uniQure BioPharma v. Pfizer: Federal Circuit Affirms Factor IX Patent Unpatentable
uniQure BioPharma BV’s patent covering a Factor IX polypeptide mutant central to gene therapy for hemophilia B was found unpatentable at the trial level — and the Federal Circuit affirmed that ruling after an 855-day appellate proceeding. The outcome removes a key IP barrier Pfizer faced in the Factor IX gene therapy space.
Federal Circuit seals uniQure’s Factor IX patent loss against Pfizer
uniQure BioPharma BV, a Dutch gene therapy company, appealed to the U.S. Court of Appeals for the Federal Circuit (Case No. 23-1406) seeking to overturn a finding that its patent US10465180B2 — covering a Factor IX polypeptide mutant and methods for its production — was unpatentable. The dispute centred on core IP underlying hemophilia B gene therapy, a rapidly commercialising space in which both uniQure and Pfizer hold significant competitive positions.
The Federal Circuit issued its order on 22 May 2025, affirming the lower tribunal’s ruling in full. An affirmance at this level means the appellate court found no reversible legal error in the original patentability determination. With the basis of termination recorded as ‘Unpatentable’, the claims of US10465180B2 are cancelled and uniQure loses the ability to assert this patent against Pfizer or any other party.
The 855-day duration from filing to close suggests substantive briefing and likely oral argument, consistent with complex biotechnology patentability questions — potentially involving enablement, written description, or prior art grounds. The public record does not disclose the specific invalidity ground upheld, nor whether uniQure has sought or will seek en banc reconsideration or certiorari. The outcome meaningfully strengthens Pfizer’s freedom to operate in the Factor IX gene therapy market.
Filing to Unpatentable in 855 days
855-day appeal — above the Federal Circuit median for patentability disputes
Federal Circuit affirms: what the unpatentability ruling means for both parties
Affirmance: no reversible error found in the patentability ruling
When the Federal Circuit ‘affirms’, it confirms that the tribunal below correctly applied the law and that its factual findings were not clearly erroneous. It does not retry the case — it reviews the record and legal reasoning. Here, the court determined that the unpatentability finding for US10465180B2 was legally sound, giving that determination full force and finality at this appellate level.
Appellate standard satisfieduniQure loses its Factor IX patent — claims cancelled, no further enforcement
uniQure’s US10465180B2 is now cancelled following affirmance of the unpatentability ruling. The company can no longer assert these claims against Pfizer or any third party in U.S. proceedings. To the extent uniQure’s licensing strategy or litigation posture in the hemophilia B space relied on this patent, that position is materially weakened. Options at this stage — en banc rehearing or Supreme Court certiorari — face a high bar and are granted rarely.
Patent cancelled — unenforceablePfizer gains clear FTO on the Factor IX claims at issue
Pfizer, as the prevailing party, now operates with confirmed freedom from this specific patent in the U.S. market. The affirmance eliminates the risk of any damages exposure or injunction tied to US10465180B2. For Pfizer’s hemophilia B gene therapy programme — which competes directly in the Factor IX space — this is a commercially significant clearance. Pfizer’s litigation team at Williams & Connolly successfully defended the unpatentability finding across two levels of review.
Freedom to operate confirmedStrengthened competitive landscape for Factor IX gene therapy developers
The cancellation of uniQure’s Factor IX polypeptide mutant patent removes a potential blocking position in a high-value therapeutic area. Hemophilia B gene therapy is at a pivotal commercial stage, with multiple programmes in late-stage development. Competitors and licensees in this space should reassess their patent exposure maps accordingly. The ruling may also embolden further validity challenges against other uniQure patents in the Factor IX cluster.
IP landscape shift — sector-wide impactFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | uniQure BioPharma BV | Individual | Gene therapy developer — holder of US10465180B2, Factor IX polypeptide mutant patentSearch in Eureka ↗ |
| Defendant | Pfizer, Inc. | Company | Pfizer, Inc. — global biopharmaceutical company with hemophilia B gene therapy programmeSearch in Eureka ↗ |
| Plaintiff counsel | Emily R. Whelan | 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 | Dov Philip Grossman | 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 order — ‘THIS CAUSE having been considered, it is ORDERED AND ADJUDGED: AFFIRMED’ — is the Federal Circuit’s final disposition, entered without qualification or remand. The absence of any remand instruction suggests the court resolved all contested issues in favour of the lower tribunal’s unpatentability finding. Under the appellate standard, factual findings are reviewed for clear error and legal conclusions de novo; the unqualified affirmance indicates neither standard favoured uniQure.
