Xiaohui Wu, 4 October 2022, first published by MIP

In the assessment of inventiveness in patent prosecuting and invalidity procedures, common knowledge evidence is often cited as a benchmark of the technical knowledge and cognisance of persons skilled in the art. However, common knowledge is ill-defined in China’s patent laws and regulations. Only the Guidelines for Patent Examination enumerate three forms of common knowledge evidence:

• Textbooks;
• Technical manuals; and
• Technical dictionaries.

In the absence of a clear definition, stakeholders often struggle in ascertaining common knowledge in practice. The Supreme People's Court (SPC) leverages Targetpharma Laboratories et al. v. CNIPA to expound the test for evaluating whether books could be admitted as common knowledge evidence.

The case relates to the invention patent application of “Tumor-targeted TNF [tumour necrosis factor]-related apoptosis-inducing ligand’s variant and the application thereof” (the ‘application’). The China National Intellectual Property Administration (CNIPA) rejected the application on the ground that the application was devoid of an inventive step. The rejection was affirmed in the re-examination procedure, where the CNIPA cited Volume 8 of the Frontier of Tumor Research as evidence of common knowledge to support the finding of obviousness of the application.

The patent applicants – Targetpharma Laboratories and High-tech Research Institute of Nanjing University, Changzhou – filed an administrative lawsuit to the Beijing Intellectual Property Court (the ‘Beijing IP Court’) challenging the re-examination decision.

The Beijing IP Court sided with the plaintiffs, holding that Volume 8 of the Frontier of Tumor Research, which was neither a textbook nor a technical dictionary, is a mere periodical on tumour research. The CNIPA erred in using such as common knowledge without assessing the admissibility of the documented technical knowledge. The Beijing IP Court quashed the CNIPA’s decision and ordered the agency to remake a decision in another round of re-examination procedure.

The CNIPA appealed to the SPC, contending that periodicals, as a continued publication, should use an ISSN (International Standard Serial Number) rather than an ISBN (International Standard Book Number). Given that Volume 8 of the Frontier of Tumor Research only has an ISBN, it is not a periodical, but a book. Volume 8 of the Frontier of Tumor Research documented the knowledge related to NGR sequence polypeptides, which was cited in the re-examination decision, is known common knowledge in the art.

SPC decision

On August 13, 2020, the SPC dismissed the appeal and upheld the decision made by the Beijing IP Court.

The SPC reasoned that, in general, whether relevant technical knowledge may be classified as common knowledge could be proved by evidence in the technical art, such as technical dictionaries, technical manuals, and textbooks. Where the aforesaid approach fails, stakeholders may resort to evidence (such as numerous patent literatures, periodicals, and magazines) that is not common knowledge in the art yet is mutually corroborative to prove that the technical knowledge is common knowledge.

However, this approach is subject to a high bar of standards of proof. In assessing whether literature other than technical dictionaries, technical manuals, and textbooks documents fundamental technical know-how in this art and thus should be admitted as common knowledge evidence, courts need to factor in metrics such as the carrier form, content and characteristics, audience, and dissemination scope.

The SPC analysed the admissibility of Volume 8 of the Frontier of Tumor Research as follows: firstly, as the acronym for an International Standard Book Number, ISBN has been used in China for many years. The fact that Volume 8 of the Frontier of Tumor Research has an ISBN substantiates that the publication falls under the category of books, if judging from the carrier form.

Secondly, in terms of content and characteristics, the publication is a book, but not a textbook of general nature. The preface of the book states its objective as keeping the peers and researchers abreast of the world’s progress in tumour research in layman’s terms, which makes it a combination of a treatise, an overview, a commentary, and a popular science reading. It indicates that the book aims to introduce the latest progress in terms of tumour research around the world, rather than to provide general technical know-how in the field. Thus, the book is not a textbook in the usual sense.

Lastly, judging from its audience and dissemination scope, the publication could hardly be ascertained as a textbook. The “content abstract” on the copyright page of the book indicates that it is not a textbook in the usual sense, but a reference book for professional researchers. The SPC therefore concluded that the cited publication is a book, not a textbook in the usual sense, which definitely does not qualify as common knowledge evidence.

Common knowledge evidence carries considerable weight in an assessment of inventiveness. That is why the SPC underlines in its decision that the determination of common knowledge should be incontrovertible and supported by sufficient evidence or argument and should not be made lightly.

Tests of common knowledge evidence

Common knowledge evidence is used as a benchmark of the fundamental technical know-how and competence of persons skilled in the technical art. The technical means that are being assessed fall under the sphere of common knowledge, provided such means have been universally acknowledged in the art. With regard to carrier form of the evidence, technical dictionaries, technical manuals, and textbooks that are extensively used as reference books may be admitted as common knowledge evidence. Books and other publications need to pass the same test to be admitted as common knowledge evidence.

In other words, if the cited evidence focuses on the latest research progress, it does not suffice to prove that the documented technical know-how has been widely used in the art, unless corroborated by the breadth and depth that such technical know-how has been utilised by persons skilled in the art.

The CNIPA submitted during the appeal several items of prior art literature in an attempt to prove that the technical means at issue fall under the category of common knowledge. The newly adduced evidence was rejected by the SPC on the ground that it altered the grounds and basis of the findings of the litigious decision. Nonetheless, the SPC affirmed that the CNIPA could still introduce the evidence and solicit comments of the applicants when remaking its re-examination decision.

It remains to be seen whether Volume 8 of the Frontier of Tumor Research, in combination with other literature, could prove the technical means at issue may be perceived as common knowledge in the CNIPA’s second round of re-examination procedure.