Sanofi, Regeneron ask court to shield Dupixent from Amgen patent attack

Sanofi
Amgen says it's ready for another patent fight with Sanofi and Regeneron, this time over their forthcoming atopic dermatitis drug.

The last time Sanofi and Regeneron launched a drug together, Amgen sued for patent infringement. Now, with an FDA decision on their key drug Dupixent due next week, the development partners are making a pre-emptive strike in patent court.

Sanofi and Regeneron sued Amgen on Monday, seeking a declaration that Dupixent, also known as dupilumab, does not infringe on a particular Amgen patent. The companies say they don’t believe Dupixent steps on Amgen’s intellectual property but want a court back that up.

The lawsuit, filed in U.S. District Court in Boston, asks a judge to determine that the two companies don’t infringe on Amgen’s ‘487 patent, which cites IL-4 and IL-13 antibodies. Dupixent is a drug targeted at IL-4 and IL-13, two immune system pathways implicated in allergic diseases.

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The lawsuit states that the companies had learned that Amgen hired counsel to prosecute infringement of the '487 patent. Amgen confirmed that it believes Dupixent infringes its intellectual property—and that it's ready to litigate.

“Amgen does have a patent covering the product, and we will defend our patent rights,” a company spokeswoman said via email.

Sanofi and Regeneron know what that means. They’re currently locked in a high-profile patent dispute over their PCSK9 cholesterol drug Praluent, which competes with Amgen’s Repatha.

It’s a high-stakes battle: Amgen demanded—and won—a district court injunction that would have pushed Praluent off the market, but its rivals persuaded the Federal Circuit Court to stay that injunction pending an appeal.

Praluent is one of Sanofi and Regeneron’s most important new drugs, but Dupixent is arguably an even bigger launch. Up for FDA approval in atopic dermatitis, a severe form of eczema, the drug would be first in its class; it’s pegged as one of the biggest rollouts of 2017, with $3 billion in projected 2022 sales.

RELATED: Can Sanofi, Regeneron steer a $3B-plus dupilumab launch through today's tough waters?

The two companies are also studying Dupixent in other allergy-related disorders, including asthma; they expect to file for an approval for that indication later this year.

Sanofi and Regeneron obviously want to keep the drug on track. “We took this proactive step to protect the value of our innovative therapy Dupixent and ensure access of this important medicine for physicians and patients,” Sanofi said in a statement.

Drug patent fights are nothing new; they’re a standard feature of the pharma business, which relies on patent-protected branded drugs. Losing patent protection means facing cheaper competitors, which, in the case of an antibody like Dupixent, means biosimilars.

Amgen has caught fire for its aggressive stance on its PCSK9 patents, which also protect its own drug in the class, Repatha. Market watchers note that a similar patent fight—Merck & Co.'s hepatitis C lawsuit against Gilead Sciences—ended in a royalty agreement last year, with no request for an injunction involved.

"They did not have to ask for an injunction and could have instead asked only for damages," Rachel Sachs, an associate professor at the Washington University in St. Louis School of Law, wrote in Harvard Law School blog in January.

One of the only previous examples of a pharma company obtaining an injunction against a rival drug involves Amgen itself: In 2009, the company won an injunction blocking Roche’s anemia drug Mircera, which, according to a court ruling, infringed on three Amgen patents. Roche later agreed to keep the drug off the market until 2014, leaving Amgen’s drugs Epogen and Aranesp in control of that market.

In the PCSK9 case, Amgen maintains that Sanofi and Regeneron are in the wrong. The two companies knew about Amgen’s intellectual property “long before the lawsuit was filed” and eventually admitted infringement of its PCSK9 patents, the company said earlier this year.

“Sanofi and Regeneron chose to launch a product that they had no right to manufacture or sell, [and] … were afforded a full and fair opportunity to challenge the validity of Amgen’s patents at trial and the jury determined our patents to be valid,” the company said in a statement.