjugate preparation. In these aspects of the invention, the conjugates are of tbe formula:
LR-B~-w-Ll]~-(nucleophile) 1 0 wherem:
(R), (B') and (W) are as described above;
(L') represents a covalent linkage between (R-B'-W) and a lw~ ,.) ' ', and ~z) represents the number of polymers attached to the ' r ~ '' The biologicaUy active materials include proteins, peptides, enzymes, medicinal chemicals or organic moieties whether synthesized or isolated from nature The e, _ methods include contacting a l . le r' ' i.e. a biologically active material, capable of umdergoing a substitution reaction with a polymer described. The reaction is carried out under conditions sufficient to effect attachment while maintaining at least a portion of the biological activity.
The present mvention also includes methods of treatmg various maladies imd conditions. In tbis aspect, a mammal m need of treatment is ' ~id an effective amount of a conjugate containing a l,;u' 3~ active material such as a protein, enzyme or organic moiety attached to a polymer of the present invention.
Some of the chief advantages of the present mvention are that the amine-2 5 derived polymers impaTt a pl andlor pH modulating effect to the conjugate. Thus, the isoelectric point of bio-active materials included in the conjugate can be adjusted to a desired point. This is to be contrasted with the effect observed with ~U...~,.IIiU~
activated polymers where shifts in isoelectric points cam be observed, often to the detriment of optimal activity.

~ WO 96100080 ~ 1 9~ 72~ P~,U~

11l addition, in those aspecb ofthe invention where anionic groups are included as part of the amine-bearing moiety, the in vivo circulating life of the conjugates is further prolonged due to reduced renal filtration.

p~lli,F DF.~( K 1 l l ION OF TH~ DRAWINGS
Figure I is a schematic ~ .uD.~ Liùl. of synthesis techniques carried out in accordance with the mvention to prepare formula (I) R-B polymer ~ ' and the compounùs of l~xamples I and 3-6.
Figure 2 is a schematic .~,., of synthesis techniques carried out in accord~Dnce with the rnvention to prepare the compounds described rn Examples 2 and 7-9.
Flgure 3 is a schematic 1~of the reactions carried out rn Examples Figure 4 is a schernatic "~;. . a of the reactions carried out m Examples 12-16.

DETAll.R'n DF~ Rn~TloN OF TFrl?l INVI~,l~ITION
I . POLYMER RESIDUES
The activated polymers of the present invention are preferably prepared from poiy(aikylene oxides) (PAO's) that are water soluble at room i , ~D. Wlthin thisgroup are mono-substituted pul~ " yh.ne oxide derivatives such as ~ hv~ ul~
(ethylene glycols) (rnPEG's) or other suitable aikyl ' ' PAO derivatives such as those cor~aioing a Cl - CJ terminai group. Straight-chained nu~: 'i,, polymers such as ' ~' PEG ~ are preferred. Alternative pol~ " yL~
2 5 oxides such as other ~,ly(el}., '.~,.. giycol) llu.. lv~,v'~ ul~ u~ "~ gylcols, other ~ alkyl-poiy(ethylene oxide) block ~iopol~ , and copolymers of block copolyrners of poly(alicylene oxides) are aiso usefui. 8ranched PAO's such as those disclosed in ~ _ ~ ' the PCT T ' AppGcation havrng ~ ' PubGcation No. W095/ 11924 are aiso of use herein. The disclosure of W095/11924 is hereby wo 96/00080 c~
7 ~ ~ r~"~ 1 ~

,u~ kid by reference herein.
Aiternative polymer substances usefui herein include materiais such as dextrans,polyvinyl ~ , ' ' , pol1a~ LIll.d~,s or other similar non- " - polymers.
Those of ordinary skiil in the art wiii appreciate that these polymers can also be r ~ and included in the mvention. The foregomg is merely iiiustrative and not intended to restrict the type of non-antigenic polymers suitable for use herein.
Thus, (R) is a water-soluble, ' ".~ non-antigenic polymer residue.
When the (R) is PEG or mPEG, molecular weights of between about 200 and about 100,000 daltons are preferred, molecular weights of about 1,000 - 50,000 daltons are more preferred and molecular weights of about 2,500 25,000 daltons are most preferred.
2. AMl~ POI~TION OF ACTIVATED POLYMER
In one aspect of the mvention, amine-based polymer ' are provided. The amine portion of the ' can be a secondary, tertiary or quaternary arnine moiety, represented herein as (B) in formula (1). Preferably, however, either secondary or tertiary amines are used.
When a secondary amine is selected for (B), amines of the formula (II) are preferred:

(II) -NH(CH2)nX

wherein (n) is an integer from 1-12, inclusive; and (X) is selected from the group consisting of H; OH, CO2R" where Rl is H or a C,4 alkyl; halogen, aryl moieties and L.,.~,l. " moieties.
These secondary amine moieties can be synthesized using standard organic techniques or can be readily obtained using reagents avaiiable from commerciai sources. A non-limiting iist of secondary amines meeting these criteria include:primary arnines such as ~' ' , beta-aianine ethyl ester, _ wo s6/onoso ;hUA~ , etc.
When a tertiary amine is desired for (B), arnines of formulae (III-VI) are preferred:
z (III) --N(CH2)mX

(IV) --N Y--(cH2)mx /

--N/~
y (cH2)mx (Vl) --N/~
\r~' (cH2~mx wherein (m) is an integer from 0-12, inclusive;
(7~ is selected from the group consisting of H; OH, CO2R" where R, is H or a C~.6 alkyl; halogen, aryl moieties and h~,t~ moieties;
(~) is N or CH; and (Z) is a C,.6 alkyl.

w096~00080 ~1~17 ? E~

The tertiary amine moieties can be synthesized using standard organic techniques or can be readily obtained from commercial sources. A nn- I' "' ~ list of tertiary amines meeting these criteria include secondary amines such as N-'.~' ' ' , piperidine-3-methanol, N-hydlw~ u~ , , sarcosme ethyl ester, etc.

