Patents Assigned to Nektar Therapeutics AL, Corporation
  • Publication number: 20090074704
    Abstract: Provided herein are water-soluble prodrugs, compositions comprising such prodrugs, and related methods of making and administering the same. The prodrugs of the invention comprise a water-soluble polymer having three or more arms, at least three of which are typically covalently attached to an active agent, e.g., a small molecule. The conjugates of the invention provide an optimal balance of polymer size and structure for achieving improved drug loading, since the conjugates of the invention possess three or more active agents releasably attached to a multi-armed water-soluble polymer. The prodrugs of the invention are therapeutically effective, and exhibit improved properties in-vivo when compared to unmodified parent drug.
    Type: Application
    Filed: November 30, 2007
    Publication date: March 19, 2009
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Xuan Zhao, Michael David Bentley, Zhongxu Ren, Tacey X. Viegas
  • Publication number: 20090054590
    Abstract: Multi-armed, monofunctional, and hydrolytically stable polymers are described having the structure wherein Z is a moiety that can be activated for attachment to biologically active molecules such as proteins and wherein P and Q represent linkage fragments that join polymer arms polya and polyb, respectively, to central carbon atom, C, by hydrolytically stable linkages in the absence of aromatic rings in the linkage fragments. R typically is hydrogen or methyl, but can be a linkage fragment that includes another polymer arm. A specific example is an mPEG disubstituted lysine having the structure where mPEGa and mPEGb have the structure CH3O—(CH2CH2O)nCH2CH2— wherein n may be the same or different for polya- and polyb- and can be from 1 to about 1,150 to provide molecular weights of from about 100 to 100,000.
    Type: Application
    Filed: September 20, 2008
    Publication date: February 26, 2009
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: J. Milton Harris, Francesco Maria Veronese, Paolo Caliceti, Oddone Schiavon
  • Publication number: 20090041714
    Abstract: Conjugates of a Factor VIII 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 are compositions comprising the conjugates, methods of making the conjugates, and methods of administering compositions comprising the conjugates to a patient.
    Type: Application
    Filed: June 6, 2008
    Publication date: February 12, 2009
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Mary J. Bossard, Michael D. Bentley, Ping Zhang
  • Publication number: 20090012241
    Abstract: The present invention is directed to hydrolytically stabilized maleimide-functionalized water soluble polymers and to methods for making and utilizing such polymers and their precursors.
    Type: Application
    Filed: August 26, 2008
    Publication date: January 8, 2009
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Antoni Kozlowski, Remy F. Gross III, Samuel P. McManus
  • Publication number: 20080262166
    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).
    Type: Application
    Filed: June 25, 2008
    Publication date: October 23, 2008
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Michael David Bentley, Xuan Zhao, Xiaoming Shen, Lihong Guo
  • Patent number: 7432330
    Abstract: The present invention is directed to hydrolytically stabilized maleimide-functionalized water soluble polymers and to methods for making and utilizing such polymers and their precursors.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: October 7, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Antoni Kozlowski, Remy F. Gross, III, Samuel P. McManus
  • Patent number: 7432331
    Abstract: The present invention is directed to hydrolytically stabilized maleimide-functionalized water soluble polymers and to methods for making and utilizing such polymers and their precursors.
    Type: Grant
    Filed: March 25, 2005
    Date of Patent: October 7, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Antoni Kozlowski, Remy F. Gross, III, Samuel P. McManus
  • Publication number: 20080234193
    Abstract: The present invention provides von Willebrand Factor-polymer conjugates and Factor VIII-polymer conjugates, each having a releasable linkage. Methods of making conjugates, methods for administering conjugates, are also provided.
    Type: Application
    Filed: December 27, 2007
    Publication date: September 25, 2008
    Applicants: Nektar Therapeutics AL, Corporation, Baxter International Inc., Baxter Healthcare SA
    Inventors: Mary J. Bossard, Gayle Stephenson, Zhihao Fang, Harold Zappe, Stacy Mitchell, Ping Zhang, Friedrich Scheiflinger, Peter Turecek, Juergen Siekmann, Katalin Varadi, Herbert Gritsch
  • Publication number: 20080227872
    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.
