Aptalis Pharmatech, Inc. v. Apotex Inc.

Case Name: Aptalis Pharmatech, Inc. v. Apotex Inc., No. 2017-1344 (Fed. Cir. Jan. 4, 2018) (Circuit Judges Reyna, Wallach, and Stoll presiding; Opinion by Stoll, J.) (Appeal from D. Del., Robinson, J.) 

Drug Product and Patent(s)-in-Suit: Amrix® (cyclobenzaprine HCl); U.S. Patents Nos. 7,790,199 (“the ’199 patent”) and 7,829,121 (“the ’121 patent”)

Nature of Case and Issue(s) Presented: Plaintiffs owned the patents-in-suit. Instead of requiring three daily doses of cyclobenzaprine, as in the prior art, the patents-in-suit disclosed an extended release cyclobenzaprine formulation that provided twenty-four- hour relief from muscle spasms with a single dose. The patents mentioned two different formulations that used a water-insoluble polymer to achieve an extended-release profile. The parties referred to these alternatives as membrane systems and matrix systems. In a membrane system, a water-insoluble polymer coating was applied onto an active-containing core. In a matrix system, the water-insoluble polymer was mixed together with the drug and compacted into a tablet. Although the identical specifications mentioned two different extended-release formulations, the claims were not expressly limited to a specific formulation by name.

Apotex argued that it did not infringe because its products contain a matrix system formulation. The infringement issue centers around the claim term “an extended release coating comprising a water insoluble polymer membrane surrounding said core.” The parties agreed that “a water insoluble polymer membrane surrounding said core” means “a water insoluble polymer covering that surrounds the active core,” but disagreed on the meaning of the term “extended release coating.” The district court construed that term to mean “[a] layer of any substance that is applied onto the surface of another, the purpose of which is to delay the release of a drug in order to maintain the drug at therapeutically effective concentrations over an extended period of time.” Applying this claim construction, the district court found that Apotex’s ANDA product contained an extended-release coating and infringed the asserted claims. The Federal Circuit found that the district court erred by not construing the term “extended release coating” to require a continuous outer film, as taught by the intrinsic evidence, and vacated the infringement finding.

Why Apotex Prevailed: The Federal Circuit first focused on the issue of claim construction. Relying on the intrinsic evidence, namely, the claim language, the specification, and the file history, the Federal Circuit concluded that it was clear that the coating must surround the core. A coating that surrounded the core or enclosed it on all sides connoted a continuous coating, i.e., one that covered the entire surface of the core.

Aptalis argued that the word “continuous” should not be read into the claim because it did not appear in the asserted patents and that a “continuous” extended-release coating would not be functional because the coating must be permeable to gastrointestinal fluids. But a continuous film covering the surface of the active-containing core would not defeat the extended release functionality because the polymer coatings described by the invention were semi-permeable to water. Aptalis also argued that the prosecution history was irrelevant to the claim-construction question here because there was no clear and unmistakable disavowal of claim scope. The Federal Circuit also rejected this argument, relying on precedent, which states that “[a]ny explanation, elaboration, or qualification presented by the inventor during patent examination is relevant, for the role of claim construction is to capture the scope of the actual invention that is disclosed, described, and patented.” Therefore, even in the absence of a clear and unmistakable disavowal, the prosecution history could be evaluated to determine how a POSA would understand a given claim term.