By Kevin E. Noonan --
The Federal Circuit recently affirmed a district court's claim construction and determination that claim terms were not indefinite in Massachusetts Institute of Technology v. Shire Pharmaceuticals, Inc.
The case involved U.S. Patent Nos. 5,770,193 and 5,759,830, directed to three-dimensional scaffolds for growing cells in vitro for in vivo organ culture. In the prior art, in vitro cell growth for in vivo organ culture was performed using either permanent synthetic polymer scaffolds or biodegradable scaffolds (the latter being comprised typically of collagen). The limitations of the prior art included the permanence of the scaffold in the former and variability in degradation of the collagen scaffold. Prior art scaffolds were also unsuitable for solid organs (liver, pancreas) due to limited diffusion into inner organ cells and resulting cell death.
The scaffolds of the '193 and '830 patents promoted vascularization that overcame the diffusion problem in the art, with the specification reciting that the scaffolding "must be 'shaped to maximize surface area to allow adequate diffusion of nutrients and growth factors to the cells.'" The scaffolds of these patents permitted "a variety of organs, including skin, liver, kidneys, blood vessels, nerves, and muscles which functionally resemble the naturally occurring organ" to be produced.
Claim 1 is representative and illustrates (in italics) the claim terms at issue:
1. A cell-scaffold composition prepared in vitro for growing cells to produce functional vascularized organ tissue in vivo, comprising:
a fibrous three-dimensional scaffold composed of fibers of a biocompatible, biodegradable, synthetic polymer; and
cells derived from a vascularized tissue attached in vitro to the surface of the fibers of the scaffold uniformly throughout the scaffold;
wherein the fibers of the scaffold provide sufficient surface area to permit attachment in vitro of an amount of the cells effective to produce the functional vascularized organ tissue in vivo; wherein the fibers of the scaffold are spaced apart such that the maximum distance over which diffusion of nutrients and gases must occur through a mass of cells attached to the fibers is between 100 and 300 microns; and
wherein the diffusion provides free exchange of nutrients, gases and waste to and from the cells uniformly attached to the fibers of the scaffold and proliferating throughout the scaffold in an amount effective to maintain cell viability throughout the scaffold in the absence of vascularization.
It was undisputed that Shire's accused infringing product, Dermagraft®, was "seeded with connective tissue cells called fibroblasts to grow the dermis (or inner) layer of skin for "the treatment of full-thickness diabetic foot ulcers." And:
After seeding onto the Dermagraft® scaffold, "[t]he fibroblasts proliferate to fill the interstices of this scaffold and secrete human dermal collagen, matrix proteins, growth factors and cytokines, to create a three-dimensional human dermal substitute containing metabolically active, living cells." Id. The fibroblasts attach to the top, bottom, and sides of the fibers of the mesh scaffolding that, after implantation, is gradually absorbed by the surrounding tissue.
Shire argued that prosecution history disclaimer applied to the claim terms "vascularized organ tissue" and "cells derived from a vascularized tissue." In particular, Shire pointed to changes in claim language necessitated by prior art rejections and declarations by the named inventors, including assertions regarding "the design of a polymer scaffold which provides adequate sites for attachment and growth of enough cells to survive and function in vivo yet does not limit survival and growth of cells adjacent to the matrix surface as cells increase in number in vitro." The claims were granted after further extensive amendment and argument to recite the allowed claims.
The District Court rejected Shire's contention that, in view of statements during prosecution distinguishing the prior art on the grounds that said art was limited to skin grafts (based on the thickness limitations in the art), MIT's claims should be limited to non-skin organs with regard to both the terms at issue ("vascularized organ tissue" and "cells derived from a vascularized tissue"). The District Court also rejected Shire's assertions that the term "three-dimensional scaffold" was indefinite. The District Court found the asserted claims of the '193 and '830 patents were not invalid and were infringed on stipulated final judgment.
