Has your post-filing data been obtained in good faith?

For a long time, applicants have found it challenging to convince Chinese Examiners to accept post-filing data during prosecution.  In 2023, China updated its Examination Guidelines (Guidelines) to require Examiners to consider post-filing data (1) when considering inventive step and sufficiency; and (2) if a skilled person in the art could derive the technical effect demonstrated by the post-filing data from the specification as originally filed.  Specifically, Section 3.5.2, Chapter 10, Part II of the Guidelines was updated to include two examples of the types of post-filing data considered acceptable by the Chinese Patent Office (Office). 

The first example describes an application claiming compound A that exhibits hypotensive effects.  The specification describes: (1) methods of preparing compound A; (2) its hypotensive effects; and (3) experimental methods for determining hypotensive activity. However, the application does not contain any experimental results.  To prove sufficiency of disclosure, the applicant submitted post-filing data demonstrating that compound A exhibits hypotensive effects.  The Guidelines state that the Office can accept the submission of post-filing data under this scenario because the hypotensive effects of compound A were disclosed in the application, such that a skilled artisan would believe that this post-filing date would be derivable from the disclosure as originally filed.  The Guidelines also clarify that this post-filing data can be considered when evaluating inventive step.  This example shows that if a specification as filed describes (1) a method of preparing a compound; (2) the technical effect of a compound; and (3) a method of determining the technical effect of a compound, but contains no experimental data, post-filing data can be submitted to the Office during prosecution supporting the claimed technical effect. 

The second example discusses an application claiming compounds of Formula I.  The specification describes (1) compounds encompassed within Formula I; (2) methods of preparing examples of specific compounds encompassed by Formula I, such as compounds A and B; (3) experimental methods for determining anti-tumor activity; and (4) experimental results disclosing IC50 values of example compounds of Formula I on tumor cells ranging from 10 to 100nM.  To demonstrate inventive step, the applicant submitted comparative experimental data showing an IC50 value of 15 nM for compound A and 87 nM for the compound of Reference 1, thereby supporting the non-obviousness and superior efficacy of the claimed invention. The Guidelines state that the Office can accept the submission of the post-filing data in this scenario because a skilled artisan would believe that compound A and its anti-tumor effects had been disclosed in the specification as originally filed, and that the technical effect demonstrated by the post-filing data would be derivable from the disclosure.  This example shows that when the specification describes the specific effects of compounds falling within a generic formula, provides numerical ranges relating to this effect, and discloses methods for testing those parameters, post-filing data containing additional information for those parameters may be submitted and accepted if the data falls within the disclosed range in disclosed in the specification and is obtained using the same methods described in the specification.

Applicants must remember that when submitting post-filing data to the Office, there is a requirement of good faith.  Most patent Offices have a good faith requirement when making certain representations and submitting information to their respective offices.  China is no exception.  Article 20 of the Chinese Patent Law stipulates that patent applications must adhere to the principle of good faith.   Rule 11 of the Rules for the Implementation of the Patent Law (Rules) requires patent applicants to act with honesty and in good faith, and to refrain from engaging in fraudulent or deceptive practices.  Rule 69 lists a lack of good faith as a ground for invalidation of a patent.   Article 20 and Rules 11 and 69 were introduced in the fourth amendment to the Patent Law and its Implementing Regulations to prevent abuse and improve patent quality.

The Office can reject an application if post-filing data is submitted in violation of the good-faith requirements of Rule 11, as demonstrated by a recent case in February 2025. 

The application at issue was Application No. 202211011233.2, entitled “A Type of Tini-Class Small Molecule Compound and Its Preparation Method.”  The application claimed a novel pharmaceutical compound having enhanced drug tolerance and reduced side effects compared to imatinib, a well-known leukemia drug.  During prosecution, the Office rejected the application due to insufficiency, citing a lack of compound characterization data and a lack of experimental data demonstrating that the claimed compounds achieved any of the claimed technical effects of antitumor activity, increased water solubility, and enhanced drug tolerance.

The applicant requested re-examination and submitted post-filing clinical trial data from a comparative study involving 100 patients suffering from chronic myeloid leukemia. 

In China, Articles 19- 21 of the Drug Administration Law and Article 23, 25, 26 and 33 of the Drug Registration Administration Measures require that all clinical trials intended for drug approval:

1.       Receive prior approval from the National Medical Products Administration.

2.       Be registered and continuously updated in the Drug Clinical Trial Registration and Information Disclosure Platform (Platform).

3.       Comply with ethical requirements, including Institutional Review Board approval and informed consent from trial participants.

These requirements ensure that only legally authorized clinical trials are used to support regulatory approvals, including those related to patents.

The re-examination panel closely examined the post-filed clinical trial data and found that there was no registered record of any clinical trial on the Platform. The panel requested that the applicant provide evidence to verify the legitimacy of the clinical data, such as clinical trial approval documentation, patient consent forms, or site agreements with medical institutions.  When the applicant failed to explain the absence of this information or submit any documentation, the re-examination panel determined that the clinical trial data submitted was falsified and that the applicant violated the principle of good faith. In rejecting the application, the panel made two important statements:

1.        Clinical trial evidence must comply with legal disclosure requirements, and the failure to register a clinical trial invalidates any data that is submitted as post-filing data to support an application.

2.       The burden of proof is on the applicant to demonstrate that any post-filing submitted data is legitimate and obtained legally and ethically. 

This case demonstrates several important lessons for applicants submitting post-filing data in China.  First, applicants must ensure that any post-filing data submitted to the Office is truthful, accurate, and obtained in a lawful manner.  Misrepresentations and inconsistencies should be avoided.  Second, clinical trial data, whether described in an application as originally filed or submitted later post-filing during prosecution, should be consistent with any other related data that may be publicly available in regulatory records, publications, presentations, or press releases. 

This post was written by Lisa Mueller and from Zhong Lun.