3. SYNTHESIS OF POLYMERS INTERMEDL~TlES
The polyrner ' ' of formula (I) can be synthesized using .,u..~. ' reaction techniques. For example, mPEG-CI can be reacted with , ' ' available from Aldrich or any other suitable primary amine in water and a sealed container at t~,...p~..al~..ca of ~ , 60~ C to form secondary amine polymer "
Similarly, mPEG-CI can be reacted with secondary amines such as N-~ t'' ' ' under similar conditions to form tertiary amine polymer "
In still other aspects of the invention, the amine-bearing groups (B) can also include an acid moiety, preferably as part ofthe alkyl portion thereo~ A non-limiting list of suitable acids include sulfonates, .,~lbu~' and l' ,' As !' ' ' m Examples 12-16, a i ~ ' spacer moiety such as Iysine or serine 2 0 is first reacted with an activated polymer such as a PEG ~ '.yl succinate ester or a PEG ~ ' carbonate. Next, an anion group is added by modifying one of the remaining functional groups on the (B) portion of the " Reagents such as ;'' u. ' sulforlic acid sodium salt, phosphonic acid esters or salts or e~" , can be used. (~tl'lJ~ ~ first forms a carboxylate ester and then can be saponified to a salt.) Fmally, the third functional group of (B) can be modrfied with a leaving group (L) described below rn section 4.
The foregoing is merely illustrative of syntheses useful to prepare the ' It is to be umderstood that alternative methods and reagents may be used without departing from the spirit of the mvention. In essence, each (R) and (B) _ wos6Joooso ;~ g ~ r~

is joined by a reaction between k . ' " functionai groups. Each (R) is suitably ~' t, i.e. rnPEG-haiides such as rnPEG-CI; PEG sulfonate esters such as PEG-tosylate, etc. to undergo l~ cllhcthllti~n and bond with (B).
r. of polymers with haiides or suifonate esters is readily apparent to those of ordinary siciil in the art.

In yet another aspect of the invention, the " described above are included as part of activated polymers which can be used to conjugate with ~ ' B E~ "~tive ~ The polymers have the fommula:
(VII) R-B'-W-L
wherein (R) is a water-soluble, ! ' ' " ~:~ no.. . 'i,, ' polymer residue;
(B') is NY, wherein Y is H or a C,.6 aikyl or cycloaikyl, ~W) is a spacer group; and ~ L) is a functionai group capable of bonding with The ~R-B') portion of the polymer can be prepared as described above with regard to ~-B).

The moiety ~W) of Fomwia ~VII) represents a spacer group between the (R-B') 2 0 and the leaving group (L). It has been found that straight or branched lower aikyls i.e. Cl~, araikyi, aryl or heteroargi groups may be employed. in this regard, aitemative ~W) ' include benzyi, ' ' benzyls, phenyiethyi, substituted ,lh.~l." phenyl, substituted phenyls, thiophene derivatives, pyridine derivatives, h, ~)~ " , etc. The foregoing hst of (W) ' is to understood as being illustrative of suitable moieties and not an e~cclusive hst. Those of ordmarg skiii wiii ~ reaiize that functionai equivaients of the foregoing are aiso possible for ~W).
The spacer adjusts the geometrg of the sgstem in order to prevent undesirable side reactions, thus increasing the yield of the desired pul~ ' , ' ' conjugate. Preferred spacer groups (W) include:

wo 96/00080 2~1 9 ~ 7 2 g l. ethyl-3-isocyanato propionate; and 2. ethyl-2. ' '.ylaLc.
The spacer groups are available from commercial sources or can be synthesrzed using standard laboratory techniques.
r.. I' i, the spacer groups can be attached to the (R-B) portion of the polymer by simple l~ ' or C~ LI~, ' ' substitution reactions.
The moiety (L) of Fonnula (VII) represents leaving groups that "activate" the amine-based polymers of the present invention for c ,, with I
(L) can be a moiety selected from:
I. Functional groups capable of reacting with an amino group such as:
a) carbonates such as the P ~ r Jl~ or 5 ,yl, b) carbonyl imidazole;
c) azlactones, d) cyclic imide thiones, e) isocyanates or ;DvLu~". " or f) other active esters.
II. Functional groups capable of reacting with carboxylic acid groups and reactive carbonyl groups such as:
a) primary amines; or b) hydrazine and hydrazide functional groups such as acyl hydrazides, carbazates, ; i' ; etc.
m. Functional groups capable of reacting with mercapto groups such as unsaturated maleimides.

