Clinical Trial Inventions in the Squeeze:

The New Transparency Rules for Clinical Trials in the EU and the Assessment of Patentability by the European Patent Office (EPO) and the Unified Patent Court (UPC)

I. Introduction

In the course of drug development (see overview in Figure 1), starting from a conception, treatment effects are generally first evaluated by preclinical in vitro and in vivo testing followed by clinical trials based on preclinical results. After clinical Phase I studies usually evaluating toxicology and pharmacokinetics/pharmacodynamics in small healthy volunteer groups,In certain diseases, where toxicity does not allow testing in healthy volunteers, already Phase I studies are conducted in patients. initial efficacy and further safety data in small patient groups are obtained in Phase II studies. Further, Phase III studies are usually required to confirm the therapeutic benefit and gather comprehensive safety information at scale before regulatory approval.For a definition of the phases see EMA, CTIS public portal: Full trial information, EMA/441147/202424, 27 January 2025, p. 3 and 4. During this process, more and more disclosure about the drug and the corresponding treatment may become available forming prior art for later filed patent applications creating obstacles for obtaining corresponding patent protection. Publication of certain documents regarding planned or ongoing clinical trialsHerein also referred to as “clinical trial-related disclosures”. may form a significant part of such disclosures. Taking into account that the content and timing of such publication is governed by regulatory law, applicants/patentees need to be aware of the effects on patentability and make an effort to control and align regulatory strategies with patent filling strategies accordingly.

II. Regulatory Transparency Policy

Since 31 January 2023, clinical trials of medicinal products in the EU must comply with Regulation (EU) 536/2014 (Clinical Trials Regulation – CTR), which aims at streamlining the submission and assessment of clinical information across the Member States. The cornerstone of this framework is the Clinical Trial Information System (CTIS), which not only provides a single EU portal for submissions by sponsors, but also contains an EU database for the submitted data and information. In order to increase transparency and foster innovation, this EU database is designed to be publicly accessible for patients and researchers.See Art. 84 para. 4 CTR. Confidentiality of submitted data and information is limited to a narrow set of exceptions, notably the protection of personal data and commercially confidential information (CCI).In lack of a legal definition, CCI shall mean “any information which is not in the public domain or publicly available and when its disclosure may undermine the legitimate economic interest or competitive position of the concerned entities, e.g., clinical trial sponsors, marketing authorisation applicants/holders or service providers”, in accordance with EMA’s understanding and CJEU, C-175/18 P and C-178/18 P. At the time CTIS was launched, this transparency concept was governed by an EMA guidance developed in 2014.EMA, Appendix on disclosure rules, EMA/228383/2015, 2 October 2015 (superseded). These transparency rules, however, required broad publication of clinical trial application dossiers and introduced complicated deferral mechanisms, which soon proved unclear and overly complex.

Against this background, on 18 June 2024, new EMA guidance entered into force accompanied by a new version of CTIS.EMA, Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/212507/2021, version 2.1, 7 November 2025. The new transparency rules aim to strike a better balance between transparency of information and protection of CCI via a more flexible approach: The total number of documents to be published in CTIS is reduced to certain key documents of interest. Deferrals have been eliminated. Instead, structured data fields are introduced for key information, which are to be filled directly by sponsors. Further, sponsors are explicitly allowed to upload two document versions: one for use by the authorities and one for publication, which may be redacted to protect CCI. Structured data fields and documents are then published following predefined publication timelines. However, the reduced complexity comes with an increased user responsibility. For sponsors and pharmaceutical companies, it is therefore even more important to understand the challenges and develop strategies to effectively protect CCI and maintain patentability of inventions.

The assessment of the relevant disclosure timelines depends mainly on the classification of clinical trials under one of three applicable categories (Table 1).EMA, Revised CTIS transparency rules and historical trials: quick guide for users, version 1.9, 7 November 2025, p. 5.

Sponsors initially select the category in the trial application, yet the Reporting Member State (RMS) may challenge that choice and issue requests for information (RFI).EMA, Q&A on the protection of CCI and Personal Data while using CTIS, EMA/898965/2022, version 2.2, 13 December 2024, p. 5 sec. 1.

