uniQure v. Pfizer: Federal Circuit Affirms Factor IX Patent Cancellation
uniQure BioPharma BV challenged Pfizer’s successful invalidation of two gene therapy patents covering Factor IX polypeptide mutants — the biological core of hemophilia B treatment. The Federal Circuit affirmed unpatentability across both patents after 855 days of appellate proceedings, foreclosing uniQure’s IP position in a high-stakes therapeutic space.
Federal Circuit closes uniQure’s gene therapy IP door against Pfizer
uniQure BioPharma BV, a Dutch gene therapy company, appealed to the U.S. Court of Appeals for the Federal Circuit seeking to overturn a finding that two of its core patents — US9982248 and US10465180 — were unpatentable. Both patents relate to Factor IX polypeptide mutants, the foundational biological mechanism behind hemophilia B gene therapies. The appeal, filed January 18, 2023, placed Pfizer, Inc. as the prevailing party from the proceedings below.
On May 22, 2025, the Federal Circuit issued a terse but definitive order affirming the unpatentability finding across both patents. An affirmance at this level means the court found no reversible legal or factual error in the tribunal below, leaving the cancellation of both patents intact. For uniQure, this extinguishes IP protection for the Factor IX mutant technology as claimed; for Pfizer, it confirms freedom to operate in the underlying therapeutic space without the overhang of these specific claims.
At 855 days, the appeal duration suggests the issues were substantively contested, consistent with the complexity of written description and enablement challenges common in biologics patent validity disputes. The public record does not disclose the precise grounds on which the lower tribunal found unpatentability, nor whether obviousness, written description, or enablement was determinative. What is clear is that uniQure has exhausted its appellate options at this level, materially weakening its patent estate in the competitive hemophilia gene therapy market.
Filing to Unpatentable in 855 days
855-day appeal — above median for Federal Circuit patent validity cases
Federal Circuit affirms: what the ruling means for both parties
Affirmance means the lower decision stands in full
When the Federal Circuit affirms, it holds that the tribunal below committed no reversible error — whether legal or factual. The standard of review varies by issue: legal questions such as claim construction are reviewed de novo, while factual findings underlying patentability (e.g., motivation to combine, reasonable expectation of success) are reviewed for substantial evidence. An affirmance here means both patents remain cancelled on the record.
No reversible error founduniQure loses enforceability across both Factor IX patents
The affirmance confirms that US9982248 and US10465180 are unpatentable, stripping uniQure of enforceable rights to the Factor IX polypeptide mutant claims as drafted. uniQure cannot re-litigate these specific claims at the Federal Circuit level. Any remaining IP protection would need to rest on continuation applications, divisionals, or foreign counterparts — none of which are guaranteed the same outcome.
Patents cancelled, unenforceablePfizer secures clear IP runway in hemophilia B gene therapy
Pfizer, as the party that successfully defended the unpatentability finding, now operates in the Factor IX gene therapy space without the litigation risk these two patents represented. The Federal Circuit’s affirmance raises the bar significantly for any future attempt by uniQure or successors to assert equivalent claims. Pfizer’s hemophilia B programme — including Beqvez (fidanacogene elaparvovec) — benefits directly from this outcome.
FTO strengthened for PfizerAffirmance reshapes the hemophilia B gene therapy patent landscape
With two uniQure Factor IX patents cancelled at the Federal Circuit, competing developers of hemophilia B gene therapies face a narrowed patent thicket in this specific mutant polypeptide space. However, the ruling also signals that broad, foundational gene therapy claims face serious patentability scrutiny — a caution for any applicant drafting wide composition or method claims in the biologics space without strong written description support.
Broader scrutiny of biologics claimsFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | uniQure BioPharma BV | Individual | Gene therapy biopharmaceutical company — holder of US9982248 and US10465180Search in Eureka ↗ |
| Defendant | Pfizer, Inc. | Company | Global pharmaceutical corporation; prevailing party in underlying patentability proceedingsSearch in Eureka ↗ |
| Plaintiff counsel | Emily R. Whelan | Attorney | Counsel for uniQure BioPharma BVSearch in Eureka ↗ |
| Plaintiff counsel | Joshua Lloyd Stern | Attorney | Counsel for uniQure BioPharma BVSearch in Eureka ↗ |
| Plaintiff counsel | Mark Christopher Fleming | Attorney | Counsel for uniQure BioPharma BVSearch in Eureka ↗ |
| Plaintiff law firm | Wilmer Cutler Pickering Hale & Dorr LLP | Law Firm | Representing uniQure BioPharma BVSearch in Eureka ↗ |
| Defendant counsel | David I. Berl | Attorney | Counsel for Pfizer, Inc.Search in Eureka ↗ |
| Defendant counsel | Dov Philip Grossman | Attorney | Counsel for Pfizer, Inc.Search in Eureka ↗ |
| Defendant counsel | Kathryn Schleckser Kayali | Attorney | Counsel for Pfizer, Inc.Search in Eureka ↗ |
| Defendant counsel | Shaun Patrick Mahaffy | Attorney | Counsel for Pfizer, Inc.Search in Eureka ↗ |
| Defendant counsel | Xun Liu Associate | Attorney | Counsel for Pfizer, Inc.Search in Eureka ↗ |
| Defendant law firm | Williams & Connolly LLP | Law Firm | Representing Pfizer, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | Court of Appeals for the Federal CircuitSearch in Eureka ↗ |
Official order — verbatim text
The Federal Circuit’s order — ‘THIS CAUSE having been considered, it is ORDERED AND ADJUDGED: AFFIRMED’ — is unqualified. There is no remand, no partial reversal, and no instructions for further proceedings. This language confirms a complete affirmance of the unpatentability finding on both US9982248 and US10465180. Under Federal Circuit review, factual findings on patentability are upheld if supported by substantial evidence; the court’s clean affirmance suggests the record below was sufficient to sustain cancellation on all challenged claims.
