This article was originally published in German on JUVE Handbuch Wirtschaftskanzleien 2022/2023.

The decision of the Enlarged Board of Appeal (GBK) of the European Patent Office (EPO) in the currently pending proceedings G2/21 is awaited with great excitement. This could have a significant impact on the future filing strategy of applicants, because at its core is the question of when an invention is “ready” to file.

Securing an early filing date for an invention is an important aspect of a patent strategy in order to secure one’s own legal position vis-à-vis competitors. For time and cost reasons, the question arises as to how much experimental effort must be expended under patent law aspects before filing a patent application in order to support the claimed effects, or whether corresponding evidence can be submitted subsequently.

Until a decision G2/21 is issued to finally clarify relevant submission questions, this article will discuss practical scenarios that will continue to exist regardless of the answer to the referred questions, but will have to be – possibly re – evaluated with the help of decision G2/21.

Suitability of “evidence” from product development as support of an invention

In the context of a product development, the product of a competitor or the internal ‘gold standard’ is often used as a reference product, regardless of whether the structure or composition of this reference product is known precisely. Such comparative data are often not usable in the context of the ‘problem-solution approach’ applied by the EPO, since, according to established case law, the claimed effect must be clearly attributable to the distinguishing characteristic.

Experimentally investigating the influence of all potentially relevant parameters on the claimed effect and thus exploring the limits of the invention can be time-consuming and financially expensive and usually does not appear to be expedient from the inventor’s point of view.

Irrespective of this, the proof of technical effects can often only be produced with pinpoint accuracy in the knowledge of the objectively closest prior art, e.g. in the examination procedure, since only then will the objectively fitting (because closest to the claimed invention) comparative form be known.

For such reasons, experimental investigations are often postponed to a later point in time. Whether this postponement is possible at all, however, is now to be clarified by the GBK.

Underlying question of G2/21

According to the questions referred, the GBK is primarily concerned with the question of whether evidence such as experimental data must be disregarded only after the patent application has been filed if it constitutes the exclusive evidence for a claimed effect. Three approaches are presented to the GBK, all of which revolve around the criterion of whether or to what extent the information originally provided in the application must render a claimed effect plausible:

The most generous scenario for the applicant would be if the exclusive evidence for a claimed effect could readily be provided after the filing date, i.e., no plausibility requirement at all. This would allow filing an invention in an early, possibly speculative (“immature”) state to secure an early filing date.

However, should the GKB come to the conclusion that minimum plausibility requirements are to be set with regard to the claimed effects in the application itself, a corresponding “ab-initio plausibility” could be applied as a standard for the technical effects.

In a third case, it could be required as a minimum that the claimed effects are at least not implausible from the outset, i.e. that there is no “ab-initio implausibility“.

State of maturity – when is an invention ready to be submitted

Regardless of how the GBK will decide, we always consider it useful to file an application only when advantages over the prior art can at least be named; proof of the technical effects, e.g. by comparative experiments, should be checked before filing.

The “state of maturity” of an invention could be classified as follows:

(i) effects are not (yet) known, only the features characterizing the desired product can be stated.

In this case, if an early filing date is a priority, one could include a “laundry list” of potential effects in the application text, and then pick the desired effect if needed. Although a lack of disclosure does not arise directly from the failure to obtain effects from the application as long as they are not reflected in the claim wording, an entirely speculative invention description could, in some circumstances, call into question the consideration of late evidence or even reworkability.

(ii) Effects are expected and the features of the invention that are causally responsible are suspected.

Here, the expected effects can already be specifically named; these should then at least not be “ab-initio implausible”. From a technical point of view, no doubts should be justified against the possible achievement of the named effects. In the description of the invention in the original application, the challenge is that it is not known which features/parameters are causal for the achievement of the effect. Regardless of decision G2/21, if possible, the “causality” between effects and the corresponding features of the invention should be investigated and explained in the application text. Previously published literature can help to substantiate this causal relationship. Patent law only requires that something works or that a set task is solved; a scientific explanation of how a claimed problem solution works is not necessarily required.

(iii) Effects are expected, it can be concluded on the basis of technical considerations which features of the invention should be causally responsible for them.

A technical explanation that the claimed effects are expected can be given in the patent application (“ab-initio plausibility”). However, a real experimental proof is still missing. In such a case, the prospects of grant – assuming the required novelty – are likely to be good, but it is to be expected that e.g. in possible opposition proceedings the opposing party could attack this “plausibility”, e.g. by submitting reasonable doubts that the theory underlying the plausibility is not correct. Without wanting to anticipate the final decision in the current referral G2/21, however, it should be possible in these case constellations on the basis of the existing “ab initio plausibility” to substantiate the expected technical effects in the factual instance – i.e. not only in appeal or appeal – by means of subsequently supplied experiments and data.

