Background
Amgen Inc. held five U.S. patents — the ‘868, ‘933, ‘698, ‘349, and ‘422 patents — covering recombinant human erythropoietin (EPO), a hormone that stimulates red blood cell production used to treat anemia in patients with chronic kidney disease or undergoing chemotherapy. These patents were among the most valuable pharmaceutical patents ever issued, covering both the composition of recombinant EPO and methods of producing it using recombinant DNA technology in host cells.
F. Hoffmann-La Roche developed MIRCERA® — a continuous erythropoietin receptor activator (CERA) — by chemically bonding polyethylene glycol (PEG) to recombinant EPO produced in Chinese hamster ovary (CHO) cells. Pegylation extends the drug’s half-life, allowing less frequent dosing. Amgen argued that MIRCERA’s active ingredient was recombinant EPO covered by its patents. After extensive district court proceedings in Massachusetts, including summary judgment rulings, a jury trial, and JMOL motions, the court entered judgment of infringement and validity for four of the five patents. Roche appealed.
The Court’s Holding
The Federal Circuit affirmed infringement and validity findings for the ‘868, ‘933, ‘698, and ‘422 patents. The court rejected Roche’s principal invalidity arguments, including anticipation and obviousness challenges. The court agreed that Roche’s pegylated EPO (CERA) fell within the scope of Amgen’s EPO claims even though it had been chemically modified — the pegylation process attached PEG to recombinant EPO produced from CHO cells, which itself was covered by Amgen’s composition claims.
However, the Federal Circuit vacated the district court’s rulings on obviousness-type double patenting as to specific claims of the ‘933, ‘422, and ‘349 patents, and remanded for proper analysis. Obviousness-type double patenting prevents a patentee from obtaining unjustified extensions of patent term by claiming the same invention in a later-filed patent in an obvious variation. The district court had not fully analyzed whether certain claims were patentably distinct from claims in related patents, and the Federal Circuit declined to resolve that question without a proper record.
Key Takeaways
- Broad composition claims covering recombinant proteins like EPO can encompass chemically modified versions (such as pegylated forms) that fall within the structural scope of the claims even if the modification itself was not described in the patent.
- Obviousness-type double patenting requires careful analysis of whether later patent claims are patentably distinct from earlier claims — mere lexical difference is insufficient if the subject matter is the same or obviously similar.
- Pharmaceutical companies challenging pioneer biotech patents must overcome a very high bar for invalidity: the historical rarity of recombinant protein production and the scope of Amgen’s pioneering disclosure weighed against obvious challenge arguments.
- The case contributed to the legal framework governing biologics patent enforcement, relevant to the later debates over biosimilar entry under the Biologics Price Competition and Innovation Act (BPCIA) of 2010.
Why It Matters
The Amgen v. Roche litigation represented one of the highest-stakes patent disputes in biotechnology history, with Amgen’s EPO franchise generating billions of dollars annually. The Federal Circuit’s affirmance of infringement kept Roche’s MIRCERA from entering the U.S. market on the basis of Amgen’s pioneer patents — ultimately Roche and Amgen reached a settlement in late 2009 under which Roche agreed to pay Amgen royalties.
For the biotechnology and pharmaceutical industries, the case confirmed that broadly claimed pioneer patents covering biological molecules like erythropoietin could block not only direct copies but also chemically modified derivatives that retained the essential biological identity covered by the original claims. It also highlighted the importance of the double-patenting doctrine as a check on the serial claiming strategies used by biotech companies to extend effective patent protection over blockbuster biological drugs.