5. ~YN ~ OF ACTIVATED AMINE-BASED POLYMERS
The activated polymers are formed using .,u..~. ' reaction techniques.
For example, an alcohol form of the ' (R-B), formula (I), or the ~ ' ~R-B'-W)offormula(VlI)canbereacted with Nh~dlw~
and :" ~l u!"Lub ''' ' ', both available from Aldrich, in dry methylene chloride Wo 96/00080 2 1 ~ 1 7 2 ~ P~

at a ICIIIPCI a~ll c of about 25~ C. Other inert organic solvents such as toluene, THF, etc can be uscd and i r ranging from l - l 00 ~ C can be employed. Synthesis reactions are ' 'l~ shown in Figures l~ for both secondary and tertiary amine-containing activated polymers.

6. BIOLOGICALLY ACTIVE M~ SUITABLE FOR
CONJUGAnON
The 'e r~ ~ conjugated with the polymers are described as "bh,lo~
active". The term, howcvcr, is not limited to IJL~.;olo~ al or l ' ~e~ ' activities. For exampl4 some nuclcophile conjugates such as those containing cnzymes, are able to catalyzc reactions in organic solvents. Likewise, some mventive polymer conjugates containing proteins such as, ~. ' A, ~ ( ' ' and the like are also useful as laboratory diagnostics. A key feature of all of the conjugates is that at least some ponion ofthe activity associated with the unmodificd bio-active material is maintained.
In other aspccts ofthe invcntion, the conjugates are biologically active and have numcrous thcrapeutic: Pr~ ~ Mamllla15 in nccd of treatment which includcs a hi~ active material can be trcated by ~ ' , am effcctive amoumt of a polymcr conjugate containing the desired bioactive matcrial. For example, mammals in nced of enzyme lc~ nt therapy or blood factors can be given polymer conjugates containing the desired material. The i~ effective doses of the conjugates will be apparent to those of ordinary skill in the mvention. It is r . ' 1, however, that the doses will be calculated of the basis of the biologically active material present in the conjugates.
2 5 Biologically active ~ , ' ' of interest of the present invention include, but are not lirnited to, proteins, peptides, pul~ ,tid._.., enzymes, organic molecules of natural and synthetic origin such as medicinal chemicals and the like.
Enzymes of mterest include ~I,~h,~Laic-specific enzymes, proteolytic enzymes, u,d"l...c.lu.,i~ , hydrolases, Iyases, isomerases and ligases.
3 0 Wrthout being limited to particular enzymes, examples of enzymes of interest include wo 96/00080 2 1 9 1 7 2 6 ~ ~ ~, , arginase, ar8inine dearninase, adenosine deaminase, superoxide dismutase, . l~ , cataiases, .,h,.~.ul.~l , lipases, uricases, adenosine d~ ' , tyrosinases and bilirubin oxidase. Cal L ' ~ e-specific enzymes of interest include glucose oxidases, glucodases, L ' ' ~lu~oc~lcL
~h.~,uulu~ id. O.~S, etc.
Proteins, polyp."uliJ. D and peptides of interest include, but are not iimited to, hemogiobin, serum proteins such as blood factors inciudmg Factors VII, Vlll, and IX, "' ' ' cytokines such as ' ' , a-, ,~- and r-interferons, colony stimulating factors including gramulocyte colony stimuiating factors, platelet derived growth factors and l' ,' li, ~tivating protein (PLAP). Other proteins of generai biological or therapeutic interest include insulin, plant proteins such as lectins and ricins, tumor necrosis factors and related aileles, growth factors such as tissue growth factors, such as TGFcds or TGF~'s and epidermai growth factors, hormones,'' , C~JIlllUr ' ", pigmentary hormones, hJ~ ' releasing factors, antidiuretic hormones, prolactin, chorionic g ': U~;ll, foiiicle-stimuiating hormone, thyroid-stirnulating hormone, tissue 1' ~, activator, and the like.
~L' ' ' of interest mclude IgG, IgE, IgM, IgA, IgD and fragments thereof Some proteins such AS the ' ' , interferons and colony stimulating factors aiso exist in non g Iy~,uO~' ' form, usually as a result of using ~c-techniques. Tbe n~ ,ly~uO~' ' versions are aiso among the biologicaily active . ' ' of the present invention.
The biologicaily active .. ' ~ ' ' of the present invention aiso include any portion of a polypeptide ~l. . : . ..l;. .~; in vivo bioactivity. This includes ammo acid sequences, antisense moieties and the iike, antibody fragments, single cbain binding antigens, see, for example U.S. Patent No. 4,946,778, disclosure of which is ~ herein by reference, binding molecules inclu&ng fusions of amtibodies or fragments, polyclonai antibodies, monoclonal antibodies, cataiytic amtibodies, nucleotides and . 'i,., The proteins or portions thereof can be prepared or isoiated by using j~ WO 96100080 21917 2 6 techniques known to those of ordinary skiD in the art such as tissue culture, eAtraction from animal sources, or by I, ' DNA ' ~C ~, Transgenic sources of the proteins, pol~ AiJ~ ~ amino acid sequences and the like are also . ' Such materials are obtained form transgenic animals, i.e., mice, pigs, cows, etc., wherein the proteins eApressed in milk, blood or tissues. Transgenic insects andbaculovirus eApression systems are also . ' ' as sources. Moreover, mutant versions of proteins, such as mutant TNF's and/or mutant interferons are also within the scope of the invention.
Other proteins of interest are aDergen proteins such as ragweed, Antigen E, honeybee venom, mite aDergen, and the hke. However, useful biologically active ,' ' are not limited to proteins and peptides. Essentially any $; k" "~
active compound is included within the scope of the present invention.
~'I ' . ; molecules such as I ' ' chemicals i.e. anti-tumor agents such as taAol, taxanes, . ' ' ~ . ' II~IlIUll 1AlLk:, etc., ~ d;u~ ' agents, .' , ~ y agents, - ' agents, central nervous system-activating agents, analgesics, fertility or - . ~, agents, anti '' ~ agents, steroidal agents, anti-uricemic agents, ~liu. ' agents, vasodilating agents, ~,~r ~ ~ agents and the hke can aD be conjugated with the amine-beariDg polymers of the present invention.
The foregoing is iDustrative of the biologically active . ' . ' ' which are suitable for conjugation with the polymers of the invention. It is to be understood that those biologically active materials not specrficaDy mentioned but having suitable nucleophilic groups are also intended and are within the scope of the present invention.