(iv) Effects are known and proven

Here, there should be nothing to argue against filing a patent application. If new prior art is invoked, e.g. in the examination procedure, it should be possible to provide further (post-published) experimental data to support the effects already shown in the application, if required.

Special cases

Special cases exist if technical effects are only proven or expected for a part of a claimed subject-matter, or if a technical effect itself constitutes a claimed feature – e.g. in a use claim. In the first case, the question then arises whether the technical effect can plausibly be generalized to the remaining part of the claim, and in the second case the criterion of “plausibility” will also be relevant in the context of examining whether the invention is sufficiently disclosed at all and thus practicable. Here, too, however, considerations similar to those explained earlier should play a role.


• The decision of the GBK in the proceedings G2/21 will hopefully provide clarity as to the “state of maturity” in which an invention must be filed in order for claimed effects to be recognized.
• In many cases, regardless of the standard to be applied under G2/21, early submission will be desired.
• It is already apparent that the question of “plausibility” does not constitute a patenting requirement in its own right, but is an important criterion in the examination for inventive step and possibly even the practicability of a claimed invention.
• In any case, it is wise to check the maturity of the invention before filing a patent application in order to achieve the best possible result and obtain a strong patent.


Dr. Susanne Sonnenhauser
Ms. Sonnenhauser has been working in the field of intellectual property since 2005 and is admitted as a German Patent Attorney and European Patent Attorney. She joined Prüfer & Partner in 2008.

Her main practice areas are patent and trademark law, mainly in the fields of pharmaceuticals and life science.
Ms. Sonnenhauser represents her clients in both patent grant and opposition proceedings. In addition, she provides expert opinions regarding the validity and infringement of intellectual property rights.

Dr. Andreas Oser, LL.M.
Andreas Oser (Dipl.-Chem. University of Freiburg; Ph.D. Max-Planck-Institute for Biochemistry Munich) has been working in the field of intellectual property since 1991, was admitted as a German and European patent attorney in 1995 and has been a managing partner at Prüfer & Partner since 2002.

Mr. Oser’s main areas of expertise are chemistry, pharmaceuticals and life science.

His practice includes patent prosecution (drafting, examination), opposition and appeal proceedings, patent litigation, infringement and validity opinions, freedom-to-operate analyses and due diligence examinations.

Prüfer & Partner mbB
Sohnckestrasse 12, 81479 München
Tel. +49 89 69 39 21 0, E-Mail,

On July 15, 2022, Montenegro completed the final step towards accession to the European Patent Convention (EPC) by depositing its instrument of accession and became the 39th member state of the European Patent Organization (EPO) on October 1, 2022.

This means that Montenegro is leaving its status as an extension state, which it obtained in 2010, and all patent applications filed on or after October 1, 2022, can be validated as a European patent with effect for Montenegro once they have been granted.

The official admission of Montenegro as a member state is a new milestone in the history of the European Patent Organization.

For more information:

In the months of May and July 2022, some amendments relevant for practice before the DPMA will enter into force. The most important ones in brief:

(1) Increase of renewal fees for German patents (entry into force: 1 July 2022).
The patent fees for annual renewals will be moderately increased with due dates from July 2022, concerning payments from the 5th renewal fee. The following list shows the old (left column) and the new (right column in brackets) fees in EURO:

Annual fees:

  • for the 3rd year . . . . . . . . . . . . . . . . . . . . . . . . 70
  • for the 4th year . . . . . . . . . . . . . . . . . . . . . . . . 70
  • for the 5th year . . . . . . . . . . . . . . . . . . . . . . . . 90 (100)
  • for the 6th year . . . . . . . . . . . . . . . . . . . . . . . . 130 (150
  • for the 7th year . . . . . . . . . . . . . . . . . . . . . . . . 180 (210)
  • for the 8th year . . . . . . . . . . . . . . . . . . . . . . . . 240 (280)
  • for the 9th year . . . . . . . . . . . . . . . . . . . . . . . . 290 (350)
  • for the 10th year . . . . . . . . . . . . . . . . . . . . . . . 350 (430)
  • for the 11th year . . . . . . . . . . . . . . . . . . . . . . . 470 (540)
  • for the 12th year . . . . . . . . . . . . . . . . . . . . . . . 620 (680)
  • for the 13th year . . . . . . . . . . . . . . . . . . . . . . . 760 (830)
  • for the 14th year . . . . . . . . . . . . . . . . . . . . . . . 910 (980)
  • for the 15th year . . . . . . . . . . . . . . . . . . . . . . . 1,060 (1,130)
  • for the 16th year . . . . . . . . . . . . . . . . . . . . . . . 1,230 (1,310)
  • for the 17th year . . . . . . . . . . . . . . . . . . . . . . . 1,410 (1,490)
  • for the 18th year . . . . . . . . . . . . . . . . . . . . . . . 1,590 (1,670)
  • for the 19th year . . . . . . . . . . . . . . . . . . . . . . . 1,760 (1,840)
  • for the 20th year . . . . . . . . . . . . . . . . . . . . . . . 1,940 (2,030)

