Responsible Business Insights


The concept of plausibility has been discussed in many academic circles especially in relation to patent applications and patent invalidity, especially in European Patent Office (“EPO”) in recent years and has been attracting more and more attention.

Although this concept was mentioned for the first time in the EPO Board of Appeal’s Factor-9/JOHN HOPKINS (28th June 2005, D1329/04) decision of the in the context of patentability evaluations, this concept has just begun to be discussed in Turkish law. Although the term plausibility does not even have a full word equivalent in Turkish, recently this concept is called “Makullük”, reasonability by academic circles in Turkey. Even though this concept does not find its place as an independent patentability requirement in legal systems, increasing debates and global trends about this concept pave the way for it to be accepted as an independent patentability condition by separating it from traditional concepts -such as inventive step, industrial applicability etc.- 

The concept of plausibility relates to the predictability ad technical traceability of the invention for which a patent application is made. 

The ability of a patent to meet the plausibility requirement can be defined as the ability to reliably and convincingly demonstrate the technical effect claimed within the scope of the invention with appropriate evidence to be presented or to infer the technical effect claimed within the scope of the invention from the latest state of technology or common general knowledge in order to avoid speculative patents that can be produced at the desk.

Plausibility is not a reason per se for the invalidity of a patent according to both the European Patent Convention and the Turkish legislation. However, in recent years, this concept has often been emphasized in cases examined by foreign courts and in cases concerning patentability and patent invalidity issued by EPO Board of Appeal, and the plausibility requirement is counted as one of the features required for the patenting of the invention. Therefore, it is important to understand the importance of the concept of plausibility and to ensure that patent applications relate to a plausible invention from the outset. 

In view of the case law established before the EPO, although the Board of Appeal accepts that it is not mandatory to have experimental data or results in patent applications, it is often emphasized in its decisions that at least some technical evidence is needed to show that the technical problem on the subject has actually been solved. In fact, in many disputes concerning a technical issue based on a predictable or definite theoretical concept, because the technical aspects were not adequately explained by the applicant and was not supported by convincing arguments, the Board of Appeal held that the patent did not meet the patentability requirements and did not reach the plausibility threshold.

Although the plausibility requirement is not one of the reasons for invalidity stipulated in the Turkish legislation or Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) or the European Patent Convention, the plausibility requirement can be the subject of evaluations made by Turkish Courts in the context of “invention not being sufficiently explained” or in the context of “inventive step” in invalidity evaluations. As a matter of fact, in cases where the plausibility requirement is used as an argument before the Turkish Courts, it is seen that the claims in this regard are included under both headings. 

For instance, in a recent decision -T 488/16 (Dasatinib/BRISTOL-MYERS SQUİBB) of the EPO Technical Board of Appeal, it was stated that although it is not always necessary to include experimental data in an application, it is required to show that the technical problem had been reasonably resolved at the time of application.

The concept of plausibility also raises the debate about whether to allow the presentation of post-published evidence (after the publication date of the patent application) showing the technical problem subject to the application has been solved by the invention, because it is seen that there are many EPO Technical Board of Appeal decisions -see also T 578/06- addressing the issue plausibility with the post-published evidence. Most of the decisions stipulate that such evidence emerging after the date of publication may also be taken into account, provided that it demonstrates the technical problem has been solved by the invention at the time of the patent application. 

In Turkish law, the concept of plausibility, which has just started to come to the agenda, has not yet been put forward as a solid argument by the parties claiming the invalidity of the patent, so this concept has not yet been subject to any high court case-law and has not been evaluated within the scope of any invalidation decision given by the courts of first instance. Considering the current situation in Turkish intellectual property law practices, it is not possible to talk about the use of advanced plausibility arguments by the parties or to argue that there are established jurisprudence that can be used as a precedent in the plausibility evaluations to be made in the doctrine.

On the other hand, considering that Turkey is a party to the European Patent Convention, since there is not enough case law that can be used as a source in Turkish legal practice, we are of the opinion that the decision in the current dated G2/21 application and other decisions will set a direct precedent before the Turkish Courts, shed light on the pending disputes in different jurisdictions and contribute to the creation of a uniform case law. 

In conclusion, it can be said that while the concept of plausibility is considered as a condition of patentability condition in the eyes of the EPO today, the threshold of plausibility is relatively low in the eyes of local legal systems. Because if there is a reasonable hypothesis or technical evidence to show that the invention is not speculative, it is likely to overcome the plausibility barrier. However, considering that this threshold is gradually rising and the concept of plausibility is being discussed globally, it is important to understand the importance of the concept and to ensure that patent applications are related to a “plausible” invention from the beginning in order not to face patent invalidity in the future. In our opinion, the threshold of plausibility will increase in order to prevent speculation-based patents in the future, and this concept will be mentioned more frequently both in Turkey and globally.


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