As part of the new EMA guidance, CTIS introduces structured data fields to be filled by the sponsor. These fields may allow free text entries or selections from predefined values and contain information of relevance to the public or researchers. The fields typically capture the trial title and identifiers, study design details, inclusion and exclusion criteria, primary and secondary endpoints, and information on the sponsor, investigational medicinal product (IMP) or clinical investigator sites. Depending on the trial category, and in the case of category 1, depending on the age of the trial subjects, the content of structured data fields is published according to the timelines in Table 2.EMA, Annex I: Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/194159/2023, 7 November 2025, Table I p. 2.

By contrast, only a limited subset of structured data fields remains generally non-public (Table 3).EMA, Revised CTIS transparency rules and historical trials: quick guide for users, version 1.9, 7 November 2025, p. 9.

With the limited exceptions set out in Table 2, CTIS application data are already made available with the decision on the clinical trial application by the first Member State Concerned (MSC), which is before the clinical trial has even started and thus long before any results are available. Additionally, structured data fields cannot be redacted. Sponsors should therefore exercise particular caution to avoid including any CCI in structured data fields. Only in exceptional cases, such as for dose details that are not yet in the public domain and are patentable, sponsors may enter “dummy data” (e.g. 00 digits).EMA, Q&A on the protection of CCI and Personal Data while using CTIS, EMA/898965/2022, version 2.2, 13 December 2024, p. 9 question 3.2.

Considering the information provided in the structured data fields, under the new transparency rules, only a reduced number of documents to be submitted by the sponsor is set to be published. The EMA narrows publication to certain key documents of interest (Table 4).EMA, Annex I: Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/194159/2023, 7 November 2025, Table II p. 3.

For example, subject information and informed consent form, recruitment arrangements, and the summary of product characteristics (SmPC), if applicable, are only subject to publication for category 2 and 3 trials. Other documents than those mentioned in the table above, such as the investigator brochure (IB), summary of intermediate data analysis results, if applicable, or assessment reports by the Member States, will not be published.For an indicative list of documents not subject to publication see EMA, Annex I: Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/194159/2023, 7 November 2025, Table VI p. 8. Conversely, with deferrals removed, documents such as protocols may be published in some cases earlier than under the former EMA guidance, which allowed deferrals of up to seven years from the end of the trial.

However, for documents to be published, CTIS offers redaction possibilities. Sponsors are allowed to submit a document version “for publication” with redacted CCI parts and a document version “not for publication” that contains CCI as required for the scientific assessment by the Member State authorities. Typical examples of CCI include information related to manufacturing processes of the IMP, to future development plans for other indications not yet known to the public, new biomarkers or, in clinical trial application dossiers, dose details not in the public domain.For further examples see EMA, Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/212507/2021, version 2.1, 7 November 2025, p. 25. In some cases, where written agreements between the sponsor and a third-party service provider expressly establish that patient facing documents (e.g. patient questionnaires or patient diaries planned to be presented to the subjects during the conduct of the clinical trial) cannot be disclosed publicly, it may be even possible to upload placeholders of those patient facing documents in the version “for publication”.EMA, Q&A on the protection of CCI and Personal Data while using CTIS, EMA/898965/2022, version 2.2, 13 December 2024, p. 9 question 3.3. In practice, yet quite a few potential sources of error are lurking. This is because sponsors remain fully responsible for the level of redaction. Member States are neither obliged to check on possible redaction errors nor to compare both submitted document versions.EMA, Q&A on the protection of CCI and Personal Data while using CTIS, EMA/898965/2022, version 2.2, 13 December 2024, p. 6 question 1.6 and 1.7. Even documents that are not required to be published, such as the IB or intermediate summaries, but are inadvertently uploaded in sections “for publication”, are published nonetheless in accordance with the applicable timelines. On the other hand, each redaction - particularly in documents submitted at the end of the trial life cycle - should be carefully weighed against the transparency principles to avoid objections and RFIs from the MSC. According to the EMA guidance, it is expected that over time, information which initially was considered CCI may no longer be considered as such due to scientific advancements in that research field, and that this should translate into fewer CCI redactions in the modified documents submitted to CTIS during the trial life cycle (Table 5).EMA, Guidance document on how to approach the protection of personal data and CCI while using CTIS, EMA/212507/2021, version 2.1, 7 November 2025, p. 23.

