Determining whether claims are supported by the description

[Key points of the judgment]

In determining whether a claim can be supported by the description, consideration should be given to whether a person skilled in the art can reasonably be convinced that the technical solution of the claim is capable of solving the technical problem to be solved by the invention and does not exceed the scope of the inventor's technical contribution. "Reasonably convinced" generally means that a person skilled in the art, on the basis of the content disclosed in the description and using conventional experimental or analytical methods rather than broad theoretical speculation, is able to reasonably generalise the scope of protection of the claim from the content disclosed in the description.

[Keywords]

Administrative　Invalidation of an invention patent right　Claims supported by the description　Technical contribution of the inventor　Reasonable conviction

[Basic facts of the case]

A German company is the patentee of an invention patent with patent number 20141014****.X entitled "Methods and nucleic acids for the analysis of cell proliferative disorders" (hereinafter "the patent at issue"). On 30 November 2018, a Jiangsu company filed a request for invalidation against the patent right at issue. The basis of examination in this case was the set of claims submitted by the German company on 25 February 2019, comprising 28 claims, specifically:

"1. Use of a device for determining the methylation level of the Septin9 gene or the genomic Septin9 sequence in the preparation of a kit for a method of detecting and/or classifying cancer in an individual, wherein the method comprises determining the methylation level of the Septin9 gene or the genomic Septin9 sequence in a biological sample isolated from the individual, wherein CpG methylation indicates the presence of the cancer or its type, and wherein the cancer is hepatocellular carcinoma or colorectal cancer.

2. The use according to claim 1, wherein the presence of CpG methylation indicates the presence of a cancerous cell proliferative disorder and its absence indicates the presence of a benign cell proliferative disorder, wherein the cancerous cell proliferative disorder is distinguished from the benign cell proliferative disorder.

3. The use according to claim 1, wherein the methylation level is determined by detecting the presence or absence of CpG methylation within the Septin9 gene or the genomic Septin9 sequence, wherein the presence of methylation indicates the presence of a cancerous cell proliferative disorder.

4. The use according to claim 1, wherein the biological sample obtained from the individual is selected from cell lines, histological sections, tissue biopsies, paraffin-embedded tissue, bodily fluids, faeces, and combinations thereof.

5. The use according to claim 1, wherein the biological sample obtained from the individual is selected from colonic effluent, urine, blood plasma, blood serum, whole blood, isolated blood cells, cells isolated from blood, and combinations thereof.

……"

On 10 July 2019 the China National Intellectual Property Administration issued Invalidation Examination Decision No. 40815 (hereinafter "the decision under review"), holding that the technical solutions of claims 1-3, 6-9, 12-17 and 20-28 of the patent at issue, and those parts of claims 4, 5, 10, 11, 18 and 19 relating to "the biological sample being selected from bodily fluids, urine, blood plasma, blood serum, whole blood, isolated blood cells and cells isolated from blood" and relating to "the cancer being hepatocellular carcinoma", were not supported by the description, and maintaining the validity of the technical solutions in claims 4, 5, 10, 11, 18 and 19 relating to "the biological sample being selected from cell lines, histological sections, tissue biopsies, paraffin-embedded tissue, faeces, colonic effluent, and combinations thereof" and to "the cancer being colorectal cancer".

Dissatisfied, the German company brought an action before the Beijing Intellectual Property Court, requesting revocation of the decision under review and an order that the China National Intellectual Property Administration issue a new decision.

On 24 December 2021 the court of first instance rendered an administrative judgment dismissing the German company's claims. Dissatisfied, the German company appealed. On 24 April 2024 the Supreme People's Court rendered administrative judgment (2022) Zui Gao Fa Zhi Xing Zhong No. 365: the appeal was dismissed and the original judgment upheld.

[Reasoning of the judgment]

The effective judgment of the court held that Article 26, paragraph 4 of the Patent Law provides: "The claims shall be supported by the description and shall define the scope of patent protection sought." Whether a claim can be supported by the description should be judged comprehensively from the perspective of a person skilled in the art, on the basis of the overall state of the prior art in the field, the content disclosed in the description and the content defined in the claim. If a person skilled in the art, on the basis of the content disclosed in the description and the overall state of the prior art, can reasonably be convinced that the technical solution claimed is capable of solving the technical problem to be solved by the invention and does not exceed the scope of the technical contribution made by the inventor, the claim should be regarded as supported by the description. That a person skilled in the art can be reasonably convinced means that, on the basis of the content disclosed in the description, a person skilled in the art can extend the content disclosed in the description to the scope of protection of the claim using conventional experimental or analytical methods rather than broad theoretical speculation.

