Pfizer, BioNTech and Moderna have failed to dismiss US patent lawsuits brought by Bayer over messenger RNA technology used in their COVID-19 vaccines.
US Circuit Judge William Bryson, sitting by designation in the US District Court for the District of Delaware, rejected motions seeking to end two separate cases brought by Bayer CropScience LLC, Monsanto Company and Monsanto Technology LLC.
The ruling allows Bayer’s infringement claims against Moderna and against Pfizer and BioNTech to continue.
It does not establish that the vaccine manufacturers infringed Bayer’s patent or that the patent is valid. Bryson instead concluded that the defendants had not shown at this early stage that the claims should be dismissed.
The litigation concerns US Patent No. 7,741,118, titled Synthetic plant genes and method for preparation.
Bayer alleges that technology developed by Monsanto in the 1980s to strengthen messenger RNA in crops was later used without authorisation to stabilise genetic material in COVID-19 vaccines.
Pfizer and BioNTech developed the Comirnaty vaccine, while Moderna developed its own mRNA-based COVID-19 vaccine.
The companies dispute Bayer’s allegations.
The vaccine manufacturers argued that their production methods operate differently from the technology covered by Bayer’s patent and therefore do not infringe.
Moderna separately argued that the patent covers an unpatentable law of nature.
Bryson declined to resolve those arguments in the defendants’ favour at the dismissal stage, finding that they had not demonstrated that Bayer’s patent was invalid or that the vaccines could not infringe it as alleged.
Bayer welcomed the ruling and said it remained confident that patented innovations developed within its Monsanto business had been used without authorisation.
Pfizer, BioNTech and Moderna had not immediately commented on the decision when Reuters reported the ruling.
The cases highlight an unusual feature of the intellectual-property disputes surrounding mRNA vaccines: some of the asserted rights originate from scientific work carried out decades before the COVID-19 pandemic and for very different commercial applications.
That can create difficult patent questions over whether older biotechnology inventions extend to later uses of related molecular techniques.
For Gilead Duty-to-Innovate Ruling — Lawyer Monthly, the litigation also illustrates how patent rights developed in one industry can later become relevant in another.
Technology originally intended for agricultural biotechnology may potentially affect pharmaceutical products where the underlying scientific processes fall within the wording of existing patent claims.
The ruling remains procedurally limited.
A motion to dismiss tests whether a claim can proceed based on the allegations and applicable law. It does not ordinarily resolve disputed scientific evidence concerning exactly how an accused product operates.
Questions of infringement and Nike, Lululemon End Mirror Patent Dispute | Lawyer Monthly can instead become central later through discovery, claim construction, expert evidence and potentially trial.
Bayer has also filed a separate lawsuit against Johnson & Johnson in New Jersey involving the same patent. That litigation remains pending.
The Delaware cases will now continue, with Bayer required to prove Apple Hit With Record $5.7bn Patent Verdict | Lawyer Monthly and the vaccine manufacturers still able to challenge both infringement and the validity of the patent.
The cases are Bayer CropScience LLC et al. v. Moderna Inc. et al., No. 1:26-cv-00012, and Bayer CropScience LLC et al. v. Pfizer Inc. et al., No. 1:26-cv-00013, in the US District Court for the District of Delaware.