In China’s patent examination practice, the technical effects demonstrated by experimental data are a crucial factor for patent applications, especially for biotech and chemical inventions.

In order to address objections such as insufficient disclosures of an application and inventiveness, post-filing data can be a game-changer for an application. For a long time, applicants have found it challenging to get post-filing data accepted by Chinese examiners. However, the situation has been shifting in favor of applicants with revisions and improvements in relevant provisions in recent years.

This article will provide the related provisions and case examples from the prosecution and legal proceedings in an attempt to offer some insights on how to make the best use of post-filing data.

Requirement for post-filing data by CNIPA – development and current practice

Changes in the Patent Examination Guidelines

According to the revised Patent Examination Guidelines effective in 2017, post-filing data should be reviewed, provided that the technical effects of the post-filing data can be determined by the skilled artisans based on the original application documents.

However, the Guidelines did not specify what types of technical effects proven by post-filing data belong to those “can be determined” based on the initial disclosure until 2021.

The updated Patent Examination Guidelines issued in 2021 specifies that post-filing data can be submitted to address ‘non-sufficient disclosure or lack of inventiveness’ rejections. It provides the following Examples 1 and 2 to facilitate the appreciation of the new provisions:

Example 1 – The claim claims a compound A

The specification describes preparation examples of compound A, its hypotensive effects, and experimental methods to determine its hypotensive activity, without disclosing the experimental results. To prove sufficient disclosure, the applicant submitted post-filing data demonstrating the hypotensive effects of compound A.

For the skilled artisans, the hypotensive effects of compound A have been disclosed in the original application documents, so the technical effects to be proven by the post-filing data can be derived from the initial disclosure. It should be noted that the post-filing data should also be examined when evaluating inventiveness.

Example 2 – The claim claims a compound of formula I.

The specification includes the following disclosures: compounds of formula I, methods for preparation and anti-tumor effects thereof, along with preparation examples of some specific compounds of formula I (such as compounds A and B).

It also provides experimental methods for determining anti-tumor activity and discloses experimental results indicating that the IC₅₀ values of the example compounds on tumor cells range from 10 to 100 nM. To demonstrate inventiveness, the applicant supplemented comparative experimental data showing that the IC₅₀ value is 15 nM for compound A and 87 nM for the compound in Reference 1.

For the skilled artisans, compound A and its anti-tumor effects have been disclosed in the original application documents, so the technical effects to be proven by the post-filing data can be derived from the initial disclosure. It should be noted that the examiner must further assess whether inventiveness can be established, taking the post-filing data into consideration.

The above Example 1 suggests that post-filing data to prove specific effects for the claimed technical solutions can be acceptable, even withoutrelevant preliminary experimental data in the original application documents, provided that the preparation method, the effects to be proven, and the methods to test the effects are described in the initial disclosure.

Also, as seen from Example 2, where the original application documents describe a specific effect of compounds of a general formula, a numerical range of parameters relating to this effect, and a testing method for those parameters, post-filing data for the same parameters on the same compounds may be acceptable if the data falls within the disclosed range and is obtained using the same method described in the initial disclosure.

Success during substantive examination

Here is a recent example of overcoming a rejection for insufficient disclosure using post-filing data.

This case involves the medical use of an antibody for treating a class of diseases (including disease A), wherein the antibody is defined as binding to region B of a protein and the binding positions are specified. The specification discloses the amino acid sequences of region B, without revealing the entire sequences of the antibodies. It also describes a mechanism through which antibodies capable of binding to region B can achieve effect C, thereby treating the recited diseases. The examples describe the experimental procedures using two in-house antibodies with the claimed binding properties to test their effect C on cell lines of disease A, and the experimental results thereof.

The Examiner objected that the claimed antibody was defined only with functional language (i.e., binding to region B) without any structural information of the antibody, thus the skilled person could not identify an enabled antibody or anticipate that any antibodies specifically binding to region B could achieve the desired technical effects.

