Amended Patent Examination Guide – determining the novelty of compounds

The China National Intellectual Property Administration’s latest amended Patent Examination Guide was implemented on 15 January 2021. This chapter reviews the amendments to Section 5.1 of Chapter 10, Part II of the guide regarding determining the novelty of a compound.

Patent Examination Guide

The pre-amended guide stipulated that:

*for a compound for which protection is sought by a patent application, it is presumed that the compound does not possess novelty if it has been mentioned in a reference document, unless the applicant can provide evidence proving the compound is unobtainable before the application date. The meaning of ‘mentioned’ here is that a clear definition or explanation of the chemical name, molecular formula (or structural formula), physical and chemical parameters or preparation method (including raw materials) of the compound is given … It is presumed that a compound claimed in a patent application does not possess novelty if an identical preparation method of the compound is disclosed in a reference document, even when the name, molecular formula (or structural formula), or physical and chemical parameters of the disclosed compound are unclear.*

The pre-amended guide did not explicitly embody a person skilled in the art as the subject in novelty determination. It can be presumed that the compound does not possess novelty if one of the following is defined or explained in a reference document:

•    chemical name;
•    molecular formula (or structural formula);
•    physical and chemical parameters; or
•    preparation method (including raw materials).

An examiner can directly presume that a compound does not possess novelty after a reference document – disclosing one of the above four points – is retrieved and the burden of proof is shifted to the applicant, demanding that the applicant fulfil the burden of proof for a negative claim that the compound cannot be obtained before the application date.

Section 5.1, Chapter 10 of the amended guide stipulates that:

*for a compound for which protection is sought by a patent application, the compound does not possess novelty if its chemical name, molecular formula (or structural formula) and other structural information is recorded in a reference document, which disposes a person skilled in the art to believe that the claimed compound has already been disclosed, unless the applicant can provide evidence proving the compound is unobtainable before the application date. If the structural information recorded in a reference document is insufficient for identifying the structural similarities/differences between the claimed compound and the compound disclosed in the reference document but a person skilled in the art has a reason to presume that they are substantially identical based on a comprehensive consideration of other information recorded in the reference document, such as physical and chemical parameters and preparation methods of the disclosed compound and experiment data of its effects, the claimed compound does not possess novelty unless the applicant can provide evidence proving a difference in structure.*

The amended guide underlines two circumstances where the examiner should follow the basic principle of novelty examination and take the perspective of a person skilled in the art to comment on the novelty of a compound.

Novelty: structural information
When judging the novelty of a compound based on structural information, lack of novelty can be determined only when the reference document records the chemical name, molecular formula (or structural formula) and other structural information of the compound, and when that structural information is disclosed in the reference document to such an extent that “a person skilled in the art is disposed to believe that the claimed compound has already been disclosed”.

According to the amended guide, the examiner should analyse the disclosure of the reference document from the perspective of a person skilled in the art. The examiner can then conclude that a compound does not possess novelty only when holding that a person skilled in the art, after evaluating the disclosure, considers that the compound claimed in the present application has been disclosed in the reference document.

Under such circumstances, if receiving examination opinions rejecting the novelty of a compound, the applicant should first attentively analyse whether the examiner concluded that the compound does not possess novelty according to the above provisions (ie, whether the reference document cited by the examiner records the substantive technical content of the corresponding technical scheme of this application, and whether a person skilled in the art can obtain the compound claimed in the application based on the disclosure of the reference document).

In response to the examiner’s rejection, the applicant can explain the novelty of the compound by providing evidence that the compound can neither be obtained through commercial channels before the filing date nor be prepared or isolated based on the information disclosed in the reference document in combination with other common knowledge available to a person skilled in the art.

Substantially identical
According to the amended guide, if the structural information recorded in a reference document is insufficient for identifying the structural similarities and differences between a claimed compound and a compound disclosed in a reference document, the examiner should consider other information recorded in the reference documents (including physical and chemical parameters and preparation methods of the compound and experimental data of its effect) before determining whether the combination of structural information and other information is sufficient to such an extent that a person skilled in the art has a reason to presume that the claimed compound is substantially identical to the compound in the reference document. Where the structural information of the compound of the application has not been fully disclosed in the reference document, the examiner will, from the perspective of a person skilled in the art, take the structural information disclosed in the reference document with other information into consideration to fully and reasonably explain why the structure of the claimed compound is considered identical to the compound disclosed in the reference document. The burden of proof may be transferred to the applicant only after the examiner has completed this fully justified preliminary burden of proof.

