Mylan & Biosimilar Coalition v. Regeneron — Federal Circuit Affirms VEGF Patent
Seven biosimilar challengers — including Mylan, Amgen, Biocon Biologics, Formycon, Celltrion, and Samsung Bioepis — appealed to the Federal Circuit seeking to overturn patent protection for Regeneron’s VEGF antagonist intravitreal formulations (US11084865B2). The Federal Circuit affirmed, closing the appeal in 217 days and leaving Regeneron’s patent position intact.
Biosimilar coalition’s Federal Circuit challenge to Regeneron VEGF patent fails
Filed 31 July 2024, Case 24-2147 saw a coalition of seven biosimilar companies — Mylan Pharmaceuticals, Amgen Inc., Amgen USA, Biocon Biologics, Formycon AG, Celltrion, and Samsung Bioepis — bring a joint appeal before the Court of Appeals for the Federal Circuit. The dispute centred on US11084865B2, a Regeneron patent protecting VEGF antagonist formulations suitable for intravitreal administration, a technology directly relevant to ocular biologics such as aflibercept (Eylea) and its biosimilar equivalents.
The Federal Circuit issued its order on 5 March 2025, affirming the decision below. The appellate court’s standard formulation — ‘THIS CAUSE having been considered, it is ORDERED AND ADJUDGED: AFFIRMED’ — signals that the panel found no reversible legal or factual error in the lower tribunal’s analysis. For Regeneron, this means the patent’s enforceability emerged from the appellate process without material impairment. For the biosimilar challengers, the affirmance forecloses this appellate avenue and raises the threshold for any future challenge to the same patent.
The 217-day resolution is notably swift for a Federal Circuit biotech appeal of this complexity, suggesting either that the appellate panel found the legal questions well-settled or that the record was sufficiently developed to enable a clean disposition. The public record does not disclose whether any specific claim construction, obviousness, or enablement arguments were central to the appeal, nor whether any party has signalled intent to seek en banc rehearing or certiorari. What remains clear is that the coalition’s attempt to dislodge Regeneron’s VEGF formulation IP at the appellate level was unsuccessful.
Filing to Appeal Dismissed in 217 days
217-day appeal — resolved faster than the median Federal Circuit biotech appeal (~14 months)
Federal Circuit affirms: what the ruling means for both parties
What ‘AFFIRMED’ means at the Federal Circuit
An affirmance by the Federal Circuit means the appellate panel reviewed the record and found no reversible error — whether legal, procedural, or factual — in the decision below. The lower court’s ruling is left intact in full. Affirmance does not require the Federal Circuit to agree with every element of the lower court’s reasoning; it requires only that the outcome was legally supportable. For US11084865B2, this is the highest appellate determination short of en banc review or Supreme Court certiorari.
No reversible error foundRegeneron’s patent survives a coordinated biosimilar challenge
The affirmance strengthens Regeneron’s enforcement position for US11084865B2 covering VEGF antagonist intravitreal formulations. A patent that has survived appellate scrutiny from a coalition of seven well-resourced biosimilar challengers typically signals robust claim drafting and a solid prosecution record. Regeneron can now assert this patent with heightened credibility against any future biosimilar entrants, and licensees may face less negotiating leverage than before the appeal.
Enforceability reinforcedBiosimilar coalition’s appellate options are now effectively exhausted
For Mylan, Amgen, Biocon, Formycon, Celltrion, and Samsung Bioepis, the affirmance closes the Federal Circuit avenue. Remaining options are narrow: en banc rehearing (rarely granted), Supreme Court certiorari (granted in fewer than 1% of patent petitions), or a fresh IPR challenge at the USPTO if a distinct prior art basis can be identified. Any biosimilar product launch in the US that falls within the scope of US11084865B2 now carries materially higher litigation risk.
Appellate path closedAffirmance raises the barrier to entry in VEGF intravitreal biologics
The Federal Circuit’s affirmance sends a clear market signal: Regeneron’s VEGF antagonist intravitreal formulation IP has withstood coordinated multi-party appellate challenge. Competing biosimilar developers in the ocular biologics space — particularly those targeting aflibercept biosimilar entry — must now navigate this patent with greater caution. Freedom-to-operate analysis against US11084865B2 is effectively mandatory for any company developing VEGF inhibitor intravitreal products intended for the US market.
Biosimilar market access at riskFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Mylan Pharmaceuticals, Inc. | Company | Biosimilar manufacturers — challengers to US11084865B2 covering VEGF intravitreal formulationsSearch in Eureka ↗ |
| Co-Plaintiff | Amgen, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Biocon Biologics, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | FORMYCON AG | Company | Search in Eureka ↗ |
| Co-Plaintiff | Celltrion, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Amgen USA, Inc. | Company | Search in Eureka ↗ |
| Co-Plaintiff | Samsung Bioepis Co., Ltd. | Company | Search in Eureka ↗ |
| Defendant | Regeneron Pharmaceuticals, Inc. | Company | Regeneron Pharmaceuticals, Inc. — originator biologic company and patent holder of US11084865B2Search in Eureka ↗ |
| Defendant counsel | Adam Pan | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Andrew V. Trask | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Arthur John Argall, III | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Christian GladdenSorensen | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | David I. Berl Esq. | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Elizabeth Weiswasser | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Jacob Hartman | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Kathryn Schleckser Kayali | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Priyata Patel At | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Rhochelle Krawetz | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Shaun Patrick Mahaffy | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | Thomas S. Fletcher | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Kellogg, Hansen, Todd, Figel & Frederick, PLLC | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Paul, Weiss, Rifkind, Wharton & Garrison LLP | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Williams & Connolly LLP | Law Firm | Representing Regeneron Pharmaceuticals, 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 a clean appellate disposition with no remand and no partial reversal. In Federal Circuit practice, this formulation confirms that every material ground of appeal was considered and rejected, leaving the lower tribunal’s findings of fact and conclusions of law fully operative. For the biosimilar appellants, the absence of any qualifying language (such as ‘affirmed-in-part’) means no relief was granted on any claim. Regeneron’s US11084865B2 emerges from the Federal Circuit without judicially imposed modification.