US10465180B2 — Factor IX polypeptide mutant for gene therapy
US10465180B2, filed under application number US15/989665, protects a Factor IX polypeptide mutant — an engineered variant of the coagulation Factor IX protein — along with its therapeutic uses and manufacturing methods. Factor IX is the deficient protein in hemophilia B; gene therapies delivering functional Factor IX represent a curative approach to this rare bleeding disorder. The patent sits at the core of next-generation AAV-based gene therapy platforms targeting this indication.
Strategically, US10465180B2 represented a potential blocking position against competitors developing or commercialising Factor IX gene therapies in the U.S. Its cancellation following the Federal Circuit affirmance removes that barrier for Pfizer and, given the public nature of the ruling, may reduce licensing leverage uniQure held across its Factor IX portfolio. Developers in the AAV gene therapy space — including those working on delivery vectors optimised for high Factor IX expression — should monitor related uniQure continuations and divisional applications.
Should you run an FTO analysis against US10465180B2?
US10465180B2 has been cancelled following the Federal Circuit’s affirmance of unpatentability — meaning this specific patent no longer poses a U.S. infringement risk. However, product and R&D teams developing Factor IX gene therapies, AAV vectors, or related polypeptide mutant platforms should not rely on this single cancellation as a clean FTO signal. uniQure’s broader patent family likely includes related claims with overlapping technical scope.
PatSnap Eureka’s FTO Search Agent can map the full uniQure Factor IX patent family — identifying granted, pending, and lapsed claims across jurisdictions — and flag which remaining patents share priority chains or claim language with US10465180B2. For teams preparing an IND, NDA, or commercial launch in the hemophilia B gene therapy space, a structured FTO analysis against uniQure’s portfolio is a prudent pre-commercialisation step.
Run a freedom-to-operate analysis on US10465180B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit patentability appeals in gene therapy and biologics
Federal Circuit appeals affirming unpatentability of gene therapy and biologics patents — cases with comparable invalidity grounds and AAV or polypeptide claim structures.
What this case signals for the gene therapy IP landscape
The Federal Circuit’s affirmance in uniQure v. Pfizer reshapes the patent enforcement calculus across the hemophilia B gene therapy sector.
Factor IX patent claims face elevated validity scrutiny at the Federal Circuit
The affirmance signals that patentability challenges to foundational gene therapy patents — particularly those covering polypeptide mutants and production methods — can succeed through appellate review. Companies asserting broad biological composition claims in this space should audit their claim scope against written description and enablement standards.
Pfizer’s clearance shifts competitive dynamics in the hemophilia B market
With US10465180B2 cancelled, Pfizer’s Factor IX programme faces one fewer IP obstacle in the U.S. Other participants in the hemophilia B gene therapy market — including emerging gene editing players — should map remaining uniQure patent families and assess whether similar challenges are viable.
BV v Pfizer — key questions answered
The Federal Circuit affirmed the lower tribunal’s finding that US10465180B2 — uniQure’s Factor IX polypeptide mutant patent — is unpatentable. The order, issued 22 May 2025, is a final disposition with no remand, meaning the patent’s claims are cancelled and cannot be enforced by uniQure.
US10465180B2 covers a Factor IX polypeptide mutant and methods for its production, filed under application US15/989665. Factor IX deficiency causes hemophilia B; gene therapies delivering engineered Factor IX variants are a leading curative strategy. This patent represented potential IP coverage over a core component of AAV-based hemophilia B gene therapy platforms.
An affirmance means the Federal Circuit found no reversible error — legal or factual — in the lower tribunal’s unpatentability ruling. Factual findings are reviewed for clear error; legal conclusions de novo. An unqualified affirmance with no remand indicates the court resolved all issues against uniQure and in favour of the patentability challenge.
The cancellation clears Pfizer of this specific U.S. patent. However, FTO in the hemophilia B gene therapy space requires analysis of uniQure’s broader Factor IX and AAV patent portfolio, as well as third-party patents. Cancellation of one claim set does not constitute a blanket clearance across the competitive landscape.
uniQure’s primary options post-affirmance are a petition for en banc rehearing before the full Federal Circuit, or a petition for certiorari to the U.S. Supreme Court. Both face very high bars — en banc rehearing is rarely granted, and the Supreme Court accepts fewer than 1% of certiorari petitions. The public record does not indicate whether uniQure has pursued either avenue.
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