Eagle Pharmaceuticals Inc. v. Slayback Pharma LLC (Fed. Cir. 2020)

McDonnell Boehnen Hulbert & Berghoff LLP

McDonnell Boehnen Hulbert & Berghoff LLP

Infringement under the doctrine of equivalents (as a basis of a successful cause of action having renewed vigor before the Federal Circuit recently (see, e.g., "Galderma Laboratories, L.P. v. Amneal Pharmaceuticals LLC") is most frequently rebutted by the doctrine of prosecution history estoppel ("Pharma Tech Solutions, Inc. v. Lifescan, Inc.").  This is not the only defense available to an accused infringer; its sister doctrine, of dedication-disclosure, can be equally effective under circumstances where a patentee has disclaimed aspects or embodiments that could fall within the scope of equivalents but was disclaimed to avoid prior art, for lack of utility, or insufficiency of disclosure under 35 U.S.C. § 112.  Last Friday, the Federal Circuit applied the dedication-disclosure doctrine to affirm the District Court's dismissal on the pleadings of plaintiff Eagle Pharmaceuticals' infringement allegations under the doctrine of equivalents in Eagle Pharmaceuticals Inc. v. Slayback Pharma LLC.

The case arose in ANDA litigation over Eagle's bendamustine formulation (BELRAPZO®).  Eagle asserted U.S. Patent Nos. 9,265,831; 9,572,796; 9,572,797; and 10,010,533 in the litigation; claim 1 of the '796 patent was considered representative by the parties and hence the Court:

1.  A non-aqueous liquid composition comprising:
    bendamustine, or a pharmaceutically acceptable salt thereof;
    a pharmaceutically acceptable fluid comprising a mixture of polyethylene glycol and propylene glycol, wherein the ratio of poly- ethylene glycol to propylene glycol in the pharmaceutically acceptable fluid is from about 95:5 to about 50:50; and
    a stabilizing amount of an antioxidant;
    wherein the composition has less than about 5% total impurities after 15 months of storage at about 5° C., as calculated on a normalized peak area response basis as determined by high performance liquid chromatography at a wavelength of 223 nm.

The emphasized limitation was the basis of the dispute, Slayback conceding that in all other respects its competing generic formulation literally infringed Eagle's claims.  Eagle contended in its complaint that that term was infringed under the doctrine of equivalents, wherein the ethanol used in Slayback's product was equivalent to Eagle's polyethylene glycol.  Slayback countered with a motion under Fed. R. Civ. Pro. 12(c) that Eagle was barred by the dedication-disclosure doctrine from prevailing on its doctrine of equivalents allegation, because the '796 specification (and the specifications of all the other asserted patents) disclosed but did not claim ethanol-containing embodiments.

Set forth in the Federal Circuit's opinion, as relied upon by the District Court, are almost a half dozen citations to the specification reciting ethanol as a "pharmaceutically acceptable fluid" used in the claimed formulation (including ones where ethanol is a dreaded "preferred" embodiment).  Eagle countered by asserting that ethanol was properly a component of the claimed invention only in the presence of chloride salts (which were not claimed) and not in the claimed embodiments comprising an antioxidant.  Eagle supported its assertions with a declaration from an expert witness that the skilled worker would appreciate this distinction and understand that patentee had not disclaimed ethanol-comprising embodiments, properly formulated; there was no rebuttal of this testimony by Slayback.  Refusing to consider the expert's testimony (and opining that Eagle was attempting to "manufacture a factual dispute"), the District Court held for Slayback and granted its motion to dismiss as a matter of law; this appeal followed.