III. Patent Law Background

Claims directed to therapeutic applications are drafted in the “product-for-use” format in accordance with the EPC 2000, Article 54(5).Before EPC 2000 entered into force, such claims were drafted in the Swiss-type format, however, the different claim formats are not generally considered to differ in substance, see, e.g., G 2/08, reasons 5.10.1 to 5.10.9. Such claims are considered to include the therapeutic effect as a functional technical feature.G 5/83, headnote II, in combination with G 2/88, headnote III, and G 6/88, headnote. See also T 158/96, reason 3.1, and T 609/02, reason 9. Thus, for demonstrating lack of novelty, the prior art needs to expressly or implicitly make available to the public this therapeutic effect, while the “doctrine of inherency” does not apply.G 2/88, reason 10.1 and G 6/88, reason 8.1. See also T 136/24, reason 6.4, and T 2506/12, reason 2.6. For demonstrating lack of inventive step, this therapeutic effect needs to be obvious in the sense that based on the prior art, there was a reasonable expectation of success for the skilled person to achieve this therapeutic effect.The “try-and-see” evaluation seems not to be used in this context, see e.g. T 293/07, reason 37.

In the drug development process (see again Figure 1), a drug may fail at any step during the development. As a consequence, confirmatory evidence for the therapeutic effect based on a regulatory standard is usually only available after the full clinical study program from Phase I to III, which, once successful, is expected to lead to an approval of the drug for this therapeutic application. It is, however, established practice that “[t]he patent system takes account of the intrinsic difficulties for a compound to be officially certified as a drug by not requiring an absolute proof that the compound is approved as a drug before it may be claimed as such. The boards of appeal have accepted that for a sufficient disclosure of a therapeutic application,As required by Art. 83 EPC. it is not always necessary that results of applying the claimed composition in clinical trials, or at least to animals are reported.” However, “[i]t is required that the patent provides some information in the form of, for example, experimental tests, to the avail that the claimed compound has a direct effect on a metabolic mechanism specifically involved in the disease, this mechanism being either known from the prior art or demonstrated in the patent per se. Showing a pharmaceutical effect in vitro may be sufficient if for the skilled person this observed effect directly and unambiguously reflects such a therapeutic application”.T 609/02, reason 9, citing T 241/95 and T 158/96. Patent applications may thus be considered to sufficiently disclose, or “render credible”G 2/21, reason 77. (Art. 83 EPC), a therapeutic effect by providing evidence in the form of in vitro experiments, a standard which allows certain extrapolation and differs significantly from the standard for regulatory approval. Further, according to the case law of the EPO’s Boards of Appeal, the requirement of an enabling disclosure for a prior art document is the same as the requirement of sufficiency of disclosure for a patent application or patent. The principles developed for evaluating the requirements of Art. 83 EPC in the case of medical use claims apply thus equally to the prior art.T 1045/21, reason 1.2.5, citing T 1437/07, reasons 25 and 26. This means that a therapeutic effect in the prior art could likewise be considered enabled by in vitro tests, long before human results are available.

Regulatory provisions, such as the new transparency rules in the EU as discussed above, mandate the publication of certain information relating to clinical trials (such as clinical trial protocols) before the corresponding study results including, for instance, therapeutic efficacy are available. Such publications become prior art for later-filed patent applications that attempt to claim the treatment effect supported by the later-available (confirmatory) evidence from the evaluation in the corresponding clinical trial.

These clinical trial-related disclosures with predetermined publication dates form part of a highly regulated development process and therefore need to be understood in this context. Such publications often explicitly mention all features of the claims directed to the treatment (such as the indication, the patient population and the dosage regimen) but lack any results and do as a rule not extrapolate by explicitly postulating the treatment effect. The treatment effect is, however, a limiting technical feature of the claim and may therefore by itself constitute patentable subject matter. This gives rise to the difficult question whether in the absence of an explicit disclosure, there is a corresponding implicit disclosure of the treatment effect (and thus lack of novelty). In case there is no such implicit disclosure, the question remains whether nevertheless there is a reasonable expectation of success (and thus lack of inventive step). These questions need to take into account that patent law differs from regulatory law and allows in general -despite the overall high uncertainty in this field of technology- certain extrapolations before any confirmatory evidence from, e.g. Phase III trials, is available. This makes the overall evaluation particularly difficult.

