It is common to say that you learn to howl when you walk with wolves. It seems that this old saying applies to Patent Examiners in charge of evaluating inventiveness and of innovating in examination processes. Recently, the concept "plausibility" began to swipe up in many prosecution stories.
In general terms, plausibility could be understood as a patentability condition that addresses the question of whether there is sufficient evidence, technical knowledge in the state of the art and in the teaching of the disclosure of the invention to conclude that the technical problem can indeed be solved by the proposed technical solution.
The term "plausibility", in the context of patentability assessment, was first introduced in the decision of the Board of Appeals of the European Patent Office: T1329/04, Factor-9/JOHN HOPKINS of June 28, 2005.
In a nutshell, in that decision it was questioned whether the problem to be solved, defined as isolating a further member of the TGF-Beta (Transforming Growth Factor-Beta) superfamily, had been plausibly solved considering the teachings of the application and the state of the art at the priority date.
In this case, the subject matter was TGF-9, a specific member of the TGF-Beta superfamily. The description of the application did not exhibit the structural feature that serves to establish whether a polypeptide belongs to the TGF-Beta family: that is, the seven cysteine residues with their characteristic spacing. In fact, only six cysteine residues were present.
At the priority date, there was no available evidence to show that the claimed compound was actually a growth differentiation factor. It was then a "speculation" that this property was given.
Therefore, the credibility of the development was doubtful, it was concluded that there was not enough evidence in the application to make "at least plausible" that a solution to the technical problem was found, the inventive step requirement was not satisfied, and that appeal was dismissed.
Another relevant precedent is found in the Canadian patent law. In this jurisdiction, the utility requirement of a claimed invention must be demonstrated or at least "soundly predicted". For a prediction to be considered "sound", it must meet the following conditions:
There must be a factual basis for the prediction;
The inventor must have at the date of the patent application an articulable and "sound" line of reasoning from which the desired result can be...