Regeneron v. Amgen: EYLEA® Patent Case Transferred to N.D. West Virginia MDL
Regeneron Pharmaceuticals filed suit against Amgen in the Central District of California asserting US12331099B2 covering EYLEA® (aflibercept). Within 42 days, the Judicial Panel on Multidistrict Litigation transferred the action to the Northern District of West Virginia MDL — joining at least two other coordinated EYLEA® infringement actions before Judge Thomas S. Kleeh.
EYLEA® Infringement Dispute Absorbed Into Growing West Virginia MDL
On June 17, 2025, Regeneron Pharmaceuticals, Inc. filed a patent infringement complaint against Amgen, Inc. in the United States District Court for the Central District of California, asserting US12331099B2 — a patent covering the EYLEA® (aflibercept) ophthalmic biologic — in Case No. 2:25-cv-05499. Regeneron is the originator of EYLEA®, a VEGF inhibitor widely used to treat neovascular age-related macular degeneration and other retinal conditions, while Amgen is a biosimilar and biologic competitor.
The case was resolved at the district level after just 42 days, not on the merits but by transfer. The Judicial Panel on Multidistrict Litigation, acting pursuant to 28 U.S.C. § 1407, transferred the action to the Northern District of West Virginia on July 29, 2025, consolidating it with at least two previously transferred EYLEA®-related civil actions for coordinated pretrial proceedings. The case has been assigned to the Honorable Thomas S. Kleeh, who is presiding over the consolidated MDL docket.
The 42-day lifecycle in C.D. Cal. is consistent with a conditional transfer order being issued promptly once the JPML identified overlapping questions of fact with the existing West Virginia MDL. This suggests the EYLEA® patent dispute landscape is broad enough to warrant centralized management. The public record does not yet reveal the specific claims asserted, Amgen’s defenses, or whether any licensing negotiations are underway — all of which will surface in the MDL proceedings.
Filing to Case Transferred in 42 days
42 days in C.D. Cal. before MDL transfer — significantly shorter than the median district court lifespan
MDL transfer under § 1407: what it means for Regeneron v. Amgen
What a § 1407 MDL transfer actually does
A transfer under 28 U.S.C. § 1407 does not end the case or decide its merits. The Judicial Panel on Multidistrict Litigation consolidates civil actions sharing common questions of fact into a single district for coordinated pretrial proceedings. Once pretrial is complete, individual actions are typically remanded to their originating courts for trial — meaning C.D. Cal. may ultimately decide this case.
Procedural consolidationWhy the Northern District of West Virginia now controls
The JPML panel determined that this action shares common questions of fact with EYLEA®-related cases already pending before Judge Thomas S. Kleeh in the N.D. West Virginia. Coordinating discovery, claim construction, and pretrial motions in one court reduces duplication and inconsistent rulings. Regeneron and Amgen will now litigate all pretrial matters — including potentially dispositive motions — on West Virginia’s docket and schedule.
N.D. West Virginia MDLMDL schedule and path to trial
Within the MDL, Judge Kleeh will set a consolidated schedule for discovery, claim construction (Markman hearings), and summary judgment. Any ruling on patent validity or infringement of US12331099B2 will affect all consolidated EYLEA® actions simultaneously. If no settlement is reached, the case may be remanded to C.D. Cal. for a jury trial. The MDL structure typically extends overall resolution timelines significantly.
Pretrial consolidation ongoingMDL centralization raises stakes for the EYLEA® biosimilar market
Centralizing multiple EYLEA® patent actions before one judge signals a contested biosimilar launch landscape. A consolidated claim construction ruling will simultaneously define the scope of Regeneron’s patents across all defendants. For Amgen and any other biosimilar entrants, the MDL outcome on patent validity and infringement carries heightened commercial risk — a single adverse ruling could affect multiple products or launch timelines across the market.
Biosimilar market risk elevatedFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Regeneron Pharmaceuticals, Inc. | Company | Biopharmaceutical company — originator and holder of US12331099B2 covering EYLEA®Search in Eureka ↗ |
| Defendant | Amgen, Inc. | Company | Amgen, Inc. — global biopharmaceutical company and biosimilar/biologic competitorSearch in Eureka ↗ |
| Plaintiff counsel | Alyssa J. Picard | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Andrew E. Goldsmith | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Andrew V Trask | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Arthur J. Argall , III | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Chorong Song | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Christian J. Gladden-Sorensen | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Christopher M. Pepe | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Elizabeth Stotland Weiswasser | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Ellen E. Oberwetter | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Grace W. Knofczynski | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Jacob E. Hartman | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Jennalee Beazley | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Kathryn S. Kayali | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Margaret E Dayton | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Mary Charlotte Y. Carroll | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Matthew Donald Umhofer | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Priyata Y. Patel | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Rhochelle Krawetz | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Sven E. Henningson | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff counsel | Teagan J. Gregory | Attorney | Counsel for Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Kellogg Hansen Todd Figel and Frederick PLLC | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Paul, Weiss, Rifkind, Wharton & Garrison LLP | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Umhofer, Mitchell And King, LLP | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Plaintiff law firm | Williams & Connolly LLP | Law Firm | Representing Regeneron Pharmaceuticals, Inc.Search in Eureka ↗ |
| Defendant counsel | David M. Stein | Attorney | Counsel for Amgen, Inc.Search in Eureka ↗ |
| Defendant law firm | Olson Stein LLP | Law Firm | Representing Amgen, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | California Central District CourtSearch in Eureka ↗ |
Official order — verbatim text
The transfer order confirms the JPML found overlapping questions of fact between this C.D. Cal. action and the existing EYLEA® MDL docket in N.D. West Virginia. No merits determination has been made — infringement and validity of US12331099B2 remain fully open. The reference to 28 U.S.C. § 1407 and the consolidated assignment to Judge Kleeh indicates this case will proceed as part of coordinated pretrial proceedings, with the originating court potentially retaining jurisdiction for trial upon remand.