While clinical trial-related disclosures such as those published on the clinicaltrials.gov website may have provided already in the past certain relevant disclosure, the new transparency rules in the EU outlined above mandate very early and much more extensive disclosure of information in particular related to Phase II and III studies. As shown in Table 4, the disclosure requirement includes, for example, the full clinical trial protocol that does not only provide details of the treatment (including information on patients, administration route, and dosing regimen), but often also includes a detailed scientific rationale for conducting the suggested clinical trial.The protocol usually gives the background and rationale for the trial, but these could be also provided in other protocol referenced documents based on the view of EMA, Guideline for good clinical practice (GCP) E6(R3), EMA/CHMP/ICH/135/1995, Step 5, 23 January 2025, p. 69. The protocol may also discuss previous preclinical and clinical data in this context.See Annex I chap. D. CTR for a full listing of the required protocol contents. The teaching of such protocols therefore goes much further than disclosures available in the past and the understanding a skilled person may gain from such documents may consequently also be much more than from previous disclosures. We will discuss in the following the existing case law at the EPO and first insights from the UPC on clinical trial-related disclosures in the prior art and venture an assessment of the expected implications of the new transparency rules for patentability of future patent applications dealing with such disclosures as prior art.

IV. Relevant Case Law at the EPO

In the last three decades, the EPO issued several decisions that discuss whether clinical trial-related disclosures anticipate or render obvious a claimed treatment effect despite such disclosures lacking the corresponding clinical trial results. Figure 2 provides an overview of decisions ordered by their date.

a) On the question of novelty of the claimed treatment

Three early decisions discuss novelty only. In the first decision, T 158/96, the Board assessed whether the person skilled in the art was in a position to conclude based on the clinical trial-related disclosure with the required certainty that the therapeutic effect, or a pharmacological effect indisputable underlying the therapeutic application, had already been shown or proven in earlier clinical or preclinical studies that would necessarily have preceded the study disclosure in question. If that were the case, the clinical trial-related disclosure would be prejudicial to novelty.T 158/96, reason 3.5. The Board summarized in the catchword of the decision:

“The information in a citation that a medicament is undergoing a clinical phase evaluation for a specific therapeutic application is not prejudicial to the novelty of a claim directed to the same therapeutic application of the same medicament if such information is plausibly contradicted by the circumstances and if the content of said citation does not allow any conclusion to be drawn with regard to the actual existence of a therapeutic effect or any pharmacological effect which directly and unambiguously underlies the claimed therapeutic application.”

While the Board in T 158/96 came to the conclusion that the circumstances did not allow the skilled person to conclude about the existence of the therapeutic effect with the required certainty,T 158/96, reason 3.5.2. the standard is formulated in the catchword more as an exception to the rule that clinical trial-related information is due to its specific context generally prejudicial to novelty. However, despite this standard, novelty was only denied in T 1031/00, where the Board found that the patent does not contain any technical information concerning the claimed treatment going beyond that of the prior art (same level of disclosure) and that therefore “the difference between that document and the application in suit resides merely in the words used but not in their technical content”.T 1031/00, reason 2.1.2. In this case, the Board focused more on a comparison of the technical teachings rather than verbatim disclosures. This approach, however, seems not to be followed by later cases. The subsequent case T 1859/08 then seems to have set a rather strict novelty standard, namely that disclosures lacking the final results of the clinical trials are generally not novelty-destroying.T 1859/08, reason 13. In line with this rather strict standard, in T 239/16, the Board stated that implicit disclosure requires that the therapeutic effect “would arise with certainty” from the treatment as described in the prior art. The Board could not derive an “explicit or implicit indication” that effects of animal models or of other drugs in the same class as the claimed drug “can be directly transferred” to the treatment as disclosed in the prior art. According to the Board, there remained “a certain residual doubt that the effect… is/will be achieved”. The Board concluded that the effective treatment was thus not directly and unambiguously disclosed.T 239/16, reason 5.2. Similar considerations are made in T 1859/08. Later decisions such as T 1123/16, T 96/20, T 3165/19, T 1941/21, T 1934/23 do not even discuss novelty or only very briefly such as T 1806/18T 1806/18, reason 6.7 regarding the treatment effect. and T 122/23.T 122/23, reason 3.

The very recent decision T 136/24 discusses again novelty in detail with reference to the early decision T 158/96. In dealing with novelty, the question of implicit disclosure had to be answered and the Board considered that the condition “plausibly contradicted by the circumstances” as in the catchword of T 158/96 (supra) “is not a necessary requirement” for novelty and “appears to have been formulated more stringently than necessary”. The Board instead emphasized the necessary condition for novelty to be “that the skilled person would not have been in a position to conclude with the required certainty that the relevant therapeutic efficacy had already been shown in earlier investigations.”T 136/24, reason 6.12.5, emphasis added.

