On December 5, 2025, the Federal Circuit vacated and remanded the dismissal of Adnexus Inc.’s v. Meta Platforms, Inc., holding that the district court prematurely resolved a claim construction dispute under the guise of Rule 12(b)(6) plausibility. The decision is a pointed reminder that, while courts retain flexibility at the pleadings stage, they may not implicitly construe disputed claim terms against the non-moving party without affording notice and an opportunity to be heard. In practical terms, the court reaffirmed that disputes over claim scope generally belong in claim construction, not on a motion to dismiss.
The opinion, authored by Judge Stark and joined by Judges Prost and Taranto, underscores a recurring theme in recent Federal Circuit jurisprudence: plausibility under Iqbal and Twombly does not license courts to decide close claim scope questions prematurely. Charles Gideon Korrell believes that this decision continues a steady line of cases curbing early dismissals that rely on unstated or one-sided constructions of disputed patent terms.
Background and the Asserted Patent
Adnexus owns U.S. Patent No. 8,719,101, directed to systems and methods of online advertising that allow advertisers to deliver targeted information to users without disrupting their browsing sessions. The patent emphasizes minimizing unwanted advertising while still enabling advertisers to gather user information and deliver follow-up communications through preferred delivery methods.
Adnexus sued Meta in the Western District of Texas, alleging that Meta’s “Lead Ads” product infringed at least claim 1 of the ’101 patent. Claim 1 recites, among other steps, providing an advertisement with an interactive element, receiving user activation of that element, determining whether an identifier is present on the user’s device, retrieving or generating a user profile, retrieving additional information based on that profile, delivering the information without interrupting the browsing session, and recording the activation as tracking data.
The dispute that ultimately drove the Rule 12(b)(6) dismissal centered on limitation [1f], which requires “retrieving a user profile … wherein the user profile comprises at least delivery method preferences and demographic information.” Adnexus alleged that Meta’s Lead Ads retrieve user profiles that include such delivery method preferences, including contact information used to prefill lead forms.
The District Court’s Dismissal
After Meta notified Adnexus of its intent to move to dismiss, Adnexus filed an amended complaint attaching detailed claim charts and preliminary infringement contentions mapping each element of claim 1 to Lead Ads. Meta nonetheless moved to dismiss, arguing that the amended complaint failed to plausibly allege that Lead Ads retrieves a user profile containing “delivery method preferences.”
The district court agreed with Meta. It concluded that “contact information” was “sufficiently distinct from delivery method preferences” such that allegations relying on prefilled contact information could not plausibly satisfy limitation [1f]. On that basis, the court dismissed the literal infringement claim, rejected the doctrine of equivalents theory as barred by prosecution history estoppel, and dismissed the indirect and willful infringement claims as derivative. Importantly, the dismissal was with prejudice, consistent with the court’s standing order limiting amendments following a motion to dismiss.
Federal Circuit Standard of Review
On appeal, the Federal Circuit applied Fifth Circuit law to review the Rule 12(b)(6) dismissal de novo, while applying its own law to determine whether the complaint adequately stated a claim for patent infringement. The court reiterated familiar principles: factual allegations must be taken as true, reasonable inferences drawn in the plaintiff’s favor, and plausibility requires more than a sheer possibility of infringement but less than proof.
Critically, the court emphasized that a patent plaintiff is not required to plead infringement on an element-by-element basis. Rather, the complaint must provide enough factual content to place the accused infringer on notice and to articulate why infringement is plausible.
Claim Construction Disguised as Plausibility
The heart of the Federal Circuit’s decision lies in its rejection of the district court’s treatment of “delivery method preferences.” According to the panel, Meta’s argument for dismissal necessarily depended on a particular construction of that term that excluded contact information. Without such a construction, Adnexus’s allegations remained plausible.
The Federal Circuit explained that this was not a case where the claim’s meaning was so clear that no construction was necessary. Instead, Meta and Adnexus advanced competing interpretations, each pointing to different portions of the specification. By concluding that contact information could not constitute delivery method preferences, the district court effectively adopted Meta’s construction without formally construing the claim or allowing Adnexus to be heard on the issue.
