Abstract: Methods for preparing polymeric reagents bearing a maleimide are provided. Also provided are compositions comprising the polymeric reagents, and conjugates prepared by polymeric reagents obtained by the described methods.

Abstract: Disclosed are water soluble polymeric reagents comprising the structure POLY-[Y—S—W]x, where POLY is a water soluble polymer; Y is a hydrocarbon-based spacer group, x is 1 to 25, and S—W is a thiol, protected thiol, or thiol-reactive derivative. Preferably, the water soluble polymer is a PEG polymer. Also disclosed are conjugates of such polymeric reagents with pharmaceutically relevant molecules, and methods of their formation and use.

Abstract: The invention provides reagents and methods for conjugating a polymer specifically to the ?-amine of a polypeptide. The invention provides monofunctional, bifunctional, and multifunctional PEGs and related polymers having a terminal thioester moiety capable of specifically conjugating to the ?-amine of a polypeptide having a cysteine or histidine residue at the N-terminus. The invention provides reactive thioester-terminated PEG polymers that have suitable reactivity with an N-terminal cysteine or histidine residue of a polypeptide to produce an amide bond between the PEG molecule and the polypeptide.

Abstract: Methods for forming maleimide functionalized polymers are provided. In one such embodiment, a maleimide functionalized polymer is prepared in a method that includes a step of carrying out a reverse Diels-Alder reaction. Intermediates useful in the methods, as well as methods for preparing the intermediates, are also provided. Also provided are polymeric reagents, methods of using polymeric reagents, compounds and conjugates.

Abstract: A water soluble polymer comprising multiple degradable carbonate linkages in a backbone and, for each carbonate linkage in the backbone, an oligomer linked thereto by the carbonate linkage, wherein the oligomer is branched.

Abstract: Methods for preparing active carbonate esters of water-soluble polymers are provided. Also provided are other methods related to the active carbonate esters of water-soluble polymers, as well as corresponding compositions.

Abstract: The invention provides a method for preparing a 1-benzotriazolylcarbonate ester of a water-soluble and non-peptidic polymer by reacting a terminal hydroxyl group of a water-soluble and non-peptidic polymer with di(1-benzotriazolyl)carbonate in the presence of an amine base and an organic solvent. The polymer backbone can be poly(ethylene glycol). The 1-benzotriazolylcarbonate ester can then be reacted directly with a biologically active agent to form a biologically active polymer conjugate or reacted with an amino acid, such as lysine, to form an amino acid derivative.

Abstract: An activated, substantially water-soluble poly(ethylene glycol) is provided having of a linear or branched poly(ethylene glycol) backbone and at least one terminus linked to the backbone through a hydrolytically stable linkage, wherein the terminus is branched and has proximal reactive groups. The free reactive groups are capable of reacting with active moieties in a biologically active agent such as a protein or peptide thus forming conjugates between the activated (polyethylene glycol) and the biologically active agent.

Abstract: The invention provides a sterically hindered polymer that comprises a water-soluble and non-peptidic polymer backbone having at least one terminus covalently bonded to an alkanoic acid or alkanoic acid derivative, wherein the carbon adjacent to the carbonyl group of the acid or acid derivative group has an alkyl or aryl group pendent thereto. The steric effects of the alkyl or aryl group allow greater control of the hydrolytic stability of polymer derivatives. The polymer backbone may be poly(ethylene glycol).

Abstract: The present invention is directed to maleamic acid derivatives of water soluble polymers, to chemically stable water-soluble polymer succinamic acid-active agent conjugates, and to methods for reproducibly preparing, characterizing and using such polymer reagents and their conjugates.

Abstract: PEG and related polymer derivatives having weak, hydrolytically unstable linkages near the reactive end of the polymer are provided for conjugation to drugs, including proteins, enzymes, small molecules, and others. These derivatives provide a sufficient circulation period for a drug-PEG conjugate, followed by hydrolytic breakdown of the conjugate and release of the bound molecule. In some cases, drugs that demonstrate reduced activity when permanently coupled to PEG maintain a therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. The PEG derivatives of the invention can be used to impart improved water solubility, increased size, a slower rate of kidney clearance, and reduced immunogenicity to a conjugate formed by attachment thereto. Controlled hydrolytic release of the bound molecule into an aqueous environment can then enhance the drug's delivery profile by providing a delivery system which employs such polymers and utilizes the teachings provided herein.

