In Amgen’s long-running dispute with biosimilar-maker Sandoz over biosimilar versions of Amgen’s filgrastim (Neupogen®) and pegfilgrastim (Neulasta®) biologics, the Federal Circuit earlier this year affirmed summary judgment of no literal infringement and no infringement under the doctrine of equivalents.  Amgen Inc. v. Sandoz Inc., 923 F.3d 1023 (Fed. Cir. May 8, 2019).  In so holding, the panel stated that “the doctrine of equivalents applies only in exceptional cases.”  Amgen petitioned for rehearing en banc, arguing that the Federal Circuit had overstated the law.  According to Amgen’s petition, “[s]uch a rule is contrary to Supreme Court precedent and [Federal Circuit] precedent.”  This week, the Federal Circuit course-corrected, granting Amgen’s petition without explanation for the limited purposes of removing the “exceptional” language from its prior decision. 

In the underlying litigation, Amgen had accused Sandoz of infringing claim 7 of U.S. Patent No. 8,940,878 based on the process used to manufacture both its approved biosimilar (Zarxio, the first-ever U.S. biosimilar) and its proposed Neulasta® biosimilar.  Amgen’s patent relates to multi-step protein refolding methods, a way to purify biologics like filgrastim and pegfilgrastim.  Under the claimed method, a protein is expressed in cells and solubilized in a refold solution, the refold solution is then “applied” to a separation matrix, and the matrix is then “washed” and the protein “eluted” from the matrix.  It was undisputed that Sandoz’s process involved only applying the refold solution to the matrix—without any separate washing or eluting steps.  Amgen pursued a claim construction-based literal infringement theory as well as infringement under the doctrine of equivalents.  The district court construed the “applying,” “washing” and “eluting” steps as three separate steps, with the eluting step necessarily occurring “after” the washing step.  Accordingly, the district court found no literal infringement and no infringement under the doctrine of equivalents.

On appeal, Amgen argued that Sandoz’s one-step process performs the same functions (namely, washing and eluting) in substantially the same way to achieve the same result as the claimed three-step process.  The Federal Circuit rejected Amgen’s argument:  “Sandoz’s one-step, one-solution process does not function in the same way as the claimed process.”  In so holding, the panel observed that “[t]he 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.’” 923 F.3d at 1029.

Amgen’s en banc petition argued that “[t]he panel decision effects a profound change in the law that appears to impose an equitable standard explicitly rejected by the Supreme Court.”  That, Amgen suggested, went too far: “the doctrine of equivalents is available in all cases and assessed without regard to equities.” 

Sandoz responded that with those few words—“the doctrine of equivalents applies only in exceptional cases”—the Federal Circuit did not usher in a sea change in doctrine of equivalents law.  Rather, Sandoz argued, they were part of a passing observation that was not essential to the Court’s holding:

Without the six words Amgen highlights, the reasoning and outcome of the Court’s decision would remain the same; the only change would be in this observation:  “The doctrine of equivalents is not ‘simply the second prong of every infringement charge, regularly available to extend protection beyond the scope of the claims.”

Indeed, Sandoz proposed that the Federal Circuit could simply cut those six words from its panel decision and otherwise leave the judgment untouched. 

That is exactly what the Court did in its order yesterday.  That is, the Federal Circuit granted Amgen’s petition for the limited purpose of amending the panel’s opinion to cut the six words on which Amgen’s petition rested.