Patents by Inventor Ravi V. J. Chari

Ravi V. J. Chari has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7585857
    Abstract: A cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for killing selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient. A method for killing selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. Novel sulfur-containing taxanes.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: September 8, 2009
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Walter A. Blättler
  • Publication number: 20090182038
    Abstract: Leptomycin derivatives having a moiety, such as a sulfide or a disulfide, that can conjugate to a cell binding reagent such as an antibody are disclosed. The therapeutic use of such leptomycin derivative conjugates is also described; such conjugates have therapeutic use because they can deliver cytotoxic leptomycin derivatives to a specific cell population in a targeted fashion.
    Type: Application
    Filed: November 24, 2008
    Publication date: July 16, 2009
    Applicant: sanofi-aventis
    Inventors: Herve Bouchard, Alain Commercon, Ravi V.J. Chari
  • Patent number: 7550609
    Abstract: A cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for killing selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient. A method for killing selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. Novel sulfur-containing taxanes.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: June 23, 2009
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Walter A. Blättler
  • Patent number: 7528130
    Abstract: A cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for killing selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient. A method for killing selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. Novel sulfur-containing taxanes.
    Type: Grant
    Filed: January 6, 2006
    Date of Patent: May 5, 2009
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Walter A. Blättler
  • Publication number: 20090076263
    Abstract: Methods of killing or inhibiting tumors comprising of heterogeneous or mixed cell populations is described. The killing or inhibition of tumors is achieved by selectively targeting a unique ligand suspected of being expressed on a particular cell population to also kill a cell population lacking the unique ligand. These conjugates have therapeutic use as they are delivered to a specific cell population to kill these cells and the cytotoxic drug is released to kill non-targeted cells, thereby eliminating the tumor.
    Type: Application
    Filed: August 5, 2008
    Publication date: March 19, 2009
    Applicant: ImmunoGen Inc.
    Inventors: Viktor S. Goldmakher, Robert J. Lutz, Ravi V.J. Chari, Yelena V. Kovtun, John M. Lambert, Rita Steeves, Hans K. Erickson
  • Patent number: 7495114
    Abstract: Included within the scope of the present invention are potent taxanes and taxanes containing a linking group. Also included is a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for inducing cell death in selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient is also included. A method for inducing cell death in selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent is included as well.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: February 24, 2009
    Assignee: Immunogen Inc.
    Inventors: Erkan Baloglu, Michael Miller, Ravi V. J. Chari
  • Publication number: 20090036431
    Abstract: The present invention is related to new tomaymycin derivatives, their process of preparation and their therapeutic uses.
    Type: Application
    Filed: July 16, 2008
    Publication date: February 5, 2009
    Applicant: SANOFI-AVENTIS
    Inventors: Laurence GAUZY, Herve BOUCHARD, Ravi V.J. CHARI, Alain COMMERCON, Robert ZHAO, Yonghong DENG, Wei LI
  • Publication number: 20090028821
    Abstract: The present invention provides prodrugs of analogs of the anti-tumor antibiotic CC-1065 having a cleavable protective group containing a sulfonic acid containing phenyl carbamate, in which the protecting group confers enhanced water solubility upon the prodrug, and in which the prodrug also has a moiety, such as a sulfide or a disulfide, that can conjugate to a cell binding reagent such as an antibody, and for the therapeutic use of such prodrug and conjugates, and for processes for preparing such prodrugs and conjugates.
    Type: Application
    Filed: September 4, 2008
    Publication date: January 29, 2009
    Applicant: SANOFI-AVENTIS
    Inventors: Robert Zhao, Ravi V.J. Chari
  • Patent number: 7476669
    Abstract: A cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for killing selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient. A method for killing selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. Novel sulfur-containing taxanes.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: January 13, 2009
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Walter A. Blättler
  • Patent number: 7473796
    Abstract: New thiol and disulfide-containing maytansinoids bearing a mono or di-alkyl substitution on the ?-carbon atom bearing the sulfur atom are disclosed. Also disclosed are methods for the synthesis of these new maytansinoids and methods for the linkage of these new maytansinoids to cell-binding agents. The maytansinoid-cell-binding agent conjugates are useful as therapeutic agents, which are delivered specifically to target cells and are cytotoxic. These conjugates display vastly improved therapeutic efficacy in animal tumor models compared to the previously described agents.
    Type: Grant
    Filed: July 16, 2007
    Date of Patent: January 6, 2009
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Wayne C. Widdison
  • Publication number: 20080260685
    Abstract: Prodrugs of analogs of the anti-tumor antibiotic CC-1065 having a cleavable protective group such as a piperazino carbamate, a 4-piperidino-piperidino carbamate or a phosphate, in which the protecting group confers enhanced water solubility and stability upon the prodrug, and in which the prodrug also has a moiety, such as a disulfide, that can conjugate to a cell binding reagent such as an antibody. The therapeutic use of such prodrug conjugates is also described; such prodrugs of cytotoxic agents have therapeutic use because they can deliver cytotoxic prodrugs to a specific cell population for enzymatic conversion to cytotoxic drugs in a targeted fashion.
    Type: Application
    Filed: June 23, 2008
    Publication date: October 23, 2008
    Applicant: ImmunoGen Inc.
