- Sanofi and Regeneron took what they considered to be a defensive measure on Monday, filing a lawsuit that claimed their eczema drug does not violate a patent held by Amgen.
- The duo have been feuding with Amgen since 2014 over competing patent claims on their respective cholesterol drugs Praluent (alirocumab) and Repatha (evolocumab).
- Citing that history, Sanofi and Regeneron said in a document filed on March 20 with the U.S. District Court for the District of Massachusetts that they anticipate more legal troubles from the California biotech, only this time for their skin disease medication, Dupixent (dupilumab).
"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," a Sanofi spokesperson said in an email to BioPharma Dive. "We remain focused on the upcoming FDA action date for Dupixent.
At the core of the new lawsuit brought by Sanofi and Regeneron is patent '487, which covers a failed asthma drug of Amgen's that was shelved several years back.
The title gives Amgen intellectual property rights over any "isolated human antibody that competes with a reference antibody for binding to human IL-4 interleukin-4 (IL-4) receptor." As it happens, Dupixent works by inhibiting IL-4, a protein that helps control immune response.
"Just days ago, counsel for Regeneron and Sanofi learned that Amgen has hired litigation counsel to prosecute a patent infringement litigation related to Amgen’s work on antibodies to the IL-4 receptor and is in the process of retaining experts," the plaintiffs said in the initial court filing.
"Given that Dupixent is the only IL-4 inhibitor expected to come to market in the near future, Regeneron and Sanofi believe that Amgen and Immunex will sue them for infringement of the claims of the ’487 Patent at a time of defendants’ choosing and for the purpose of impairing plaintiffs’ ability to sell Dupixent in the United States," they added.
Sanofi and Regeneron argued the use of "antibody" in the 487 patent is too vague, only applying to a handful of protein structures that compete with the IL-4 receptor.
"Because Dupixent is markedly different structurally from [those examples] and any embodiments that may qualify as equivalent, Dupixent does not infringe any of the 17 claims of the ’487 Patent," the lawsuit states.
"Amgen does have a patent covering the product and we will defend our patent rights," Amgen said in an email response to a request for comment.
This kind of preventative strike makes sense for Sanofi and Regeneron, especially after Amgen's recent legal success against the two companies.
Earlier this year, a U.S. District Court judge unexpectedly granted Amgen's request for a permanent injunction against Sanofi and Regeneron, effectively banning sales of their drug Praluent (alirocumab) in U.S. markets. While an appeals court has since granted a temporary stay of that ruling, the ruling has cast a legal shadow over Praluent.
Getting Dupixent smoothly to market is especially important for Sanofi amid slumping sales from its diabetes and cardiovascular businesses. The target action date for the eczema drug is set for mid-next week and Sanofi has geared up for a fast launch, aiming for a commercial ramp up similar to that seen with Novartis' Cosentyx (secukinumab).
Together with the expected entry of Kevzara (sarilumab), Sanofi hopes to build a leading immunology franchise and it's clear they don't want any legal headaches to stand in their way.