<em>Actelion Pharms. LTD v. Mylan Pharms. Inc.</em>
No. 2022-1889, 2023 WL 7289417 (Nov. 6, 2023)
The Federal Circuit Court vacated the District Court for the Northern District of West Virginia’s claim construction order and remanded the case to consider extrinsic evidence and its impact on claim construction.
Actelion Pharmaceuticals LTD was founded in 1997 and is headquartered near Basel Switzerland. In 2017, Actelion was acquired by Johnson and Johnson for $30 billion and generates much of its revenue from hypertension drugs. Mylan Pharmaceuticals Inc. was founded in 1961 and has a primary place of business located in Morgantown, West Virginia. Mylan generates its revenues from both generics and specialty drugs, including the EpiPen.
Actelion Pharmaceuticals LTD (Plaintiff) alleges that Mylan Pharmaceuticals Inc. (Defendant) infringed US 8,318,802, herein the ‘802, and US 8,598,227, herein the ‘227. In 2020, Actelion brought suit against Mylan in the District Court for the Northern District of West Virginia, alleging infringement of the ‘802 and the ‘227. The ‘227 is a continuation based on the ‘802. Both the ‘227 and ‘802 are directed to improve epoprostenol formulations and treat pulmonary arterial hypertension. In 2020, Mylan filed an Abbreviated New Drug Application (ANDA), which Actelion alleges infringes the ‘802 and the ‘227.
The heart of the case is the term, “a pH of 13.” Both parties dispute the meaning of “a pH of 13 or higher” as it appears in all the independent claims of the ’802 and ’227. Actelion pointed to the intrinsic evidence within the ‘802 and ‘227 patents indicating a conventional definition of “a pH of 13” ordinarily encompasses values rounded to 13, ranging from 12.5 to 13.4. Mylan presented extrinsic evidence from textbooks supporting a narrower range of 12.995–13.004. The District Court declined to consider the extrinsic evidence and relied on intrinsic evidence in its claim construction. The District Court distinguished from AstraZeneca AB v. Mylan Pharmaceuticals Inc. (Fed. Cir. 2021) since the specification nor prosecution history indicated a more precise pH range was required. The Court, therefore, ruled in favor of Actelion, finding that Mylan infringed Actelion’s patents. Mylan appealed.
On appeal, the Court of Appeals for the Federal Circuit conducted a de novo review of both extrinsic and intrinsic evidence since the district court only considered intrinsic evidence. In its reasoning to conduct a de novo review, the Court pointed to MasterMine Software, Inc. v. Microsoft Corp. (Fed. Cir. 2017), which found that claim construction that reviews only intrinsic evidence is subject to de novo review.
After determining to conduct a de novo review, the Court then reviewed the claim language, starting with the intrinsic evidence. As held in Sunovion Pharms., Inc. v. Teva Pharms. USA, Inc. (Fed. Cir. 2013), reviewing intrinsic evidence comprises examining the claim language itself. In this case, the Court found that the term, “a pH of 13 or higher,” indicates there is a bottom range. Mylan argued that the claims did not use any approximation language and that any rounding rules do not apply. Mylan asserted that “a pH of 13” is exactly 13 and pointed the cases, Quantum Corp. v. Rodime, PLC (Fed. Cir. 1995) and Adams Respiratory Therapeutics, Inc. v. Perrigo Co. (Fed. Cir. 2010), that found the use of approximation language expressly represents uncertainty for a range. Additionally, Mylan further argued that approximation language is used in other claims and, therefore, the absence of approximation language in the term “a pH of 13” implies that “a pH of 13” is exactly 13.
The Court disagreed with Mylan and found “there is no blanket rule that ranges, or specifically open-ended ranges, must foreclose rounding.” In other words, the Court rejected creating a bright-line rule requiring approximation language to avoid rounding interpretation.
The Court then turned to the specification, since it is “the single best guide to the meaning of a disputed term.” See Vitronics Corp. v. Conceptronic, Inc. (Fed. Cir. 1996). The Court found that the specification inconsistently defines a pH of 13. For example, portions of the specification indicated that, “[t]he pH of the bulk solution is preferably adjusted to about 12.5-13.5, most preferably 13,” whereas other sections equated a pH of 13.0 to be equivalent to a pH of 13. As such, the court contrasted the specification compared to the specification in AstraZeneca AB v. Mylan Pharmaceuticals Inc. (Fed. Cir. 2021), which showed that the concentration of a chemical down to four decimal points (0.0005%) was important for stability. The Court concluded that, “the specification supplies the same clarity as to the desired level of precision as muddied water.”
Next, the Court examined the prosecution history for clarity for the term, “a pH of 13.” The Court found that the pH in the claims had been amended several times throughout prosecution. Moreover, the Examiner indicated in the Final Rejection that the Applicant had not shown compositions of a pH of 12 were superior to a composition of pH of 10.5. The Examiner acknowledged that there was a significant difference at a pH of 13 and, in response, the Applicant amended the claim to a pH of 13 or higher. Consequently, the analysis of the prosecution history revealed a distinction between a pH of 12 and a pH of 13; however, this analysis did not further elucidate if a pH of 13 further encompasses a rounded value.
The Court concluded that intrinsic evidence was insufficient to determine the meaning of the term, “a pH of 13,” since the claim language, specification, and prosecution history did not provide any further clarification. Accordingly, the Court indicated extrinsic evidence would be required to determine the meaning of this term and that the District Court should have initially considered the extrinsic evidence to determine the meaning of a disputed claim term. Since a district court must make factual findings regarding extrinsic evidence, the Court remanded the case back to the District Court for the Northern District of West Virginia.
Thus, the Court of Appeals for the Federal Circuit vacated the district court’s claim construction order and remanded the district court to consider extrinsic evidence for proper claim construction.