Several of the Federal Circuit’s initial decisions involving the Biologics Price Competition and Innovation Act (the “BPCIA”) focused on unpacking the contours of the statute. The Federal Circuit’s recently issued opinion in Amgen Inc. v. Apotex Inc., No. 2017-1010, Slip Op. Nov. 13, 2017, by contrast, involves standard principles of appellate review.

We previously described the district court litigation, and the factual background, in detail. Briefly then, this litigation involves Apotex’s efforts to bring to market biosimilar versions of filgrastim and pegfilgrastim. The bench trial focused on a single patent, U.S. Patent No. 8,952,138. Claim 1 of the ’138 Patent, the only independent claim, is as follows:

  1. A method of refolding a protein expressed in a non-mammalian expression system and present in a volume at a concentration of 2.0 g/L or greater comprising:

(a) contacting the protein with a refold buffer comprising a redox component comprising a final thiol-pair ratio having a range of 0.001 to 100 and a redox buffer strength of 2 mM or greater and one or more of:

(i) a denaturant;

(ii) an aggregation suppressor; and

(iii) a protein stabilizer;

to form a refold mixture;

(b) incubating the refold mixture; and

(c) isolating the protein from the refold mixture.

’138 Patent, Claim 1. Importantly for present purposes, the district court construed the term “refold mixture” to have “high protein concentration[] . . . at or above about 1 g/L.” Slip Op. at 5. This construction was not challenged on appeal.

As noted in our initial post, the parties here (unlike some other BPCIA cases) engaged in the “patent dance.” During that process, Apotex stated that it did not infringe the ’138 Patent because its “concentration of [filgrastim or filgrastim critical intermediate] in the refold buffer” was limited to 0.9–1.4 g/L (i.e., the “inclusion body concentration” listed on the applications).” Slip Op. at 5-6. Of course, under the Court’s construction of “refold mixture,” this would be infringing. But Apotex changed its position at trial. Specifically, an Apotex fact witness testified “that the maximum concentration of protein in its refold mixture would actually be 0.708 g/L.” Slip Op. at 6. The witness testified that Apotex’s letters were incorrect, as the “inclusion bodies” were not pure protein but instead were two-thirds water. Apotex supported this testimony with “batch records.” The district court ultimately credited this testimony and concluded that Apotex did not infringe the ’138 Patent. Amgen challenged this conclusion on appeal.

First, Amgen argued that the district court incorrectly dismissed Apotex’s pre-litigation letters. Indeed, the district court stated that the letters “are not probative on the issue of protein concentration.” Slip Op. at 8. The Federal Circuit stated that while this would be incorrect as an absolute statement, it read the district court as concluding that the letters did not outweigh Apotex’s evidence of non-infringement. The Federal Circuit found that the district court did not err in crediting Apotex’s evidence and reaching this conclusion.

Second, Amgen offered a claim construction argument of sorts, contending that the “protein concentration” in the patent was interchangeable with the “inclusion body.” In this way, Amgen sought to equate the inclusion bodies with protein, resulting in infringement. The Federal Circuit disagreed, finding that the patent’s specification “pervasively disprove[d]” of this theory.

Third and finally, Amgen argued that under Sunovion Pharm., Inc. v. Teva Pharm. USA, Inc., 731 F.3d 1271 (Fed. Cir. 2013), the district court was required to “assess infringement based on the full range of processes that would be consistent with Apotex’s applications.” Slip Op. at 12. The Federal Circuit agreed with the legal principle, but found that the district court’s decision was without error in concluding that Apotex’s applications did not authorize infringing processes. Again, the district court found credible Apotex’s fact testimony, as well as Apotex’s batch records.

While the Federal Circuit’s opinion is in large part an application of straight-forward legal principles, it provides important lessons for future litigation. First, although a party should always be careful in its written representations (pre-litigation or otherwise), this opinion is useful in demonstrating that a party should not fear that it is unequivocally bound by a factual statement that it later determines to be inaccurate. Second, this opinion demonstrates the importance of witness credibility—both the district court and the Federal Circuit relied heavily on the testimony of a single company witness. Finally, the Federal Circuit’s opinion is indicative of the uphill battle of an appeal, particularly where the arguments rest on findings of fact rather than conclusions of law.