On December 11, 2025, Regeneron filed a Memorandum in Support of Its Motion to Bifurcate and Stay Amgen’s Antitrust Claims in the ongoing aflibercept patent litigation in the U.S. District Court for the Northern District of West Virginia.
As we previously reported, Regeneron filed a second complaint against Amgen in June 2025, alleging infringement of a patent that had issued after Amgen launched its PAVBLU® (aflibercept-ayyh). In response, Amgen filed an answer and counterclaims, alleging violations of the Sherman Act, unfair competition under California law, inequitable conduct, and patent misuse, among others.
Regeneron argues that a stay of Amgen’s antitrust claims “will promote judicial economy, spare the parties and Court the extraordinary burden presented by antitrust litigation, and present no meaningful prejudice to Amgen, which already has launched its accused product.” Id. at 3. In support of its position, Regeneron argues that it is “standard practice” to bifurcate and stay antitrust counterclaims pending resolution of patent infringement claims. Id. at 7. Regeneron argues that antitrust litigation could lead to “potentially enormous expense” that would “consume disproportionate judicial resources.” See id. at 10.
In its recent Motion, Regeneron characterizes Amgen’s goal as a “desire to bog down and thwart progress of the patent case, which is otherwise ready to proceed.” Memo. at 4. Further, Regeneron states: “This case is complicated enough. . . . In its latest gambit to delay judgment, Amgen now seeks to inject a series of antitrust-related counterclaims into this already overflowing litigation.” Id. at 1–2.
In the alternative, Regeneron requests that the court bifurcate and stay Amgen’s antitrust claims pending resolution of Regeneron’s Motion to Strike Certain Affirmative Defenses and Dismiss Certain Counterclaims. Regeneron contends that this will spare a considerable burden to the court and to Regeneron, as Amgen “has made clear that it intends to employ a scorched-earth approach” to discovery, which has already included significant document productions. Id. at 13.
On December 19, 2025, the parties filed a stipulation and proposed order to extend the briefing schedule on Regeneron’s motion. Per the stipulation, Amgen’s response will be due on January 9, 2026, and Regeneron’s reply will be due on January 23, 2026.
Stay tuned to Goodwin’s Big Molecule Watch as we continue to monitor the pending aflibercept BPCIA litigation.