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Ewan MacAulay


James Johnston


On 2 July 2024, Mr Justice Meade handed down his decision in Moderna v Pfizer & BioNTech. This is the latest decision in the ongoing and wide-ranging litigation that has arisen in relation to the Covid-19 vaccines.

This trial dealt only with the validity of two patents, EP (UK) 3 590 949 (EP 949) and EP (UK) 3 718 565 (EP 565) owned by the defendant, ModernaTx, Inc (Moderna). The Claimants, Pfizer and BioNTech (together, Pfizer) had effectively admitted that the patents were infringed by their Covid-19 vaccine, Comirnaty. Moderna were not seeking injunctive relief in the proceedings – however, given that Comirnaty had sales of nearly $40 billion in 2022, any financial remedies are likely to be substantial.

This trial did not deal with the effect of Moderna’s pledge, made in 2020, that it would not enforce its patents for the duration of the Covid-19 Pandemic. Issues relating to the pledge were heard simultaneously in a trial before Jonathan Richards J, for which judgment was also handed down on 2 July 2024.

EP 949
EP 949 relates to a modified form of mRNA in which the uracil bases are replaced with N1-methyl- pseudouridine (m1Ψ). Moderna sought to defend claims to mRNA with 100% of the uracil bases replaced by m1Ψ, and which comprised an additional structure called a “PolyA tail”. Pfizer sought to argue that EP 949 was invalid for anticipation by patent application WO 2007/024708 A2 (UPenn), and for obviousness over UPenn or a paper by 2023 Nobel Laureate Katalin Karikó (Karikó 2008).

EP 949 had previously been the subject of a negative preliminary opinion at the EPO. However, in an oral decision given in May 2024, the Opposition Division (OD) had upheld the patent in amended form.

In parallel Dutch proceedings, EP 949 was held invalid for obviousness over UPenn by the District Court of the Hague in December 2023.

Identity of the Skilled Person
The parties agreed that the problem which the invention sought to solve was to increase the level of mRNA translation while reducing immunogenicity. Moderna argued that the skilled person would be interested in this specifically for “transcript therapy”, whereas Pfizer thought they would be interested for either fundamental or therapeutic purposes.

The Judge did not fully accept either party’s conception of the skilled person, preferring a formulation where the skilled person was interested in any of a number of fields identified in cross-examination, including cellular reprogramming, immunotherapy, or direct vaccination. Contrary to Moderna’s conception, the claims of EP 949 were not limited to therapeutic use. The Judge also held that Pfizer had adopted an improper approach to the skilled person – a patent is addressed to a reader with a “practical” interest in the field, and the skilled person should have a practical interest in the application of EP 949 to at least one of the identified fields.

Novelty over UPenn
Although UPenn disclosed techniques for replacing uracil bases with substitutions including m1Ψ, the Judge held that (i) m1Ψ was only one compound in a long list suggested by UPenn, with no particular indication that it was preferred, and (ii) there was no direction to replace 100% of the uracil bases in an mRNA strand. The Judge therefore rejected the novelty attack. The Judge noted that his decision had differed from that of the Dutch Court, but put this down to the evidence (particularly expert evidence) available before him.

The parties agreed that the skilled person would have found the results in UPenn to be very promising and of real interest. Pfizer submitted that, having read UPenn, the skilled person would have decided to explore other nucleotide modifications, especially those similar to pseudouridine, of which m1Ψ was one. The Judge rejected this, noting that UPenn did not specifically direct towards using pseudouridine derivatives such as m1Ψ, nor did it give any particular explanation as to why the pseudouridine used in its examples had apparently worked so well. Additionally, a prominent review article on pseudouridine in RNA had provided a teach away from the use of m1Ψ.

The Judge conceded that Pfizer’s approach would not be scientifically unmeritorious – but it would not be obvious to the notionally skilled person at the priority date.

The Judge held there was strong similarity between UPenn and Karikó 2008 and took largely the same approach to obviousness. He also rejected secondary evidence submitted by Moderna that Karikó 2008 had not led to other groups pursuing the approach which Pfizer had contended was obvious. The Judge therefore held that EP 949 was not obvious over either of the pleaded pieces of prior art.

EP 565
The EP 565 patent, titled “Respiratory Virus Vaccines,” relates to a betacoronavirus mRNA vaccine formulated in a lipid nanoparticle. The issues in dispute were the identity of the skilled person, common general knowledge (CGK), anticipation and obviousness over Moderna’s WO2015/164674 (WO 674) application, and added matter.

This patent was found invalid and revoked for added matter by the OD in December 2023, though Moderna are appealing this decision. Although added matter was also considered in the present judgment (and the Judge agreed with the OD decision), the claim amendments that amounted to added matter did not impact the validity assessment, as they aimed to avoid anticipation arguments that were not applicable based on the validity analysis.

