Regeneron v. Mylan: Federal Circuit Affirms EYLEA® Patent Portfolio
Regeneron Pharmaceuticals successfully defended 13 patents covering its blockbuster EYLEA® (aflibercept) ophthalmic biologic against Mylan Pharmaceuticals at the Federal Circuit. The court affirmed the lower court’s ruling in a 197-day appeal, reinforcing Regeneron’s IP barrier against biosimilar entry into the EYLEA® market.
Federal Circuit locks in Regeneron’s 13-patent EYLEA® fortress
Regeneron Pharmaceuticals, Inc. brought this infringement action to defend 13 U.S. patents covering its EYLEA® (aflibercept) therapeutic product — a vascular endothelial growth factor (VEGF) trap used in the treatment of neovascular age-related macular degeneration and other retinal conditions. Mylan Pharmaceuticals, Inc., seeking to launch a biosimilar version of EYLEA®, challenged those patents as part of the Biologics Price Competition and Innovation Act (BPCIA) pathway. The appeal, docketed as Case No. 24-2083 at the Court of Appeals for the Federal Circuit, was filed on July 16, 2024 and closed January 29, 2025.
The Federal Circuit issued an affirmance, finding no reversible error in the district court’s ruling in Regeneron’s favour. An affirmance at the Federal Circuit means the appellate panel reviewed the lower court’s legal conclusions de novo and factual findings for clear error, and found neither standard met by Mylan’s challenge. The practical consequence is that Regeneron’s 13 asserted patents remain valid and enforceable as against Mylan’s proposed biosimilar, preserving Regeneron’s exclusivity position for EYLEA®.
A 197-day resolution suggests the Federal Circuit disposed of this appeal with relative efficiency, consistent with cases where the appellate record did not raise novel legal questions requiring extended briefing or oral argument. The breadth of the patent portfolio asserted — 13 patents spanning multiple application families — suggests Regeneron pursued a layered enforcement strategy typical of complex biologics litigation. The precise claim-by-claim scope of the affirmance and any dissent are not visible from the public docket summary alone.
Filing to Appeal Dismissed in 197 days
197-day appeal — faster than the Federal Circuit median for pharma patent disputes
Federal Circuit affirms: what the ruling means for both parties
Affirmance means no reversible error found below
When the Federal Circuit affirms, it signals that the appellate panel — reviewing legal questions de novo and facts for clear error — found the district court committed no reversible error on any determinative issue. For a 13-patent infringement portfolio like EYLEA®, affirmance validates both the validity findings and any infringement determinations upheld below. The lower court’s judgment is now final at this appellate level.
No reversible error foundRegeneron’s EYLEA® exclusivity barrier survives intact
Affirmance leaves all 13 asserted patents valid and enforceable against Mylan’s proposed biosimilar. Regeneron retains its ability to block Mylan’s BPCIA-pathway aflibercept product from market entry under these patents. The ruling strengthens the commercial durability of EYLEA®’s IP estate and signals to other potential biosimilar challengers that this portfolio has survived adversarial appellate scrutiny.
Patents valid and enforceableMylan’s appellate path exhausted at Federal Circuit level
Mylan’s loss at the Federal Circuit means its primary appellate route is closed. Further review would require a petition for certiorari to the Supreme Court — a high bar with low grant rates in patent cases absent a circuit split or constitutional question. Mylan’s biosimilar launch remains blocked under the affirmed patents unless it can distinguish its product or pursue inter partes review proceedings at the USPTO to invalidate specific claims.
Appellate options exhaustedStrengthened biologic fortress raises the bar for EYLEA® biosimilar entry
A Federal Circuit affirmance on a 13-patent portfolio sends a strong deterrence signal across the ophthalmology biologics market. Competing biosimilar developers will need to design around or successfully challenge each patent layer through IPR or litigation. The ruling also reinforces the value of layered BPCIA patent strategies, suggesting innovators with robust continuation portfolios can sustain exclusivity well into a product’s commercial lifecycle.
Higher bar for future biosimilar entryFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | REGENERON PHARMACEUTICALS, INC | Company | Biopharmaceutical innovator — holder of US9222106B2 and 12 further EYLEA® patentsSearch in Eureka ↗ |
| Defendant | Mylan Pharmaceuticals, Inc. | Company | Generic and biosimilar manufacturer seeking BPCIA approval to market afliberceptSearch in Eureka ↗ |
| Plaintiff counsel | ADAM PAN | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | ANDREW V. TRASK | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | ARTHUR JOHN ARGALL, III | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | CHRISTIAN GLADDEN-SORENSEN | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | David I. Berl | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | ELIZABETH WEISWASSER | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | JACOB HARTMAN | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | KATHRYN SCHLECKSER KAYALI | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | Priyata Patel | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | RHOCHELLE KRAWETZ | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | SHAUN PATRICK MAHAFFY | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff counsel | THOMAS S. FLETCHER | Attorney | Counsel for REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff law firm | Kellogg, Hansen, Todd, Figel & Frederick, PLLC | Law Firm | Representing REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Plaintiff law firm | Paul, Weiss, Rifkind, Wharton & Garrison LLP | Law Firm | Representing REGENERON PHARMACEUTICALS, INCSearch in Eureka ↗ |
| Defendant counsel | LAURA FAIRNENY | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | LAUREN MARTIN | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | MATTHEW A. TRAUPMAN | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | MATTHEW D. ROBSON | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | RAYMOND NIMROD | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | WILLIAM ADAMS | Attorney | Counsel for Mylan Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant law firm | Quinn Emanuel Urquhart & Sullivan, LLP | Law Firm | Representing Mylan 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 single-word verdict — ‘AFFIRMED’ — reflects the appellate court’s determination that the district court committed no reversible legal error across all challenged issues in this 13-patent EYLEA® infringement action. At the Federal Circuit, claim construction is reviewed de novo and factual findings for clear error; affirmance on both standards in a multi-patent biologic case suggests the lower court’s record was well-developed and Mylan’s appellate arguments did not identify a controlling legal deficiency. The result is final and binding at the appellate level absent Supreme Court review.