Abstract: This invention provides a method for preparing, in high purity and high yield, heterobifunctional derivatives of poly(ethylene glycol) or related polymers. A chromatographic purification step is not necessary in the method. In accordance with the method of the invention, an intermediate polymer having a formula of W-Poly-OH is provided bearing a removable group W at one terminus. The intermediate polymer W-Poly-OH is first altered by modifying the OH group to a first functional group X, followed by the removal of W to generate a second hydroxyl group. The latter hydroxyl group may then be further converted to a second functional group Y, thus providing the desired heterobifunctional derivative.

Abstract: Poly(ethylene glycol) carbamate derivatives useful as water-soluble pro-drugs are disclosed. These degradable poly(ethylene glycol) carbamate derivatives also have potential applications in controlled hydrolytic degradation of hydrogels. In such degradable hydrogels, drugs may be either trapped in the gel and released by diffusion as the gel degrades, or they may be covalently bound through hydrolyzable carbamate linkages. Hydrolysis of these carbamate linkages releases the amine drug at a controllable rate as the gel degrades.

Abstract: A water soluble polymer is described, the water soluble polymer comprising multiple hydrolytically degradable carbonate linkages in a backbone and, for each carbonate linkage in the backbone, an oligomer linked thereto by the carbonate linkage, wherein the oligomer is branched and, prior to being linked by the carbonate linkage, has the formula: R3[O—(—CHR1CH2—O—)n—]mH where R3 is a core branching moiety, R1 is H, (n) can range from 2 to 2000, and m is at least 3.

Abstract: The invention provides methods for preparing polymers bearing a terminal propionic acid. The method involves first reacting a water soluble and non-peptidic polymer comprising at least one hydroxyl group with a tertiary alkyl acrylate in the presence of a catalyst to form a propionic acid ester of the polymer, wherein the polymer has a weight average molecular weight of at least about 10,000 Da; and then treating the propionic acid ester of the polymer with a strong acid to form a propionic acid of the polymer.

Abstract: The present invention provides both crosslinked polymer compositions capable of forming hydrogels upon exposure to an aqueous environment and thiosulfonate hydrogel-forming components. The thiosulfonate hydrogel-forming components of the invention are preferably multi-arm thiosulfonate polymer derivatives that form a crosslinked polymer composition when exposed to a base without requiring the presence of a second cross-linking reagent, redox catalyst, or radiation. Methods for forming hydrogel compositions, as well as methods for using the hydrogels, are also provided.

Abstract: The invention provides methods for making copolymers and multi-arm block copolymers useful as drug delivery vehicles. The multi-arm block copolymers comprise a central core molecule, such as a residue of a polyol, and at least three copolymer arms covalently attached to the central core molecule, each copolymer arm comprising an inner hydrophobic polymer segment covalently attached to the central core molecule and an outer hydrophilic polymer segment covalently attached to the hydrophobic polymer segment, wherein the central core molecule and the hydrophobic polymer segment define a hydrophobic core region. The solubility of hydrophobic biologically active agents can be improved by entrapment within the hydrophobic core region of the block copolymer. The invention further includes pharmaceutical compositions including such block copolymers, pharmaceutical compositions, and methods of using the block copolymers as drug delivery vehicles.

Abstract: Conjugates of a Factor IX moiety and one or more water-soluble polymers are provided. Typically, the water-soluble polymer is poly(ethylene glycol) or a derivative thereof. Also provided (among other things) are compositions comprising the conjugates, methods of making the conjugates, and methods of administering to a patient compositions comprising the conjugates.

Abstract: A method is provided for preparing water-soluble polymer derivatives bearing a terminal carboxylic acid or ester thereof. The method involves the hydrolyzing an ortho ester of a water-soluble polymer so as provide the corresponding acid. In addition, the invention provides water-soluble polymers bearing a terminal carboxylic acid or ester thereof, intermediates and reagents useful in carrying out the method, as well as gels, pharmaceutical formulations, conjugates related to the described water-soluble polymer derivatives.

Abstract: The invention provides a method for preparing a 1-benzotriazolylcarbonate ester of a water-soluble and non-peptidic polymer by reacting a terminal hydroxyl group of a water-soluble and non-peptidic polymer with di(1-benzotriazolyl)carbonate in the presence of an amine base and an organic solvent. The polymer backbone can be poly(ethylene glycol). The 1-benzotriazolylcarbonate ester can then be reacted directly with a biologically active agent to form a biologically active polymer conjugate or reacted with an amino acid, such as lysine, to form an amino acid derivative.