The Federal Circuit affirmed, in an opinion by Judge Reyna, joined by Judges O'Malley and Chen.  The opinion sets out the relationship between the doctrine of equivalents as defined by the Supreme Court in Graver Tank & Mfg. Co. v. Linde Air Prods. Co., 339 U.S. 605 (1950), and Warner-Jenkinson Co. v. Hilton Davis Chem. Co., 520 U.S. 17 (1997), and its limitation by the disclosure-dedication doctrine in Johnson & Johnston Assoc. v. R.E. Servs., 285 F.3d 1046 (Fed. Cir. 2002) (en banc).  The equitable principle of the doctrine recognized by the Court is that it "reinforces 'the primacy of the claims in defining the scope of the patentee's exclusive right.'"  To be properly applied, the specification must "disclose[] unclaimed subject matter with 'such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed,'" citing PSC Comput. Prods., Inc. v. Foxconn Int'l, Inc., 355 F.3d 1353, 1360 (Fed. Cir. 2004).

The panel appreciated Eagle's challenge to be procedural, regarding whether the District Court properly dismissed its complaint on the pleadings, as well as on the merits of whether plaintiff had disclaimed ethanol-comprising embodiments by disclosing but not claiming them.  The Court recognized that Eagle claimed its bendamustine formulations were disclosed in three alternatives:  "(i) chloride salt formulations; (ii) antioxidant formulations; and (iii) dimethyl sulfoxide ("DMSO") formulations," and that ethanol was an alternative only in the "unclaimed chloride salt formulations" (emphasis in opinion).  According to Eagle, the skilled worker would appreciate that distinction and that it had not disclaimed ethanol as an equivalent to polyethylene glycol in other formulations.  As pithily put in the opinion, the Court "disagreed."

Citing Johnson, the opinion asserts that "[t]he disclosure-dedication doctrine does not require the specification to disclose the allegedly dedicated subject matter in an embodiment that exactly matches the claimed embodiment"; indeed, according to the opinion the patentee made arguments (unsuccessfully) in that case similar to Eagle's arguments here.  The issue of whether the disclosure-dedication doctrine applies is resolved "only [where] the specification disclose[s] the unclaimed matter 'as an alternative to the relevant claim limitation,'" citing Pfizer, Inc. v. Teva Pharm. USA, Inc., 429 F.3d 1364, 1378 (Fed. Cir. 2005).  The panel found no qualifications in the specification as now asserted by Eagle regarding limitations to where ethanol is or is not an alternative to polyethylene glycol.  The Court was "not persuaded" that the facts here track those in Pfizer (where the Court deigned not to apply the doctrine), on the grounds that in Pfizer the limitation in dispute was directed to a unique, specific purpose ("a suitable amount of a saccharide to inhibit hydrolysis"; emphasis in opinion) whereas in this case the alternatives all have only one purpose (i.e., to be "pharmaceutically acceptable").

Turning to Eagle's procedural objections, the opinion sets these forth as 1) there was a factual dispute that precluded judgment; 2) the District Court did not draw all inferences in non-movant Eagle's favor; and 3) the District Court did not consider its proffered expert's testimony.  In rejecting these contentions, the opinion notes that considering evidence (like Eagle's expert's) outside the pleadings is within the District Court's discretion (and in doing so converts the motion to be one for summary judgment), citing Kulwicki v. Dawson, 969 F.2d 1454, 1462 (3d Cir. 1992), and 5C WRIGHT & MILLER, FED. PRAC. & PROC. CIV. § 1371 (3d ed.).  The standard of review is thus abuse of discretion and the panel found no such abuse in relying on the disclosure in the asserted patents themselves.  Nor was there any error in deciding the issue as a matter of law, and the opinion states that "[e]xpert testimony is not always required for a district court to determine how a skilled artisan would understand a patent's disclosure and claimed invention," citing Union Carbide Corp. v. Am. Can Co., 724 F.2d 1567, 1573 (Fed. Cir. 1984), and Amgen Inc. v. Coherus BioSciences Inc., 931 F.3d 1154, 1160 (Fed. Cir. 2019).

Finding these and all other Eagle arguments unpersuasive, the Federal Circuit affirmed.

Eagle Pharmaceuticals Inc. v. Slayback Pharma LLC (Fed. Cir. 2020)
Panel: Circuit Judges O'Malley, Reyna, and Chen
Opinion by Circuit Judge Reyna

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

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