US9222106B2 and 12 further patents — EYLEA® aflibercept biologic therapeutic portfolio
The 13 patents asserted by Regeneron span U.S. application filings from 2013 (US9222106B2, application 13/752647) through 2021 (US11306135B2, application 17/460578), reflecting a multi-decade prosecution strategy anchored in aflibercept — a recombinant fusion protein that acts as a VEGF trap. EYLEA® is approved for neovascular age-related macular degeneration, diabetic macular edema, and related retinal conditions. The portfolio spans composition-of-matter, formulation, manufacturing, and method-of-treatment claims, creating a multi-layered IP barrier.
The strategic depth of this portfolio is significant for the ophthalmic biologics sector. By maintaining continuation families across more than a decade, Regeneron has created overlapping patent coverage that forces any biosimilar developer to challenge claims across multiple independent patent families. The Federal Circuit’s affirmance validates this strategy and suggests that each patent layer withstood adversarial scrutiny — raising the commercial and legal cost of any future biosimilar market entry attempt against EYLEA®.
Should your biosimilar programme run an FTO against EYLEA®’s 13-patent estate?
Any company developing an aflibercept biosimilar, VEGF-trap biologic, or ophthalmic anti-VEGF therapeutic should treat the 13 patents affirmed in this case as active enforcement risk. The Federal Circuit affirmance means these patents have survived full appellate review, and each must be individually assessed for claim scope, expiry, and design-around feasibility before any biosimilar IND or BLA filing proceeds.
PatSnap Eureka’s FTO Search Agent can map each of the 13 affirmed patents against your candidate molecule’s sequence, formulation, and manufacturing process, flagging claim overlap and identifying published prior art relevant to any planned IPR petition. Eureka’s citation graph and family tree tools also surface related continuation applications that may not yet have issued, helping your R&D and regulatory teams anticipate future enforcement risk before it materialises.
Run a freedom-to-operate analysis on US9222106B2 to assess your product’s exposure
Run FTO in Eureka →Similar BPCIA biologics patent appeals at the Federal Circuit
Cases involving multi-patent BPCIA infringement appeals at the Federal Circuit, particularly in ophthalmology and anti-VEGF biologics, provide direct precedent for this dispute.
What this case signals for the biologics and ophthalmology IP landscape
This Federal Circuit affirmance has immediate implications for biosimilar strategy, BPCIA enforcement, and portfolio management across the ophthalmic biologic sector.
Layered patent portfolios are the decisive biosimilar defence mechanism
Regeneron’s 13-patent enforcement strategy — spanning multiple application families — illustrates how innovator biologics companies construct overlapping IP layers. Each layer forces a challenger to invalidate or design around multiple independent claims. Companies holding single-patent positions around biologic products face materially higher risk of market entry by biosimilar developers.
Federal Circuit affirmance elevates future IPR and litigation cost for challengers
Once a patent portfolio survives Federal Circuit review, the evidentiary and procedural bar for a subsequent challenger rises. Future IPR petitions against these 13 patents will face the argument that claim scope and validity have already been tested at the highest patent appellate level. Biosimilar developers should factor this precedent into their BPCIA litigation budget models.
REGENERON v Mylan — key questions answered
The Federal Circuit affirmed the lower court’s ruling in favour of Regeneron, upholding all 13 EYLEA® (aflibercept) patents asserted against Mylan’s proposed biosimilar. The affirmance means the appellate court found no reversible error in the district court’s decision, leaving Regeneron’s patent exclusivity over EYLEA® intact against Mylan’s BPCIA challenge.
Regeneron asserted 13 U.S. patents: US9222106B2, US11084865B2, US9816110B2, US11253572B2, US10415055B2, US10669594B2, US10888601B2, US10130681B2, US10464992B2, US11066458B2, US9254338B2, US11306135B2, and US11104715B2. These patents span formulation, composition, manufacturing, and method-of-treatment claims covering the aflibercept VEGF-trap biologic product marketed as EYLEA®.
An affirmance from the Federal Circuit means Mylan’s appeal failed and the district court’s ruling against Mylan stands. Mylan’s biosimilar product remains blocked from market entry under the 13 affirmed patents. Mylan’s main remaining options are a Supreme Court certiorari petition (rarely granted in patent cases) or inter partes review petitions at the USPTO targeting individual patent claims.
The appeal was filed on July 16, 2024 and closed on January 29, 2025 — a duration of 197 days, or approximately six and a half months. This is relatively efficient for a Federal Circuit pharmaceutical patent appeal involving 13 patents, suggesting the appellate panel did not require extended supplemental briefing or raise novel procedural issues.
Yes, but the options narrow materially. Mylan could file inter partes review petitions at the USPTO to challenge individual patent claims on prior art grounds not fully litigated at district court. It could also petition the Supreme Court for certiorari, though grant rates in patent infringement cases are low absent a circuit split. The Federal Circuit affirmance does not bar USPTO proceedings as a matter of law, but does raise the evidentiary credibility of the existing patent record.
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