The certainty standard for an implicit disclosure of the therapeutic effect thus seems to be established by the case law and appears much closer to the regulatory standard of confirmed evidence of a treatment effect, which is generally provided by Phase III study results. The earlier decisions could have been interpreted in that the standard for anticipation by a prior art disclosure including also implicit disclosures (Art. 54 EPC) is the same or at least similar as the standard for sufficient disclosure of a patent application or patent (Art. 83 EPC) and could thus be fulfilled by a credible disclosure of the treatment effect which may also be established based on preclinical and possibly earlier stage clinical experiments including Phase I results.T 158/96, reason 3.5.2 stating that “[i]t is indeed not exceptional that a pharmacological effect observed in an early investigation may directly and unambiguously reflect a therapeutic effect, thus underlying a therapeutic application“ and may be sufficient proof thereof. See also T 1031/00, reason 2.1.2, and T 609/02, reason 9 with reference to T 158/69. However, later decisions emphasize the gold standard of direct and unambiguous disclosure and apply the general definition of an implicit disclosure referring to what “is immediately apparent to the skilled person” and set the required level of confidence in the treatment effect at certainty.T 136/24, reason 6.3. In the very recent decision T 136/24, the Board considered that enablement of the prior art is a second independent criterion in addition to the requirement of a direct and unambiguous disclosure.T 136/24, reason 6.18. See also earlier decision T 108/21, reason 6.4.1. A prior art disclosure of a treatment effect in order to be anticipating thus appears to have to provide both (i) a direct and unambiguous disclosure (in line with the added subject matter standard of Article 123(2) EPCG 2/10, reason 4.6, regarding the “uniform concept of disclosure”.), which, in the context of an implicit disclosure of the treatment effect, requires certainty, as well as (ii) an enabling disclosure requiring credibility of a treatment effect (in line with the sufficiency standard of Article 83 EPC) (Figure 3).See also T 209/22, in particular reason 5.6, regarding the relationship of the disclosure standard for sufficiency and novelty, rendered by the same Board as in T 136/24. Reference is also made to an article by Eva Ehlich and Anja Fux on July 3, 2024, in Managing IP (“Is the medical use disclosure standard different for novelty and sufficiency?”). Since the “direct and unambiguous” standard requires certainty for an implicit disclosure, the second criterion of enablement with the lower “credibility” standard seems not relevant in the case of an implicit disclosure. There would, consequently, be a significant difference in the overall level of confidence in the treatment effect required when an explicit disclosure (such as a verbal statement of the treatment effect in the prior art, as is often the case in a prior patent application) is compared to an implicit disclosure (such as in clinical trial-related disclosures that do as a rule not extrapolate by explicitly postulating the treatment effect). This approach could be seen to emphasize for novelty the very strict disclosure standard of the EPO with high hurdles for implicit disclosure giving more weight to the words used rather than the overall technical content, which appears to differ from considerations in T 1031/00.T 1031/00, reason 2.1.2.

Taken together, the current standard for anticipation by clinical trial-related disclosures lacking trial results according to the case law of the Boards of Appeal is very high in requiring certainty for an implicit disclosure of a treatment effect. Although it remains to be seen whether a full protocol according to the new EU transparency rules including a summary of preclinical and previous clinical test results and a detailed scientific rationale may meet this very high standard for novelty, it seems that even with these additional details compared to other clinical trial protocol formats (such as those published on clinicaltrials.gov), the standard for an implicit disclosure might still not be fulfilled in the absence of the trial results.

During finalization of the present article in February 2026, a preview of the 2026 version of the Guidelines for Examination in the EPO due to enter into force on 1 April 2026 was published. Interestingly, the chapter on novelty includes now a new section directed to clinical trial-related disclosures (Figure 4).

The new section in the Guidelines does not refer to specific case law. It is interesting to note that “plausibility” seems to be the criterium for establishing the underlying therapeutic effect in the Guidelines while the case law seems to emphasize “certainty” as the criterium in such situations (supra). On the other hand, from the first reading, the Guidelines emphasize that a clinical trial disclosure without results may not in itself establish such plausibility due to the general failure rate, which may result in lack of anticipation more as a rule and lead to similar results as the case law. It remains to be seen whether a full protocol according to the new EU transparency rules including a summary of preclinical and previous clinical test results and a detailed scientific rationale may meet the plausibility requirement of prong ii) of the Guidelines and consequently may lead to lack of novelty in the future.

b) Assessment of inventive step

There are several decisions which discuss inventive step.