7. SYNT~IESIS OF BIOLOGICALLY ACTIVE~ CONJUGATES
One or more ofthe activated polymers can be attached to a biologically active nucleophile by standard chemical reactions. The conjugate is represented by the formula:
~vm~ [R-B'-W-L~]z-( wo 96/ooo~o ~ 6 P~
.

wherein:
(R) is a water-soluble ' 'l~ non-antigenic polymer residue, (B') is NY, wherem Y is H or a C,.~; aUcyl or cycloalkyl;
(W) is a spacer moiety;
(L') represents a covalent linkage between (R-B'-W) and the ' , ' ' ~; and ~z) Represents the number of polymers attached to the ' . ' ' The variable (z) is an integer 2 ~ " " the number of polymers conjugated to the biologically active ~ ' ~e, ' ' - The upper limit for (z) wiU be determined by the rumber of avAilAble nucleophi,ic attachment sites and the degree of polymer attachment 10 sought by the artisan. The degree of ; v can be modified by varying the reaction ~ y using well-known techniques. More than one polymer conjugated to the nucleopbile can be obtained by reacting a I ' ~cess of the activated polymer with the . 'e . ' ' The biologically Active ' r ~ ~ CAII be reacted with the activated polymers 15 in an aqueous reaction medium which can be buffered, depending upon the pH
IC~Ill;ltln_...:~ of tbe, ' ,' ' The optimum pEI for the reaction is generdly between about 6.5 and about 8.0 amd preferably about 7.4 for yl~ 'pulJ}J_~iUI~, materiAls. Ol~sr....l h~ h~ moieties csm be reacted in non-aqueous systems. The optimum reaction conditions for the 2 0 t~ stability, reaction efficiency, etc. is within level of ordinary slcill in the art.
Thepreferredie r ~rangeisbetween4'Cand37~C. Thei, _ofthe reaction medium cannot e cceed the temperature at which the nucleophile may denature or d.~ lj It is preferred that the nucleophile be reacted with an eJccess of theactivated polymer. Following the reaction, the coùjugate is recovered and purified 2 5 such as by d; ~ tr~til~n, columm ~,h., " , ' " i: ' thereof, or the like.
It cstn be readily appreciated that the activated non-antigenic polymers ofthe present invention are a new and useful tool in the conjugation of biologically active materials, especially when shifts in pI and/or pH optimum are sought.

~ WO 96/00080 2 1 9 1 7 2 ~; r~ 1, L................... , _. . ~

F,XAMPI ,Tr,~
The following non-limiting examples illustrate celtain aspects of the invention.All parts and p~ ~ Lg~.. are by weight unless other~ise noted and all t~ la~UI t;D
are in degrees Celsius. The r~mbers associated with al H~VI~ ' ' m the examples correspond to those shown m the fgures.
MATF'l~IAT ,!~
M ~ oly(ethylene glycol) (m-PEG) having a molecular weight of about 5,000 was obtamed from Union Carbide. All pGl~LhJL~ glycols were molecular weight 5,000 unless stated otherwise. The solvents were obtained from Aldrich 1 0 Chemical of Milwaukee, Wisconsm. Each of the products prepared was confirmed structurally by carbon - 13 NMR.
T'XAMPT.T~'. I
m-PEG-CI:
A total of I kg (0.2 moles) of m-PEG-OH was placed under high vacuum and heated to 70~ C with stirring until the evolution of gas (H,0) ceased after , 4 hours. The i r ' ~ was lowered to 50~ C, followed by the addition of 100 ml (I .4 moles) of thionyl chloride. Tbis mixture was stirred overnight at 70~ C under nitrogen, cooled to 30~ C, and titrated with ethyl ether to yield 990 g (99% yield) of product. UC NMR: (CDC13)~ CI, 42.3.

F.XAMpT.TC
m-PEG r~ ' (7):
Amixtureof25.0g(5.0mmoles)ofm-PEG-Clamd5.75g(50mmoles)of3-~ .. ' ' ' (6) in 100 ml of water was placed in a 250 ml polyl,.v~ bottle.
The bottle was sealed amd kept in a water bath at 60~ C for 48 hours followed by~ cooling to room i . t: and removal of the solvent by distillation in Yasa~
Re~ " of the residue from 2-propanol yielded of product (7). ~3C NMR:
(CDCI3~); CH2 (ring), 23.94, 26.47, ~HCH20H,37.56, CH2N, 53.91, 56.96, 57.38;
CH30, 57.93, ~H2OH, 65.05.

