Article: June 2020: Patent Litigation Update

Federal Circuit Weighs in on Applicability of Prosecution History Estoppel in View of Statements Made During Co-pending IPR

In Galderma Laboratories, L.P. v. Amneal Pharmaceuticals LLC, No. 19-1021, 806 F. App’x 1007 (Fed. Cir. 2020) [hereinafter “Op.”], the Federal Circuit recently revisited the issue of whether arguments during proceedings before the Patent Trial and Appeal Board (PTAB) can result in a surrender of claim scope in district court proceedings.  The court’s rationale in holding that Galderma was not estopped due to unsuccessful arguments made during inter partes review (IPR) proceedings provides helpful guidance for parties in the common position of facing actions both in district court and before the PTAB.

Amneal’s Unsuccessful IPR Challenges to the Chang Patents

In 2011, Amneal filed an Abbreviated New Drug Application (ANDA) for its generic version of Oracea, an orally administered medication (in pill form) for treating acne.  Galderma Labs., L.P. v. Amneal Pharms. LLC, No. 1:16-cv-00207-LPS, Compl. ¶ 42 (D. Del.).  In June 2013, Amneal filed IPR petitions against three Galderma patents related to Oracea (the “Chang Patents”).  Appellant’s Opening Br. 14 & n.3; J.A. 17018.  The Chang Patents are all directed to particular formulations of Oracea in which one portion of the pill (30 mg) is an “immediate release” component, and another portion (10 mg) is a “delayed release” component.  Op. 3.

Amneal sought to invalidate the Chang Patents in view of a combination based primarily on U.S. Patent No. 5,348,748 (“Sheth”).  Id. at 3–4.  Galderma responded by attempting to distinguish Sheth on the grounds that the claim term “delayed release (DR) portion” requires that there be no “substantial release” until after the pill passed through the stomach and upper gastrointestinal tract.  Id.  By contrast, Galderma argued, Sheth disclosed formulations where the alleged delayed release potion (the “‘secondary loading’ portion”) was intentionally designed to “leak” in the stomach.  Id. at 4.  

The PTAB disagreed with Galderma’s proposed construction, instead concluding that “delayed release” (under a “broadest reasonable interpretation standard) was more properly construed as requiring release only “at a time other than immediately following oral administration.”  Id. at 5 (emphasis added).  However, because Sheth disclosed water-soluble coatings permitting at least some release immediately after administration, the PTAB found that, under the appropriate construction, Amneal had failed to prove unpatentability.  See id. at 4–5; J.A. 17029.

District Court’s Finding of No Prosecution History Estoppel

After prevailing before the PTAB, Galderma filed suit against Amneal in district court alleging infringement of several of the Chang Patents by Amneal’s generic version of Oracea.  Op. 5.  During claim construction proceedings, Galderma proposed the same broad construction of “delayed release” that the PTAB had adopted during IPR, i.e., “release of a drug at a time other than immediately following oral administration.”  J.A. 3163.  Applying this construction, Galderma asserted infringement under the doctrine of equivalents, arguing that the 2 mg delayed-release portions of generic Oracea were equivalent to the claimed 10 mg “delayed release” portions of the Chang Patents.  J.A. 4963.

Amneal moved in limine to preclude Galderma from asserting that formulations that begin release in the stomach could be found to meet the claimed “delayed release” limitation under the doctrine of equivalents in view of Galderma’s statements during IPR.  J.A. 4964–65.  In particular, Amneal asked the court to exclude evidence at trial that a formulation that does not fall within the court’s construction of “delayed release” could nonetheless be equivalent to it, given the patent owner’s representations to the PTAB which Amneal characterized as having “surrendered” “any such equivalents.”  J.A. 5228.  

The district court denied Amneal’s motion in limine, as well as its post-trial arguments to defeat infringement on the same basis, finding no clear disavowals of claim scope by the patent owner.  J.A. 70.  Following a bench trial, the court held that Amneal’s 2-mg “delayed release” formulation infringed under the doctrine of equivalents.  J.A. 71–81.  Amneal then appealed, arguing that the district court erred in holding that Amneal’s formulations that allegedly had the “same features as the prior art that Galderma said in IPR proceedings was ‘substantially different’ from the claims,” could be found equivalent to the claimed “delayed release . . . portion comprising 10 mg doxycycline.”  Op. 3.

The Federal Circuit Affirms Finding of No Prosecution History Estoppel

Relying on American Piledriving Equipment, Inc. v. Geoquip, Inc., 637 F.3d 1324 (Fed. Cir. 2011), Amneal argued on appeal that, “even though ‘the [PTAB] explicitly disagreed with’ the patentee’s argument,” the court should nevertheless have found a disclaimer based on Galderma’s express statements in those PTAB proceedings.  Appellant’s Reply 12 (quoting American Piledriving, 637 F.3d at 1336).  However, in affirming the district court’s holding that prosecution history estoppel did not apply, the Federal Circuit rejected a dogmatic approach that would bind the patent owner to any arguments made in IPR proceedings. 

Instead, the court re-emphasized that a patent owner’s statements “are not considered in a vacuum,” but must be viewed in the context of “the record as a whole.”  Op. 6.  The court observed, in finding no “clear and unmistakable” disavowal of Galderma’s infringement theory under the doctrine of equivalents, that the PTAB had rejected the patent owner’s argument that “delayed release” required no substantial release in the stomach.  Id. at 6–7.  In other words, the best source of notice regarding the meaning of the asserted claims was the PTAB’s ultimate construction of “delayed release,” not the earlier patent-owner arguments that the PTAB “clearly and expressly rejected.”  Id.  

In reaching its conclusion, the Federal Circuit distinguished its prior holding in American Piledriving on the grounds that that case did not involve prosecution history disclaimer, but rather the ancillary question of whether statements by a patent owner before the Patent Office could inform claim construction.  The Federal Circuit further observed that, in American Piledriving, the claim language and specification fully supported the construction adopted by the court, so the patentee’s consistent statements made during reexamination proceedings were given limited weight, serving only to “remove[] all doubt”  as to the correct construction.  Id. at 8; see also Krippelz v. Ford Motor Co., 667 F.3d 1261, 1266 (Fed. Cir. 2012) (citing American Piledriving, 637 F.3d at 1336, for the rule that a “patentee’s statements during reexamination can be considered during claim construction, in keeping with the doctrine of prosecution disclaimer”)

For future litigants, an important takeaway from these decisions is that courts will consider a patent owner’s statements before the Patent Office in resolving both estoppel and claim construction, but the weight accorded will depend on the full context in which they are made.  For example, where the Patent Office has clearly rejected a patent owner’s arguments in administrative proceedings, defendants may face an uphill battle in attempting to establish estoppel.  Where rejected arguments are fully consistent with the claims and specification, however, a district court may find they simply provide confirmatory weight for adopting a particular construction.