    Type: Application
    Filed: April 25, 2008
    Publication date: September 18, 2008
    Applicant: Nektar Therapeutics AL, Corporation
    Inventor: Antoni Kozlowski
  • Patent number: 7419600
    Abstract: Multi-armed, monofunctional, and hydrolytically stable polymers are described having the structure wherein Z is a moiety that can be activated for attachment to biologically active molecules such as proteins and wherein P and Q represent linkage fragments that join polymer arms polya and polyb, respectively, to central carbon atom, C, by hydrolytically stable linkages in the absence of aromatic rings in the linkage fragments. R typically is hydrogen or methyl, but can be a linkage fragment that includes another polymer arm. A specific example is an mPEG disubstituted lysine having the structure where mPEGa and mPEGb have the structure CH3O—(CH2CH2O)nCH2CH2— wherein n may be the same or different for polya- and polyb- and can be from 1 to about 1,150 to provide molecular weights of from about 100 to 100,000.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: September 2, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: J. Milton Harris, Francesco Maria Veronese, Paola Caliceti, Oddone Schiavon
  • Publication number: 20080194612
    Abstract: Provided herein are water-soluble prodrugs. The prodrugs of the invention comprise a water-soluble polymer having three or more arms, at least three of which are covalently attached to an active agent, e.g., a small molecule. The conjugates of the invention provide an optimal balance of polymer size and structure for achieving improved drug loading, since the conjugates of the invention possess three or more active agents releasably attached to a multi-armed water soluble polymer. The prodrugs of the invention are therapeutically effective, and exhibit improved properties in-vivo when compared to unmodified parent drug.
    Type: Application
    Filed: February 11, 2008
    Publication date: August 14, 2008
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Xuan Zhao, Michael D. Bentley, Zhongxu Ren, Tacey X. Viegas
  • Publication number: 20080188414
    Abstract: The present invention provides Factor IX moiety-polymer conjugates having a releaseable linkage. Methods of making conjugates, methods for administering conjugates, are also provided.
    Type: Application
    Filed: December 27, 2007
    Publication date: August 7, 2008
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Mary J. Bossard, Gayle Stephenson
  • Patent number: 7405266
    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).
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: July 29, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Michael David Bentley, Xuan Zhao, Xiaoming Shen, Lihong Guo
  • Patent number: 7378469
    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.
    Type: Grant
    Filed: July 24, 2006
    Date of Patent: May 27, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventor: Antoni Kozlowski
  • Publication number: 20080069902
    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: Application
    Filed: November 14, 2007
    Publication date: March 20, 2008
    Applicant: Nektar Therapeutics AL, Corporation
    Inventors: Xuan Zhao, Zhongxu Ren, Kazunori Emoto
  • Patent number: 7329721
    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.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: February 12, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Antoni Kozlowski, Remy F. Gross, III, Samuel P. McManus
  • Publication number: 20080015151
    Abstract: The present invention provides variants of cyanovirin-N and water-soluble polymer conjugates thereof, and methods of preparing such conjugates. The cyanovirin-N of the invention are particularly suited for site-selective covalent attachment of one or more water soluble polymers, to provide polymer conjugates of cyanovirin-N variants exhibiting antiviral activity.
    Type: Application
    Filed: August 2, 2007
    Publication date: January 17, 2008
    Applicants: The Govt. of the U.S.A. as represented by The Secretary of The Dept. of, Nektar Therapeutics AL, Corporation
    Inventors: M. Snell, Michael Roberts, Toshiyuki Mori, Barry O'Keefe, Michael Boyd
  • Patent number: 7316811
    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: December 24, 2003
    Date of Patent: January 8, 2008
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Xuan Zhao, Zhongxu Ren, Kazunori Emoto
  • Patent number: 7312301
    Abstract: The present invention provides both crosslinked polymer compositions capable of forming hydrogel 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 hydrogel, are also provided.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: December 25, 2007
    Assignee: Nektar Therapeutics AL, Corporation
    Inventors: Zhihao Fang, Michael D. Bentley
  • Patent number: 7265186
    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 8, 2004
    Date of Patent: September 4, 2007
    Assignee: Nektar Therapeutics AL, Corporation
    Inventor: Xuan Zhao