The US Court of Appeals for the Federal Circuit found that the US District Court for the District of Delaware erred in its claim construction and consequently vacated the ruling that Apotex's proposed abbreviated new drug application (ANDA) product infringed Aptalis/Ivax's asserted patent claiming an extended release form of the muscle relaxant cyclobenzaprine hydrochloride. Aptalis Pharmatech, Inc. v. Apotex Inc., et al., Case No. 2017-1344 (Fed. Cir., Jan. 4, 2018) (Stoll, J).
Aptalis and Ivax own US Patent Nos. 7,790,199 and 7,829,121, which are Orange Book-listed for AMRIX®, approved for treating muscle spasms. Apotex filed an ANDA seeking to market a generic version of the product prior to patent expiry.
At the district court, Aptalis asserted three claims, each of which included "an extended release coating comprising a water soluble polymer membrane surrounding said [active] core." The parties contested the meaning of "extended release coating," which the court construed to be "a layer of any substance that is applied onto the surface of another, the purpose of which is to delay the release of drug in order to maintain the drug at therapeutically effective concentrations over an extended period of time." Applying this construction, the district court concluded that Apotex infringed all asserted claims.
The Federal Circuit, applying de novo review, found that the district court erred in its construction of "extended release coating." The Federal Circuit stated that this case "tiptoes [the] line" between "reading a claim in light of the specification, and reading a limitation into the claim from the specification."
The Federal Circuit concluded that the construction of "extended release coating" should be "a continuous outer film applied onto the surface of the active-containing core." This construction is narrower than that applied in the district court in two ways. First, the Federal Circuit's construction specifies that the extended release coating be positioned onto the surface of the active-containing core, as opposed to in any position external to the active core. Second, the Federal Circuit's construction specifies that the extended release coating be a continuous film.
The Federal Circuit began its analysis with the plain language of the claims, finding that the use of the word "surrounding" (which has a dictionary meaning of "to enclose on all sides") connoted that the active core was continuously surrounded by this layer. Turning to the specification, the court found that "every embodiment . . . describes . . . the coating external to the core." The court further observed that the while the inventors described the prior art as including non-continuous coatings, they did not describe or claim their coating as such. In fact, the court found that an expert declaration submitted during prosecution supported the interpretation of the claim element as referring to continuous films.
Aptalis argued that the Federal Circuit's construction requiring the extended release coating to be placed "onto the surface of the active-containing core" excluded a preferred embodiment with an intervening seal coat layer. The court stated that the construction was not so limiting, nor did it limit the extended release coating to the outermost layer. Aptalis also argued that the addition of "continuous" imported a limitation not expressly stated in the claim language, and that such a limitation required the coating to be impermeable, which is contrary to the purpose of the invention. The Federal Circuit disagreed, stating that a continuous coating need not be impermeable. Finally, Aptalis argued that reliance on the expert's statement in the file history was inappropriate because claim scope was not disavowed during prosecution. The Federal Circuit stated that precedent supports using the file history to inform one of skill as to the meaning of claim language, whether or not narrowing amendments or arguments were made.
To date, there is no activity on the district court docket following this decision.
Apotex Released from Infringement Finding After Claim Construction Appeal
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