US12331099B2 — EYLEA® Aflibercept Ophthalmic Biologic Patent
US12331099B2 (application no. US18/924707) is a U.S. patent asserted by Regeneron covering EYLEA® (aflibercept), a VEGF-trap biologic approved for treating neovascular age-related macular degeneration, diabetic macular edema, and related retinal conditions. The patent is part of Regeneron’s intellectual property portfolio protecting one of the highest-revenue ophthalmic biologics in the world. Its specific claims — and the precise technical scope being asserted against Amgen — have not yet been disclosed in the public MDL record.
EYLEA® generated billions in annual revenue for Regeneron before biosimilar competition emerged, making its patent portfolio among the most commercially significant in ophthalmology. Amgen has developed aflibercept biosimilar products, and patent disputes in this space involve complex claim construction questions around formulation, dosing, and manufacturing. The MDL consolidation suggests multiple companies have launched or are preparing to launch aflibercept biosimilars, making the outcome of US12331099B2 litigation critical to competitive dynamics in retinal therapeutics.
Should you run an FTO against US12331099B2 for EYLEA® biosimilar development?
Any company developing, manufacturing, or commercializing an aflibercept biosimilar — or any ophthalmic biologic that targets VEGF pathways — should treat US12331099B2 as a priority FTO target. The MDL consolidation confirms that Regeneron is actively enforcing this patent against at least two entities. An FTO analysis should map the specific claims of US12331099B2 against your product’s formulation, dosing, and administration features before any regulatory or commercial launch decision.
PatSnap Eureka’s FTO Search Agent can pull the full claim set of US12331099B2, map it against your product specifications, and surface related Regeneron family members and continuation applications that may extend the IP perimeter. Eureka also monitors MDL docket filings in real time, alerting you to claim construction rulings that redefine the patent’s scope — critical intelligence for any biosimilar program in the aflibercept space.
Run a freedom-to-operate analysis on US12331099B2 to assess your product’s exposure
Run FTO in Eureka →Similar EYLEA® and Aflibercept Biosimilar Patent Infringement Cases
Related EYLEA® (aflibercept) patent infringement actions consolidated in the N.D. West Virginia MDL and C.D. Cal. biosimilar enforcement cases.
What this MDL transfer signals for the EYLEA® biosimilar IP landscape
Coordinated pretrial proceedings in West Virginia consolidate risk — and leverage — for all EYLEA® patent disputes simultaneously.
MDL consolidation amplifies the impact of every pretrial ruling
When JPML consolidates related patent cases, a single claim construction or summary judgment ruling binds all consolidated actions. For biosimilar entrants challenging EYLEA® patents, an adverse Markman ruling in the MDL is far more damaging than losing a standalone case — it constrains every defendant’s litigation position at once.
42-day transfer timeline suggests the EYLEA® MDL is a well-established vehicle
The speed of this transfer — conditional order issued rapidly after filing — is consistent with a JPML that had already established the MDL framework in April 2024. New EYLEA®-related filings in any district are now likely to be swept into the West Virginia MDL almost automatically, concentrating all enforcement activity before Judge Kleeh.
Regeneron v Amgen — key questions answered
The case was transferred — not dismissed or decided on the merits. On July 29, 2025, after 42 days in the Central District of California, the action was transferred by the JPML to the Northern District of West Virginia MDL pursuant to 28 U.S.C. § 1407 for coordinated pretrial proceedings before Judge Thomas S. Kleeh.
Regeneron asserts US12331099B2 (application no. US18/924707) covering EYLEA® (aflibercept), a VEGF-trap biologic used in the treatment of neovascular age-related macular degeneration and diabetic macular edema. The specific claims being asserted have not been made public in available docket records.
The JPML determined that this action shares common questions of fact with previously transferred EYLEA® patent cases consolidated in the Northern District of West Virginia. The MDL was established on April 11, 2024, under 28 U.S.C. § 1407. Centralizing pretrial proceedings avoids duplicative discovery and the risk of inconsistent rulings across multiple districts.
The Honorable Thomas S. Kleeh of the United States District Court for the Northern District of West Virginia presides over the consolidated EYLEA® MDL. Judge Kleeh was assigned with the consent of the N.D. West Virginia court, consistent with standard JPML practice for MDL assignments.
No. An MDL transfer under 28 U.S.C. § 1407 is a procedural consolidation — it makes no determination on the merits of the patent infringement claims. Infringement and validity of US12331099B2 remain fully open issues to be litigated in the MDL. The case is ongoing, and Amgen has not obtained any favorable ruling on the substance of Regeneron’s claims.
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