Actelion Pharms. Ltd. v. Mylan Pharms. Inc., Appeal No. 2024-1641 (Fed. Cir. May 13, 2026)

In our Case of the Week, the Federal Circuit affirmed a judgment that Mylar’s proposed generic hypertension drug would not infringe patents covering Actelion’s Veletri® medication.  The case turned on the district court’s construction of the claim phrase “a pH of 13 or higher,” which the Federal Circuit had vacated in a previous appeal (our short write-up here) after Mylar initially stipulated to infringing.  This time, the reviewing panel affirmed the lower court’s construction requiring measurement at a standard temperature of 25±2°C, and affirmed the resulting bench trial determination of non-infringement, either literally or under the doctrine of equivalents.

Actelion’s asserted patents are directed to a freeze-dried composition of epoprostenol, a compound known to be effective in the treatment of hypertension but which can rapidly destabilize in an acidic environment.  As relevant here, the patents claim an epoprostenol composition “formed from a bulk solution having a pH of 13 or higher.”  pH is a measure of hydrogen ion concentration expressed on a scale of 0-14, with values below 7 being considered acidic and values above 7 being considered alkaline.  Because hydrogen atoms dissociate more at higher temperatures, it is known that raising a solution’s temperature can render it more acidic, lowering its pH.  Here, the bulk solution of Mylar’s generic would allegedly have a pH above 13 when measured at the refrigerated temperature required for manufacture, but below 13 when measured at the “standard” temperature of 25±2°C.

The asserted patents do not expressly recite any temperature at which pH is to be measured.  In affirming that the claims referred to a pH measured at 25±2°C, however, the Federal Circuit noted that the patents’ specification identified “an alkaline environment” as one with “pH>7,” “a definition that undisputably is accurate only at standard temperature.”  The Court also reviewed the experimental values recited in the specification, observing that the experimenters compared the pH of different solutions with no mention of adjusting for any temperature differences.  The parties’ experts also agreed that “at least some (even most)” of the data tables reflected standard-temperature pH measurements, supporting an inference that all of the pH values were so measured.  The Federal Circuit thus found that that specification supported an interpretation requiring measurement at 25±2°C, and that the district court properly relied on extrinsic evidence of pharmaceutical standards in further support of its construction.

The Court thus affirmed the district court’s determination of no literal infringement, and also affirmed that Actelion was precluded from capturing Mylar’s formulation through the doctrine of equivalents.  While the patents disclosed operable compounds with pH ranges “of pH 12.5 to 13, 12 to 13, and greater than 12,” during prosecution, Actelion had amended the recital in its claims from “a pH of greater than 12” to “a pH of 13 or higher” to overcome an obviousness rejection.  As such, the Court found both that Actelion was barred by prosecution history estoppel from recapturing the broader range through equivalence, and independently that the disclosure-dedication rule precluded equivalence by the now-unclaimed ranges set forth in the specification.

The opinion can be found here.

By Jason A. Wrubleski

ALSO THIS WEEK

MCom IP, LLC v. City National Bank of Florida, Appeal No. 2024-2089 (Fed. Cir. May 15, 2026)

On review of a dismissal of patent claims concerning a “unified electronic banking system,” the Federal Circuit affirmed the district court’s dismissal decision on grounds sounding in patent invalidity, but reversed the lower court’s fee award and imposition of sanctions under 35 U.S.C. § 285 and 28 U.S.C. § 1927.

Following a 2023 inter partes review that invalidated most of the claims of its asserted patent,  mCom sued City National Bank alleging infringement of the four remaining claims. The district court dismissed the complaint with prejudice, holding that the remaining claims were obvious under 35 U.S.C § 103 because they were not meaningfully different from the claims already invalidated in the PTO proceeding. The district court then went further, declaring the case “exceptional” under 35 U.S.C. § 285 and litigated in bath faith under 28 U.S.C. § 1927, and awarded $87,111 in fees and costs to City National Bank. The Federal Circuit affirmed the dismissal on invalidity grounds, rejecting mCom’s arguments as unpersuasive and irrelevant.

However, the Federal Circuit reversed the award of fees and costs, finding that the district court lacked evidence that the lawsuit was frivolous, brought in bad faith, or exceptionally unreasonable. The district court reasoned that mCom’s case was unusually weak because the asserted patent claims were invalid. But mere invalidity is not legally sufficient to find a case exceptional. Moreover, City National failed to present a sound basis for deeming mCom’s validity position to be exceptionally weak. Finally, considering the § 1927 sanction, the Federal Circuit noted that in order for it to stand, mCom’s conduct must have “needlessly obstructed” the litigation of mCom’s non-frivolous suit. But the district court made no finding to that effect; rather, the district court ruled only that mCom’s counsel was insufficiently diligent in investigating the case and the material provided during discovery. Because there was no stated reason to conclude that mCom should have dropped its suit prior to the Rule 12(b)(6) dismissal ruling, it was not unreasonable for counsel to litigate the case to that stage. The Court ordered the parties to bear their own costs.

The opinion can be found here.

By Julia Davis 

Bissell, Inc. v. Int’l. Trade Commission, Appeal Nos. 2024-1509, 2024-1709 (Fed. Cir. May 11, 2026)

On review of a Section 337 investigation involving certain wet dry vacuum cleaners, the Federal Circuit affirmed that Bissell had shown a domestic industry based on expert testimony that relied on source code that was not admitted as a trial exhibit.  Respondent Tineco argued the ALJ erred because Bissell’s expert relied on the unadmitted source code to opine Bissell’s products practiced its asserted patent claims.  The court rejected that argument and held expert testimony may be more extensive than exhibits introduced into the evidentiary record.  Citing Federal Rule of Evidence 703, the court explained an expert may base an opinion on facts or data the expert was made aware of or personally observed, even if those facts are not themselves admissible.  The court stated it knew of no authority requiring the relied-on materials to be admitted as exhibits for the expert’s opinion to be admissible.

The record showed Bissell’s source code was produced in discovery and reasonably relied upon by experts in the field to understand product operation.  Tineco did not offer contrary expert opinions, did not raise the limitation in its prehearing brief, and did not cross-examine Bissell’s expert on this point.  The court held that, under these circumstances, an expert can rely on source code without the party introducing the code as a trial exhibit.  The court further held that the expert’s unrebutted testimony, grounded in his source code review, constituted nonconclusory substantial evidence supporting the ALJ’s finding.  The ALJ also relied on an internal Bissel product documentation that corroborated the expert’s opinion.  Accordingly, the Commission’s domestic industry finding was affirmed on substantial evidence.  Separately, the court affirmed no infringement by Tineco’s redesigned products.

The opinion can be found here.

By Jason Evans

This article summarizes aspects of the law and does not constitute legal advice. For legal advice with regard to your situation, you should contact an attorney.