We are pleased to share that our firm Prüfer & Partner together with four of our intellectual property attorneys have been recognized for their outstanding work in patent prosecution and nullity in the newly published 2023 Edition of iam Patent 1000, one of the world’s leading rankings with regard to patent services providers.

What the ranking said
Prüfer & Partner
“The attorneys at Prüfer & Partner stand out from their peers for their thoughtful consideration of the position of the client. They are always responsive and provide detailed and pragmatic solutions. Their service is very satisfactory and the whole team is highly recommended.”

Jürgen Feldmeier
“Jürgen Feldmeier is an experienced, go-to patent attorney in the field of high-tech engineering, and is highly appreciated for his clear-cut advice. He handles EPO proceedings and nullity actions with ease – typically with a successful result. He is great to cooperate with and he has sharp technical understanding.”

Dr. Dorothea Hofer
“Dorothea Hofer is excellent. She delivers great service, responds quickly and appropriately, and she has a strong ability to understand complicated technical matters. She appropriately selects her associates to form a solid team to handle important cases like litigation cases. The quality and cost effectiveness of her work is totally satisfactory. Dorothea and her firm are among the most recommendable patent experts in Germany.”

Dr. Andreas Oser
“For prosecution, EPO oppositions and technically informed opinions, Andreas Oser is definitely recommended. He is reliable and brings deep experience in the field. He is customer oriented and very nice to work with.”

Markus Adamczyk
Joining the above-mentioned attorneys in the IAM Patent 1000 this year is Markus Adamczyk, a noted expert in AI and computer-implemented inventions. With skills in computer science and mechanical engineering, and research experience in-house at Vodafone, Adamczyk’s technical expertise cannot be doubted. He supports Feldmeier for printing industry leader Brother Industries and special machinery and plant engineering company Hymmen GmbH.

About IAM Patent 1000
The prestigious ranking IAM Patent 1000, published by Globe Business Media Group in London, is commonly regarded as the definitive ‘go-to’ resource for those seeking to identify world-class, private practice patent expertise as well as leading patent service providers. IAM undertook an exhaustive qualitative research project to identify outstanding firms and individuals across multiple jurisdictions. When identifying the leading firms, factors such as depth of knowledge, market presence, and the level of work on which they are typically instructed were all taken into account, as well as positive peer and client feedback.

We are very pleased that our patent attorneys Dr. Dorothea Hofer, Mr. Jürgen Feldmeier as well as Dr. Andreas Oser are listed as beste Anwälte des Jahres 2023 (best attorneys of the year 2023) in the ranking published by Handelsblatt on June 16, 2023.

It is a great honor for our firm that three of our experts are represented in this prestigious ranking. We would like to thank our colleagues for the numerous recommendations and the good cooperation!

We look forward to continuing to provide our clients with the best possible support in all intellectual property matters and to protect their rights.

About the Best Lawyers ranking by Handelsblatt
In cooperation with the US publishing House Best Lawyers, the renowned business magazine Handelsblatt has determined the well-known ranking of the best lawyers and business law firms in Germany for the year 2023. The current edition in Handelsblatt is based on the 15th edition of the Best Lawyers rating.

In the procedure, lawyers are asked which competitors they can particularly recommend. The selection procedure follows the conviction that lawyers themselves are best able to judge which colleagues are particularly qualified for certain areas of law. Lawyers can be nominated by anyone except themselves.

Prüfer & Partner mbB Patent- und Rechtsanwälte is again recognised for its outstanding performance in the current ranking of “The Legal 500 – Germany”. The firm is recommended in the areas of “Patent Law: Patent Attorneys: Patent Prosecution” and “Patent Law: Patent Attorneys: Litigation” and is thus listed among the best IP law firms in Germany.

Recommended IP law firm

According to Legal 500, PRÜFER & PARTNER has made a name for itself through its many years of experience in handling patents that are to be filed after grant by the DPMA or EPO, in particular also in the USA. In addition to an extensive German practice, PRÜFER & PARTNER also handles a broad range of international mandates and is well-equipped for mandates relating to Japan, China and Korea, in particular, thanks to a combination of established partner firms in Asia and in-house patent specialists including native speakers.

The firm has also been able to expand its domestic business through new direct mandates, including advice on strategic issues. It is familiar with drafting patent and utility model applications in a wide range of technologies. Managing partners Dorothea Hofer, Jürgen Feldmeier and Andreas Oser deserve special praise.


‘Very competent international coverage.’

‘Friendly, competent and very reliable.’

‘Systematic work, level of knowledge about files in the entire team, competence in all (for us) required areas.’

The cooperation is very pleasant and the partners involved are characterized in particular by a collegial cooperation. I would like to single out Jürgen Feldmeier.

‘Very courteous, patient – even if you’re not an IP expert, honest advice: what makes sense is suggested, what doesn’t make sense is pushed aside. Competence is definitely present in all people in their areas.’

‘The overall level of their services is excellent. Their response is always very quick and appropriate, and their ability to understand and analyze legal and technical issues is high.’

Dorothea Hofer, Jürgen Feldmeier, Andreas Oser are particularly good. They have a strong ability to understand complicated technical issues, give appropriate advice and deal with urgent matters.’

Mr. Feldmeier selects his staff properly to form a strong team capable of handling important cases such as litigation. Our Japanese clients are completely satisfied with the quality and cost-effectiveness of the work done by the team.

About Legal 500

Legal 500 researches and evaluates law firms in over 150 jurisdictions worldwide. The rankings, published annually, are based on the assessment of 300,000 clients, law firm submissions, interviews with leading lawyers and experts with extensive knowledge of the legal market.

Please find the current ranking here.

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 office@pruefer.eu, www.pruefer.eu

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: https://www.epo.org/news-events/news/2022/20221001.html

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. (office@pruefer.eu)

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

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: office@pruefer.eu)


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