In the very early decisions T 715/03T 715/03, reason 2.4.3. and T 385/07,T 385/07, reasons 13 to 18.the Boards evaluated the circumstances of the case and came to the conclusion that the clinical trial-related disclosures in the prior art did not lead to a reasonable expectation of success without providing general test criteria for such an evaluation.

In T 2506/12, the Board pointed out that clinical trial designs are “based on existing favorable scientific data”.T 2506/12, reason 3.10. It rejected “the general consideration that any clinical trial might fail” given that clinical studies “are routine tests and the fact that their outcome is uncertain does not in itself turn their results into an invention”.T 2506/12, reason 3.12.2. The Board concluded that there was a reasonable expectation of success as “no particular reason was known which would have **_discouraged”_** the person skilled in the art from carrying out an experimental evaluation to confirm the usefulness of the combination treatment.“T 2506/12, reason 3.15, emphasis added. In the later decision T 239/16, the Board held that the mere fact that the claimed active agent is being tested in a clinical trial for the claimed treatment “leads to an expectation of success, due to the fact that clinical studies are based on data obtained by pre-clinical testing both in vitro and in animals and require authority approval which takes ethical considerations into account.” As a consequence, the skilled person would expect all study arms to provide an effective treatment, “unless he was dissuaded from this by the prior art” and expect the study arms to fail.T 239/16, reason 6.5, emphasis added. According to the Board, “[f]or the assessment of inventive step, certainty as to the outcome of a clinical study is not necessary…Clinical trials in humans are planned scientific investigations. They require authority approval, which is only given after a risk/benefit evaluation. For ethical (but also economic) reasons it has to be ensured that research risks are minimised and are reasonable in relation to any potential benefits. Ethical and economical considerations require that the “benefit” will arise with reasonable certainty and will not only “be hoped for”. This has to be taken into consideration as part of the technical circumstances when assessing the level of confidence of the skilled person in making rational predictions about achieving the envisaged treatment.”T 239/16, reason 6.6. Both T 2506/12 and T 239/16 have been cited by several decisions and several decisions seem to follow the consideration that disclosures relating to planned or ongoing clinical trials, in particular in view of the regulatory context of these disclosures, can provide for a reasonable expectation of success unless there is evidence in the prior art for a dissuasion, such as T 1123/16,T 1123/16, reasons 11 and 13. T 96/20,T 96/20, reasons 8, 9 and 16 to 19. T 3165/19,T 3165/19, reasons 22 and 23. T 108/21,T 108/21, reason 7.9. T 1941/21,T 1941/21, reasons 1.5 and 1.6. and the very recent decision T 1934/23.T 1934/23, reasons 2.4.2 and 2.4.5. In T 96/20, for example, the Board generally held that “[c]linical trials are conventionally based on earlier preclinical studies, and the potential therapeutics tested in clinical trials are duly selected based on experimental data suggesting their success” and that therefore, “the announcement of a detailed safety and efficacy clinical trial protocol for a particular therapeutic and disease provided the skilled person with a reasonable expectation of the success of this particular therapeutic, unless there was evidence to the contrary in the state of the art”.T 96/20, reasons 8 and 9, emphasis added.