Following our suggestions, the applicant submitted post-filing data and argued that the key to achieving the desired technical effects lied in the defined binding properties of the antibodies. The applicant also submitted that the initial disclosure of the patent application already disclosed a list of known antibodies with the specific binding properties and verified the effects of the two in-house antibodies. Therefore, the skilled artisans could understand the application has provided sufficient information to enable the skilled person to implement the invention.

The post-filing data included the following information: (1) sequences for the two in-house antibodies used in the examples, along with an inventor’s declaration affirming the authenticity of the supporting data, and (2) additional data to verify that some of the known antibodies listed in the specification with the same binding properties exhibited similar functions to those verified in the examples. The supplementary data was generated using the same methods described in the patent application. This data was accepted by the Examiner, and the rejection was overcome.

This case demonstrates that post-filing data to address insufficient disclosure issues has become feasible. Nonetheless, it is essential to build a reasonable correlation between post-filing data and the effects to be verified.

In recent years, we have also succeeded in overcoming rejections for lack of inventiveness in several cases by using post-filing data.

Regarding non-support objections, CNIPA has not provided guidance on whether post-filing data can be used to address a non-support issue. Nevertheless, we have successfully employed post-filing data to address non-support rejections. In this regard, please refer to our previous articles: Post-filing data in addressing non-support issues and Case study: A successful example of post-filing data to address the support issue under China patent practice for details.

Requirement for post-filing data by Courts

The Supreme People’s Court (SPC) issued the Provisions of the Supreme People’s Court on Several Issues concerning the Trial of Administrative Cases involving the Granting and Confirmation of Patent Rights (I) (hereafter referred to as “Provision I”), effective from 12 September 2020. This provision requires the people’s court to consider post-filing data, as prescribed in Article 10:

“The people’s court shall review post-filing data submitted by a pharmaceutical patent applicant, claiming that the patent application satisfies the requirements of Article 22.3 and Article 26.3, etc., of the Patent Law based on this data.”

Following Provision I, there are several instances where post-filing data was accepted by the courts. Examples include AstraZeneca vs. Salubris [(2019), Zui Gao Fa Zhi Xing Zhong No. 33], Regents of the University of California vs. CNIPA [(2022) Zui Gao Fa Zhi Xing Zhong No. 287], Novo Nordisk vs. CNIPA [Beijing Intellectual Property Court (2023) Jing 73 Xing Chu No. 1324 Administrative Judgment], and the like.

Four case studies

1. AstraZeneca vs. Salubris [(2019), Zui Gao Fa Zhi Xing Zhong No. 33 issued on 26 October 2020])

On 26 October 2020, six weeks after the Provision I came into force, the SPC issued a Judgement [(2019) Zui Gao Fa Zhi Xing Zhong No. 33], supporting the patentee’s claim that the post-filing data should be considered, and clearly establishing the following criteria in assessing the admissibility of post-filing data:

(i) positive criterion: the facts to be directly proven by the supplementary experimental data should be clearly recorded or implicitly disclosed in the original application documents; and

(ii) negative criterion: the supplementary experimental data cannot be used to remedy the inherent defects of the original application documents.

During the invalidation proceedings of this case, post-filing data was submitted to demonstrate that the claimed compound possesses the “surprisingly high metabolic stability” mentioned in the Background section of the specification. However, the CNIPA did not accept this data.

The court of first instance found the data unacceptable for several reasons: (i) it was generated after the filing date of the patent; and (ii) the effect proven by the post-filing data was only described in the Background section of the patent, without further description or experimental data in other parts of the specification to support said effect. Thus, the skilled artisans could not determine if the claimed compound could achieve said effect based on the prior art.

The SPC reversed the conclusions made by the first instance court, ruling that: (i) experimental data submitted after the filing date should be evaluated, citing Article 10 of Provision I; and (ii) if the effect to be directly proven by the post-filing data is directly or implicitly disclosed in the original application documents, it should be deemed that the Applicant has completed the related research, and it would not undermine the principle of “first to file” to accept such post filing data. In summary, the SPC determined that the technical effect demonstrated by the post-filing data was already described in the original application documents and the data did not serve the purpose of addressing any deficiencies in those documents (i.e., meeting the aforementioned positive and negative criteria); therefore, the data was acceptable.