wo 96/00080 ~ 1 9 ~ 7 2 6 ~ L c.~

F.XAMPI,~ 3 n -PEGPiV~ u~, ~l (2): ~
A mixture of 25 .0 g (5 .0 mmoles) of m-PEG-CI and 7.2 g (50 mmoles) of N-hyL~L7~ u~ , (1) in 100 ml of water was placed in a 250 ml 1..1~,..,~.,1~..~, bottle. The bottle was sealed and kept in a water bath at 60~ C for 48 hours followed by cooling to room t~ tL.. ~, and removal of the solvent by distillation in ~UQ
R~l~. " ofthe residue from 2-propanol yielded 24.5 g (96% yield) of product (2) 13C NMR: (CDCI3)~; CH2CH20H, 26.85, CH2N (endocyclic), 52.19, 52 48;
~H2N (exocyclic), 56 66, 56.81; CH30, 57 90, _H2OH, 6218 EX~MPLE 4 SYNTHESIS OF CO~LPOUND (3a) rnPEG-piperazine propanol (2), (16 g, 3 1 mtnol) in toluene (240 ml) was azeotroped for 2 hours, followed by the removal of 100 ml toluene. Thereafter, ethyl-3-iaO~ ' (E34 g, 9 36 mmol) and dibutyl tin dilaurate (0.99 g, 1 56 mmol) were added to this solution at room i ~ h e. The resulting mixture was heated to 60~C for 30 hours. The solvent was removed under reduced pressure and the solid obtained was 1~1~ "' ' from 2-propanol to give (3a) in 96% yield 13C NMR
(CDCI3) ~;13.43 (OCH2CH3); 25 40 (CH2~H2CH2); 33.63 (~H2C); 35 73 (CN~H2);
5156, 52 19 (~H~N endocvclic); 53.92, 56 61 (~H2N exocyclic); 58.11 (OCH3); 59-60 (O~H2CH3); 62.01 (~H2OC); 155.62 (O~N), 171.14 (COC2H,).
F.XAMPl,F. 5 SYNTHESIS OF COMI'OUND (3b) Compound (3a) (15 g, 2.9 mmol) was dissolved in H20 (200 ml) followed by the addition of lithium hydroxide (733 mg, 125 mmol). The solution was stirred for 18 hours and pH was adjusted to 4.0 using 6N HCI. The aqueous solution was extracted with methylene chloride and the solvent was removed in vacuo. The solid obtained was I~W~ " ' from CH2CI2/ether to give (3b) in 96.6% yield. 13c NMR: (CDCI3) ~;
24.21 (CH2_H2CH2); 33.49 (~H2C); 35.94 (NH~H2); 49.71, 50.52 (_H2N
endocyclic); 53.29, 55.79 (5~H,N exocyclic); 58 12 (OCH~); 61.19 (~H,OC); 155.49 ~_ WO 96/00080 (O5;~N); 172.96 (~OH).

A SYNTHESIS OF COMPOUND (4) Compound 3b (14 g, 2.71 mmol) was dissolved in anhydrous methylene chioride (70 mi) foiiowed by the addition of N L~Lv~ f (619 mg; 5.4 mmol) and 1,3-diisopropyl ~ ~ ' ' (683 mg,5.42 mmol). The mixture was stirred overnight at room . . t;. The resuitmg solids were fiitered and the solvent was removed under reduced pressure. The crude product was ~ . " ' from 2-propanol to give compound (4) in 94~/0 yield. 13C NMR: (CDCi3) ô; 24.84 1 0 (CHZSH2CH2~H2~ ' ); 30.94 (CHzC); 35.74 ~NI;~H2)~ 49.84, 49.98, 50.05, 50.74 (CH2N endocyclic); 53.29, 55.90 ~H2N exocyciic); 58.15 (O~H3); 61 48 (~H20C); 155.56 (~N); 166.51 (~H2CO); 168 73 ~
B. SYNTHESIS OF COMPOUND (5) BY CONJUGATION OF CO~OUND (4) WITH BENZYL AMINE
B~ ' - (9 ,ul) was added to the solution of compound (4) (0.4 g) in CDCI3 in the NMR tube. Resulting soiids were dissolved by gentie heating and tapping and left at room temperature for 18 hours 13C Ni~fR of the resulting solution indicates the forrnation of product. Thus, it is shown that the amine-based polymers of the present invention react readily with I . -I~ to form conjugates UC NMR:
(CDCI3) ~; 24.67 (CH2CHzCHz); 24.58 (CH2 free ' ); 34.87 (~HzC); 36.50 (HN~Hz);4231,42.81(~H2benzyl);50.76,51.18~H2N endocyclic);53.58,56.16 ~HzN);58.12 ~H30);61.50~H20C); 126.77to 138.11 (~Benzenering); 155.67 (~N); 170.77 (CH~ON); 172.55 (CO free 'o.).

