A UK Court of Appeal judgment opines on the skilled person for obviousness assessment as an anthropomorphic concept in upholding a key Moderna patent

The EWCA has recently provided a significant legal victory for Moderna in upholding validity of its European Patent (UK) no. 3590949 (EP949) concerning modified mRNA and thus infringement by Pfizer/BioNTech’s COVID-19 vaccine Comirnaty®. This marked the first second-instance decision validating a patent involved in Moderna’s dispute with Pifzer/ BioNTech (PBNT) over COVID-19 vaccine sales post-March 2022. A complete copy of the EWCA judgment is available via this link: Modernatx Inc v Pfizer Ltd & Ors [2025] EWCA Civ 1032 (01 August 2025). It remains to be seen if EPO Appeal Board 3.3.08 will quickly follow the EWCA in upholding EP949 on the basis of the same single claim covering modified mRNA. The relevant oral proceedings for appeal T1127/24 are scheduled for 8-9 September 2025.

The claim at issue of EP949, as previously also upheld in EPO Opposition proceedings, reads:

An mRNA wherein 100% of nucleotides comprising uracil are replaced with N1- methyl-pseudouridine

The only prior art document to be considered before the EWCA was a published international application also concerning modification of RNAs. This did mention N1-methyl-pseudouridine (m1Ψ) but was held not to be novelty destroying owing to need for selection from lists.

Of particular interest for patent professionals is how Lord Justice Arnold as the lead appeal judge dealt in the appeal judgment with the identity of the skilled person for assessment of obviousness. There was dispute between the parties over this with Moderna favouring someone working on using mRNA for transcript therapy while PBNT favoured an RNA biologist with an interest in using RNA for research, whether fundamental or applied to therapeutic purposes. The judge of first instance chose to formulate a third identity – “someone with knowledge of RNA biology, with practical interest in improving the use of mRNA in relation to translation and immunogenicity in a variety of fields”, even though he appreciated this was not aligned with any real team in the breadth of their interest. Arnold saw no reason to criticise this and the consequent rejection of PBNT’s contention that it would be obvious for the skilled person to try m1Ψ without any particular goal in mind. Rather Arnold endorsed that the skilled person can rightly be considered an anthropomorphic concept as explained at [96]:

“Like many anthropomorphic conceptions in the law, the skilled person is partly an empirical and partly a normative creature. It is an empirical concept in that… the skilled person should embody the skills and experience of real scientists working in the relevant field at the relevant time. It is a normative concept in that the skilled person has qualities which do not correspond to that of any real person, such as being deemed to be aware of any item of prior art which has been made available to the public, and in that it provides a benchmark for the assessment of issues such as obviousness.”

Thus, Arnold went on to emphasise that when considering expert evidence in relation to assessment of obviousness, it is right to consider amongst other things the extent to which the parties’ expert witnesses embody the attributes of the appropriate skilled person; it may be that no expert witness can be aligned entirely with the skilled person, although often highly important to the court in other roles, e.g. educating the court as to the relevant technology and putting it in possession of the skilled person’s common general knowledge.

More detailed report on the judgment is due to appear in the on-line version of the CIPA J. here.