The UPC’s Growing Role In COVID Patent Disputes

In its decision of 7 July 2026 in Promosome v BioNTech and Pfizer, the Munich Local Division revoked EP 2 401 365, concerning methods of improving protein expression by modifying mRNA structures. The decision is the latest in a series of patent disputes arising from COVID-19 treatments and vaccines.

Promosome v BioNTech and Pfizer: enablement and aggregated inventions

EP 2 401 365 concerns methods of improving protein expression by modifying mRNA structures. Three aspects of the decision are particularly relevant to UPC validity practice: the requirement that prior art be enabling before it can destroy novelty; the Court’s formulation of the UPC approach to inventive step; and its treatment of a claim combining two independently known methods.

Enablement and novelty

The Court held that claim 1 lacked novelty over WO 91/01374 (D1). The Court found that D1 directly and unambiguously disclosed the claimed method and the resulting improvement in protein expression.

The proprietor argued that D1 was not enabling. The Court agreed that a document only anticipates a claim if the skilled person can reproduce its technical teaching, using common general knowledge and without undue burden. However, the Court also addressed the allocation of the evidential burden: once a party has substantiated that the prior art discloses the claimed method steps, a proprietor alleging that the disclosure is nevertheless non-enabling must explain concretely why the skilled person could not perform it.

In this instance, the proprietor had not identified any material gap in D1’s teaching. The Court confirmed that the prior art document’s author did not need to give the correct scientific explanation for the result or provide experimental proof that the method had been carried out. It was enough that D1 disclosed at least one reproducible way of performing the method and obtaining the stated result. This treatment of enablement is broadly consistent with EPO and UK practice.

Inventive step

For the auxiliary requests, the Court applied the framework set out by the Court of Appeal in Amgen v Sanofi and Meril v Edwards. A helpful summary of this framework is provided at paragraphs 197 to 208 of the decision. The paragraphs on obviousness are of particular note:

“205. A claimed solution is obvious if the skilled person would have taken the next step in expectation of finding an envisaged solution of his technical problem. This is generally the case when results of the next step were clearly predictable, or where there was a reasonable expectation of success.

206. The burden of proof that the results were clearly predictable or the skilled person would have reasonably expected success, i.e. that the solution he envisages by taking the next step would solve the objective problem, lies on the party asserting invalidity of the patent.

207. A reasonable expectation of success implies the ability of the skilled person to predict rationally, on the basis of scientific appraisal of the known facts before a research project was started, the successful conclusion of that project within acceptable time limits.

208. Whether there is a reasonable expectation of success depends on the circumstances of the case. The more unexplored a technical field of research, the more difficult it was to make predictions about its successful conclusion and the lower the expectation of success. Envisaged practical or technical difficulties as well as costs involved in testing whether the desired result will be obtained when taking a next step may also withhold the skilled person from taking that step. On the other hand, the stronger a pointer towards the claimed solution, the lower the threshold for a reasonable expectation of success.”

All of the auxiliary requests were rejected for a lack of inventive step. The Court’s comments on Auxiliary Request 4 were perhaps of most interest. Claim 1 of this Auxiliary Request combined two methods (from granted claims 1 and 10): mutating secondary initiation codons to improve full-length protein expression, and mutating miRNA binding sites to reduce miRNA-mediated downregulation.

At the EPO, the inventiveness of such a claim would typically be assessed using the partial-problems approach. The Court acknowledged this but did not decide whether the UPC had to follow this approach in exactly the same way. Instead, the Court stuck to its holistic approach to assessing inventive step, establishing what the invention contributes to the state of the art (with an emphasis on looking at the patent as a whole and determining the essence of the invention) and then assessing whether the skilled person would have arrived at the claimed invention with a reasonable expectation of success. As part of this, the Court considered whether the methods interdependently solved the objective problem. In the Court’s view, the answer was no – the claim was treated as a juxtaposition of independent methods. As each was already known or obvious, their combination was also held to be obvious. Thus, despite not expressly following the EPO’s partial-problem approach, the Court’s reasoning was ultimately very similar.

