In the field of biochemistry, particularly in medicine, the verification of technical effects often hinges on experimental data. Consequently, the documentation of experimental data plays a crucial role in meeting the requirements of Chinese patent law. Additionally, the acceptance of supplementary experimental data is a widely debated topic.

This article delves into Chinese patent law concerning experimental data, examining it from disclosure sufficiency and inventive step perspectives and exploring the acceptance of supplementary experimental data in subsequent processes.

1. Sufficiency of disclosure 

According to Article 26.3 of the Chinese Patent Law, the description should set forth the invention clearly and completely. In practical terms, the description should articulate the technical solution clearly, detail specific methods for carrying out the invention, and fully disclose the technical contents necessary for a person skilled in the art to understand and implement the invention.

The applicant must furnish the related experimental data for inventions needing patent protection that rely on experimental data to prove the technical scheme's efficacy in solving a technical problem.

For example, novel uses of known compounds; in these cases, experimental evidence is generally required in the specification to verify the described uses and effects. Provide such evidence to ensure the description complies with the Sufficiency of Disclosure requirement. Furthermore, the necessary experimental conditions and methods should be documented in the description to support the experimental data.

In summary, meeting the sufficient disclosure requirements of Chinese Patent Law mandates recording experimental data in the description to substantiate the technical effect. Particularly in experimental sciences like chemistry and medicine, where predicting technical effects is challenging, providing experimental data, conditions, and methods is necessary to verify that the invention can solve the technical problem and achieve the stated technical effect.

2. For sufficient of disclosure issue: Can supplementary experimental data can be accepted in subsequent process? 

As per the Guidelines for Patent Examination (Item 3.4, Chapter 10, Part II) of China, the judgment on whether the description is sufficiently disclosed is based on the disclosure contained in the initial description and claims. Any embodiments and experimental data submitted after the filing date are generally not considered.

This aligns with the "first-to-file" principle in China, ensuring that undisclosed or unfinished contents on the filing date or the priority date do not under the protection from the filing date or priority date, thus do not unfairly damage the interests of others.

3. Case study

A case example further illustrates this point: Two of CATL's patents in the lithium-ion battery industry were declared invalid due to insufficient disclosure. The reexamination panel found insufficient data supporting issue, the inventions requiring more technical details and a solid foundation to verify the described technical uses and effects. Additionally, the patent holder failed to provide the sources and processes of the experimental data, raising doubts about its authenticity. Consequently, these inventions did not meet the requirements for sufficient disclosure, resulting in the invalidation of patent rights.

This case indicates that China maintains strict standards for accepting supplementary experimental data to overcome insufficient disclosure issues.

4. Inventive step

Article 22.3 of the Chinese Patent Law defines an inventive step as a comparison with prior art, requiring the invention to have prominent substantive features and represent notable progress.

For determining the inventiveness of a claim, two factors are required:

• Non-obviousness: Compared with prior art, the technical scheme should be non-obvious to a person skilled in the art.
• Notable progress: Compared with prior art, the technical scheme should produce advantageous technical effects.

It is evident that proving the technical effect is crucial for arguing inventive steps. Therefore, experimental data plays a vital role in proving that the invention achieves a beneficial technical effect in experimental sciences like chemistry and medicine, where predicting technical effects is difficult.

5. For inventive step issue: Can Supplementary Experimental Data Be Accepted in Subsequent Processes?

According to the newly revised Guidelines for Patent Examination of China, examiners shall examine the experimental data submitted by the applicant after the filing date to satisfy the requirements of the Patent Law for inventive step. That means, supplementary experimental data for proving inventive step cannot be added to the application documents; but it should be examined during the examination process. There is a condition that the technical effect evidenced by the supplementary experimental data should be recorded in the initial application or can be obtained by a person skilled in the art from the disclosure of the initial application.

Two examples provided in the guidelines illustrate scenarios where supplementary experimental data is considered for inventive step:

• The patent application describes a preparation example of Compound A, a hypotensive effect, and an experimental method for measuring hypotensive activity. Although no experimental result data are recorded, the applicant has submitted experimental data to prove the hypotensive effect described in the application document. Such supplementary experimental data should be considered when judging the inventive step.
• The patent application describes a general compound of formula I, including preparation examples of specific compounds, the anti-tumor effect of compounds, and experimental methods for determining anti-tumor activity. The recorded experimental data shows that the IC50 values of the compounds in the examples against tumor cells are within the range of 10-100 nmol•L-1. To prove the inventive step, the applicant supplements the comparative experiment data, showing that the IC50 value of compound A was 15 nmol•L-1, while the IC50 value of the comparative compound was 87 nmol•L-1. Since the technical effect to be demonstrated by the supplemental experiment data can be obtained from the contents disclosed in the initial application, such supplementary experimental data should be considered when judging the inventive step.

It is crucial to note that the above two examples were considered to meet the requirements of sufficient disclosure. Thus, the supplementary experimental data can be accepted to demonstrate inventiveness. This indicates that the nature of supplementary experimental data is just evidential support, which cannot compensate for inherent deficiencies in the application documents, such as the insufficient disclosure issue. However, it can be used to strengthen the explanation of the technical effects of the invention, thereby proving the inventive step of claims.

Based on the Above Provisions and Recent Patent Invalidation Cases:

For experimental sciences like chemistry and medicine:

• Supplementary experimental data is generally not acceptable to overcome insufficient disclosure issues.
•  Supplementary experimental data should be considered for the inventive step on the condition that the evidenced technical effect is recorded in or can be obtained by a person skilled in  the art from the disclosure of the initial application.
•  Necessary conditions for supplementary experimental data to be accepted and examined:
• Meet the sufficient disclosure requirement.
• For proving the inventive step, the technical effect can be derived by a person skilled in the art from the disclosure of the initial patent application.

6. Our Recommendation

In crafting patent applications in the field of chemistry and medicine:

• Record preparation examples, experimental methods and conditions, and experimental effect data of technical schemes as comprehensively as possible.
• If specific experimental effect data cannot be provided, record experimental methods and procedures and include a range of values for the technical effect, along with qualitative or quantitative experimental results based on theoretical or empirical inference.
• For the first filing application in China, consider using "domestic priority" to submit supplementary experimental data within 12 months from the first application's filing date. Within this timeframe, the applicant can file another application to add experimental data and claim the priority of the first application. Subsequently, the first application will be deemed withdrawn.
• Supplementary experimental data generally will not be accepted when responding to an "insufficient disclosure" issue. Instead, emphasize that a person skilled in the art can implement the technical scheme and obtain the technical effect based on the contents recorded in the initial description, even if there is no experimental data.
• When responding to an "inventive step" issue, if the technical effect to be proved is recorded in or can be determined from the original application document, consider submitting supplementary experimental data, such as comparative experiment data, to further verify the technical effect and prove the inventive step.

Author: Lei Su 

Ms. Su has over 15 years of experience in comprehensive IP management. She has worked at both companies and IP agencies, and specializes in international patent applications, patent analysis and patent litigation. She has handled thousands of foreign-related patent applications across the whole process, from drafting and responding to office action to requesting re-examination, as well as multiple patent invalidation and administrative litigation cases. Prior to joining Purplevine IP Group, Ms. Su previously worked at Foxconn Technology Group and AFD China Intellectual Property. Contact Ms. Su at lei.su@purplevineip.com.