EP Case Law in Brief: Commercial success and inventive step


“Commercial success alone is not to be regarded as indicative of inventive step, but evidence of immediate commercial success when coupled with evidence of a long-felt want is of relevance provided the examiner is satisfied that the success derives from the technical features of the invention and not from other influences (e.g. selling techniques or advertising).”

The EPO Guidelines (G-VII, 10.3) describe the basic approach to the concept of commercial success, an example of a secondary indicator of inventive step. Secondary indicators are factors which, although on their own may not be enough to indicate an inventive step, may be supportive of inventive step along with other arguments and depending on the specific context. Other examples of secondary indicators include technical prejudice and unexpected technical effect. As noted in the Case Law of the Boards of Appeal (section I.D. 10.1), secondary indicators “are only of importance in cases of doubt, i.e. when objective evaluation of the prior art teachings has yet to provide a clear picture”.

Section I.D. 10.5 of the Case Law of the Boards of Appeal indicates how and when an argument relying commercial success as a secondary indicator may be successful. In T 478/91, the Board explained that there are two conditions which need to be fulfilled for commercial success to be considered an indication of inventive step: “first, it must be established that a long-standing need has been met; and secondly, that this commercial success is due to the technical characteristics of the invention and not to other factors (e.g. sales or advertising techniques).” For example, the Board noted that ‘it was well known that the commercial success of a product could just as easily be due to factors other than its properties, in particular more streamlined manufacture, a market monopoly, advertising campaigns or efficient selling technique’.

Further guidance on how to establish commercial success as an indicia of inventive step was provided in T 1212/01, which was concerned with a patent related to Viagra. In this decision, the Board said that two evidentiary steps were required. Firstly, commercial success must be demonstrated and, secondly, it must be shown that such success resulted from the claimed invention and not from one or more other causes. Although Viagra had received ‘various awards and praise’, the nature of the prizes was significant. The Board said that “the prizes would be significant if awarded by person who understood patent law”, but that awards for “high standard of research”, or “high level of sales”, may not have significance in terms of inventive step.

The Board commented on an exemplary document filed by the appellant (patentee) in support of commercial success. The appellant argued that the document describes that “the Prix Galien [was] awarded in 2000 to Viagra” for “no fewer than four reasons - research and development effort, corporate teamwork, the first oral therapy for erectile dysfunction, and making advice on that condition easier to obtain”. The Board concluded that “[o]nly the third of those reasons comes anywhere near the nature of the invention - if the appellants claim three other reasons for such a prize, how can the Board accept it was in fact awarded for the technical nature of the alleged invention?”

Thus, in this case, the Board concluded that the evidence did not establish that the prizes had resulted from the claimed inventive step. In addition, in relation to “evidence of commercial success in the form of sales figures (whether by market share or money value or units sold or, in the case of pharmaceuticals, prescriptions written or dispensed)” the Board stated that “the figure for one year is of little if any value, however high that figure may be. Only some comparison can make such evidence meaningful and the comparison must be such as to show at least a prima facie case of success - such as a comparison between sales of prior art products and patented products, or between the patentee's sales before and after manufacture in accordance with the invention. A prudent patentee will also provide parallel information relating to advertising and similar expenditure to anticipate the argument that such activities could explain the growth in sales.”

In T 110/92, the Board reminded that “a mere investigation for so called ‘indications’ of the presence of inventive step is no substitute for the technically relevant assessment of the inventions vis-à- vis the state of the art, involving the recognition and solution of the technical problem in the case. The Board stated that it “does not dispute that the [product] according to Claim 1 may have become a commercial success. However, such a commercial success alone, with the technically relevant examination of the claimed subject-matter leading to a negative result, cannot be regarded as forming the basis for an indication of inventive step even if the Board were convinced that the success derives from technical features of the [product] and not from other causes such as of commercial nature”.

It appears, therefore, that arguments pertaining to commercial success can be challenging.  However, there are cases in which the Boards of Appeal found that commercial success could be an indicator of inventive step.

In T 106/84, the commercial success argument was considered persuasive, because the applicant’s company was small and “[could not] afford to indulge in major sales campaigns and sophisticated marketing techniques”. Therefore, the Board accepted that the commercial success resulted from the technical advantages of the claimed features. This was combined with the argument that the claimed device, whilst seemingly a simple solution to the objective technical problem, provided an “improved performance in use and the solution of a long-standing problem”. In this regard, the Board noted that “[c]are must be taken not to destroy applications for lack of inventive step when persons in the related industry would recognise that it is very surprising that no one had ever hit upon the simple solution before”.

In T 677/91, the Board stated that it was “not in a position to determine the exact extent to which the evidence of commercial success can be directly attributed to the claimed invention”, but that “it would be wrong to ignore the practical impact that the invention has made in its own field since the priority date”. In several passages of a textbook “reference [was] made to the various advantages of the ‘successive mass selective ejection through instability’ techniques of the claimed invention bringing in a new era in mass spectrometry”. The Board concluded that it was “difficult to reconcile the contents of such passages with the idea that the claimed invention was in fact a matter of mere routine development for a skilled person at the priority date”. Therefore, whilst cited prior art disclosures were “technically close to the claimed invention”, “the circumstances surrounding the claimed invention have also to be taken into account”. In this case, the Board found that the claimed subject matter involved an inventive step.

Finally, in T626/96, “commercial success [of the claimed water tap] was achieved in a very short space of time after the appellant's invention”. Specifically, commercial success was achieved within a year of the filing date of the first priority application. The Board stated that it appeared “therefore that there was a pressing commercial need for such a simple solution”. “As presented in the declaration of Mr Racz, filtered water has been commonly available in the United States for 20 years and has always been provided by use of a separate tap, i.e. separate to the hot/cold water tap. In the [claimed] Triflow tap all the water types are delivered from a single nozzle, providing benefits in manufacturing costs and simplicity for the user and in which cross-contamination of the filtered water path with hot/cold water path(s) is excluded. Thus the commercial success is to be attributed to these substantial advantages which obviously stem directly from the technical features set forth in claim 1.” The Board also noted that “the applicant's company was created in late 1990 for the purpose of trading the invented tap. It seems therefore clear that this quite new company was not in a position to finance a marketing campaign in Europe, the USA and elsewhere”. In addition, the Board found that the “period of nearly 60 years between the publication date of the closest prior art document and the filing date of the patent application in suit [may be] regarded as a further secondary indicator of inventive step”.

In conclusion, whilst commercial success remains only a secondary indicator of inventive step, and even then is only persuasive in limited circumstances, the case law shows that it can be a powerful tool in the arsenal of a patentee.