In a decisive reversal, the Federal Circuit handed Boston Scientific Corporation a complete victory in Board of Regents of the University of Texas System v. Boston Scientific Corp., vacating a jury verdict that had found Boston Scientific’s drug-eluting coronary stent infringed the University of Texas’s patent for drug-releasing biodegradable fiber implants. The Federal Circuit concluded that Boston Scientific was entitled to judgment as a matter of law (JMOL) on both anticipation and noninfringement — wiping out the almost $50 million damages award in favor of the University of Texas (UT) and ending the case.
Link to Background Background
U.S. Patent No. 6,596,296 (the ʼ296 patent) generally relates to compositions containing at least one biodegradable polymer fiber in which a therapeutic agent is dispersed. The ʼ296 patent is directed to the controlled delivery of therapeutic agents — including anti-inflammatory compounds and long-term cardiovascular drugs — via biodegradable fibers that can be used in conjunction with commercially available stents. Claim 1, the representative independent claim, requires a composition with at least one biodegradable polymer fiber made up of two immiscible phases, i.e., the polymer portion of the fiber and the discrete drug-containing regions dispersed throughout the fiber:
A composition comprising at least one biodegradable polymer fiber wherein said fiber is composed of a first phase and a second phase, the first and second phases being immiscible, and wherein the second phase comprises one or more therapeutic agents.
UT sued Boston Scientific in 2017 in the Western District of Texas alleging that Boston Scientific’s drug-eluting coronary stent systems infringed the ʼ296 patent. Boston Scientific’s accused stent consists of a metal frame containing linked, serpentine (zigzag-shaped) rings coated with a liquid drug-containing biodegradable polymer coating that dries like paint and adheres to the outer surface of the metal frame. As the coating biodegrades, the drug of interest is released over time.
The case was ultimately transferred to the District of Delaware where, after a two-phase trial, the jury found that Boston Scientific infringed asserted claims 1, 11, 17, and 26 of the ʼ296 patent, that the claims were not invalid as anticipated by U.S. Patent No. 5,364,627 (Song), and that Boston Scientific’s infringement was willful. As a result, the jury awarded damages to UT in the amount of $42 million (plus ~$7.4 million in pre-judgment interest). The district court subsequently set aside the willfulness finding as legally unsupported but otherwise upheld the verdict.
Boston Scientific appealed and UT cross-appealed the rejection of the willfulness finding.
Link to The Appeal The Appeal
On appeal, a central question was whether Song — which Boston Scientific’s expert characterized as disclosing a fiber-based drug delivery system — anticipates the asserted claims of the ʼ296 patent. Song discloses a delivery system for the gradual release of an active agent (such as a drug or chewing-gum flavorant) from a fiber, with the agent dispersed throughout the fiber and released upon exposure to a solvent. Yet, the district court had credited UT’s expert testimony that Song is effectively a “chewing gum” patent with a manner of biodegradation relevantly different from the ʼ296 patent. The Federal Circuit rejected this characterization across all four asserted claims. More specifically, with respect to the biodegradable polymer fiber limitation of claim 1, the Federal Circuit found Song’s express disclosures compelling, e.g., Song teaches a “fiber having a support matrix” made of biodegradable polymers. Indeed, the appellate panel found no reasonable basis for restricting Song’s teachings in the way UT proposed, i.e., limited to chewing gum applications.
On the two-phases limitation, the Federal Circuit found that Song’s express disclosure that the active agent “does not necessarily have to be in a contiguous phase” directly teaches the claimed “discrete drug-containing regions.” And, despite UT’s expert’s attempts to distinguish Song’s mechanism of drug release from the asserted claims — arguing that Song releases drugs through channels exposed by chewing and deformation as opposed the ʼ296 patent’s radially release of drugs — the court found this argument unpersuasive and beside the point. In particular, the appellate panel explained that the district court’s claim construction of “second phase” does not require any particular mechanism of release, so evidence about how the drug releases does not address the actual claim requirement. On the immiscibility limitation, the appellate panel noted that Song itself expressly states that the active agent and the fibrous wall material “must be immiscible with each other,” and UT did not separately argue otherwise.
With respect to the “varying rates” limitation in claim 26, the uncontradicted testimony of Boston Scientific’s expert established that all drug delivery systems release agents at varying rates because it is “very, very difficult” to manufacture a system where the release rate does not change with time. In this aspect, UT presented no expert testimony to the contrary and offered no persuasive counterargument at oral argument. The panel found that UT’s own trial submissions further supported the conclusion. In fact, during closing argument, UT’s counsel described the chewing mechanism as producing varying deformations and varying openings where solvent contacts the active agent, which the panel read as implicitly acknowledging varying rates. The panel also noted that Song’s figures depicted openings of various sizes at the ends and sides of a fiber, which affirmatively corroborated Boston Scientific’s expert.