Surcharge for late payment of the annual fee . . 50

(2) Extension of the time limit for entering the German national phase in PCT applications (entry into force: 1 May 2022)
The time limit for entering the German national phase in PCT applications is extended from 30 to 31 months from the filing or priority date. This gives more time to pay the fee for the initiation of the national phase at the DPMA and, if necessary, to submit the translation of the application in German. This is now also a welcome harmonisation with the corresponding 31-month time limit for the entering the regional phase before the European Patent Office (EPO).

(3) Conduct of hearings and oral proceedings by video (entry into force: 1 May 2022)
In patent, utility model, trade mark and design procedures before the DPMA, the possibility to participate in hearings and oral proceedings by video transmission will be opened. However, the possibility to participate in on-site personal hearings instead will continue to exist

If you have any questions, please do not hesitate to contact our team. Dr Andreas Oser, LL.M. (

Intellectual Property specialists Prüfer & Partner are celebrating as the firm together with its Managing Partner Andreas Jacob were listed in the prestigious ranking Word Trademark Review WTR 1000 2022. Consistently listed in WTR 1000’s sister publication, the IAM Patent 1000, Prüfer & Partner makes its first appearance in the trademark rankings this year thanks to its growing profile on the soft IP side and to the efforts of Andreas Jacob, who was recommended by WTR for his anti-counterfeiting knowledge.

What the ranking said
WTR recognized Prüfer & Partner as “it is sought after for portfolio management and enforcement work both online and offline – and increasingly for litigation, thanks to the efforts of Andreas Jacob” and emphasized that its “State-of-the-art IT systems and digital solutions keep it ahead of the curve, while a sizeable worldwide network renders it highly capable on the global stage”.

As a listed individual, Andreas Jacob was recommended for his “rarely seen level of anti-counterfeiting knowledge”. As a managing partner of the firm, Jacob has recently been masterminding several trademark infringement actions for Knorr-Bremse, as well as managing its filing strategy and guiding the IP aspects of the restructuring of its entire product portfolio.

About WTR 1000

The prestigious ranking WTR 1000, published by the Globe Business Media Group in London, is one of the world’s leading rankings with regard to trademark services providers. It identifies the top trademark professionals in key jurisdictions around the globe. The WTR 1000 focuses exclusively on trademark practice and has firmly established itself as the definitive ‘go-to’ resource for those seeking world-class legal trademark expertise.

Prüfer & Partner has again been awarded by the renowned professional publisher Legal500 in the field of Intellectual Property Law, both in the category “Prosecution” and in “Litigation”! We are very pleased about this further award for our work and would like to sincerely thank all our clients, foreign colleagues as well as employees for the trust they have placed in us and the good cooperation.

The link to the detailed ranking result on LEGAL500 can be found here.


“Prüfer & Partner are a strong team, which is particularly effective in the interaction between back office (very strong and extremely friendly!), drafting of applications/prosecution and legal advice in the conflict/licensing environment.”

“Dorothea Hofer: Excellent, conscientious and comprehensive advice in the conflict/licensing environment, very pragmatic and savvy and exceptionally helpful.”

“Very high level of expertise.”

“Dorothea Hofer, Jürgen Feldmeier and Andreas Oser. They are very good at understanding complex technical issues, give appropriate advice, and handle urgent matters expeditiously. Mr. Feldmeier selects his associates very well in order to be able to handle important mandates well, especially litigation.”

“Dorothea Hofer and Jürgen Feldmeier are IP veterans, which is apparent in their practical advice and background knowledge of procedures and possible outcomes of office actions or conflicts. I find them very strong and attentive, especially with clients from Asia who feel safe with them. Perfect English and cultural sensitivity help them.”

The Legal 500 is a renowned research agency that specializes in law firm recommendations. As part of its research, the independent team of experienced editors conducts hundreds of interviews with attorneys and consults more than 23,000 clients each year, allowing for a comprehensive and thorough evaluation of law firms in a wide range of practice areas.


With the Epidemic Protection Act of March 27, 2020, Germany declared an “emergency of national dimension” in view of the COVID-19 pandemic. At the same time, tensions and international pressure to “abrogate certain IP rights” increased. In addition to the Federal Republic of Germany, there are numerous other countries around the world that, in principle, can make use of emergency decrees to fundamentally restrict patent rights, such as in the United Kingdom, France, the United States, Canada, Israel, Australia, China, Japan and Korea. However, up to now, in the summer of 2021, neither an order for use (Section 13 PatG) nor – according to current knowledge – an action for a compulsory license (Section 24 PatG) has been brought before the courts responsible for this. The demand to be met is enormous, especially for vaccine developments that have been described as “game changers”.