In T 2963/19, however, the Board gave the evaluation a different nuance and acknowledged that the claimed disease “represents a particular challenge taking account of the poor prognosis and low success rates of clinical trials.” According to the Board, “the approval of a clinical study depends on the assessment of the foreseeable risks in relation to the anticipated benefit in terms of relevance of the findings, which does not necessarily imply an expected positive outcome and does not represent a scientific advice on the development programme of the investigational product tested.” The Board was not convinced that the mere fact that the prior art reported the testing of the claimed treatment in a Phase III clinical trial “already by itself provided the skilled person with a reasonable expectation that the treatment under investigation would be safe and effective”. 2963/19, reason 4.3.1, emphasis added. T 1437/21 affirms that “[t]he approval of a clinical trial does… not, by way of a heuristic, imply an expected positive outcome of the treatment.”T 1437/21, reason 4.3.1, emphasis added. T 122/23 follows the rationale in T 2963/19 and T 1437/21.T 122/23, reason 4.2.1. These decisions thus emphasize that there is no automatic assumption of a reasonable expectation of success in case of prior art disclosing that a clinical study had been proposed or was underway and that the focus has to be on the individual technical evaluation. The considerations in the earlier decisions T 2506/12, T 239/16 and T 1123/16 were held to be linked to the further circumstances of these cases.T 1437/21, reason 4.3.1 and T 2963/19, reason 4.3.1. The very recent decision T 136/24 emphasizes that the “case law mainly focuses on balancing positive and negative pointers” which are linked with the individual circumstances of the case and also rejects the idea that “ongoing clinical studies automatically establish a Iegal presumption of success”.T 136/24, reason 7.14. The Board in T 136/24, reason 7.14.10, expressly stated that it does not follow the rationale in T 96/20 (supra).

While it can be inferred from decisions such as T 2506/12, T 239/16, and T 96/20 that there could be a legal presumption that clinical trial-related disclosures due to their regulatory context automatically provide for a reasonable expectation of success unless there is a dissuasion, there are several decisions such as T 1437/21 and T 136/24 that emphasize that there is no such automatism and that the question of whether there was a reasonable expectation of success must instead be answered on the basis of the specific circumstances of the case such as the nature of the active agent, how far the clinical testing had advanced, and how much was known about clinical efficacy and safety.

It will again have to be seen how a full protocol disclosure including details of the preclinical and previous clinical results and the scientific rationale for conducting the clinical trial under the new EU transparency rules will influence the evaluation. As discussed above, while the certainty standard for implicit disclosure of the treatment effect may still shield from anticipation, lack of obviousness may become difficult to argue, thus all the more calling for fling a patent application before publication of such clinical trial-related disclosures. Such an early filing will, however, also have to meet the sufficiency hurdle (Art. 83 EPC) by rendering the treatment effect credible even in the absence of the corresponding clinical trial results. As the current case law also accepts preclinical and earlier clinical data for establishing a credible disclosure, an earlier filing seems to be the less risky option but requires careful drafting to be able to argue compliance with both Art. 83 and 56 EPC. On the other hand, a later filing after the clinical trial-related disclosure is published would require a very careful alignment of the information to be included in the regulatory documents submitted to the authorities and redaction of the clinical trial-related disclosures. In any event, the evaluation of the best strategy will be very case specific and requires cross-functional effort involving scientists, regulatory experts and patent attorneys.

V. First Insights from the UPC

The legal framework for establishing inventive step has been established by the UPC’s Court of Appeal (CoA) in the two landmark decisions Amgen v. Sanofi and Regeneron (UPC_CoA_528/2924 and UPC_CoA_529/2024) and Meril v. Edwards (UPC_CoA_464/2024 et al.) that both issued on 25 November 2025. While under the UPC’s “more holistic” approach the objective problem is established first and based on the claim as a whole and the patentWhile the CoA in Amgen v. Sanofi and Regeneron and Meril v. Edwards refers to the application (for example, Headnote 11 of Amgen v. Sanofi and Regeneron), the CoA in the more recent decision VMR v. NJOY (UPC_CoA_71/2025) of 29 December 2025 refers to the patent. rather than by looking at individual features of the claim and by comparing to a specific prior art,For example, Headnote 11 of Amgen v. Sanofi and Regeneron. the subsequent obviousness analysis appears to be quite similar to the obviousness evaluation under the EPO’s problem-solution approach (Figure 5). For instance, also in the UPC’s approach, a solution is considered obvious when there was a reasonable expectation of success.Headnote 17 of Amgen v. Sanofi and Regeneron.

It is important to note for the evaluation of second medical use claims, that the Court of Appeal for the interpretation considered that “it is an inherent claim feature that the claimed product must be objectively suitable for the claimed use, i.e. be therapeutically effective. This requires that the claimed treatment causes a noticeable improvement _of the medical condition of the patient suffering from the disease mentioned in the claim, i.e. the treatment must be meaningful. The fact that the skilled person does not derive any minimum required effect from the claim or the description does not lead to another conclusion …–”Headnote 2 and 3 of Amgen v. Sanofi and Regeneron, emphasis added.