SYNlEiESIS OF CO~OUND (811) mPEG-piperidine methanol (7) (5 g, I mmol) in toluene (75 mi) was azeotroped for 2 hours, foilowed by the removai of 30 ml toluene. To this solution ethyl-3-isocyamate propionate (421 mg, 2.9 mmol) and dibutyl tin diiaurate (310 mg, 0.49 mmol) were added at room temperature were added and the resuiting mixture was w096/00080 ~ 1 g 17 2 ~ r~l~u.. v.

heated to 60aC for 30 hours. The solvent was removed under reduced pressure and the solid obtained was .~,~ . " ' from 2-propanol to give (8a) in 91% yield. 13C NMR:
(CDCI3) o; 13.30 (OCH2GH3),23.32 (CHz ring); 33.47 (CH,C); 35.65 (N5~H2); 34.75 (~H2 rin~); 53.37,56.32 (~1),57.94, (OCH3); 59.42 (O~HzCH3); 66.17 (~H20C);
155.49 C~l); 170.92 (CH CO).
I;'.XAMPI .F. 8 SYNTHESIS OF COMPOUND (8b) Compound (8a), (4.5 g, 0.86 mmol) was dissolved ) in H2O (60 ml) follùwed by the addition of hthium hydroxide (216 mg, 5.15 mmol) . The solution was stirred for 18 hours and pH was adjusted to 4.0 using 6N HCI. The aqueous solution was extracted with CH2CI2 and the solvent was removed under reduced pressure. The solid obtained was ~c~"y: " I from CH2CI2/ether mixture to give (8b) in 98% yield. ~3CNMR: (CDCI3jo;21.23,24.19(CH2ring);32.95(5~H~C); 133.88(CHring);36.12 (NCH2); 57.99, (OCH3); 64.90 (~H2OC); 155.27 (O~); 173.56 (C-OH).
1 5 ~.Y ~MPI ,F. 9 A. SYNTHESIS OF COMPOUND (9) Compound (8b) (2 g, 0.38 mmol) was dissolved in anhydrous methylene chloride (10 rnl) followed by the addition of N h~u~.y: ' ' (88.3 mg, 0.77 mmol) and 1,3 ii;~,.u~"~l~l " ' (96.7 mg, 0.77 mmol). The mixture was stirred 2 0 overnight at room ~ ,.aLulc. The resulting solids were filtered and the solvent was removed under reduced pressure. The crude product was lc"i~ " ' from 2-propanol to give compound (9) in 88% yield. 13C NMR: (CDCI3) ~; 21.67, 24.65 (CH2 ring); 24.50 (CH2 succinimide); 30.62 (CH2C); 33.36 (CH ring); 35.58 (NCH2);
52.64,54.98,55.06 (CH2N); 57.94 (OCH3), 155.32 (OCN); 166.31 (CH2CO); 168.60 (succir~imide).
B SYNTHESIS OF CO~OUND (10) BY CONJUGATION WITH
COMPOUND (9) WITH BENZYLAM~E
B~ ' (9.1 ,ul) was added to the solution of compound (9) (0.4 g) in CDCIl m the NMR tube. Resulting sohds were dissolved by ~entle heating and tapping ~ W096100080 ~l?17~6 ~

and left at room temperature for 18 hours. 13C NMR of the resulting solution indicates theformationofproduct(l0). '3CNMR:(CDCI3)o;21.80,21.49(CH2ring),24.39 (CH2, ' ); 33.44 (~H2C), 36.39 ~_H2N); 34.72 (CH ring), 42.08, 42.65 (~H2 L..,~' ), 52.51, 55.07, 55.98 (~H2N); 57.91 (O5;EI3); 126.06 to 138.03 (C
Benzene ring); 155.53 (OCN), 170.56 (CH2CN); 172.31 (C ' ).
T~',XAMPI,T', 10 SYNTHESIS OF N-PEG SARCOSINE (12) mPEG-Cl (25 g, 4.98 mmol) was added to the solution of N-methyl glycine (sarcosine) (11) in NaOH solution (150 ml, 0.33 M) and the mixture was placed in a sealed pul~ ",Jl~ , bottle and heated at 75 ~ C for 4 days. The reaction mix~ure was cooled to room i.,l.~ and pH was adjusted to 6.0/6.5 with dilute HCI. The aqueous solution was extracted with CH2Cl2 and the solvent was removed under reduced pressure. The resulting solid was ~c~,ly~ l!;~J from 2-propanol to give compound (12) in 77% yield. 13C NMR: (CDCl3) o; 41.31 (NCH3); 54.57 (CHlN);
57.85 (CH2C); 58.04 (OCH3); 167.98 (CO).
T~',XAMPT,T', 11 A SYNTHESIS OF COMPOUND (13) rnPEG sarcosine (12) (18 g, 3.55 mmol) was dissolved in anhydrous methylene chloride (90 ml) followed by the addition of N hrJl~y ' (612 mg, 5.32 2 0 mmol) and diisopropyl ~L ' ' (671 mg, 5.32 mmol). The mixture was stirred overnight at room i , ~. The resulting soLds were filtered and the solvent was removed in vacuo. The crude product was lt~,ly " ' from 2-propanol to give the compound (13) in 94~/0 yield. ~3C NMR: (CDCl3) o; 24.73 (CH2 ' ); 41.60 (N-CH3); 54.57 (NCH2); 54.44 (CH2C); 58.11 (OCH3); 165.13 (CO) 168.48 (C
succinimide).
B. SYNTE~SIS OF COMPOUND (14) BY CONJUGATION WITH
COMPOUND (13) WITH BENZYLAMINE
Bw~' (41.45 mg, 0.39 mmol) was added to Compound (13) (I g, 0.19 mmol) in anhydrous CH,Cl7 (5 ml). The reaction mixture was kept at room WO 96100080 21917 2 ~ r ~