The Federal Circuit affirmed, in an opinion by Judge Stoll, joined by Judges O'Malley and Chen; Judge O'Malley filed a concurring opinion. Consistent with recent Federal Circuit precedent (Avid Tech., Inc. v. Harmonic, Inc., 812 F.3d 1040, 1045 (Fed. Cir. 2016), quoting Cordis Corp. v. Medtronic AVE, Inc., 339 F.3d 1352, 1359 (Fed. Cir. 2003), and citing Omega Eng'g, Inc. v. Raytek Corp., 334 F.3d 1314, 1323 (Fed. Cir. 2003)), the panel asserted that the standard for prosecution disclaimer was a stringent one, requiring such disclaimer to be "clear and unmistakable," citing Trivascular, Inc. v. Samuels, 812 F.3d 1056, 1063–64 (Fed. Cir. 2016). With regard to the claim term "vascularized organ tissue," the District Court construed the term to include skin on the basis that the ordinary meaning of the word "organ" would include skin and that there was no clear and unmistakable disclaimer of this scope in the prosecution history. The District Court also found, and the Federal Circuit agreed, that this use of the term was consistent with how the term was used in the '193 and '830 patent specifications. (More tellingly, the District Court found that this interpretation of the term was consistent with the parties' Joint Technology Tutorial, which was provided to the District Court as "background" during claim construction.) Neither the District Court nor the Federal Circuit was convinced by Shire's arguments to the contrary, which the panel opinion characterized as relying on "a single sentence" from an interview summary of the priority patent that ultimately resulted in the '193 and '830 patents, regarding claims that did not recite the "vascularized organ tissue" language. "Reading the selected sentence in the context of the entire summary and the claim terms then at issue reveals that MIT emphasized the structure of the invention's scaffold, not the type of organ it can be used to grow," according to the panel opinion. Also unavailing was Shire's citation of statements in an inventor (Dr. Vacanti) declaration, which the District Court found were not made to distinguish the claimed invention from prior art skin grafts but rather to emphasize the diffusion-related advantages of the claimed invention. "In the context of the overall prosecution history, the isolated statements plucked from Dr. Vacanti's declaration do not meet the high standard for prosecution disclaimer to attach," according to the Court.
Both the District Court and the Federal Circuit were further convinced that the claims did not disclaim skin as an artificial organ falling within the scope of the claims because MIT attempted during prosecution to include this limitation but the Examiner rejected the amendment as being new matter (wherein thereafter MIT never reintroduced this limitation). Relevant to this argument was also the fact that the claims at issue at that time contained an express organ thickness limitation and that the statements cited by Shire were used in relation to those limitations (which were not in the claims that issued in either the '193 or '830 patents).
With regard to the District Court's construction that the claim term "cells derived from a vascularized tissue" comprise both parenchymal and non-parenchymal cells, the Federal Circuit first noted that "[t]he claims themselves do not distinguish between parenchymal and non-parenchymal cells." Further, even Shire's expert admitted that bone-forming cells (which are a type of parenchymal cells) fell within the scope of the '193 and '830 patent claims. In addition to this "plain meaning" interpretation, the Court found that the specification(s) of these patents were consistent with the District Court's construction. As with Shire's earlier arguments (regarding the ""vascularized organ tissue" term), the Court found the arguments related to parenchymal versus non-parenchymal cells were not supported by Shire's citation to portions of the prosecution history, and that a skilled worker "would not read MIT's statement made during prosecution of [a related] patent—and directed to very different claim language—as limiting the term 'cells derived from a vascularized tissue' to parenchymal cells."
Finally, the Federal Circuit reviewed the District Court's determination that the term "three-dimensional scaffold" was not indefinite. Citing Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120, 2124 (2014), the opinion affirmed the District Court's construction according to the plain meaning of the words "three-dimensional" and the Court's reliance on a dictionary definition in rendering its decision. In addition, the panel opinion stated, this "plain meaning" definition was supported by Shire's own expert.
Judge O'Malley concurred to address the question of whether the District Court's judgment was "final" (and thus ripe for appeal) without a determination of damages and the question of willful infringement. According to Judge O'Malley, "[i]n Robert Bosch, LLC v. Pylon Manufacturing Corp., 719 F.3d 1305 (Fed. Cir. 2013) (en banc), we created a broad jurisdictional rule that excepts this court from the rules of finality followed by every other Article III court of appeals" in its interpretation of 28 U.S.C. § 1292(c)(2). This interpretation, in addition to being contrary to the interpretation of the statute by all other circuits (and producing another special rule for patent cases disfavored by the Supreme Court), is contrary to "a strong congressional policy against piecemeal reviews, and against obstructing or impeding an ongoing judicial proceeding by interlocutory appeals." It also results, according to Judge O'Malley, in disruption of district court proceedings and encourages "piecemeal" litigation practices, contrary to the Supreme Court's interpretation of the statute in other contexts. Flanagan v. United States, 465 U.S. 259, 263–64 (1984).
Massachusetts Institute of Technology v. Shire Pharmaceuticals, Inc. (Fed. Cir. 2016)
Panel: Circuit Judges O'Malley, Chen, and Stoll
Opinion by Circuit Judge Stoll; concurring opinion by Circuit Judge O'Malley