Published November 2026
Building to Survive: Designing Life Sciences Patent Portfolios to Withstand a Challenge
The strongest life sciences IP strategies are not designed simply just to obtain a series of patents. They are designed around the challenges those patents may have to withstand five, ten or fifteen years later. A challenge-ready portfolio therefore starts by assuming that its most commercially important patents may eventually be attacked.
As EPO opposition and UPC proceedings increasingly intersect, decisions made on claim scope, technical effect, inventive step and amendment basis during the prosecution phase may later form part of a validity and enforcement strategy that must withstand scrutiny before both the EPO and UPC in respect of multiple commercially important countries designated by the European patent.
For commercially important patent families, stress testing a case during prosecution, rather than only after grant, is therefore increasingly important. Stress testing enables identification of vulnerable claims, the design of strategies to preserve commercially relevant fallback positions and consideration of how surviving claims can ultimately be enforced.
One patent, two forums, two clocks
The arrival of the Unified Patent Court (UPC) has changed the intensity and speed with which European patents can be tested. The UPC Court of Appeal has made clear that the existence of a parallel EPO opposition does not, by itself, mean that UPC proceedings will be stayed. A patent may face EPO opposition while simultaneously becoming the subject of infringement or revocation proceedings before the UPC. A proprietor may have to defend closely related validity propositions in two forums, under different procedures and on different clocks. That makes decisions taken during drafting and prosecution increasingly important to the eventual European enforcement strategy.
The interaction is already visible in the sequencing technology dispute between Illumina and Element Biosciences, concerning European patent EP 3 714 978. Illumina’s infringement action is proceeding before the Lisbon Local Division alongside Element’s counterclaim for revocation[1], while Element has also opposed the patent before the EPO. The dispute therefore provides a particularly direct example of a commercially significant omics patent potentially being tested through infringement and validity proceedings before the UPC while its validity is also challenged centrally before the EPO.
Developing UPC case law involving omics and molecular diagnostics provides useful illustrations of matters which may be raised in a European enforcement strategy.
Rapid assessment of validity with substantive and territorial reach
The early litigation at the UPC between 10x Genomics, Inc. and NanoString concerning European patent EP 4 108 782 illustrated the speed at which issues could be considered at the UPC and how patents could be subjected to substantive validity scrutiny. In September 2023, the Munich Local Division granted provisional measures (preliminary injunction) against NanoString, but the Court of Appeal reversed that outcome in February 2024[2].
Although this litigation raised several issues, it demonstrated that assumptions about validity may be tested very quickly in the UPC and with considerable commercial outcomes at stake. For example, it is critical that supported fallback positions that remain commercially useful are designed into the patent during prosecution. Ask yourself: If Claim 1 falls, what are you defending?
The Oxford Nanopore v MGI proceedings[3] also illustrate that, in appropriate circumstances, the commercial reach of UPC measures may extend beyond participating Contracting Member States of the UPCA and the EU[4]. For globally marketed sequencing platforms, the UPC may therefore become a focal point for disputes whose commercial consequences extend well beyond the UPC’s geographical boundaries.
Layered portfolio architecture
In the Oxford Nanopore proceedings[5], an application was made to the Munich Local Division for provisional measures (injunctive relief) based on four European patents:
- EP 2 422 198, Lipid bilayer sensor array;
- EP 2 715 343, Coupling method;
- EP 2 964 779, Use of spacer elements in a nucleic acid to control movement of a helicase; and
- EP 3 097 210, Method for attaching one or more polynucleotide binding proteins to a target polynucleotide.
The portfolio approach provides an opportunity to present independently defensible patents protecting different commercially significant layers of a platform. The multiple patents can be litigated in parallel, and this approach may be less vulnerable to a single point of failure than an approach depending on one broad patent. However, it is to be stressed that the primary objective is not simply to obtain more patents. A portfolio approach is strongest where the portfolio rights provide genuinely independent lines of defence around the commercially important technology. Protecting commercially important technical layers, through differentiated claims and patent families means that if a competitor successfully removes one layer, another layer may still create a meaningful barrier.
Determining infringement
In the proceedings between Guardant Health, Inc. and companies of the Sophia Genetics group, Guardant sought provisional measures before the Paris Local Division based on four European patents addressing technologies including disease-cell heterogeneity, copy-number variation and early cancer detection[6]. These patents were EP 3 470 533, EP 3 591 073, EP 3 443 066 and EP 3 766 986, but wherein the request was withdrawn for the EP’533 patent at the stage of the Reply to the Objection.
The Paris Local Division addressed both validity and infringement issues. Whilst added-matter difficulties challenged the EP’073 and EP’066 patents, it was considered that Guardant had not demonstrated the alleged infringement with the necessary degree of certainty in relation to the claims of EP’986. At a claim level, challenge readiness therefore requires more than validity. A commercially important claim should ideally remain valid when challenged, remain commercially valuable if narrowed to a fallback position, and be provable when enforced.
