Case Overview

The Parties

Patents at Issue

This landmark case centered on a method-of-treatment patent covering fundamental therapeutic applications of VEGF-blocking agents. Such patents are a critical layer of exclusivity that branded pharmaceutical companies deploy to extend market protection beyond compound patents.

• • US 9,254,338 — Use of VEGF antagonist to treat angiogenic eye disorders

The Verdict & Legal Analysis

Outcome

The Federal Circuit entered a formal order dismissing all appeals in *Regeneron Pharmaceuticals, Inc. v. Mylan Pharmaceuticals, Inc.* (Case No. 23-1396) under Federal Rule of Appellate Procedure 42(b), with each side bearing its own costs. No damages were awarded, and no injunctive relief was ordered. Critically, the recorded basis of termination is “Unpatentable” — indicating that at the underlying proceeding level (most likely PTAB), U.S. Patent No. 9,254,338 had been found unpatentable.

Key Legal Issues

The dispute focused squarely on the patentability and invalidity of the ‘338 patent, rather than infringement. This framing is characteristic of Hatch-Waxman ANDA litigation strategy, where generic challengers frequently pursue IPR petitions at the PTAB as a parallel or alternative track to district court invalidity defenses. An “Unpatentable” determination at the PTAB on a method-of-treatment patent like the ‘338 — covering use of a VEGF antagonist for angiogenic eye disorders — would typically implicate obviousness grounds under 35 U.S.C. § 103, given the voluminous prior art in anti-VEGF therapeutics. The decision by Regeneron to ultimately dismiss rather than pursue the Federal Circuit appeal to judgment may reflect a calculated risk assessment: an adverse Federal Circuit ruling would set binding precedent undermining ‘338 and potentially related patents.