In an administrative appeal case, the Supreme People's Court (SPC) clarified that in the field of microbe genetic engineering, when a patent involves an engineered strain obtained through gene overexpression, the description may be considered sufficiently disclosed if (1) the synthesized product has a clear connection to known strains or processes that can demonstrate the feasibility of the technical solution; and (2) a person skilled in the art can reasonably expect the technical effects based on existing knowledge, or if the patent specification provides experimental data sufficient to prove those effects.
This case involves a review decision on an invalidation request against a microbe related invention patent. The facts are briefly summarized as follows.
The patent in question is titled "Engineered Sphingomonas, Its Construction Method, and Applications." Company A was the patent owner. Individual X filed a request to invalidate the patent. In response, the China National Intellectual Property Administration (CNIPA) issued a decision maintaining the validity of the patent.
X disagreed and filed a lawsuit with the first instance court, arguing that the patent specification did not sufficiently disclose the invention, violating the provisions of Article 26, Paragraph 3 of the Patent Law. X requested the court to revoke the decision and order the CNIPA to issue a new one.
The first instance court dismissed X’s claims. It found that the patent specification described the process for obtaining the final recombinant strain MH-10. The process involved steps such as gene amplification, plasmid ligation, and conjugative transfer, all of which were conventional techniques that a person skilled in the art would know. Based on the starting strain deposited with the administrative department for patent under the State Council and a commercially available starting plasmid, a person skilled in the art using ordinary technical skills could reproduce the patented method and obtain the recombinant bacterial strain. There was no evidence suggesting any obstacle that would prevent reproduction.
X appealed to the SPC. He argued that based solely on the method described in the patent specification, the stable acquisition of a viable engineered Sphingomonas strain MH-10 cannot be ensured. Genetically engineered bacteria are inherently genetically unstable and prone to phenomena such as loss, rearrangement, and modification of recombinant plasmids. Thus, the patent cannot definitively provide the strain MH-10, nor can it confirm that the fermentation product is Sanzan Gum. Consequently, the patent specification is insufficiently disclosed regarding the construction of the engineered strain MH-10 and the confirmation that the fermentation product is Sanzan Gum. As a result, it fails to enable a person skilled in the art to carry out the invention and obtain the expected product.
The SPC dismissed the appeal in the second instance and affirmed the first instance court's decision. The SPC held that the patent clearly provides the nucleotide sequences of key genes, the deposit number of the designated host strain, and describes the primer sequences, as well as the strain and plasmid information in the specification. The Examples provide detailed records of operations such as plasmid construction and conjugative transfer. The framework map of the recombinant plasmid is clear, and the culture medium formulations including carbon sources, nitrogen sources, and inorganic salt concentrations, as well as culture parameters such as temperature and pH value, are disclosed. The starting biological material strain and the plasmid are readily accessible. Based on the deposited starting strain and the commercially available plasmid, combined with the gene sequences, operating steps, and culture conditions described in the patent, a person skilled in the art, using conventional technical means, is able to stably and reproducibly construct the engineered strain MH-10 with the expected characteristics. Therefore, the technical solution of the patent is reproducible.
Regarding whether the fermentation product was indeed Sanzan Gum with the expected properties, the second instance judgment, through an analysis of the strain's relevance, the effect of gene overexpression, and the predictability of the technical effect, determined that a person skilled in the art could reasonably infer that the fermentation product of the obtained engineered strain MH-10 is Sanzan Gum. Through the origin of the strain, the mechanism of engineering modification, the optimization of fermentation processes, product functionality tests, and cross-verification with prior art, a complete chain of evidence has been established, sufficient to confirm that the fermentation product of the engineered strain MH-10 is Sanzan Gum, as well as its technical effects. In summary, the patent discloses the deposited strain, specifies the gene sequences, discloses the source and construction method of the plasmid as well as the culture medium and conditions, thereby enabling the reproducibility of the technical solution and the confirmation of the fermentation product. Furthermore, the technical effects are in line with the reasonable expectations of a person skilled in the art. Therefore, the patent meets the criteria for sufficient disclosure of the specification as required.
The final judgment in this case sets a clear benchmark for the judicial determination of “sufficient disclosure” in the field of microbial genetic engineering patents. The SPC systematically reviewed the completeness and enforceability of the technical information across key aspects, including gene sequences, strain deposit, plasmid construction, fermentation processes, and product verification. It determined that the technical solution is stably reproducible. Furthermore, through analyses of strain relevance, gene expression, and the predictability of the technical effects, the Court established a complete evidentiary chain to confirm the identity of the fermentation product, thereby precisely grasping the examination principles for patents in the biotechnology field. This case not only clarifies the disclosure standards that the specification must meet but also provides important guidance for the drafting and validation of patents related to genetically engineered strains and biological fermentation.
(2024) Zui Gao Fa Zhi Xing Zhong No. 1241
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