US11084865B2 — VEGF antagonist intravitreal formulations
US11084865B2, filed under application number US16/739559, protects VEGF antagonist formulations specifically engineered for intravitreal administration — the injection route used to deliver ocular biologics directly into the vitreous humour of the eye. VEGF (vascular endothelial growth factor) antagonists are the mechanistic class underlying major retinal disease therapies, including treatments for wet age-related macular degeneration (AMD), diabetic macular oedema, and diabetic retinopathy. The patent’s formulation claims typically cover excipient composition, pH, tonicity, and stability characteristics that enable safe and effective delivery to ocular tissue.
Strategically, US11084865B2 occupies a critical position in Regeneron’s Eylea (aflibercept) IP fortress. Formulation patents of this type are frequently among the last barriers biosimilar entrants must clear after compound patents expire, making them high-value enforcement assets. The fact that a seven-company coalition pursued Federal Circuit review — and failed — suggests the claims are well-drafted with strong support in the specification. For competing VEGF antagonist developers, this patent represents a formulation design-around challenge that cannot be dismissed as a minor prosecution artefact.
Should you run an FTO against US11084865B2?
Any company developing, manufacturing, or commercialising VEGF antagonist intravitreal formulations for the US market should treat US11084865B2 as a priority FTO target. This applies directly to aflibercept biosimilar developers, but also extends to any company developing novel anti-VEGF biologics delivered via intravitreal injection if their formulation strategy overlaps with Regeneron’s claimed excipient and stability parameters. The Federal Circuit affirmance means this patent cannot be assumed invalid — it must be designed around or licensed.
PatSnap Eureka’s FTO Search Agent can map the claim scope of US11084865B2 against your formulation parameters in minutes, flagging overlapping claims and identifying prior art that may support a design-around strategy or future IPR petition. Eureka also tracks the full Regeneron VEGF patent family, enabling your team to identify continuation and divisional risk before committing to a formulation approach. For biosimilar programme leads and in-house IP counsel, this level of pre-launch visibility is no longer optional.
Run a freedom-to-operate analysis on US11084865B2 to assess your product’s exposure
Run FTO in Eureka →Similar Federal Circuit cases: VEGF biologics & biosimilar patent appeals
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What this case signals for the ocular biologics IP landscape
A coordinated biosimilar challenge failing at the Federal Circuit is a rare and consequential data point for the VEGF antagonist sector.
Multi-party coalitions don’t automatically improve appeal odds
Seven well-resourced companies mounting a joint Federal Circuit challenge and still receiving an affirmance suggests the lower court’s analysis of US11084865B2 was legally durable. IP teams at biosimilar developers should not assume strength in numbers at the appellate level — argument quality and claim differentiation matter more than party count.
FTO against US11084865B2 is now non-negotiable for VEGF biologics developers
Any company developing VEGF antagonist formulations for intravitreal use targeting the US market should treat this patent as a live enforcement risk. The Federal Circuit’s affirmance removes the most likely near-term invalidation pathway. Product teams and R&D leaders should commission an updated FTO analysis before any IND filing or commercial launch planning.
Mylan v Regeneron — key questions answered
The Federal Circuit affirmed the lower court’s ruling in favour of Regeneron in an infringement action concerning US11084865B2, which covers VEGF antagonist formulations for intravitreal administration. The appellate court found no reversible error, leaving Regeneron’s patent fully intact. The case closed on 5 March 2025, 217 days after the appeal was filed.
Seven entities joined as appellants: Mylan Pharmaceuticals Inc. (lead plaintiff), Amgen Inc., Amgen USA Inc., Biocon Biologics Inc., Formycon AG, Celltrion Inc., and Samsung Bioepis Co. Ltd. The coalition represents a significant cross-section of the global aflibercept biosimilar development landscape.
US11084865B2 (application no. US16/739559) protects VEGF antagonist formulations specifically designed for intravitreal administration. Formulation patents of this type define the excipient, pH, and stability characteristics enabling safe ocular delivery. For biosimilar developers targeting Eylea (aflibercept), matching the originator’s clinical profile without infringing formulation claims is a critical regulatory and legal challenge. Post-affirmance, this patent must be actively designed around.
The Federal Circuit affirmance closes the direct appellate avenue. Remaining options are: (1) en banc rehearing petition — rarely granted; (2) Supreme Court certiorari — granted in under 1% of patent cases; (3) a new IPR petition at the USPTO, subject to estoppel analysis on previously raised or raiseable grounds. Any challenger pursuing IPR should first audit which prior art grounds remain available and unestoppped.
The appeal was filed 31 July 2024 and decided 5 March 2025 — a 217-day resolution. For a Federal Circuit biotech appeal involving seven co-appellants and a complex biologics formulation patent, this duration is notably shorter than the typical 12–18 month range, suggesting the panel may have found the legal questions sufficiently settled to reach a relatively swift disposition.
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