Ic~ ).,.aLL.c overnight. The solvent was removed under reduced pressure and the residue was It~ ' from 2-propanol to give compound (14) in 80% yield. 13C
N~ (CDCI3) ô, 41.94(NCH3);42.65(CH~Bel~' -);56.32(NCH2),58.12 (OCH3), 60.22 (CH~C); 126.32 to 137.99 (C Benzene ring);l69.70 (CO).
T',XAMPT,T~. 12 N-epsilon-Boc Iysine (15), (0.246 g, I rnmol) PEG 5,000-N-h~bu~.~ . ' ester (16) ( 5 g, I mmol) are added to pH 8 borate buffer (30 ml).
The m3xture is stirred at room temperature for about 3 hours and then neutralized with dilute hJ.II . ' ' acid. The aqueous solution was extracted with d ' ~ . ' (3 x 20 rnl). The organic layer was dried (anhyd. Na~SOJ) and evaporated under reduced pressure to yield 4.1 g, 79% N-epsilon-tert.-' _ y~l,u..,: . '.1 ' PEGcarbamate of L-lysine (17) T~.XAMPT .l~
N-epsilon-tert.-l......... ,tv,,.~,~bu~ ' PEGcarbamate of L-lysine (17) (5.2 g;
1 5 1.0 rnmol) is dissolved in ~ acid and ' ' ' , ~ ' (1 :2, 30 ml) and left to stand at room I Ij c for one hour. The solution is evaporated to dryness in ~ and the residue is triturated with dry ether, filtered, washed with ether and dried i~Q to yield (3 g, 60%) of Iysine-N-alpha-PEGcar~amate (18).
T~.XAMPI.T~'.14 Arnixtureof l~. N .1~' PE~' ' (18) (5.1 g, 1 mmol) ' ' , ' sulfonic acid sodium salt (1.84 8, 10 rnmol) in 20 rnl of water is placed m a 10 rnl pvl~nu~ , bottle. The bottle is sealed and kept in a water bath at 60~C for 48 hours followed by cooling to room L~ UIe and removal of the solvent by distillation in vacuo. Re~ . " of the residue from 2-propanol yields (5.5 g, 2 5 80%) of the compound (19).
T~.XAMPl.T('. l~i A solution of the compound (19) (5.2 g, I mmol) and N h, .' u,.y (115 mg, I mmol) in dry " '" ' ~ is cooled in an ice water bath and d;; v~v~ " ' (0.126 ~. Immol) is added with stirrin~. The mixture is kept ~ WO 96/00080 2 1 9 ~ 7 2 S

in a refrigerator overnight. The solvent is removed and the solid obtained is IC~ ' 1" ' from 2-propanol to give 4.3 g, (80%) of the product (19).
~,XAl~/IPT,T~'. 16 The following procedure details the, l; ~, of bovine ~ - g' ' (Hb), 9.8% solution, usmg an 18 fold molar excess of piperidine pl PEG (9) in the presence of 10% NaCI.
Piperidine pl PEG (9) 1.461 g, 2.842 x 10' M, is dissolved in 2 ml of pH 7.0 phosphate buffer (0.1 M) in a jacketed reaction vessel (0~C) and stirred for 10 minutes.
Ten rnl of the Hb solution is pipetted into another jacketed reaction vessel (8~C), along with 2.3 g NaCI. The pH is adjusted to 7.8 The pI PEG solution is added to the reaction vessel containing the Hb and the container is washed with 2 x 0.5 ml of the pH 7.0 buffer. The washings are then transferred to the Hb vessel. Seven ml of pH
7.8 phosphate buffer is added and the pH is adjusted to 7.8 with 1.0 N NaOH. Thereaction mixture is stirred uniformly and slowly for about 2 hours at 8~ C whilemaintaining the pH at 7.8.
After 2 hours, the reaction is quenched with cysteine HCI (0.105 g) and 124 111 of glycine solution (2.25 x 10~ ~. The pH is adjusted to 7.8 with 2 N NaOH. The conjugate can now be stored in the refrigerator between 4-6~ C.
As will be readily ~ l, numerous variations and ' of the features set forth above can be utilized without departing from the present invention as set forth in the claims. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such "~ are intended to be included within the scope of the followmg claims.

Claims (37)

WHAT IS CLAIMED IS:

1. A substantially non-antigenic polymer comprising the formula:
(I) R-B
wherein (R) is a water-soluble, substantially non-antigenic polymer residue; and (B) is a secondary amine or a tertiary amine.

2. The polymer of claim 1, wherein said secondary amine comprises the formula:
(II) -NH(CH2)nX
wherein (n) is an integer from 1-12, inclusive; and (X) is selected from the group consisting of H; OH; CO2R1, where R1 is H
or a C1-6 alkyl; halogen, aryl moieties and heteroaromatic moieties.

3. The polymer of claim 1, wherein said tertiary amine comprises a formula selected from the group consisting of wherein (m) is an integer from 0-12, inclusive;
(X) is selected from the group consisting of H; OH; CO2R1, where R1 is H or a C1-6 alkyl; halogen, aryl moieties and heteroaromatic moieties;
(Y) is N or CH; and (Z) is a C1-6 alkyl.

4. The polymer of claim 1, wherein said polymer is a poly(alkylene oxide) residue.

5. The polymer of claim 4, wherein said poly(alkylene oxide) residue is capped with a C1-4 alkyl group distal to said (B) moiety.

6. The polymer of claim 5, wherein said poly(alkylene oxide) residue is selected from the group consisting of poly(ethylene glycol) homopolymers, alkyl-capped poly(ethylene oxides), and copolymers of block copolymers of poly(alkylene oxides).