While its anticipation conclusion was sufficient to resolve the appeal, the Federal Circuit panel also addressed noninfringement. The district court had construed “fiber” to mean “a thread-like structure of any length or shape.” UT’s infringement theory did not rest on the stent as a whole but instead focused on the polymer coating stripped from the metal frame (more specifically, the portion of the coating covering one serpentine (zigzag) loop around the stent). The appellate panel found that no reasonable jury could characterize that artificially separated section of stent coating as “thread-like” and further noted that the coating in Boston Scientific’s stent is not a structure that ever had or would have independent existence. Rather, the coating is the result of adhering a liquid to the frame and letting it dry such that it is not meant to be stripped from its frame or to retain its form on its own. The resulting detached coating section is tubular in overall shape with zigzag walls, not essentially one-dimensional like a thread but visibly two-dimensional like a ribbon. The panel drew a pointed analogy to further explain its finding:
[O]ne cannot reasonably say that a uniform sheet of paper contains a narrow strip simply because one could cut such a strip from the paper.
Notably, UT’s expert admitted that he had not at any point in the case opined that the polymer coating on Boston Scientific’s stents is thread-like. On that record, the appellate panel found that Boston Scientific was also entitled to JMOL of noninfringement.
As a side note, a threshold issue on appeal was the standard of review. Anticipation is a question of fact, and noninfringement based on claim construction is reviewed for substantial evidence when a jury has made the underlying factual findings. Under that deferential standard, the Federal Circuit would uphold the jury’s verdict so long as it was supported by substantial evidence. Here, however, Boston Scientific did not directly challenge the jury’s factual findings. Instead, it appealed the district court’s denial of its renewed motion for JMOL. Because the Federal Circuit applies the procedural law of the regional circuit in which the case was tried, the standard of review for the JMOL denial was governed by 3rd Circuit law, which reviews JMOL denials de novo. Under de novo review, the appellate court examines the record anew and asks whether the evidence, viewed in the light most favorable to the verdict winner, permits only one reasonable conclusion — the one favoring the movant. This procedural posture proved critical: De novo review gave the Federal Circuit substantially more latitude to reexamine and ultimately reject the evidentiary basis for both the anticipation and noninfringement findings than it would have had under substantial evidence review.
The result here is a clean sweep for Boston Scientific. In the end, the fiber in the polymer composition claimed in the ʼ296 patent could not hold the verdict together any better than it could hold its shape off the stent.
Link to Takeaways Takeaways
This case serves as a stark reminder that even multimillion-dollar jury verdicts can unravel on appeal — and that the procedural vehicle chosen for the appeal can be outcome-determinative. The Federal Circuit’s decision offers important guidance on the strategic significance of the standard of review, anticipation analysis, the scope of expert testimony in invalidity disputes, and the limits of infringement theories built on artificial claim-element constructions:
- The procedural vehicle for appeal can be outcome-determinative. Boston Scientific appealed the district court’s denial of its renewed JMOL motion rather than directly challenging the jury’s factual findings. Because the Federal Circuit applies regional circuit procedural law, this meant the appeal was reviewed under the 3rd Circuit’s de novo standard for JMOL denials — not the more deferential substantial evidence standard that would have applied to a direct challenge to the jury’s verdict. Under substantial evidence review, the jury’s findings on anticipation and noninfringement — which were supported by UT’s expert testimony — might well have survived. The de novo posture gave the Federal Circuit the latitude to independently assess the sufficiency of the evidence and conclude that no reasonable jury could have found in UT’s favor. Appellate practitioners should carefully consider whether the procedural framing of an appeal can unlock a more favorable standard of review.
- Expert testimony that misses the claim requirement cannot rescue a verdict. UT’s expert testified extensively about how Song’s manner of drug release differed from the ʼ296 patent, but claim construction imposed no limitation on the mechanism of release. The Federal Circuit was unsparing: Testimony about an unclaimed aspect of the invention provides no legally sufficient evidentiary basis to support the verdict. Before trial, patent owners must carefully map every element of expert testimony to the actual construed claim language, not just to the broader inventive concept.
- Prior art is what it says, not how it’s used. UT tried to pigeonhole Song as a “chewing gum” patent with a narrow field of application. The Federal Circuit rejected this framing because Song itself expressly discloses “drugs” as an active agent and clearly is not limited to gum or saliva as a solvent. When a prior art reference expressly discloses broader uses — here, drugs as well as flavorants — courts will not artificially narrow its teachings based on certain embodiments. Patent owners should not optimistically rely on a narrow characterization of the purpose of a prior art reference to avoid anticipation.
- Uncontradicted expert testimony on anticipation creates real risk. On the “varying rates” limitation of claim 26, Boston Scientific presented expert testimony that went entirely unrebutted by UT. The one-sided record proved fatal to UT’s attempt to avoid anticipation. When faced with credible expert testimony on a specific invalidity ground, patent owners should ensure they put forward affirmative counterevidence at trial, not just legal argument on appeal.
- Infringement theories must rest on the accused product as it actually exists. UT’s infringement case required the jury to imagine a portion of a stent coating stripped from its metal frame and treated as an independent thread-like structure. The Federal Circuit made clear that this kind of artificial reconstruction, which relied on a hypothetically detached section of a product that was never meant to exist independently, is not sufficient. Infringement theories must be grounded in the accused product’s actual structure and function, not in what a component might look like if removed and reimagined. Patent owners must make sure that the infringement theory matches reality.