Identity of the Skilled Person
Moderna contended that while the skilled team would include a Coronavirus Virologist, their role would be minimal. The Virologist would only be consulted by the Nucleic Acid Vaccinologist (NAV) if the NAV independently decided to develop a coronavirus vaccine. In such a case, the Virologist would recommend the spike protein as the viral antigen but this would not influence the initial choice of pathogen.

Pfizer argued that the skilled team, including a Coronavirus Virologist, would inherently possess extensive knowledge about coronaviruses and coronavirus vaccines from the outset, directly influencing the pathogen selection process.

The Judge found that the skilled team would indeed possess virology expertise, including knowledge of coronaviruses, sufficient to identify relevant pathogens. However, it was unnecessary for the team to have a dedicated coronavirus expert. Pfizer successfully demonstrated that the team’s expertise would extend to coronavirus virology, contrary to Moderna’s assertion that the NAV would lack substantial knowledge about coronaviruses.

Common General Knowledge (CGK) Disputes
There were two disputes in relation to CGK for EP 565. The first dispute centred on whether betacoronaviruses were considered viable vaccine targets at the priority date. The Judge found that Pfizer had provided an “extremely clear picture” that post-SARS-CoV and MERS-CoV outbreaks, betacoronaviruses were recognised as significant vaccine targets with a high risk of future outbreaks, and that this was widely known within the vaccine community at the priority date.

The second dispute concerned factors affecting the efficacy of a nucleic acid vaccine. It was determined to be CGK that antigen-producing neutralizing antibodies should be chosen, that using an effective delivery vehicle was necessary, and that DNA was best avoided. Moreover, it was CGK that the requirements for an effective nucleic acid vaccine could not be guaranteed to work and would ultimately need to be tested.

Anticipation by and Obviousness over WO 674, Added Matter
Pfizer argued that the skilled team would view Example 20 in WO 674 as an attractive approach, given MERS’s significance as a vaccine target. The spike protein was anticipated to generate neutralising antibodies, and liquid nanoparticle formulations were seen as a promising platform based on positive flu vaccine results.

Moderna argued that WO 674 did not primarily focus on coronaviruses and that the skilled team would not prioritise them as vaccine targets. They maintained that the team would focus on more prominent targets such as flu, and would not have reasonable expectations of success with coronaviruses.

The Judge deemed EP 565 obvious over WO 674. Example 20 provided a clear direction towards developing an effective coronavirus vaccine, using a validated platform with promising results against flu. The availability of alternative targets and platforms did not undermine this conclusion. As he had reached a clear conclusion on obviousness, the Judge set out only briefly his conclusions on anticipation and added matter, but noted that he would have also found EP 565 invalid for added matter. The Judge also noted that he had denied Pfizer permission to rely on an unpleaded plausibility attack as part of the arguments on added matter.

Case Management
The Judgment also contains some helpful commentary on case management for UK patent practitioners to bear in mind.

The Judge noted that hearing actions relating to two separate patents can impose a significant burden on the Court. In this case, the two patents had little in common, with very different priority dates, CGK and skilled teams. Nevertheless, the trial was timed such that all the evidence for EP 565 was heard in between the evidence and the closings for EP 949 in a way that the Judge clearly found less than optimal. To avoid this in future, the Judge advised parties in multi-patent trials to try to engage the Court as early as possible regarding the structure of the trial, and if possible, to avoid committing to decisions without the Court’s input.

The Judge also suggested that having separate legal teams in the same multi-patent trial could lead to overlap on some of the issues – in particular, he drew attention to the fact that the two Moderna teams had taken opposite positions in relation to the EPO’s “serious contemplation” standard for added matter and novelty. Further, the increased bandwidth of the separate teams might allow relatively unimportant issues to be pursued for longer than necessary or helpful¹

Finally, in relation to the instruction of multiple expert witnesses, the Judge was not satisfied with Pfizer’s approach. The witnesses had not had the chance to view each other’s draft reports, and were only told by their instructing solicitors what each other would say. The Judge explained that the “bare minimum” should be that expert witnesses should have sight of advanced drafts of each other’s reports. In circumstances where the interaction of the skilled team turned out to be critical, it would be preferable for some kind of remote discussion or dialogue to occur between the experts so that they can take each the other’s views into account.

¹ The Judge’s point that the increased bandwidth of separate teams of solicitors and counsel does not change the bandwidth of the Judge is reminiscent of the comments of Mellor J in Interdigital v Lenovo [2023] EWHC 539 (Pat): “By playing tag team through the hearing, the respective teams have the opportunity to decompress and assess their part of the case, whilst the other team is in Court. There is no equivalent respite for the Court.”

A copy of the judgment can be read here.