ZymoGenetics, Inc. filed an infringement suit against Bristol-Myers Squibb over its patents related to fusion protein technology. The lawsuit, ZymoGenetics, Inc. v. Bristol-Myers Squibb Co., et al., District Court of Delaware, is for injunctive relief and damages over infringement, contributory infringement and/or inducement of infringement of US Patent Nos. 5,843,725 and 6,018,026.
The ‘026 Patent and the ‘725 Patent are directed to biologically active polypeptide fusion compositions and methods for producing biologically active polypeptide fusion compositions. Immunoglobulin fusion proteins are proteins that are produced using recombinant DNA technology where a portion of an antibody (e.g., heavy chain constant domain) is combined with the portion of a second protein (typically the portion of a cell-surface receptor that is responsible for binding to a growth factor). Amgen and Regeneron have previously licensed the use of the fusion protein technology.
Specifically, the ‘725 patent discloses a method for producing a secreted, biologically active dimerized polypeptide fusion. The method generally comprises a) introducing into a eukaryotic host cell a DNA construct comprising a transcriptional promoter operatively linked to a secretory signal sequence followed downstream by and in proper reading frame with a DNA sequence encoding a non-immunoglobulin polypeptide requiring dimerization for biological activity joined to a dimerizing protein; (b) growing the host cell in an appropriate growth medium under physiological conditions to allow the secretion of a dimerized polypeptide fusion encodes by said DNA sequence; and (c) isolating the biologically active dimerized polypeptide fusion from the host cell.
The ‘026 patent discloses a biologically active, dimerized polypeptide fusion, comprising first and second polypeptide chains, wherein each of said polypeptide chains comprises a non-immunoglobulin polypeptide requiring dimerization for biological activity joined to a dimerizing protein heterologous to said non-immunoglobulin polypeptide.
ZymoGenetics now alleges that Bristol is infringing the ‘725 and ‘026 patents by making, using, selling, distributing, advertising and marketing products, including but not limited to abatacept, that infringes the ‘725 and ‘026 Patents.
Abatacept (CTLA-4Ig; sold by Bristol-Myers Squibb as Orencia ®) is a fully human recombinant fusion protein categorized as a costimulatory or second-signal blocker of T cell activation. Abatacept disrupts the activation pathway of T cells causing a disturbance in key mechanisms of inflammation and progressive joint destruction in rheumatoid arthritis (RA). Because a large number of patients with RA have an inadequate or unsustained response to anti-tumor necrosis factor (TNF) therapy, abatacept, with its novel mechanism of action, has been studied in this population.
