Selection, motivation, and success—lessons from Moderna v Pfizer (Modernatx Inc v Pfizer Ltd and other companies)
IP analysis: In a closely watched dispute over mRNA vaccine technology, the Court of Appeal upheld the validity of European Patent (UK) No 3 590 949 (‘EP949’), Moderna’s patent for mRNA molecules with all uracil nucleotides replaced by N1-methylpseudouridine–a modification at the heart of COVID-19 vaccine development. Pfizer/BioNTech’s challenge failed on both novelty and obviousness: the court found that the prior art (the UPenn patent application) did not clearly and unambiguously disclose Moderna’s specific combination, and that inventive step cannot be denied simply because a modification is “obvious to try” without a concrete expectation of success. For patent practitioners, the judgment reinforces that selection inventions are protected where prior art lacks a direct pointer, and that robust, practically relevant expert evidence is essential in complex biotech litigation. The decision sets a high bar for invalidating foundational patents in fast-moving scientific fields, especially where the technology is central to public health innovation. Written by Ruby Zahra, associate at Shoosmiths LLP.