Amgen Inc. v. Sandoz Inc. (Fed. Cir. 2019)
Amgen sued Sandoz for infringing its U.S. Patents 6,162,427 and 8,940,878. Both patents relate to Amgen’s biologic products (filgrastim and pefilgrastim) used as treatments for neutropenia. The lawsuit here is unique because it was filed under Biologics Price Competition and Innovation Act (“BPCIA”). As an add-on to Hatch-Waxman, the BPCIA defines submission of an FDA biosimilar application (aBLA) as a form of patent infringement. See 35 U.S.C. § 271(e)(2)(C) (defining submission of an aBLA as an act of patent infringement).
The ‘472 patent claims a “method of treating a disease” by giving a patient Filgrastim/Pegfilgrastim prior to chemotherapy in order to stimulate stem-cell growth. After treatment with Filgrastim, the claims require “administering to the patient a disease treating-effective amount of at least one chemotherapeutic agent.” The idea here appears to be that the Filgrastim will stimulate stem-cell growth so that stem cells will survive harsh cancer treatment.
In this case, Amgen argued that its “disease treating-effective amount of … chemotherapeutic agent” would not necessary require that the chemotherapy drug treat the underlying disease — rather, Amgen argues that the drug could be used to further mobilize stem cells. Both the district and appellate courts rejected this claim construction proposal — noting that the focus of the claims is “treating a disease” and construing the claim otherwise does not make sense:
As an initial matter, the preamble of claim 1, as construed, arguably precludes Amgen’s construction. The district court construed the preamble, “[a] method of treating a disease requiring peripheral stem cell transplantation,” as requiring that the stem cell transplant be incorporated as a component of a method of treating an underlying disease, such as cancer, Claim Construction Order, 2016 WL 4137563, at *5–6, and Amgen does not dispute that construction on appeal. The claimed method therefore must be performed to treat an underlying disease. As the claim itself states, the “disease treating-effective amount” of a chemotherapeutic agent does precisely that.
The court suggests here that if Amgen had not wanted to claim treatment of an underlying disease, it should have drafted different claims. “Had Amgen simply wanted to claim a method of mobilizing stem cells, in any context, it could have done so.”
The ‘878 patent is not a method of treatment but instead directed to a multi-step method of preparing purified biologic products. This begins with growing cells that express the protein of interest and ends with eluting the protein from a separation matrix such as ion exchange resin.
In its claim construction, the district court held that the claims required separate steps of “applying a refold solution”; washing the solution; and eulting the protein. That construction eliminated infringement since Sandoz process only requires one step — applying the refold solution without washing or eluting. On appeal, the Federal Circuit argued that Sandoz’ approach is effectively the same — and that its claims should be read as functional requirements rather than actual process steps.
The Federal Circuit sided with the accused infringer — holding that each step in the method is a separate process step that must be done in a particular order. Most notably, the court noted (1) the fact that the patentee had sequentially listed its steps a-g; and (2) the washing and eluting steps are “consistently described in the specification as separate steps performed by different solutions.”
Doctrine of Equivalents: The claim construction here naturally raises a doctrine of equivalents question, which the Federal Circuit also rejected:
Amgen argues that Sandoz’s one-step, one-solution process is insubstantially different from the claimed three-step, three-solution process because it “achieves the same functions (washing and eluting), in substantially the same way (binding protein preferentially compared to contaminants, and then raising salt concentration to reverse protein binding) to achieve the same result (protein purification).”
The Federal Circuit found, however, that the one-step approach offered by Sandoz, “does not function in the same way as the claimed process.” In particular, the court focused-in on the notion that doctrine of equivalents is handled on an element-by-element level. Here, since each claim step is a separate step occurring in sequence – it would be improper to say that that a single-step approach is the equivalent. The court explains:
The doctrine of equivalents applies only in exceptional cases and is not “simply the second prong of every infringement charge, regularly available to extend protection beyond the scope of the claims.” Duncan Parking Techs., Inc. v. IPS Grp., Inc., 914 F.3d 1347, 1362 (Fed. Cir. 2019) (“[T]he doctrine of equivalents cannot be used to effectively read out a claim limitation . . . because the public has a right to rely on the language of patent claims.” )
Although I follow the court’s line of thinking on claim construction, but the court’s limit of the DOE to “exceptional cases” seems to be a major step without precedential backing.