US9982248 & US10465180 — Factor IX polypeptide mutant gene therapy
US9982248 (application US15/650070) and US10465180 (application US15/989665) both cover inventions in the Factor IX polypeptide mutant space — specifically engineered variants of the coagulation Factor IX protein used in gene therapy for hemophilia B. These patents sit at the intersection of protein engineering and viral vector gene delivery, a technically demanding area where claim scope and specification support are frequently contested before the PTAB and Federal Circuit.
Factor IX gene therapy is among the most commercially significant applications in rare disease biologics, with approved therapies now on market from both uniQure (Hemgenix) and Pfizer (Beqvez). Patent protection over specific Factor IX mutants — particularly gain-of-function variants with enhanced coagulation activity — is central to competitive differentiation. The cancellation of these two patents materially narrows uniQure’s ability to exclude competitors from using related Factor IX mutant technologies, and signals that the specific claim constructions pursued did not satisfy patentability standards at the Federal Circuit level.
Should you run an FTO against US9982248 and US10465180?
Any company developing, manufacturing, or licensing hemophilia B gene therapy products incorporating engineered Factor IX polypeptide variants should take note: both US9982248 and US10465180 have been affirmed as unpatentable by the Federal Circuit. While these specific claims no longer represent an enforcement risk, related uniQure IP — including continuation applications, divisionals, and foreign counterparts — may cover overlapping technology and remain enforceable. A targeted FTO is still warranted for product teams working in this space.
PatSnap Eureka’s FTO Search Agent can rapidly map uniQure’s surviving patent family members, identify continuation chains stemming from the same priority applications, and surface any EPO or PCT equivalents that remain active. For R&D and regulatory teams advancing Factor IX gene therapy candidates toward IND or BLA filing, this analysis provides the evidentiary foundation needed to brief legal counsel and identify any residual clearance gaps before commercial launch.
Run a freedom-to-operate analysis on US9982248 to assess your product’s exposure
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What this case signals for the gene therapy IP landscape
The Federal Circuit’s affirmance in uniQure v. Pfizer carries real consequence for anyone developing or licensing hemophilia B gene therapy IP.
Unpatentability at the Federal Circuit level is near-final for these claims
With the Federal Circuit affirming, uniQure’s only remaining avenue would be a petition for certiorari to the Supreme Court — a rarely granted, high-bar path. Practically, US9982248 and US10465180 are extinguished as competitive weapons. Companies monitoring uniQure’s IP portfolio should update FTO analyses to reflect this cancellation.
Factor IX mutant composition claims face elevated validity risk post-ruling
The affirmance suggests the claims as drafted failed to survive patentability challenge — consistent with broader PTAB and Federal Circuit trends tightening written description and enablement standards for biologic composition claims. R&D teams drafting or prosecuting Factor IX or related coagulation factor gene therapy patents should audit specification support carefully before allowance.
BV v Pfizer — key questions answered
The Federal Circuit affirmed the unpatentability of uniQure’s two Factor IX gene therapy patents — US9982248 and US10465180. The May 22, 2025 order confirmed no reversible error in the lower tribunal’s cancellation of both patents, ending uniQure’s appeal and leaving both patents extinguished.
The two patents at issue were US9982248 (application US15/650070) and US10465180 (application US15/989665). Both cover Factor IX polypeptide mutant technology — engineered variants of the coagulation protein Factor IX used in gene therapy for hemophilia B, including methods for their production and use.
The affirmance confirms that neither US9982248 nor US10465180 can be enforced against Pfizer. This strengthens Pfizer’s freedom-to-operate for its hemophilia B gene therapy Beqvez (fidanacogene elaparvovec) and related Factor IX pipeline, removing the litigation overhang these uniQure patents represented.
At the Federal Circuit level, the affirmance is final for these specific claims. uniQure’s only remaining avenue would be a petition for writ of certiorari to the U.S. Supreme Court — an extraordinary remedy granted in a very small fraction of cases. uniQure may also have continuing prosecution activity in related applications, but the cancelled claims themselves cannot be revived.
The cancellation of these two patents removes them as potential barriers for third-party developers of Factor IX gene therapies. However, uniQure’s broader patent estate — including foreign counterparts and related continuation applications — may still be active. Companies in this space should conduct updated FTO analyses to assess residual IP risk from uniQure’s surviving portfolio.
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