Board of Regents of the University of Texas System v. Boston Scientific Corp., Appeal No. 2042-2062, etc. (Fed. Cir. July 27, 2026)

In its only precedential patent case this week, the Federal Circuit upended a victory for the University of Texas against Boston Scientific, in which a jury had found willful infringement of a patent directed to a drug-releasing biodegradable polymer fiber—i.e., a fiber in which a therapeutic agent is dispersed.  The University of Texas had accused the coating on Boston Scientific’s stents of infringing the patent, and a jury awarded $49.4 million in damages, and further found the infringement to be willful.  On appeal, the Federal Circuit wiped that verdict out in multiple ways, including by holding that the jury clearly erred in finding the patent-in-suit not invalid as anticipated over another patent.

The patent in suit claimed:

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 BSC in 2017, alleging the drug-eluding stents infringed.  Those stents have a metal frame with zigzag-shaped rings.  The entire metal frame is dipped and rolled in a liquid drug-containing biodegradable coating, which “dries like paint.”  The drug of interest is released over time as the stent’s coating biodegrades.

The district court construed several terms of the patent, including that “first phase” is the polymer portion of the fiber, “second phase” is the discrete, drug-containing regions dispersed throughout the fiber, and “immiscible” as meaning that it can’t be mixed.  The district court construed “fiber” to have its plain and ordinary meaning, or “a thread-like structure of any length or shape.”  At trial, the jury found the patent valid and infringed, and further found willful infringement.

On appeal, a unanimous panel reversed on two grounds.  First, the Court found the patent anticipated, contrary to the jury’s verdict and the district court’s denial of JMOL.  The prior art patent of interest (“Song”) disclosed a delivery system for enabling the gradual release of an active agent (e.g., a drug or a chewing gum flavorant) from a fiber, wherein the agent is dispersed throughout the fiber and is released from the fiber when the agent is exposed to a solvent.  The Court found the jury erred in not finding invalidity with respect to each element of the asserted patent.  Song disclosed a two phase biodegradable polymer fiber, wherein the phases were immiscible and wherein they comprised one or more therapeutic agents.  The Court walked through the testimony that the University of Texas offered in support of Song not anticipating, and found the testimony did not support a finding of no anticipation.  For example, UT’s expert referred to the patent as “the chewing gum patent,” even though it taught that it could be used for drugs, and testified that the polymer fibers in Song release using a different mechanism and were useful for different purposes.  The Court found this testimony irrelevant to the question of anticipation, and pointed to the portions of the specification that clearly supported the elements of the claims.  The Court held that “there was no legally sufficient evidentiary basis to find that Song does not teach the claimed biodegradable polymer fiber.”

The Court also walked through various dependent claims and reached the same conclusion, ultimately finding all asserted claims invalid as anticipated.

The Court also reversed the jury’s finding of infringement and the district court’s denial of JMOL on that issue.  Specifically, UT has asserted that the “fibers” in BSC’s product were the polymeric coating on the stents—if the polymeric coating was excised from each separate portion of the zigzag metallic structure of the stent.  Specifically, “UT relied entirely on the portions of coating on the outside of zigzag struts making up a single ring around the stent—a zigzag-shaped section of coating stripped from the frame.”  The Court held that “[i]t is not reasonable to characterize that artificially separated section of the stent coating as a ‘thread-like’ structure.  It is not a structure that has ever had or would have independent existence.  It is just the result of adhering a liquid (which UT does not assert to be a fiber in that form) to the frame, and then letting it dry.”

Accordingly, the district court’s decision was reversed.  The opinion can be found here.

By Nika Aldrich

This article summarizes aspects of the law and does not constitute legal advice. For legal advice with regard to your situation, you should contact an attorney.