Patents Assigned to Shearwater Corporation
  • Publication number: 20040038899
    Abstract: A substantially hydrophilic conjugate is provided having a peptide that is capable of passing the blood-brain barrier covalently linked to a water-soluble nonpeptidic polymer such as polyethylene glycol. The conjugate exhibits improved solubility and in vivo stability and is capable of passing the blood-brain barrier of an animal.
    Type: Application
    Filed: August 25, 2003
    Publication date: February 26, 2004
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Michael James Roberts
  • Publication number: 20030220447
    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 and then for hydrolytic breakdown of the conjugate and release of the bound molecule. In some cases, drugs that previously had reduced activity when permanently coupled to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. The PEG of the invention can be used to impart water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate. Controlled hydrolytic release of the bound molecule in the aqueous environment can then enhance the drug delivery system.
    Type: Application
    Filed: December 12, 2002
    Publication date: November 27, 2003
    Applicant: Shearwater Corporation
    Inventor: J. Milton Harris
  • Patent number: 6624246
    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: February 6, 2002
    Date of Patent: September 23, 2003
    Assignee: Shearwater Corporation
    Inventor: Antoni Kozlowski
  • Patent number: 6610281
    Abstract: Water soluble activated polymers are provided containing an active ethyl sulfone moiety having a reactive site located at the second carbon from the sulfone group. In an embodiment, a poly(ethylene glycol) (PEG) derivative is disclosed that is activated with the active ethyl sulfone moiety for selective attachment to thiol moieties on molecules and surfaces. The activated PEG is water soluble, hydrolytically stable for extended periods, and forms hydrolytically stable linkages with thiol moieties. The linkages generally are not reversible in reducing environments. The PEG derivative is useful for modifying the characteristics of substances including modifying biologically active molecules and surfaces for biocompatibility.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: August 26, 2003
    Assignee: Shearwater Corporation
    Inventor: J. Milton Harris
  • Publication number: 20030158333
    Abstract: The invention provides reagents and methods for conjugating a polymer specifically to the &agr;-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 &agr;-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: Application
    Filed: October 9, 2002
    Publication date: August 21, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael J. Roberts, Zhihao Fang
  • Patent number: 6602498
    Abstract: The invention is directed to multi-functional N-maleimidyl polymer derivatives comprising a water soluble and non-peptidic polymer backbone having a terminal carbon, such as a poly(alkylene glycol), the terminal carbon of the polymer backbone being directly bonded to the nitrogen atom of a N-maleimidyl moiety without a linking group therebetween. The invention also provides two methods of preparing such linkerless N-maleimidyl polymer derivatives.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: August 5, 2003
    Assignee: Shearwater Corporation
    Inventor: Xiaoming Shen
  • Patent number: 6602952
    Abstract: The invention provides a polymeric structure comprising a multifunctional poly(alkylene oxide), such as a poly(ethylene glycol) derivative, covalently cross-linked to a polymer selected from the group consisting of chitosan and conjugates of chitosan and a monofunctional poly(alkylene oxide), such as methoxy poly(ethylene glycol). In aqueous media, the polymeric structure forms a hydrogel that is useful as a drug delivery device, a surgical sealant, or as a delivery system for a medical imaging agent.
    Type: Grant
    Filed: June 8, 2000
    Date of Patent: August 5, 2003
    Assignee: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao
  • Publication number: 20030144207
    Abstract: A substantially hydrophilic conjugate is provided having a peptide that is capable of passing the blood-brain barrier covalently linked to a water-soluble nonpeptidic polymer such as polyethylene glycol. The conjugate exhibits improved solubility and in vivo stability and is capable of passing the blood-brain barrier of an animal.
    Type: Application
    Filed: January 30, 2003
    Publication date: July 31, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Michael James Roberts
  • Publication number: 20030143185
    Abstract: The invention provides polymer conjugates of protein kinase C (PKC) inhibitors comprising a polymer, such as poly(ethylene glycol), covalently attached to a PKC inhibitor, such as a bisindolylmaleimide molecule. The linkage between the polymer and the PKC inhibitor is preferably hydrolytically degradable. The invention also includes a pharmaceutical composition comprising a polymer conjugate of a PKC inhibitor and a method of treating any condition responsive to a PKC inhibitor by administering a polymer conjugate of the invention.
    Type: Application
    Filed: October 29, 2002
    Publication date: July 31, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao
  • Publication number: 20030143596
    Abstract: The present invention is directed to branched reactive water-soluble polymers comprising at least two polymer arms, such as poly(ethylene glycol), attached to a central aliphatic hydrocarbon core molecule through heteroatom linkages. The branched polymers bear at least one functional group for reacting with a biologically active agent to form a biologically active conjugate. The functional group of the branched polymer can be directly attached to the aliphatic hydrocarbon core or via an intervening linkage, such as a heteroatom, -alkylene-, —O-alkylene-O—, -alkylene-O-alkylene-, -aryl-O—, —O— aryl-, (—O-alkylene-)m, or (-alkylene-O—)m linkage, wherein m is 1-10.
