Actelion Pharmaceuticals Ltd. V. Mylan Pharmaceuticals Inc.
Docket No. 2022-1889 (https://cafc.uscourts.gov/opinions-orders/22-1889.OPINION.11-6-2023_2217732.pdf)
REYNA, STOLL, STARK
November 6, 2023
Brief Summary: DC decision vacated and remanded for consideration of extrinsic evidence.
Summary: Mylan appealed the DC’s claim construction of the term “a pH of 13 or higher” in Actelion’s patents (family members but not identical US 8,318,802 and 8,598,227, the sole patents listed on the Orange Book for Veletri®) directed to epoprostenol formulations. The patent specification explains that “[t]he inventor “unexpectedly found that epoprostenol solution in the presence of an alkalinizing agent, and high pH (>11) is very stable compared to Flolan” (GSK’s epoprostenol product). The claims recite a “bulk solution” having “a pH of 13 or higher”. Actelion argued the claimed pH “is ‘a value of acidity that is given as an order of magnitude that is subject to rounding’”, allowing “a pH of 12.5, which rounds to 13” (to claim “a specific pH value, and not an order of magnitude, there would need to be a significant figure to the right of the decimal point or clear context to the contrary”), citing three textbooks for support. Mylan argued that “Actelion’s three chemical textbooks support a narrower range of 12.995–13.004.” The FC panel explains that “[t]he textbooks explain how to calculate pH” and that “the number of significant figures in the concentration equals the number of digits to the right of the decimal point in the logarithm”. The DC (citing Viskase Corp., FC 2007) did not consider the textbook evidence (the extrinsic evidence), “adopted Actelion’s proposed construction based on the intrinsic record alone”, and concluded there was nothing in the specification or prosecution history “to indicate that Actelion intended to import any higher degree of precision to ‘a pH of 13’” (distinguishing this case from AstraZeneca, FC 2021 (“claim construction…would exclude 0.0005% and focus on smaller variations”)). Based on this claim construction, the parties stipulated to infringement by Mylan. The FC panel explained that when the DC bases its review only on the intrinsic evidence, “its claim construction will amount solely to a ruling of law and will therefore be subject to de novo review”, while a decision based on a review of extrinsic evidence “must be reviewed under the clear error standard” (MasterMine, FC 2017). “But”, the FC panel added, the “ultimate interpretation of the claim in light of the facts as found remains a conclusion of law subject to de novo review on appeal.” The FC panel first explained that “there is no blanket rule that ranges, or specifically open-ended ranges, must foreclose rounding” and the claims lack the term “about” (Sunovion, FC 2013; Quantum, FC 1995; Adams Respiratory, FC 2010). It also found the PHE distinguished the stability of a composition with a pH of 13 and that of 12” but not whether it could include values that round to 13, in particular 12.5” and the specification does not clarify the issue. It found this case to be “one where the proper claim construction cannot be reached without the aid of extrinsic evidence, and that the district court should have considered, at minimum, the textbook excerpts offered and addressed by the parties” (Teva, US 2015; Pickholtz, FC 2002). The FC panel therefore vacated and remanded the DC’s decision for consideration of the extrinsic evidence.