An application for a European patent was rejected as lacking an inventive step. The cited patent documents were quite old. We then considered the proposition that since no similar product is in the market, why would it be obvious to combine the cited technologies? Our curiosity was directed to European case law (appeal practice) to estimate the likelihood of overcoming an inventive step rejection on the basis that known technologies had not been combined for a considerably long time.
In T 1014/92 the board did not accept the appellant's argument that the long period of time (about 35 years) during which the cited documents had been available to the public without having been combined, was in itself cogent evidence that there was no obvious connection between them. The board held that this conclusion might only be drawn if evidence relating to time were corroborated by other evidence, such as long-felt want.
According to section 10.3 Long-felt need; commercial success of Guidelines for Examination (EPO), if the invention solves a technical problem which workers in the art have been attempting to solve for a long time, or otherwise fulfills a long-felt need, this may be regarded as an indication of 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.
Translating from legalese into common language, if we can prove that the product is successfully sold due to product properties per se, rather than mere aggressive advertising, there is long-felt want. If this is not the case, the commercial success cannot be an argument of possessing an inventive step.
To provide a broader picture, it should be pointed out that, in the US, according to Graham v. John Deere, “secondary considerations” may include evidence of commercial success, long-felt but unsolved needs, failure of others, and unexpected results. In other words, commercial success per se can be an argument to overcome obviousness rejection. There is no need to provide any proofs of “test integrity” to identify whether the commercial success was due to product properties or marketing.