    Inventors: Robert Yongxin ZHAO, Ravi V.J. Chari
  • Patent number: 7414073
    Abstract: Included within the scope of the present invention are potent taxanes and taxanes containing a linking group. Also included is a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for inducing cell death in selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a link, and (B) a pharmaceutically acceptable carrier, diluent or excipient is also included. A method for inducing cell death in selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent is included as well.
    Type: Grant
    Filed: October 14, 2004
    Date of Patent: August 19, 2008
    Assignee: Immunogen Inc.
    Inventors: Erkan Baloglu, Michael Miller, Ravi V. J. Chari
  • Patent number: 7411063
    Abstract: The present invention describes the preparation of maytansinol by methods that minimize processing steps, and reduce solvent volumes, making the process more efficient, and scaleable. This process comprises a step of converting bridged acetals of maytansinol to maytansinol. The simplified processing also aids in lowering the potential for human exposure to chemicals. Also provided is an isolated C3 to C9 bridged acetal of maytansinol.
    Type: Grant
    Filed: November 8, 2006
    Date of Patent: August 12, 2008
    Assignee: Immunogen, Inc.
    Inventors: Wayne C. Widdison, Ravi V. J. Chari
  • Patent number: 7390898
    Abstract: Included within the scope of the present invention are potent taxanes containing a linking group. Also included is a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for inducing cell death in selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient is also included. A method for inducing cell death in selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent is included as well.
    Type: Grant
    Filed: February 21, 2003
    Date of Patent: June 24, 2008
    Assignee: Immunogen Inc.
    Inventors: Erkan Baloglu, Michael Miller, Ravi V. J. Chari
  • Patent number: 7388026
    Abstract: Prodrugs of analogs of the anti-tumor antibiotic CC-1065 having a cleavable protective group such as a piperazino carbamate, a 4-piperidino-piperidino carbamate or a phosphate, in which the protecting group confers enhanced water solubility and stability upon the prodrug, and in which the prodrug also has a moiety, such as a disulfide, that can conjugate to a cell binding reagent such as an antibody. The therapeutic use of such prodrug conjugates is also described; such prodrugs of cytotoxic agents have therapeutic use because they can deliver cytotoxic prodrugs to a specific cell population for enzymatic conversion to cytoxic drugs in a targeted fashion.
    Type: Grant
    Filed: September 2, 2005
    Date of Patent: June 17, 2008
    Assignee: Immunogen, Inc.
    Inventors: Robert Yongxin Zhao, Ravi V. J. Chari
  • Patent number: 7368565
    Abstract: The present invention discloses a one-step process for the production of cytotoxic conjugates of maytansinoids and cell binding agents. Maytansinoids having a disulfide linker that bears a reactive moiety are linked to cell binding agents, such as antibodies, without prior modification of the cell binding agent. These conjugates are useful as therapeutic agents which are delivered specifically to target cells and are cytotoxic.
    Type: Grant
    Filed: June 5, 2002
    Date of Patent: May 6, 2008
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Wayne C. Widdison
  • Patent number: 7329760
    Abstract: Improved synthesis of seco(?)CBI (5-hydroxy-3-amino-1-[S]-(chloromethyl)-1,2-dihydro-3H-benz(e)indole): and improved syntheses therefrom of a wide variety of CC-1065 analogs that comprise a cyclopropabenzidole (CBI) alkylating moiety, and which are collectively DC1 and its derivatives, for the synthesis of cell-targeted therapeutic agents.
    Type: Grant
    Filed: October 7, 2002
    Date of Patent: February 12, 2008
    Assignee: Immunogen Inc.
    Inventors: Robert Yongxin Zhao, Ravi V. J. Chari
  • Patent number: 7303749
    Abstract: The present invention is based on the discovery that the administration of at least one immunoconjugate and at least one chemotherapeutic agent provides an unexpectedly superior treatment for cancer. The present invention is directed to compositions comprising at least one immunoconjugate and at least one chemotherapeutic agent and to methods of treating cancer using at least one immunoconjugate and at least one chemotherapeutic agent. The present invention also provides methods of modulating the growth of selected cell populations, such as cancer cells, by administering a therapeutically effective amount of at least one chemotherapeutic agent and at least one immunoconjugate.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: December 4, 2007
    Assignee: Immunogen Inc.
    Inventor: Ravi V. J. Chari
  • Patent number: 7301019
    Abstract: Improved processes for the preparation and purification of maytansinoid esters, especially thiol and disulfide-containing maytansinoids are described. In one aspect the process comprises a process of making a maytansinoid ester comprising forming an anion of maytansinol or a maytansinoid bearing a free C-3 hydroxyl moiety and reacting the anion with an activated carboxyl compound to thereby produce the maytansinoid ester.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: November 27, 2007
    Assignee: Immunogen, Inc.
    Inventors: Wayne C. Widdison, Ravi V. J. Chari
  • Patent number: 7276499
    Abstract: A cytotoxic agent comprising one or more taxanes linked to a cell binding agent. A therapeutic composition for killing selected cell populations comprising: (A) a cytotoxic amount of one or more taxanes covalently bonded to a cell binding agent through a linking group, and (B) a pharmaceutically acceptable carrier, diluent or excipient. A method for killing selected cell populations comprising contacting target cells or tissue containing target cells with an effective amount of a cytotoxic agent comprising one or more taxanes linked to a cell binding agent. Novel sulfur-containing taxanes.
    Type: Grant
    Filed: January 13, 2006
    Date of Patent: October 2, 2007
    Assignee: Immunogen Inc.
    Inventors: Ravi V. J. Chari, Walter A. Blattler