The following download pdf summarize why this is so – despite numerous and strongly debated demands.

For more details follow the link

Wir freuen uns sehr bekannt zu geben, dass unsere Kollegin Frau Rechtsanwältin Agnieszka Furmanczuk den Titel Fachanwältin für gewerblichen Rechtsschutz verliehen bekommen hat. Dieser Titel dient als Nachweis einer umfangreichen praktischen Erfahrung und besonderer Kenntnisse im IP-Bereich.

Frau Furmanczuk, die sich im IP-Bereich vor allem auf die markenrechtliche Beratung und das Arbeitnehmererfinderrecht spezialisiert hat, unterstützt Sie mit ihrer Erfahrung kompetent bei der Anmeldung und Durchsetzung von Marken und berät zum Aufbau und der Strukturierung von Markenportfolien auf nationaler und internationaler Ebene. Die Kombination von 4.0-Technologien mit der traditionellen Beratungstätigkeit als Anwältin ermöglicht es ihr, Markenportfolien von Mandanten oder deren Wettbewerbern effizient zu analysieren, zu benchmarken und zu bewerten. Im Rahmen der Beratung zu IP-Strategien unserer Mandanten koordiniert Frau Furmanczuk internationale Maßnahmen zum Plagiatsmonitoring und zur Plagiatsbekämpfung. Ihr Fachanwaltstitel spiegelt somit Frau Furmanczuks vertiefte Kenntnisse und Kompetenzen im IP-Bereich wieder.

Wir beglückwünschen Frau Furmanczuk zu diesem Erfolg und sind sehr froh, dass unsere Mandanten von ihren besonderen Fachkenntnissen und ihrer Erfahrung profitieren können.

In the recently published handbook for Germany, the publisher The Legal 500 recognises Prüfer & Partner as Leading Firm in the field of patent application and office actions. The Munich boutique Prüfer & Partner convinces with its brisk filing activity before the German Patent and Trade Mark Office (GPTO) and the European Patent Office (EPO) as well as its continuously growing business in China.

‘The level of service is excellent. Their responses are always very quick and appropriate.’

‘We appreciate the high level of professionalism and expertise, the comprehensive advice and the prudent and timely handling of tasks.’

‘They are very good at getting to grips with the product to be registered and thereby also finding the appropriate formulations.’

‘Excellent and highly agile capacity provision; even short-notice requests are always handled and finalised in a highly professional manner. Strong problem-solving awareness even with complex non-standard requests.’

‘Jürgen Feldmeier: Very good and broad technical understanding; excellent direct ‘line’ to developers and inventors; holistic understanding of company-specific strategies and processes.’

The renowned research agency for in-house counsels, The Legal 500, has been dealing with law firm recommendations since 1987. As part of its research, the independent team of experienced editors conducts hundreds of interviews with lawyers and surveys more than 23,000 clients every year. The research feeds into a detailed analysis that provides a comprehensive and thorough assessment of law firms’ strengths and capabilities across a wide range of practice areas.

Despite successfully passing by the two German chambers, Bundestag and Bundesrat, the planned EU Unified Patent Court is again back on “on-hold” before the German Federal Constitutional Court (BVerfG).

It looked like it was finally done: on November 26, 2020, the German Bundestag had passed the ratification law on the Unified Patent Court for the second time – and now correctly with the required two-thirds majority. Only a few days later, the second chamber, the Bundesrat, had also waved the law through. This seemed to clear the way for the start of the Unified Patent Court. However, unsurprisingly, two appeals have now been filed with the Federal Constitutional Court.

As a reminder: as we reported on March 20, 2020, the BVerfG had declared the German law approving the UPC and the EU unitary patent null and void due to the lack of the required two-thirds majority. This problem had been solved by the German Bundestag and Bundesrat shortly before the turn of the year, and it seemed that entry into force would only be a formality in the form of the signature of the Federal President.

Now, at the beginning of the year, the BVerfG has again received two constitutional complaints directed against the law on the Agreement of February 19, 2013 on a Unified Patent Court, as a press spokesman of the BVerfG confirmed to LTO (Ref. 2 BvR 2216/20 and 2 BvR 2217/20). Next, it remains to be seen whether the BVerfG will accept the complaints or not. If it does not accept the appeals, the Unified Patent Court and the Unitary Patent can be launched in 2021 and is expected to begin operations in 2022. However, if any one of the appeals will be accepted by the court, we can again expect longer delays.

So even without the UK, it’s just a case of wait and see… we’ll stay tuned.

If you have any questions, please do not hesitate to contact us.

Jürgen Feldmeier, LL.M., Prüfer & Partner (E-Mail:


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