Patents Represented by Attorney Mark A. Wilson
  • Patent number: 8338545
    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.
    Type: Grant
    Filed: November 2, 2011
    Date of Patent: December 25, 2012
    Assignee: Nektar Therapeutics
    Inventor: Xuan Zhao
  • Patent number: 8329876
    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.
    Type: Grant
    Filed: October 26, 2011
    Date of Patent: December 11, 2012
    Assignee: Nektar Therapeutics
    Inventors: Michael J. Roberts, Zhihao Fang
  • Patent number: 8323632
    Abstract: The invention provides a multi-arm block copolymer for use in delivering a variety of bioactive agents. The copolymer of the invention contains a central core from which extend multiple (3 or more) copolymer arms. Each copolymer arm possesses an inner polypeptide segment and an outer hydrophilic polymer segment. Thus, the overall structure of the copolymer comprises an inner core region that includes the central core and the inner polypeptide segment, while the outer core region is hydrophilic in nature. The multi-arm copolymer of the invention is particularly useful for delivery of biologically active agents that can be entrapped within the inner core region.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: December 4, 2012
    Assignee: Nektar Therapeutics
    Inventors: Xuan Zhao, Zhongxu Ren, Kazunori Emoto
  • Patent number: 8309680
    Abstract: The present invention provides, among other things, segmented, degradable polymeric reagents suitable for reaction with biologically active agents to form conjugates, the polymeric reagents comprising one or more polymer chains divided or separated by one or more degradable linkages into polymer segments having a molecular weight suitable for renal clearance. The polymeric reagents can have a substantially linear structure, a branched structure, or a multiarm structure. Each structure includes one or more linkages capable of degradation in vivo.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: November 13, 2012
    Assignee: Nektar Therapeutics
    Inventors: Samuel P. McManus, Antoni Kozlowski
  • Patent number: 8304511
    Abstract: The present invention is directed a method comprising administering a composition to an individual, wherein the composition comprises a plurality of conjugates, each conjugate in the plurality a protein derivatized with a water-soluble polymer, wherein the polymer is coupled to the protein via succinimide groups covalently attached to either cysteine sulfhydryl groups or lysine amino groups, and substantially all of the succinimide groups present in the composition are present in a ring-opened form.
    Type: Grant
    Filed: June 29, 2011
    Date of Patent: November 6, 2012
    Assignee: Nektar Therapeutics
    Inventors: Antoni Kozlowski, Remy F. Gross, III, Samuel P. McManus
  • Patent number: 8299173
    Abstract: The invention provides a method comprising the steps of (i) reacting a water-soluble and non-peptidic polymer having two or more terminal hydroxyl groups with di(1-benzotriazolyl)carbonate to form a water-soluble and non-peptidic polymer having two or more 1-benzotriazolylcarbonate ester groups; and (ii) reacting the water-soluble and non-peptidic polymer having two or more 1-benzotriazolylcarbonate ester groups with a water-soluble and non-peptidic polymer having three or more primary amino groups under conditions effective to form a cross-linked polymer composition.
    Type: Grant
    Filed: June 7, 2011
    Date of Patent: October 30, 2012
    Assignee: Nektar Therapeutics
    Inventor: Antoni Kozlowski
  • Patent number: 8293869
    Abstract: Conjugates of a GLP-I moiety may be covalently attached to one or more water-soluble polymers. For instance, a GLP-I polymer conjugate may include a GLP-I moiety releasably attached at its N-terminus to a water-soluble polymer. The GLP-I polymer conjugate may include a GLP-I moiety covalently attached to a water-soluble polymer, wherein the GLP-I moiety possesses an N-methyl substituent. The GLP-I polymer conjugate may include a GLP-I moiety covalently attached at a polymer attachment site to a water-soluble polymer, wherein the GLP-I moiety is glycosylated at a site separate from the polymer attachment site.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: October 23, 2012
    Assignee: Nektar Therapeutics
    Inventors: Mary J. Bossard, Zhihao Fang, Tacey X. Viegas, Stewart A. Thompson, Mei-chang Kuo
  • Patent number: 8283434
    Abstract: Methods for preparing a poly(ether carbonates) of the formula HO—[(CH2CH2—O)n—CO2]m—(CH2CH2—O)n—H are provided. The method comprises polymerizing an activated oligomer of the formula of H—O—(CH2CH2—O)n—CO2—Z, where Z is reactive leaving group.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: October 9, 2012
    Assignee: Nektar Therapeutics
    Inventors: J. Milton Harris, Michael David Bentley, Xuan Zhao, Xiaoming Shen
  • Patent number: 8273339
    Abstract: Provided herein are water-soluble polymer conjugates and polymer-based compositions of antimicrobial agents. Also provided are methods for synthesizing and administering such conjugates and compositions.
