By Donald Zuhn --
Osprey Pharmaceuticals Ltd. announced today that it had been granted U.S. Patent Nos. 7,157,418; 7,166,702; and 7,192,736. The claims of the '418 patent are directed to methods for treating secondary tissue damage and other inflammatory conditions and disorders using a chemokine-cell toxin conjugate, the claims of the '702 patent are directed to chemokine-cell toxin conjugates (e.g., fusion proteins), and the claims of the '736 patent are directed to nucleic acid molecules encoding chemokine-cell toxin conjugates. The '418, '702, and '736 patents, which issued on January 2, January 23, and March 23, respectively, are the first U.S. patents to be awarded to the Saint Laurent, Quebec-based biotech company.
According to the statement released by Osprey Pharmaceuticals, the '418, '702, and '736 patents "protect the use of conjugated chemokines to selectively and systematically eliminate overactive leukocytes implicated in most chronic diseases, the core technology behind Osprey's Leukocyte Population Modulator (LPM) platform." Osprey co-founder Dr. John McDonald noted that "[t]he timing of the patent issuance comes at an important stage of the company's development, as we move our first LPM for the treatment of chronic kidney disease into the clinic later this year."
Osprey's LPMs are chemokine-toxin fusion proteins that kill cells expressing chemokine receptors, most of which are leukocytes. The foundation of Osprey's therapeutic strategy is that more than 100 common diseases and traumas - such as nephritis, multiple sclerosis, arthritis, asthma, and some cancers - are due to a generalized failure in the chemokine regulated controls that maintain the balance of leukocyte numbers and activity at the core of the immune system. Thus, Osprey postulates that because leukocytes effectively are the fuel that keeps a disease going, killing them off with an LPM removes that fuel.
The '418 patent issued from U.S. Application No. 09/360,242 and claims the benefit of International Application PCT/CA99/00659, filed July 21, 1999, and U.S. Provisional Application No. 60/155,186, filed July 22, 1998. Representative independent claims 1, 9, and 29 of the '418 patent recite:
1. A method for inhibiting proliferation or migration of activated immune effector cells, comprising administering a conjugate to an animal, whereby proliferation or migration of the immune effector cells is inhibited, wherein:
the conjugate comprises a targeted agent or a portion thereof and a chemokine receptor targeting agent or a portion thereof sufficient to bind to a chemokine receptor on immune effector cells and facilitate internalization of the conjugate;
the chemokine receptor targeting agent is a chemokine, an antibody that specifically binds to a chemokine receptor or a fragment of the chemokine or antibody, wherein the chemokine, antibody or fragment thereof binds to the receptor and internalizes the targeted agent in a cell;
the targeted agent or portion thereof, when internalized in a cell, alters metabolism or gene expression in the cell, regulates or alters protein synthesis in the cell, inhibits proliferation of the cell or kills the cell; and
the conjugate binds to a chemokine receptor resulting in internalization of the targeted agent in cells bearing the receptor.
9. A method for inhibiting the proliferation, migration or activity of secondary tissue damage-promoting inflammatory cells, comprising administering to a subject in need thereof an effective amount of a therapeutic agent that inhibits the proliferation, migration or physiological activity of secondary tissue damage-promoting inflammatory cells, wherein the therapeutic agent is a conjugate that comprises a chemokine receptor targeting agent and a targeted agent or portion thereof selected so that conjugate binds to a chemokine receptor and internalizes the targeted agent, which inhibits the proliferation, migration or physiological activity of the secondary tissue damage-promoting cells.
29. A method of targeted delivery of an agent into cells that express chemokine receptors, comprising associating the agent with a chemokine receptor targeting agent, whereby:
the chemokine receptor targeting agent binds to a chemokine receptor expressed on the cells; and
the agent is internalized by the cells, wherein the cells are immune effector cells.
The '702 patent issued from U.S. Application No. 09/453,851, which is a divisional of the application from which the '418 patent issued. Representative independent claim 1 of the '702 patent recites:
1. A conjugate, comprising a targeted agent and a chemokine receptor targeting agent, or a portion thereof, wherein the conjugate binds to a chemokine receptor present on activated leukocytes resulting in internalization of the targeted agent in cells bearing the receptor.
The '736 patent issued from U.S. Application No. 09/792,793, which is a divisional of the application from which the '702 patent issued. Representative independent claim 1 of the '736 patent recites:
1. A nucleic acid molecule, comprising a sequence of nucleotides encoding a conjugate that comprises a toxin and a chemokine receptor targeting agent, or a portion thereof sufficient for binding to a chemokine receptor and internalization of the chemokine receptor targeting agent, wherein:
the conjugate binds to a chemokine receptor resulting in internalization of the toxin in cells bearing the receptor; and
the receptor occurs on activated immune cells.
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