The German company argued that the evidence it submitted in the invalidation proceedings and at first and second instance was sufficient to show that blood-based tumour testing was a fairly common approach in the field; therefore a person skilled in the art would not question that tumour DNA in blood is present at extremely low levels and is difficult to detect, nor would there be interference from methylation of other genes with the Septin9 gene background; blood testing was a reasonable deduction by a person skilled in the art from tissue testing, and therefore the technical solutions in the claims involving non-tissue test samples were supported by the description.

In this regard, the analysis is as follows:

First, the several items of academic-paper evidence submitted by the German company and the Jiangsu company in this case show that, even after the priority date of the patent at issue, cancer screening by means of blood testing remained at the stage of scientific exploration, with no settled conclusion that it could serve as kit-based testing. Moreover, evidence 6 submitted by the German company at second instance (an article entitled "K-ras point mutations in the blood plasma DNA of patients with colorectal tumor" and a partial Chinese translation thereof, Vasioukhin, V. et al., In Challenges of modern medicine, Biotechnology Today 1994, Vol. 5, pp. 141-150, offered to prove that methods of detecting cancer gene mutations in the blood of colorectal cancer patients already existed more than ten years before the patent at issue) states: "Heparinised blood samples were collected from 15 consenting patients with colorectal adenocarcinoma at various stages... It is evident that there are no, or only very few, circulating tumour cells in the blood. However, Tada et al., using the same sensitive technique, did find mutations in the peripheral blood cells of two of eight pancreatic cancer patients. This difference may be explained by the characteristics of intestinal tissue, which sheds its cells after the last direct division into the intestinal tract and therefore they are not present in the bloodstream." This content further corroborates that whether blood testing can be used for cancers of different primary sites needs to be demonstrated through research.

Second, methods of detecting circulating DNA in blood do exist in the prior art; however, as stated above, the source of ct-DNA in blood differs for different cancers, and it cannot be concluded that conventional technical means would necessarily allow detection by means of a blood or similar test kit.

Third, the patent at issue concerns the use of a device for determining the methylation level of the Septin9 gene or the genomic Septin9 sequence in the preparation of a kit; the content disclosed in the description should therefore be sufficient to demonstrate that a technical solution using blood or similar testing kits can achieve that use, rather than a conclusion drawn from broad teachings in academic papers around the earliest priority date or from general attention to and demand for blood testing in the field. However, the description of the patent at issue does not disclose experimental data verifying Septin9 methylation levels in blood based on colorectal cancer positive cases, nor does it disclose a specific technical solution for achieving that use with a blood test kit.

Finally, the China National Intellectual Property Administration reached its conclusion that tumour DNA in blood is present at extremely low levels and is difficult to detect on the basis of the fundamental knowledge of a person skilled in the art at the earliest priority date, and that conclusion is consistent with the corresponding conclusion recorded in evidence 5 submitted by the German company at second instance (an article entitled "Free DNA in the Serum of Cancer Patients and the Effect of Therapy" and a partial Chinese translation thereof, S. A. Leon et al., CANCER RESEARCH 37, pp. 646-650, 1977, offered to prove that methods of measuring cancer DNA in blood already existed as early as 1977), namely "we conclude that normal serum contains only very little free DNA". By the same token, the same conclusion as for blood testing may be drawn for the testing of other non-tissue samples. On this basis, the conclusion in the decision under review that the technical solutions of claims 1-3, 6-9, 12-17 and 20-28 of the patent at issue and those parts of claims 4, 5, 10, 11, 18 and 19 relating to "the biological sample being selected from bodily fluids, urine, blood plasma, blood serum, whole blood, isolated blood cells and cells isolated from blood" were not supported by the description was not improper.

[Related index]

Article 26, paragraph 4 of the Patent Law of the People's Republic of China (the version applied in this case is Article 26, paragraph 4 of the Patent Law of the People's Republic of China in force from 1 July 2001)

Source: Intellectual Property Court of the Supreme People's Court　Date: 17 September 2026　Original link: https://ipc.court.gov.cn/zh-cn/news/view-6073.html