    Type: Application
    Filed: November 7, 2002
    Publication date: July 31, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao, Xiaoming Shen, William Dudley Battle
  • Publication number: 20030124086
    Abstract: The invention provides polymer conjugates of opioid antagonists comprising a polymer, such as poly(ethylene glycol), covalently attached to an opioid antagonist. The linkage between the polymer and the opioid antagonist is preferably hydrolytically stable. The invention also includes a method of treating one or more side effects associated with the use of opioid analgesics, such as constipation, nausea, or pruritus, by administering a polymer conjugate of the invention.
    Type: Application
    Filed: October 18, 2002
    Publication date: July 3, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Michael James Roberts, Xiaoming Shen, Lin Cheng
  • Publication number: 20030114647
    Abstract: Multi-armed, monofunctional, and hydrolytically stable polymers are described having the structure 1
    Type: Application
    Filed: April 10, 2002
    Publication date: June 19, 2003
    Applicant: Shearwater Corporation
    Inventors: J. Milton Harris, Francesco Maria Veronese, Paolo Caliceti, Oddone Schiavon
  • Publication number: 20030105224
    Abstract: The invention provides reagents and methods for conjugating polymers specifically to the &agr;-amine of polypeptides in high yield. The invention provides monofunctional, bifunctional, and multifunctional PEGs and related polymers having a thioester moiety capable of specifically conjugating to the &agr;-amine of a polypeptide having a cysteine or histidine at the N-terminus. The invention provides active thioester derivatives of PEG that have suitable reactivity with an N-terminal cysteine or histidine residue of a polypeptide to produce an amide bond between the PEG and polypeptide. Use of these active esters to prepare PEG-proteins and PEG-peptides is described.
    Type: Application
    Filed: October 9, 2001
    Publication date: June 5, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael J. Roberts, Zhihao Fang
  • Publication number: 20030105275
    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: October 30, 2002
    Publication date: June 5, 2003
    Applicant: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao, Xiaoming Shen, Lihong Guo
  • Patent number: 6541543
    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 poly(ethylene glycol) and the biologically active agent.
    Type: Grant
    Filed: November 5, 2001
    Date of Patent: April 1, 2003
    Assignee: Shearwater Corporation
    Inventors: J. Milton Harris, Antoni Kozlowski
  • Patent number: 6541015
    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.
    Type: Grant
    Filed: April 26, 2001
    Date of Patent: April 1, 2003
    Assignee: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao
  • Patent number: 6515100
    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 and then for hydrolytic breakdown of the conjugate and release of the bound molecule. In some cases, drugs that previously had reduced activity when permanently coupled to PEG can have therapeutically suitable activity when coupled to a degradable PEG in accordance with the invention. The PEG of the invention can be used to impart water solubility, size, slow rate of kidney clearance, and reduced immunogenicity to the conjugate. Controlled hydrolytic release of the bound molecule in the aqueous environment can then enhance the drug delivery system.
    Type: Grant
    Filed: April 2, 2001
    Date of Patent: February 4, 2003
    Assignee: Shearwater Corporation
    Inventor: J. Milton Harris
  • Patent number: 6514491
    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.
    Type: Grant
    Filed: April 26, 2001
    Date of Patent: February 4, 2003
    Assignee: Shearwater Corporation
    Inventors: Michael David Bentley, Xuan Zhao
  • Publication number: 20030023023
    Abstract: A water soluble polymer is provided having two or more oligomers linked to each other by hydrolytically degradable carbonate linkages. The polymer can be hydrolytically degraded into oligomers (e.g., oligomers of ethylene oxide) under physiological conditions. The polymer can be conjugated to biologically active agents such as proteins or peptides to impart improved water solubility, reduced immunogenicity, reduced rate of renal clearance, and increased stability. The polymer is useful in making hydrolytically degradable hydrogels which can be used in drug delivery and related biomedical applications. On example of the polymer is a poly(ether carbonate) of the formula X—O—[(—CH2CH2—O—)n—CO2—]n(CH2CH2))n-y where X and Y are independently H, alkyl, alkenyl, aryl, or a reactive moiety, and at least one of X and Y is a reactive moiety.
    Type: Application
    Filed: February 14, 2002
    Publication date: January 30, 2003
    Applicant: Shearwater Corporation
    Inventors: J. Milton Harris, Michael David Bentley, Xuan Zhao, Xiaoming Shen
  • Publication number: 20030017504
    Abstract: The present invention provides IgG monoclonal antibodies and IgG monoclonal antibody fragments that selectively bind to PEG, hybridoma cell lines and methods for producing these antibodies, and methods for using the PEG-selective monoclonal antibodies. The methods of the invention include methods for detecting molecules, viruses, cells, or organelles that contain at least one poly(ethylene glycol) group and methods for purifying for purifying molecules, viruses, cells, or organelles that contain at least one poly(ethylene glycol) group. Also provided are methods for using the anti-PEG monoclonal antibodies in vivo to modulate the level of a PEG-containing molecule.
    Type: Application
    Filed: May 21, 2002
    Publication date: January 23, 2003
    Applicant: SHEARWATER CORPORATION
    Inventors: Michael J. Roberts, Mary Elizabeth Green