A claim that survives validity challenge, but whose infringement cannot readily be demonstrated may provide less practical commercial protection than its breadth initially suggests. For example, a claim that depends on an internal analytical step, parameter or computational process that is technically important, but difficult to establish from the finished product or externally observable workflow, may be valid, but may not meet the third step of provable.
Parallel EPO and UPC strategy
Unlike some national courts which prefer EPO proceedings to be resolved, the developing case law illustrates that patentees cannot assume that UPC proceedings will simply wait for EPO opposition proceedings to conclude. The result may be substantially related validity issues progressing simultaneously before the two institutions[7].
The front-loaded approach of the UPC and the trend for acceleration of opposition proceedings in the presence of parallel UPC actions, places a premium on strategic consistency and the ability to execute at pace. Furthermore, EPO opposition proceedings and UPC revocation proceedings should not typically be regarded as sequential events. Positions on claim construction, amendments, technical effect, inventive step and validity need to be developed on the basis that they may be considered before two institutions, under different procedures and potentially on the same or different timescales.
More recently, Sidel Participations v Omnia Technologies[8], drawing on the earlier 10x v NanoString case[9] suggests the interaction between the EPO prosecution and UPC litigation may get underway before formal grant of the European patent and therefore before the opposition period starts. A competitor monitoring a late-stage European application may seek to commence UPC proceedings before formal grant, particularly once the intended claims are apparent from a Rule 71(3) EPC communication.
In the omics field, where important platform protection frequently develops through continuing divisional portfolios, prosecution monitoring may therefore become part of the UPC litigation strategy rather than merely freedom-to-operate practice. If a patentee considers keeping a European patent outside of the UPC is important, they should consider opting their European patent applications out of the UPC as soon as they are published, to minimise the risk of a subsequently granted patent being locked into the UPC.
Designing the challenge-ready portfolio
Taken together, the referenced cases suggest several important characteristics of a challenge-ready European patent portfolio.
- Attack – Where might a competitor attack?
If you were acting for the principal competitor, which claim would you attack and why? You need to identify the patent claims on which the commercial position most heavily depends and ask how a well-resourced competitor would seek to invalidate or narrow them. You also need to determine the strongest realistically available attacks.
- Fallback – What survives if the broadest claim falls?
During prosecution, it is important to identify and to preserve support for claim positions that remain commercially meaningful if the broadest claims cannot later be sustained. However, it has to be borne in mind that a narrower fallback is valuable only if it remains valid, supported and, critically, commercially relevant. In addition, it should be tested against the competitor’s likely implementation, rather than merely against the applicant’s own product.
- Proof – Can infringement of a surviving position be demonstrated?
Here, it is necessary to ask the question: Can a surviving claim actually be mapped onto a competitor’s observable activity? Claims directed to inaccessible parameters, internal workflow steps or proprietary software processes may create evidential difficulties even where the underlying invention is valuable. However, that does not mean such features should necessarily be avoided, but evidential accessibility should form part of the commercial assessment when selecting and prosecuting claim positions.
- Portfolio – What is the commercial impact if the patent fails?
For suitable technologies, it is important to consider differentiated claims and patent filing strategies around commercially significant technical layers. Complementary patent families, pending applications and divisional strategies may provide resilience that a single dominant patent cannot. Questions to be asked include: (a) Would another patent family independently protect a different critical layer of the platform? (b) Is that alternative right independently vulnerable to the same validity attack? A portfolio containing multiple patents may still contain a single point of failure if those rights depend upon the same vulnerable priority position, technical effect or inventive-step proposition. Resilience therefore depends on independent lines of defence, not simply patent numbers.
- Parallel Proceedings – Can the position be defended consistently in both forums?
In our view, Opposition counsel and UPC litigators, including prosecution teams, should not operate in silos. Arguments and amendments made before the EPO need to remain coherent and consistent with those before the UPC and vice versa. In particular, it is critical to consider whether an amendment or argument that resolves an immediate validity problem might narrow the commercially relevant case or make infringement harder to establish.
It is recognised that the strongest European patent portfolio may not be the one containing the broadest claims at grant. Instead, it is often the patent that continues to protect commercially important territory after its most valuable claims have been rigorously challenged.
For strategically important life-science patent families, that commercially desirable end-point requires strategic thinking about challenge during drafting and prosecution, and periodically stress testing the resulting portfolio against the attacks a well-resourced competitor might realistically make.
Accordingly, the best time to discover that a fallback position lacks support, no longer covers the competitor, or creates an infringement problem is before the competitor discovers it. Commercially important patents should not simply be prosecuted simply to obtain grant. They should be built to survive a post grant challenge.
This article was prepared by HGF Partners Russell Thom & Douglas Drysdale
[1] UPC-CFI-0001920/2025
[2] UPC_CoA_335/2023