2. Novartis AG vs. CNIPA [(2019) Zui Gao Fa Zhi Xing Zhong No. 235 issued on 30 June 2021]

The first instance court rejected the post-filing data based on the grounds that the initial specification only disclosed the technical effect without providing any data to support the claimed effect.

The SPC overruled this reasoning based on Article 10 of Provision I but rejected the post-filing data as well for different reasons.

The SPC held that:

“if the original patent application documents have disclosed the relevant experimental methods and conclusions but only lacks experimental data, and if the experimental conclusions indeed correspond to the facts to be proven by the supplementary experimental data, then it can be presumed, in principle, that the patent applicant completed the experiments outlined in the original patent application documents before the filing date or priority date, based on the principle of good faith. Such supplementary experimental data should be relevant original experimental data. If the original experimental data cannot be provided for a valid reason, the applicant/patentee shall provide supplementary experimental data using methods and conditions consistent with those described in the original patent application documents.”

With this stance, the SPC finally rejected the post-filing data for the following reasons: (i) the applicant failed to provide the original experimental data, nor provided any explanation for its unavailability; and (ii) some of the experimental conditions used in the supplementary experimental data, such as the animal models, were different from those used in the experiments in the original application documents, and the applicant failed to justify the different animal models.

3. Regents of the University of California vs. CNIPA [(2022) Zui Gao Fa Zhi Xing Zhong No. 287 issued on April 2024]

This case relates to an Enzalutamide compound patent and represents the first judicial ruling from the SPC to confirm the technical effects based on post-filing data in an administrative litigation for confirmation of patent right.

The first instance court, though overruled the invalidation decision issued by the CNIPA in which the patent was invalidated as lack of inventiveness, rejected the post-filing data (in vivo tests conducted on experimental animals) submitted during administrative litigation. The first instance court held that the technical effect provided in the patent specification was the higher antagonistic and lower agonistic AR activity in in vitro experiments. However, the supplementary experimental data, exhibiting the effect on tumor size changes in in vivo animal experiments, could not prove that the claimed compound had a better effect (i.e., higher antagonistic and lower agonistic AR activity) than the prior art compound, as the in vivo and in vitro effects do not necessarily correspond to each other

The case was appealed to the IP tribunal of the SPC. The SPC, however, accepted the post-filing data, and again, adopted the above-mentioned positive and negative criteria. Specifically, the SPC opined that the post-filing data generated by a third party aimed to prove the technical effects of the claimed Enzalutamide compound disclosed in the initial disclosure and demonstrated better technical effect of this compound compared with the prior art compound, using the same model animal and experimental methods as those disclosed in the patent application documents. The in vivo post-filing data was closely related to the in vivo and in vitro experiments detailed in the patent. As for the slight differences in specific experimental conditions between the examples of the patent and the post-filing data, the SPC considered them to be acceptable adjustments based on actual conditions used in different labs, which shall not affect the accuracy of the result and the probative force thereof. Accordingly, the SPC ruled that the conclusion regarding the post filing data by the first instance court was incorrect.       

Notably, in overturning the invalidation decision, the court of first instance appears to have considered the commercialization status of the patented compound. The court noted that “for granted compound patents, especially those involving marketed drugs, patentees usually have provided substantial reasoning and evidence during the patent prosecution process. The complexity of the drug marketing approval process and the marketing approval result already confirm the technical effect of the patent to a certain extent.”

4. Mr/Ms. Jin vs. CNIPA [(2021) Zui Gao Fa Zhi Xing Zhong No. 832 issued on 28 June 2023]

Both the CNIPA and the first instance court upheld the validity of the patent during the invalidation procedure and subsequent administrative appealing. The case was then appealed to the SPC. One of the key disputes during the litigation is whether the post-filing data submitted by the patent applicant during substantive examination should be accepted.

