Last month, Sanofi and Regeneron sued Amgen in a move to fend off a nasty patent court battle over their new atopic dermatitis drug Dupixent. After all, the two companies were already fighting Amgen to keep their PCSK9 cholesterol-fighter Praluent on the market.
Amgen has since sued back—but its new complaint suggests this legal fight will be different from the bruising PCSK9 case, which is now under review by a federal appeals court.
Amgen threw down its own legal gauntlet—somewhat covertly—by suing Sanofi and Regeneron for patent infringement in California earlier this month, under the auspices of Immunex, its patent-owning subsidiary.
There’s an obvious reason for the locale: Thousand Oaks, California-based Amgen has asked the federal court in Boston, where Sanofi and Regeneron sued, to move that case to its home state. Naturally, Amgen’s lawyers have also demanded that the judge toss the claims completely.
What Amgen hasn’t demanded is an injunction to push Dupixent off the market, as it did in the PCSK9 field. Amgen doesn’t have a rival drug, either approved or in the works, according to its published pipeline.
That’s the big difference. In the PCSK9 fight, Amgen pushed hard for an injunction that would force Sanofi and Regeneron to pull Praluent, giving Amgen’s Repatha sole access to the field. At the trial court level, Amgen won; Sanofi and Regeneron persuaded the U.S. Federal Circuit Court to stay that injunction pending appeal. If that decision stands on appeal, and Amgen doesn’t settle for cash instead, then Praluent will have to bow out. Here, Amgen’s subsidiary is simply asking for the usual monetary damages.
The Immunex complaint recites the background: Sanofi and Regeneron developed Dupixent (dupilumab) to block the IL-4 and IL-13 immune system pathways by binding to IL-4R. Immunex owns a patent—the ‘487 patent—on using antibodies that bind to IL-4R, and that patent identifies a particular antibody, 12B5, whose amino-acid sequences are specified in the ‘487 patent.
Specifics aside (the lawsuit itself is here), Immunex claims that Regeneron, in developing the antibody that would become dupilumab, used 12B5, partly by employing that antibody as a control.
Eventually, dupilumab succeeded in clinical trials, won FDA approval March 28, and the two partners have started commercial manufacturing and begun marketing the med to payers and doctors. Analysts have pegged it with $4 billion in 2022 sales, the suit says.
Amgen, meanwhile, had been trying to develop an asthma med using the IL-4R binding approach. That drug failed in phase 2 and is now wiped off Amgen’s pipeline listing on its website.
A drugmaker suing for payments and royalties isn’t unusual; in one current example, Merck & Co. and Gilead Sciences are squabbling over hepatitis C intellectual property.
The push for an injunction, however, isn’t common, and Amgen has caught flak from other drugmakers and legal experts for that move. Several major drugmakers have supported Sanofi and Regeneron in their PCSK9 patent appeal with amicus briefs.
What’s Amgen’s end game here? The company isn’t saying. Legal experts and market analysts have some theories, one of which links Amgen’s IL-4R patent and Dupixent to the PCSK9-Repatha-Praluent fight. In addition to claiming Dupixent royalties, Amgen “may also look to trade this patent against the Praluent litigation,” Bernstein analyst Ronny Gal said in a note when the pre-emptive patent suit was filed. What would such a trade look like? If Gal’s speculation turns to reality, we may soon find out.