The amended guide proposes the physical and chemical parameters, preparation methods, experimental data of effect and other factors that need to be taken into consideration under the circumstances, which provides reference and guidance for both examiners and applicants when adducing evidence.

In response to the examination opinions, the applicant may judge whether the examiner’s presumption is reasonable and whether the examination opinions are sufficiently justified according to the disclosure of both the reference document and the present application. If the examiner simply lists the physical and chemical parameters, preparation methods and other information in the reference document to presume that the compound of the application does not possess novelty, and fails to fulfil the preliminary burden of proof in accordance with the amended guide, the applicant can argue in the observation and, if necessary, demand the examiner give a justifiable and sufficient reasoning as prescribed by the above provisions to complete the preliminary burden of proof. It can be anticipated that the substantive examiner will be more cautious about presuming that a compound in an application is substantially identical to a compound in a reference document.

Meanwhile, the amended guide changes the exception to “unless the applicant can provide evidence proving a difference in structure”. This requires that the applicant prove a positive claim, which relatively reduces the difficulty of the applicant’s proof compared with the pre-amended requirement that “the applicant can provide evidence proving the compound is unavailable before the application date”, which demands that the applicant prove a negative claim. In practice, in response to the presumption of lack of novelty, the applicant can demonstrate that the claimed compound possesses novelty by providing evidence to prove that there is a structural difference between the claimed compound and the compound disclosed in the reference document. For example, where the reference document does not disclose physical and chemical parameters or effect experimental data, among other things, in response to the examiner’s presumption that the claimed compound is essentially identical to the compound in the reference document, the applicant can prove that the compound of the present application has a different structure from the compound obtained in the reference document by providing a comparative experiment including physical and chemical parameters and effect experimental data, so as to show that the compound of the present application possesses novelty.

Compared to the pre-amended guide, the amended guide holds that the subject of novelty determination should be a person skilled in the art. It underlines that the examiner should take the perspective of a person skilled in the art and observe the basic principles of novelty examination to comment on the novelty of a compound. The amended guide has therefore incorporated the criteria for determining the novelty of a compound into the general principle for judging the novelty of any invention.

In addition, the amended guide respectively clarifies the burden of proof carried by the examiner and that carried by the applicant according to the extent of the sufficiency of the disclosure of a compound’s structural information in a reference document. If the examiner’s presumption is ’identical’ based on a disclosed structure and their comments are valid, the applicant is required to demonstrate the novelty of the compound in the application by proving a negative claim that “the compound is unavailable before the application date”. If the examiner’s presumption is ‘substantially identical’ based on a combination of structural information and other information disclosed in a reference document, after the examiner fulfils the preliminary burden of proof, the applicant need only provide evidence proving a positive claim that “a difference in structure exists” to demonstrate the compound in the application possesses novelty.

Preparation is key

In light of the above changes, for applicants seeking patent protection for a compound invention in China, it is advisable to prepare in advance of the filing of the patent application.

Conduct a full search
Conduct a full search before submitting the patent application, as the examiner follows the principle that a compound is seen as having been disclosed as long as its structural information (eg, chemical name, molecular formula or structural formula) is mentioned. If the search reveals that there is structural information of a compound in the prior art that could have an impact on the novelty of the compound to be protected, the applicant can make amendments and adjustment pre-emptively before submitting the patent application. The applicant would be at a disadvantage when having to amend the patent application documents to overcome the novelty issues pointed out by a substantive examiner under the constraints of Article 33 of the Patent Law, which prescribes that while the applicant may amend the patent application documents after submitting them, the amendment will not go beyond the scope recorded in the initial description and claims. This clause is strictly enforced.

Fully disclose information
Fully disclose the information of preparation, structure identification, use and effect of the claimed compound in the patent application documents to tackle any presumption that a claimed compound is substantially identical to a compound in a reference document. If necessary, the applicant should provide the data of a comparative experiment with the compound in the closest prior art and specify the use and effect of the claimed compound explicitly or with experimental data. In addition, the experiments and results on preparation, structure identification and application effect must be clearly and fully recorded in the application documents, so that if novelty issues are highlighted during the examination stage, the applicant can compare and/or supplement comparative experiments according to the records in the patent application documents with the reference documents to prove that the structure of the compound is indeed different from that in the cited reference documents.