The SPC ruled that: the inventors had already noticed that DIPAS (an amino silane precursor defined in granted claim 1) was a preferred precursor for preparing low-etching rate silicon oxide films, with greater stability and longer lifespan compared to other silane precursors, as indicated in the initial disclosure.

The SPC further noted that, although the patent specification did not explicitly mention DNPAS (also an amino silane precursor) disclosed in the prior art reference cited during the invalidation proceeding, post-filing data demonstrating whether DIPAS exhibits the preferred effects compared to the prior art DNPAS shall be allowed. The post-filing data related to the effects mentioned in the initial disclosure and served to establish that DIPAS had better stability than the prior art precursors including DNPAS, rather than making up for any inherent deficiencies in the disclosure of the patent document. Therefore, this data was acceptable.

It is worth mentioning that the method used in the post-filing data to test the stability of the precursor compound is a prior art method conventionally used to test the stability of chemical products, which is not disclosed in the specification of the patent. While the post-filing data is a record of original experiments conducted before the priority date of the patent, further evidence was submitted during the invalidation procedure to verify the authenticity of the post-filing data, and a witness was subjected to cross-examination during the court hearing.

Again, in the verdict, the SPC clarified the criteria for evaluating post-filing data submitted to demonstrate inventiveness. The examination should focus on the following aspects: (a) the authenticity, legality, and relevance of the experimental data and corresponding evidence; and (b) whether the data meet two conditions simultaneously: the patent document must clearly state or implicitly disclose the facts to be proven, and the experimental data must not be used to address inherent defects in the original application documents.

Summary

The 2021 update to the Patent Examination Guidelines, along with the SPC’s Provision I, allow for a more flexible and practical approach to the admissibility of post-filing data. Moreover, the positive and negative criteria established in Zui Gao Fa Zhi Xing Zhong No. 33 are particularly insightful. These criteria have been applied in several pharmaceutical patent litigation cases, providing applicants with essential guidance in evaluating the acceptability of their post-filing data.

Now it is clear that a mere literal disclosure of effects to be proven by post-filing data in the initial disclosure, without the backing of preliminary experimental results, should not automatically disqualify such data from consideration. Additionally, it is not strictly necessary for post-filing data to be generated prior to the priority/filing date of an application/patent.

Prior to the introduction of these new provisions, the SPC used to adopt a stringent stance on the acceptance of post-filing data. For instance, in a judgment issued on 31 December 2019, Boehringer Ingelheim Pharma GmbH & Co.KG vs. CNIPA [(2018) Zui Gao Fa Xing Shen No. 4176], the SPC rejected the post-filing data for reasons including: (a) there was no evidence demonstrating that the post-filing data was obtained before the priority date, and (b) the specification only literally described the effects to be proven by the post-filing data without providing any qualitative or quantitative experimental data or other evidence to support those effects.

Take-away information

Despite improvements in the acceptance of post-filing data, applicants must remain cautious when providing such information.

Acceptable experimental data provided after the priority or filing date can include:

1. data generated before the priority or filing date/ original data
2. data generated using the same or similar conditions (including materials, methods, temperatures, devices, and the like) as those described in the application, particularly in the working examples, and
3. data generated using prior art methods if the specification does not disclose the relevant method, together with solid further supporting evidence.

In case there are any inconsistencies between the experimental conditions used in the post-filing data and those described in the initial disclosure of the patents/patent applications, it is crucial to provide a reasonable explanation for these discrepancies.

It is essential to present strong arguments that clearly connect the disclosure in the original application and the technical results presented in the post-filing data. In addition, further evidence or supporting information to validate the data’s authenticity, including having a witness to accept cross-examination during a court hearing, and any other evidence to prove the legality, and relevance of the experimental data, can increase the likelihood of acceptance of the post-filing data.

Last but not least, while post-filing data may be acceptable, it does not belong to contents disclosed in the original application documents and can only be used to demonstrate effects directly or implicitly described in the initial disclosure. Therefore, it is advisable to include, as much as possible, a reasonable description of technical effects and the details of experimental data, experimental conditions, etc., in the initial application documents.

If you have questions or would like assistance, please don’t hesitate to reach out to our team.