Gilead v AMMS: reasonable expectation of success

In May 2026, the Milan Central Division revoked EP 3 854 403, a second medical use patent owned by the Academy of Military Medical Sciences of China and directed to remdesivir for treating SARS-CoV-2 infection. Gilead filed the revocation action on the day the patent was granted, and the written decision followed within 11 months, far outpacing the parallel EPO opposition.

The patent claimed priority from 21 January 2020, shortly after the SARS-CoV-2 genome had been published but before the WHO declared a Public Health Emergency of International Concern.

Coronaviruses use an enzyme called RNA-dependent RNA polymerase (RdRP) to copy their genetic material. This means that RdRP is critical for viral replication. Remdesivir mimics the natural nucleotides incorporated into RNA strands by RdRP to block RdRp’s activity, halting viral replication.

Formulating the problem

Applying the approach in Amgen v Sanofi/Regeneron, the Court framed the objective problem (with reference to what was put forward in the patent) as identifying an effective antiviral substance against SARS-CoV-2. It rejected both a narrower formulation limited to testing remdesivir and a more ambitious one based on finding a cure. The latter was not supported by an application containing only in vitro data.

The Court defined the skilled person as a virologist researching emerging viral diseases, particularly coronaviruses, and possible antiviral treatments. The Court rejected attempts to define that person by reference to links with a particular pharmaceutical company. It also held that uncertainty at the start of the pandemic did not reduce every proposed treatment to a speculative hope. In the Court’s words, the skilled person is cautious, but does not have a “fear of failure” where there is a scientific basis for testing a candidate.

Reasonable expectation of success

The prior art identified remdesivir as a candidate with activity against coronaviruses including SARS-CoV-1 and MERS-CoV, and as a broad-spectrum antiviral targeting RdRP. Material published shortly before the priority date discussed its possible use against the newly identified coronavirus. For example, a commentary by a leader in the field Professor Sheahan appeared ten days before the priority date. The available genome data at the priority date also showed substantial similarity between SARS-CoV-2 and earlier coronaviruses, including in the region encoding RdRP. Given the speed at which knowledge of the new virus was developing, the Court considered the most recent and detailed sources particularly relevant.

On that evidence, the Court found that there was a reason to test remdesivir and a reasonable expectation that it would have antiviral activity against SARS-CoV-2, such that confirming that activity in a routine in vitro experiment was an obvious next step. The Court reiterated that certainty was not required: the question was whether the scientific material supported a rational prediction of success.

The decision also illustrates the effect of the extent of the technological contribution disclosed in the patent on the objective problem and subsequent obviousness analysis. Because the application did not contain clinical data, the Court adopted a relatively limited problem, which was correspondingly easier to solve. As a patentee, it may therefore be worth considering at the drafting stage how the technical problem would be formulated and making clear what the invention adds to the state of the art. The objective technical problem will be formulated at the UPC under its holistic approach with regard to the inventive narrative told in the patent, not by carrying out a rigid problem-solution analysis. Including data as far as possible to support the formulation of a more ambitious technical problem is therefore worth considering.

Looking forwards

On 16 July 2026, Arbutus and Genevant announced UPC proceedings against Pfizer and BioNTech concerning two European patents for lipid nanoparticle technology. The new actions are another example of pandemic-related patent disputes moving through the UPC: it seems that the UPC will continue to be busy playing host to the some of the largest IP battles arising out of the COVID-19 pandemic.

J A Kemp LLP acts for clients in the USA, Europe and globally, advising on UK and European patent practice and representing them before the European Patent Office, UKIPO and Unified Patent Court. We have in-depth expertise in a wide range of technologies, including Biotech and Life Sciences, Pharmaceuticals, Software and IT, Chemistry, Electronics and Engineering and many others. See our website to find out more.

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