The US Court of Appeals for the Federal Circuit affirmed a summary judgment non-infringement ruling, finding that where both the claim language and the specification require that the disclosed steps be performed in the order written, the claims must be limited to that specific order for claim construction and infringement analysis. Amgen, Inc. v. Sandoz Inc., Case Nos. 18-1551, -1552 (Fed. Cir. May 8, 2019) (Lourie, J).

This case relates to a dispute over Amgen’s patents covering filgrastim (marketed as Neupogen^®) and pegfilgrastim (marketed as Neulasta^®). Amgen sued Sandoz for patent infringement under the Biologics Price Competition and Innovation Act (BPCIA) in relation to its biosimilars of these products. Sandoz had received approval for its biosimilar of filgrastim (marketed as Zarxio^®) but had not yet received approval for its proposed pegfilgrastim biosimilar. Amgen’s lawsuit was based on allegations that Sandoz’s BPCIA filings infringed two of its patents: one directed to methods of protein purification by adsorbent chromatography, and another directed to methods of treating “diseases requiring peripheral stem cell transplantation.”

With respect to the protein purification patent, Amgen argued that the district court, in both its claim construction and summary judgment decisions, misconstrued claim limitations reciting “washing” and “eluting” as requiring distinct solutions to be added to the claimed separation matrix at different times. Amgen argued that the claims cover any number of solutions or steps as long as the functions of washing and eluting happen in sequence. Thus, Amgen argued that even though the step of washing precedes the step of elution at any given point in the separation matrix in Sandoz’s process, the Sandoz process nevertheless infringed. Sandoz responded that the patent claim at issue requires a series of steps and thus is limited to the disclosed order of steps. The district court agreed with Sandoz and found that Sandoz’s process did not infringe.

The Federal Circuit affirmed, citing Mformation Technologies v. Research in Motion (Fed. Cir 2014), and concluded that the washing and eluting steps in the asserted claim required discrete solutions. The Court provided two reasons in support of its construction: first, the claim language logically requires that the process steps, lettered (a) through (g), be performed in sequence, and second, washing and eluting are consistently described in the specification as separate steps performed by different solutions. Because the accused process only uses one step and one solution, the Court reasoned that the Sandoz process did not literally infringe. The Court rejected Amgen’s doctrine of equivalence argument, finding that it sought to cover much more than the invention as recited in the natural language of the asserted claim. The Court cautioned that the doctrine of equivalents applies only in exceptional cases and is not regularly available as a method to extend protection beyond the scope of the claims.

With respect to the stem cell treatment patent, Amgen argued that the district court misconstrued the limitation of “disease treating-effective amount” of a chemotherapeutic agent as “an amount sufficient to treat a disease for which at least one chemotherapeutic agent is prescribed.” Amgen argued that this phrase only limited the amount of the chemotherapeutic agent administered, and not the purpose for which the agent is administered. Under the claim scope urged by Amgen, the claim would cover administration of the agent solely for the purpose of mobilizing stem cells. The Federal Circuit, agreeing with Sandoz, concluded that Amgen’s construction improperly read “disease treatment” out of the claim, and found that the claim preamble “[a] method of treating a disease requiring peripheral stem cell transplantation” precluded Amgen’s construction by requiring the limitation of disease treatment in the claims.