After holding a bench trial in January and considering post-trial briefing, Judge Stark recently issued findings of fact and conclusions of law in an ANDA patent infringement action between Bristol-Myers Squibb and Mylan Pharmaceuticals related to the drug efavirenz, which is a reverse transcriptase inhibitor used to treat HIV infection. Judge Stark concluded that Mylan’s ANDA product infringed the asserted claims of the patent-in-suit and that Mylan had not proven that the patent was invalid. Bristol-Myers Squibb Co., et al. v. Mylan Pharmas. Inc., et al., C.A. No. 09-651-LPS, Memo. Op. at 1 (D. Del. Sep. 30, 2013). Judge Stark rejected not only anticipation arguments, but also indefiniteness, enablement, and written description arguments. Id. at 20-36.
The decision involved an interest matter of claim construction clarification: Mylan argued that the phrase “selected from the group consisting of” limited an x-ray powder diffraction claim to the “eleven 28 values specifically recited in the claim, and nothing more. According to Mylan, if a crystal sample has an x-ray powder diffraction pattern with more than the eleven claimed 28 values, that sample is outside the scope of [the asserted] claim.” BMS contended in response that the word “comprising” rendered the claim open-ended and that “the transitional phrase ‘consisting of,’ used in the Markush group, closes only the group of alternative 28 values, not the entire claim.” Judge Stark agreed with BMS and explained that “[t]o the extent the Court’s holding involves a clarification of its prior claim construction, such clarification is permissible.” Id. at 17 (citing Guttman, Inc. v. Kopykake Enters., 302 F.3d 1352, 1361 (Fed. Cir. 2002) (“District courts may engage in a rolling claim construction, in which the court revisits and alters its interpretation of the claim terms as its understanding of the technology evolves.”).