Aptalis Fails to “Surround’ Apotex’s Generic ER Tablet
Although non-precedential, Aptalis Pharmatech, Inc. v. Apotex, Inc., Appeal No. 2017-1344 (Fed. Cir., January 4, 2018) provides a useful outline of Phillips-type claim construction and requires a close reading to see why the infringement finding by the district court was reversed.
In this Hatch-Waxman litigation, Aptalis asserted U.S. Pat. Nos. 7,790,199 and 7,289,121 against Apotex’s extended release (ER) version of cyclobenzaprine hydrochloride (“the drug”). The Fed. Cir. panel noted that there are two routes to make ER tablets disclosed in the patents – the membrane system in which an inert core is coated with the active drug yielding a core that is further coated with polymer membrane that controls the rate of release of the drug from the tablet once it is ingested, and the matrix system in which the tablets are formed by mixing the drug with the polymer and granulating it to yield beads with ER properties.
However, claim 1 did not specify which type system was used to make the ER beads but, rather, claims extended release beads that comprise an “active-containing core particle” comprising the drug and “an extended release coating comprising a water insoluble polymer membrane surrounding said core.” It may well be that claim 1 was intended to cover the membrane and the matrix system, since the core could be 100% drug. Apotex asserted that its product was made by the matrix system, while Aptalis’ product was made by the membrane system.
The parties agreed that “a water insoluble polymer membrane surrounding said core” means “a water insoluble polymer covering that surrounds the active core.” The district court then construed “extended release coating” as “[a] layer of any substance that is applied onto the surface of another in order to maintain the drug at therapeutically effective concentrations over an extended period of time.” This construction was broad enough to permit the district court to find that Apotex infringed, since the matrix system involves contacting the drug with the polymer by mixing them.
However, the Fed. Cir. considered all of the intrinsic evidence and concluded that the single word “coating” in combination with the words “surrounding said active containing core” meant that the coating must be continuous, e.g., “one that covers the entire surface of the core” and “must be located outside of the core” (and not simply that the core and the coating are in contact).
Could the same result have been reached by construing the claim term “an active-containing core particle” to require something in the core other that the drug – such as the inert sugar pellet? Then the language “a polymer membrane surrounding said core” could simply be interpreted to mean “enclosing (or encasing) said core.” Even the parties agreed that the term in question should be read as “a water insoluble polymer covering surrounding said core.”
In other words, “membrane” had already been construed by the parties to mean “a covering”, and “surrounding said core” was already in the claim. The district court tried in vain to impose a broader definition of coating that it believed would ensnare Apotex, but I think that Apotex was in the clear with “membrane” or “surrounding” already in the claim.
In case you think that this is a case that was won or lost by splitting legal hairs, the takeaway is to consider the elements of your finished claim set to ensure that your coverage will not be subject to shrinkage you did not intend. One of the first things the Fed. Cir. noted is that the claims did not recite that they were directed to either the matrix or the membrane system. This should have been a good thing for patentee, but it would have been better if claims were present that were directed to each system. In any case, if you have to stretch the construction of any claim element to ensnare a future opponent, perhaps it is time to write a few more independent claims.