Decision: Amgen, Inc. v. Sandoz, Inc., __ F.3d __, 2018-1551, -1552 (Fed. Cir. May 8, 2019) (LOURIE, O'Malley, and Reyna)

Holding: The Federal Circuit affirmed the district court's summary judgment of noninfringement of Amgen's biologic products, filgrastim (marketed as Neupogen®) and pegfilgrastim (marketed as Neulasta®) by Sandoz's biosimilars.

Background: Amgen, the reference product sponsor, sued Sandoz under the Biologics Price Competition and Innovation Act (BPCIA) on U.S. Patents 6,162,427 (the “'427 patent”) and 8,940,878 (the “'878 patent”). Sandoz submitted abbreviated Biologics License Applications (“aBLAs”) referencing Neupogen® and Neulasta®, but had elected not to provide Amgen with its aBLAs or manufacturing information. Sandoz received FDA approval for its filgrastim biosimilar, Zarxio®, but has not yet received approval for its proposed pegfilgrastim biosimilar.

Claim 7 of the '878 patent reads:

1. A method of purifying a protein expressed in a non-native limited solubility form in a non-mammalian expression system comprising:

(a) expressing a protein in a non-native limited solubility form in a non-mammalian cell;

(b) lysing a non-mammalian cell;

(c) solubilizing the expressed protein in a solubilization solution comprising one or more of the following:

(i) a denaturant;

(ii) a reductant; and

(iii) a surfactant;

(d) forming a refold solution comprising the solubilization solution and a refold buffer, the refold buffer comprising one or more of the following:

(i) a denaturant;

(ii) an aggregation suppressor;

(iii) a protein stabilizer; and

(iv) a redox component;

(e) directly applying the refold solution to a separation matrix under conditions suitable for the protein to associate with the matrix;

(f) washing the separation matrix; and

(g) eluting the protein from the separation matrix, wherein the separation matrix is a non-affinity resin selected from the group consisting of ion exchange, mixed mode, and a hydrophobic interaction resin.

The district court construed limitations (f) and (g) as separate steps that must occur in order:

performing limitations (e)–(g) of the process of claim 7 requires:

(e) applying the refold solution to a separation matrix . . . , 

(f) applying a solution to remove . . . unwanted components of the refold solution . . . while preserving [protein] binding . . . ; and

(g) applying a solution that reverses the binding of the purified protein . . . .

Id. at *7.

Sandoz's process only involves one step—applying the refold solution to the matrix, with no separate washing or eluting steps ((f) and (g) of claim 7). The district court granted summary judgment that neither Zarxio® nor Sandoz's proposed pegfilgrastim biosimilar infringed claim 7 of the '878 patent.

Claim 1 of the second patent in suit (the ‘427 patent) reads:

1. A method of treating a disease requiring peripheral stem cell transplantation in a patient in need of such treatment, comprising
administering to the patient a hematopoietic stem cell mobilizing-effective amount of G-CSF;
and
thereafter administering to the patient a disease treating-effective amount of at least one chemotherapeutic agent (emphasis added).

Amgen proposed that the '427 claim limitation “disease treating-effective amount of at least one chemotherapeutic agent” be construed as “sufficient to enhance the mobilization of stem cells,” regardless of its effect on the underlying disease. But the district court construed the limitation more narrowly as limited to “[a]n amount sufficient to treat a disease for which at least one chemotherapeutic agent is prescribed.” Based on the district court's claim construction, Amgen stipulated to noninfringement of the '427 patent contingent upon its right to appeal.

On appeal, Amgen argued that it was an error to require the “washing” and “eluting” to be separate steps in claim 1 of the '878 patent. “Instead, Amgen argues, the claims cover any number of solutions or steps as long as the functions of washing and eluting happen in sequence[.]” Id. at *8.

The Federal Circuit affirmed the district court's claim construction of the washing and eluting limitations as separate process steps performed by adding discrete solutions to the separation matrix in sequence. The Federal Circuit characterized Amgen's argument as a proposition that the washing and eluting steps describe functions rather than actual process steps. It rejected this argument:

First, . . . the claim language logically requires that the process steps, lettered (a) through (g), be performed in sequence. For example, expressing the protein in a nonmammalian cell (limitation (a)) obviously must occur before the step of lysing that cell (limitation (b)). There is no indication on the face of claim 7 that the washing and eluting steps are any different. Second, washing and eluting are consistently described in the specification as separate steps performed by different solutions.

Id. at *9.

Even if it adopted Amgen's proposed construction, the Federal Circuit still found no literal infringement because Sandoz's current process only uses one step and one solution.

The Federal Circuit also rejected Amgen's doctrine of equivalents argument. “Sandoz's one-step, one-solution process does not function in the same way as the claimed” three-step, three-solution process.

In essence, Amgen seeks to cover, one way or another, any method of using a salt concentration gradient in an adsorbent matrix to separate a protein of interest from other solutes. But claim 7 is not that broad.

Id. at *11.

With respect to claim 1 of the '427 patent, the Federal Circuit rejected Amgen's argument that the phrase “a disease treating-effective amount of at least one chemotherapeutic agent” only limits the amount of the chemotherapeutic agent administered͟—precluding Amgen's argument that the method of claim 1 more broadly encompasses “situations where the chemotherapeutic agent is prescribed only for stem cell mobilization rather than treatment of an underlying disease.” The Federal Circuit found that the preamble “a method of treating a disease” as well as the plain language of the claim, “disease treating-effective amount” precluded Amgen's proposed construction. Noting that the claim included the different terms “a hematopoietic stem cell mobilizing-effective amount” and “a disease treating-effective amount,” the Federal Circuit stated that precedent requires a presumption that different claim terms have different meanings. Thus, the district court did not err in construing claim 1 as being directed to treatment of the underlying disease.

Practice Takeaways:

Every case depends on its own facts and circumstances. In this case, Amgen's process claim in the '878 patent was written in a sequential way, which was also how the process was described in the specification. This eliminated the possibility of capturing a competitor who changed the order of the steps or skipped steps.

As we've heard so often, “the name of the game is the claim.” In re Hiniker, 150 F.3d 1362, 1369 (Fed. Cir. 1998). The claim defines the boundaries of the exclusive rights granted under 35 U.S.C. § 154, providing notice of the claim scope to the public. Although using the term “comprising” may have literally captured an accused method employing additional steps, a process with fewer or different steps has been found to not literally infringe. Smith & Nephew, Inc. v. Ethicon, Inc., 276 F.3d 1304 (Fed. Cir. 2002) (Additional steps may be performed in carrying out a claimed method because the claim includes the word “comprising.”). If the goal is to cover processes that do not require all steps to be performed in a particular order, process claims should ideally be drafted that way. And if the goal is to cover processes that accomplish particular functions rather than actual steps, consider drafting claims in that manner.  

The claim language of claim 1 of the '427 patent also left Amgen with no room to wiggle. Even if the preamble was found non-limiting, the phrase “disease treating-effective amount” was in the body of the claim and the Federal Circuit found it to be limiting.

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