A first decision with clinical trial-related disclosure was rendered by the UPC’s Local Division (LD) Munich on 12 December 2025 (UPC_CFI_146/2024 et al.) on the validity of the patent underlying the decision in T 136/24 as discussed above. See Figure 6 for an overview.

As the EPO, the LD Munich did not consider prior art on the ongoing Phase III clinical trial to anticipate the claimed treatment. According to the LD Munich, such clinical trial-related disclosure only discloses the treatment “in the form of a hypothesis that is currently being verified”.Section B.3.c.dd.(2) of the grounds for the decision. This would imply that also at the UPC, an implicit disclosure is very hard to establish. However, while the EPO held the claimed treatment inventive, the UPC concluded that it was obvious since there was a reasonable expectation of success. As the EPO, the UPC evaluated “various indicators in the prior art” and provided an overall assessment.Section B.3.c.dd.(4) of the grounds for the decision. According to the LD Munich, “reasonable expectation of success is not the certainty or even the near certainty of success.”Section B.3.c.ee.(6) of the grounds for the decision. Next to defining the technical problem differently and weighing the prior art pointers differently compared to the EPO, one important point for the Court appears to have been that the ongoing Phase III clinical trial was near completion. According to the Court, “the crucial point in the present case is not the authorisation of the trial, it is the course of the trial without incident and the near ending of the trial, which leads to an expectation of success”,Section B.3.c.ee.(10) of the grounds for the decision. while the Board in T 136/24 considered that “[t]he fact that a study is nearing completion per se… is neither a positive nor a negative pointer when assessing expectation of success.”T 136/24, reason 7.15.5.

As the UPC’s decision was rendered in first instance, it remains to be seen how the UPC’s Court of Appeal will assess cases with clinical trial-related disclosure in the prior art.The decision from the LD Munich is currently under appeal (UPC_CoA_22/2026 to 27/2026). However, this first insight would indicate an even more difficult situation for inventive step at the UPC and therefore speak even more for an early filing of a patent application completely avoiding clinical trial-related disclosure or, as an alternative, at least mandate a very good control of such disclosure in case of a later filing.

VI. Conclusion and Practical Recommendations

The new EU regulatory transparency requirements and corresponding mandated early and more detailed disclosures are a challenge for the patent system in a sector where patents play a very important economic role. The disclosures are global and thus have implications on patent filings around the world with different legal standards in different jurisdictions.Reference is also made to an article of October 2024 in Managing IP co-authored by Eva Ehlich and Anja Fux (“Patenting medical treatments in the US and Europe – a guide for practitioners”). Courts will be asked to find a way of dealing with these challenges while maintaining a coherent interpretation of the law. Pharmaceutical companies, however, will also have to do their best to navigate simultaneously the regulatory and patent law requirements. The following practical recommendations for pharmaceutical companies may be derived:

• Minimize the information included in relevant clinical trial documents at draft stage: What is scientifically really relevant and absolutely necessary? For example, according to the EMA guidance mentioned above, the background and rationale for a trial does not necessarily have to be included in the clinical trial protocol (which is published), but could also be included in other protocol referenced documents. Thus, mentioning the rationale in the Investigator Brochure (which is not published) appears to be possible.
• Establish clear communication between research and regulatory teams: What is already in the public domain? What could qualify as CCI – now or in the future?
• Engage external specialists with relevant scientific and technical expertise early in the process such as medical writers.
• Align regulatory and patent law advisors through close, ongoing coordination.
• Ensure consistency among all structured data fields and related documents.
• Implement a robust redaction process: Which documents do I need to redact? How do I redact parts of the protocol or patient facing documents?
• File patent applications before clinical trial disclosures become public under the EU transparency rules and when enough data are available to establish a credible disclosure.
• If patent applications are filed after clinical trial disclosures became public under the EU transparency rules: Provide claims with new treatment features arising from the results of the study or features, which have been successfully redacted (e.g. dosing) in case the treatment effect in itself will not be considered patentable.
• In evaluating the circumstances of an individual case: Be aware not only of the technical evaluation of the clinical trial disclosures, but also take into account the regulatory circumstances, such as the status of the overall development or the status of the individual trial.

Disclaimer: the views and opinions presented in this article are solely personal views and do not necessarily reflect the views, policies, or positions of Heuking and Maiwald. The information provided is intended for information purposes only and should not be construed as legal advice or as representing the official position of Heuking and Maiwald.

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