    Type: Grant
    Filed: April 11, 2006
    Date of Patent: September 25, 2012
    Assignee: Nektar Therapeutics
    Inventors: Mary J. Bossard, Stacy Mitchell
  • Patent number: 8268948
    Abstract: The present invention provides conjugates having a degradable linkage and polymeric reagents useful in preparing such conjugates. Methods of making polymeric reagents and conjugates, as well as methods for administering conjugates and compositions, are also provided.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: September 18, 2012
    Assignee: Nektar Therapeutics
    Inventors: Sean M. Culbertson, Samuel P. McManus
  • Patent number: 8258324
    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.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: September 4, 2012
    Assignee: Nektar Therapeutics
    Inventors: Samuel P. McManus, Antoni Kozlowski, Tracy L. Hutchison, Brian Bray, Xiaoming Shen
  • Patent number: 8252275
    Abstract: The present invention provides conjugates having a degradable linkage and polymeric reagents useful in preparing such conjugates. The conjugates as well as the polymeric reagents used to form the conjugates include at least one of each the following: an aromatic moiety comprising an ionizable hydrogen atom, a spacer moiety, and a water-soluble polymer. Methods of making polymeric reagents and conjugates, as well as methods for administering conjugates and compositions, are also provided.
    Type: Grant
    Filed: June 16, 2006
    Date of Patent: August 28, 2012
    Assignee: Nektar Therapeutics
    Inventors: Michael D. Bentley, Sean Culbertson, Samuel P. McManus
  • Patent number: 8247598
    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.
    Type: Grant
    Filed: December 14, 2011
    Date of Patent: August 21, 2012
    Assignee: Nektar Therapeutics
    Inventors: Zhihao Fang, Michael D. Bentley
  • Patent number: 8227558
    Abstract: Methods for preparing polymeric reagents bearing a maleimide are provided. Also provided are related compositions.
    Type: Grant
    Filed: October 4, 2011
    Date of Patent: July 24, 2012
    Assignee: Nektar Therapeutics
    Inventors: Antoni Kozlowski, John R. Handley, Anthony G. Schaefer, Brian Bray, Ryan Odom, Tony L. Sander
  • Patent number: 8227555
    Abstract: The present invention is directed to conjugates of hydrolytically stabilized maleimide-functionalized water soluble polymers and to methods for making and utilizing such polymers and their precursors.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: July 24, 2012
    Assignee: Nektar Therapeutics
    Inventors: Antoni Kozlowski, Remy F. Gross, III, Samuel P. McManus
  • Patent number: 8217123
    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.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: July 10, 2012
    Assignee: Nektar Therapeutics
    Inventors: Antoni Kozlowski, Samuel P. McManus
  • Patent number: 8193306
    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.
    Type: Grant
    Filed: June 21, 2010
    Date of Patent: June 5, 2012
    Assignee: Nektar Therapeutics
    Inventors: Antoni Kozlowski, Jon McKannan, Samuel P. McManus
  • Patent number: 8182801
    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.
    Type: Grant
    Filed: July 1, 2009
    Date of Patent: May 22, 2012
    Assignee: Nektar Therapeutics
    Inventor: Antoni Kozlowski
  • Patent number: 8183338
    Abstract: The invention provides a sterically hindered polymers and conjugates formed therefrom that comprise a water-soluble and non-peptidic polymer backbone having at least one terminus covalently bonded to an alkanoic acid or alkanoic acid derivative prior to conjugation, 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).
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: May 22, 2012
    Assignee: Nektar Therapeutics
    Inventors: Michael D. Bentley, Xuan Zhao, Xiaoming Shen, Lihong Guo
  • Patent number: 8173666
    Abstract: The invention provides compounds that are chemically modified by covalent attachment of a water-soluble oligomer. A compound of the invention, when administered by any of a number of administration routes, exhibits characteristics that are different from those of the compound not attached to the water-soluble oligomer.
    Type: Grant
    Filed: September 11, 2009
    Date of Patent: May 8, 2012
    Assignee: Nektar Therapeutics
    Inventors: Jennifer Riggs-Sauthier, Bo-Liang Deng, Timothy A. Riley