Regeneron vs. Mylan: Settlement Ends Major Eylea® Biosimilar Patent Battle

Case Overview

The Parties

The Patents at Issue

Regeneron asserted 24 U.S. patents spanning multiple technology domains critical to aflibercept’s commercial embodiment, including:

• • US7070959B1 — Protein expression and production
• • US9222106B2 — Protein expression and production
• • US9816110B2 — Protein expression and production
• • US10406226B2 — Formulation and stability
• • US10888601B2 — Formulation and stability
• • US11084865B2 — Formulation and stability
• • US10927342B2 — Manufacturing processes and cell culture
• • US11332771B2 — Manufacturing processes and cell culture
• • US11174283B2 — Manufacturing processes and cell culture
• • US10857205B2 — Therapeutic methods and dosing
• • US11253572B2 — Therapeutic methods and dosing
• • US11299532B2 — Therapeutic methods and dosing

This layered, multi-patent assertion strategy—commonly called a “patent thicket”—is characteristic of originator biologics litigation designed to create overlapping layers of IP protection across product lifecycle.

Legal Representation

Regeneron assembled an expansive plaintiff team including attorneys from Williams & Connolly LLP, Paul, Weiss, Rifkind, Wharton & Garrison LLP, Kellogg Huber Hansen Todd Evans & Figel PLLC, and Carey, Douglas, Kessler & Ruby, PLLC, reflecting the resource intensity of defending a blockbuster biologic franchise.

Mylan retained Rakoczy, Molino, Mazzochi, Siwik LLP—a specialist biosimilar litigation firm—alongside Steptoe & Johnson PLLC and Bernstein-Burkley, P.C., assembling experienced BPCIA (Biologics Price Competition and Innovation Act) defense counsel.

Litigation Timeline & Procedural History

Filed in the Northern District of West Virginia (Clarksburg Division), the case ran for 994 days—nearly three years. This duration reflects the complexity inherent in BPCIA patent litigation, where multi-patent assertions, Paragraph IV-equivalent certification disputes, extensive claim construction proceedings, and biosimilar-specific regulatory timing considerations routinely extend timelines beyond standard Hatch-Waxman cases.

Significantly, the case was consolidated into MDL No. 24-md-3103-TSK, indicating parallel biosimilar litigation involving additional defendants, which substantially increased procedural complexity.

The Verdict & Legal Analysis

Outcome

The case closed via stipulated dismissal with prejudice under Federal Rule of Civil Procedure 41(a)(1), following a negotiated settlement between Regeneron and Defendants (Biocon Biologics Inc. and Mylan Pharmaceuticals Inc.). Critically, the stipulation included vacatur of three significant prior court orders:

• • The Order Granting Motion for Permanent Injunction (ECF No. 162, June 11, 2024)
• • The Final Judgment (ECF No. 163, June 11, 2024)
• • The Final Order for Injunctive Relief (ECF No. 189, June 21, 2024)

No damages amount was publicly disclosed. All parties agreed to bear their own attorneys’ fees and costs—a notable concession given the scale of litigation on both sides.

Strategic Turning Point: The Injunction and Its Vacatur

The most legally significant procedural arc in this case is Regeneron’s successful motion for permanent injunction in June 2024, followed by its ultimate vacatur upon settlement fourteen months later. Permanent injunctions in biologic patent cases are relatively rare outcomes; obtaining one represents a high-water mark for a patent holder. Yet the parties’ decision to vacate it—rather than allow it to stand as precedent—signals that both sides found the negotiated resolution more strategically valuable than the litigation record.

For Regeneron, settlement likely secured licensing terms or market entry timing controls that a contested Federal Circuit appeal might have jeopardized. For Mylan/Biocon, vacatur of the injunction removed an enforceable barrier that could have been cited in parallel proceedings against other biosimilar entrants.

Precedential Value and BPCIA Implications

Because the permanent injunction was vacated by stipulation, it carries no precedential weight before the Federal Circuit or other district courts. This is a deliberate and strategically significant outcome. Patent practitioners should note that vacated injunctions do not establish claim construction precedent, do not resolve patent validity, and cannot be cited in related litigation.

The 24-patent assertion spanning formulation, manufacturing, and method-of-treatment claims reflects the layered BPCIA litigation strategy increasingly deployed by biologics originators. Unlike Hatch-Waxman litigation—which typically focuses on a limited patent list—BPCIA’s patent dance mechanism can result in expansive multi-patent disputes exactly like this one.

Strategic Takeaways

For Patent Holders: A robust, multi-layered patent portfolio covering process, formulation, and therapeutic method claims creates maximum negotiating leverage in biosimilar litigation—even if no single patent is adjudicated to be infringed. The ability to secure a permanent injunction, even temporarily, represents powerful settlement currency.

For Accused Infringers: Appealing to the Federal Circuit immediately while simultaneously pursuing settlement negotiations is a viable dual-track strategy. Obtaining vacatur of adverse orders as a settlement condition preserves design-around flexibility and prevents adverse precedent from binding future biosimilar programs.

For R&D Teams: The 24-patent portfolio at issue underscores that freedom-to-operate (FTO) analysis for biosimilar candidates must extend well beyond core molecule patents to encompass manufacturing process, cell culture, formulation stability, and clinical dosing method claims.

Industry & Competitive Implications

The Regeneron v. Mylan resolution reflects broader dynamics reshaping anti-VEGF biosimilar competition in the U.S. market. Eylea® faces mounting biosimilar pressure, with multiple applicants seeking FDA approval for aflibercept reference biologics. Litigation outcomes—or their absence—in cases like this one send market-timing signals to all competitors.

The MDL consolidation (MDL No. 24-md-3103) suggests Regeneron simultaneously pursued biosimilar challengers beyond Mylan, consistent with an aggressive IP enforcement posture designed to delay market entry across the competitive field. How those parallel actions resolve will materially affect when and how competition enters this multi-billion-dollar therapeutic segment.

From a licensing and settlement trend perspective, this case aligns with industry patterns where originator biologics companies convert litigation victories into negotiated market access agreements—granting biosimilar entry on controlled timelines in exchange for royalties or exclusivity windows—rather than litigating to final appellate resolution.

Companies operating in the anti-VEGF, ophthalmology, or broader biologics space should treat this case as a signal that comprehensive patent thicket strategies remain enforceable leverage tools, even when final adjudication is ultimately avoided.

Frequently Asked Questions

What patents were involved in Regeneron v. Mylan?

Regeneron asserted 24 U.S. patents covering protein expression, manufacturing processes, formulation, and therapeutic methods for aflibercept (Eylea®), including US7070959B1, US9222106B2, US11174283B2, and US11084865B2, among others.

Why was the permanent injunction vacated?

The parties reached a private settlement agreement resolving all claims. As a condition of dismissal, both sides stipulated to vacate the June 2024 permanent injunction and final judgment, preventing those orders from establishing binding precedent in related litigation.

How does this case affect anti-VEGF biosimilar patent litigation?

It reinforces that broad, layered patent portfolios remain effective tools for biologics originators in BPCIA disputes, and that permanent injunctions—even when later vacated—serve as powerful settlement leverage driving negotiated market-entry agreements.

Search patent records for this case on PACER (Case No. 1:22-cv-00061, N.D. W. Va.) and review the patents at issue via the USPTO Patent Full-Text Database.