This approach, the panel held, contravened established precedent. The court cited Nalco v. Chem-Mod, where dismissal was reversed because the defendant’s objections “read like classic Markman arguments.” The same was true here. Charles Gideon Korrell notes that the Federal Circuit has repeatedly cautioned district courts against resolving claim scope disputes implicitly at the pleadings stage, particularly when those disputes are outcome-determinative.
The panel acknowledged that district courts have discretion to engage in claim construction when evaluating a motion to dismiss, but only if they provide notice and an opportunity to be heard or adopt the non-moving party’s construction for purposes of the motion. What the district court could not do was silently construe the disputed term against Adnexus.
Plausibility of the Amended Complaint
Turning to the allegations themselves, the Federal Circuit concluded that Adnexus had adequately pleaded limitation [1f]. The amended complaint expressly alleged direct infringement and incorporated detailed claim charts mapping claim elements to Lead Ads functionality. In particular, the charts alleged that Lead Ads uses cookies to identify users, retrieves information from user profiles to prefill forms, and that these prefilled fields can include contact information, delivery method preferences, and demographic information.
At the motion to dismiss stage, these allegations had to be taken as true. The court rejected Meta’s argument that Adnexus forfeited reliance on its preliminary infringement analysis attached as Exhibit D, noting that documents attached to the complaint and referenced therein may be considered. That analysis expressly alleged that a Facebook user profile includes an email address as a delivery preference and demographic information such as age and interests.
Viewed in the light most favorable to Adnexus, the allegations plausibly stated that Lead Ads retrieves user profiles containing delivery method preferences and uses them to deliver information in accordance with claim 1. That was enough to survive Rule 12(b)(6).
Relationship to Prior Precedent
The decision sits comfortably alongside several recent Federal Circuit cases reinforcing limits on early dismissal. In Bot M8 v. Sony, the court clarified that while complaints must articulate why infringement is plausible, courts must not demand evidentiary detail. In AlexSam v. Aetna, the court reiterated that claim charts are not required but may bolster plausibility when provided. And in Aatrix Software v. Green Shades, the court held that factual disputes underlying claim construction often preclude dismissal.
Here, the court also cited UTTO v. Metrotech and Teva v. Amneal to emphasize that claim construction at the pleadings stage must be handled carefully. Charles Gideon Korrell believes that Adnexus reinforces a consistent message: Rule 12(b)(6) is not a shortcut to claim construction wins.
Practical Implications
For patentees, Adnexus offers reassurance that detailed infringement allegations, particularly those supported by claim charts and incorporated analyses, can withstand early dismissal even when defendants challenge claim scope. For accused infringers, the case is a warning that arguments hinging on narrow interpretations of claim terms are unlikely to succeed on a motion to dismiss absent a clear and undisputed meaning.
For district courts, the opinion provides a clear procedural roadmap. If claim construction is necessary to resolve a motion to dismiss, courts must either adopt the non-moving party’s construction for purposes of the motion or provide notice and an opportunity to be heard before resolving the dispute. Silent or implicit constructions against the patentee will not survive appellate review.
Charles Gideon Korrell notes that the decision also has implications for standing orders that limit amendments. While the Federal Circuit did not reach the validity of the Western District of Texas’s practice, the vacatur avoided the harsh consequence of a with-prejudice dismissal based on a premature construction. Practitioners should nonetheless remain mindful of local rules and standing orders when pleading infringement.
Conclusion
Adnexus v. Meta reinforces a fundamental boundary between plausibility and claim construction. While patent complaints must do more than recite conclusory assertions, they need not anticipate and defeat every conceivable claim construction argument at the pleadings stage. When plausibility turns on how a disputed term is construed, that dispute generally belongs later in the case.
In vacating and remanding, the Federal Circuit ensured that Adnexus will have the opportunity to litigate claim scope in the proper procedural posture. The opinion serves as another clear signal that early dismissal is the exception, not the rule, when infringement allegations hinge on unresolved questions of claim meaning.