7. The polymer of claim 6, wherein said poly(alkylene oxide) has a molecular weight between about 200 and about 100,000.

8. The polymer of claim 7, wherein said poly(alkylene oxide) has a molecular weight between 1,000 and about 50,000.

9. The polymer of claim 8, wherein said poly(ethylene glycol) homopolymer has a molecular weight of from about 2,500 to about 25,000.

10. The polymer of claim 5, wherein (R) is a poly(ethylene glycol).

11. A substantially non-antigenic polymer comprising the formula:
(VII) R-B'-W-L
wherein (R) is a water-soluble, substantially non-antigenic polymer residue;
(B') is NY, wherein Y is H or a C1-6 alkyl or cycloalkyl;
(W) is a spacer moiety: and (L) is a functional group capable of bonding with nucleophiles.

12. The polymer of claim 11, wherein said secondary amine comprises the formula:
HN-(CH2)nX, wherein:
(n) is an integer from 1-12, inclusive; and (X) is selected from the group consisting of H; OH; CO2R1 where R1 is H or a C1-6 alkyl; halogen; aryl moieties and heteroaromatic moieties.

13. The polymer of claim 11, wherein said tertiary amine comprises a formula selected from the group consisting of wherein (m) is an integer from 0-12 inclusive;
(X) is selected from the group consisting of H; OH; CO2R1, where R1 is H or a C1-6 alkyl; halogen; aryl moieties and heteroaromatic moieties;
(Y) is N or CH; and (Z) is a C1-6 alkyl.

14. The polymer of claim 11, wherein said polymer is a poly(alkylene oxide) residue.

15. The polymer of claim 14, wherein said poly(alkylene oxide) residue is capped with a C1-4 alkyl group distal to said (B') moiety.

16. The polymer of claim 14, wherein said poly(alkylene oxide) residue is selected from the group consisting of poly(ethylene glycol) homopolymers, alkyl-capped poly(ethylene oxides), and copolymers of block copolymers of poly(alkylene oxides).

17. The polymer of claim 16, wherein said poly(alkylene oxide) has a molecular weight between about 200 and about 100,000.

18. The polymer of claim 17, wherein said poly(alkylene oxide) has a molecular weight between 1,000 and about 50,000.

19. The polymer of claim 18, wherein said poly(ethylene glycol) homopolymer has a molecular weight of about 2,500 to about 25,000.

20. The polymer of claim 11, wherein (W) is a moiety selected from the group consisting of straight or branched C1-4 alkyls, aralkyl, aryl and heteroaryl moieties.

21. The polymer of claim 20, wherein said moiety (W) is selected from the group consisting of ethyl-3-isocyanato propionate and ethyl-2-aminobutyrate.

22. The polymer of claim 11, wherein (L) is a moiety selected from the group consisting of:
functional groups capable of reacting with amino groups, functional groups capable of reacting with carboxylic acid groups;
functional groups capable of reacting with reactive carbonyl groups, and functional groups capable of reacting with mercapto groups

23. The polymer of claim 22, wherein (L) is a succinimidyl or a p-nitrophenyl carbonate active ester.

24. A polymer conjugate comprising the formula:
[R-B'-W-L1]z,-(nucleophile) wherein:
(R) is a water-soluble substantially non-antigenic polymer residue;
(B') is NY, wherein Y is H or a C1-6 alkyl or cycloalkyl, (W) is a spacer moiety;
(L1) represents a covalent linkage between (R-B-W) and the nucleophile; and (z) represents the number of polymers attached to the nucleophile.

25. The conjugate of claim 24, wherein R is a poly(alkylene oxide).

26. The conjugate of claim 25, wherein said poly(alkylene oxide residue is capped with a C1-4 alkyl group distal to said covalent linkage (L1).

27. The conjugate of claim 26, wherein said poly(alkylene oxide) is selected from the group consisting of poly(ethylene glycol) homopolymers, alkyl-capped poly(ethylene oxides), and copolymers of block copolymers of poly(alkylene oxides).

28. The conjugate of claim 24, wherein said poly(alkylene oxide) has a molecular weight between about 200 and about 100,000.

29.. The conjugate of claim 28, wherein said poly(alkylene oxide) has a molecular weight between 1,000 and about 50,000.

30. The conjugate of claim 29, wherein said poly(ethylene glycol) homopolymer has a molecular weight of about 2,500 and about 25,000.

31. The conjugate of claim 24, wherein R is a poly(ethylene glycol) homopolymer.

32. The conjugate of claim 24, wherein said nucleophile is selected from consisting of proteins, peptides, enzymes and polypeptides.

33. The conjugate of claim 32, wherein said enzyme is glucocerebrosidase.

34. The conjugate of claim 32, wherein said protein is selected from the group consisting of antibodies, monoclonal antibodies, fragments of antibodies and single chain-binding antigens.

35. The conjugate of claim 24, wherein said nucleophile is a member of the group consisting of anti-neoplastics, anti-infectives, anti-anxiety agents, anti-gastrointestinal agents, central nervous system-activating agents, analgesics, fertility, contraceptive agents, anti-inflammatory agents, steroidal agents, anti-urecemic agents, cardiovascular agents, vasodilating agents and vasconstricting agents.

36. The conjugate of claim 35, wherein said antineoplastic agent is selected from the group consisting of taxol, taxanes, camptothecins, anthracyclines and methotrexates.

37. A method of treatment comprising administering to a mammal in need thereof a therapeutically effective amount of the polymer conjugate of claim 24.