In a recent decision (2023 Xing Zhuan Su Zi No. 16), the Intellectual Property Court of Taiwan set important standards regarding the burden of proof in assessing inventive step and the admissibility of supplementary experimental data. The case concerned Taiwanese Patent No. I682882, which describes a biodegradable composition. The patent holder faced an invalidation action on the grounds that the invention lacked an inventive step. The court concluded that all features of the claimed invention were either already disclosed in the prior art or considered part of the so-called common general knowledge. Although the plaintiff attempted to demonstrate unexpected technical effects through supplementary experimental data—effects that could not have been anticipated by a person skilled in the art—the court found these efforts unconvincing.
The court made it particularly clear that referencing common general knowledge in legal proceedings must not be done in a blanket or unsubstantiated manner. While patent examiners may occasionally rely on such assumptions during prosecution, significantly stricter standards apply in contested legal proceedings. Any party—whether a public authority or a claimant in invalidation proceedings—who asserts the existence of common general knowledge must substantiate that claim with concrete, objectively verifiable evidence. In the case at hand, the Intellectual Property Office (IPO) was able to convincingly demonstrate through scientific literature and patents that the technical solution of the disputed invention—especially the use of specific bioplastics—was already known in the relevant technical field. For a person of ordinary skill, applying the claimed materials would have been an obvious step without the need for inventive activity.
Another key aspect of the ruling relates to the requirements for supplementary experimental data. Such data may, in principle, be used to retrospectively substantiate a claimed technical effect and support inventive step. However, the court emphasized that these data must meet high standards: they must be clearly documented, methodologically sound, and ideally generated by independent third parties or at least be independently verifiable. In the present case, critical information about the experimental setup—such as specific testing methods, materials used, and conditions under which measurements were taken—was missing. Furthermore, there were no complete test reports or expert opinions from accredited third-party laboratories. As a result, the submitted data failed to provide credible evidence of a surprising technical effect and did not meet the evidentiary standards required by the court.
Anyone seeking to defend the inventive step of a patent against an invalidation action in Taiwan should therefore exercise the utmost care in both arguing the existence of common general knowledge and presenting supplementary experimental data. Common general knowledge must always be substantiated by concrete, verifiable sources—mere references to technical plausibility or widespread practice are not sufficient. Supplementary data, in turn, should be transparently documented, reproducible, and scientifically robust, ideally supported by reports from independent testing institutions. Only when these requirements are met can the court recognize the full evidentiary value of such submissions.
Source: Intellectual Property and Trade Court of the Republic of China (Taiwan)
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