Changing Rules for post-filing Experimental data -Some reflections on the newly-issued Invalidation cases

Author:CAO Lili , ZHANG Yuan | UpdateTime:2021-02-02 | Hits:
The admissibility of post-filing experimental data during prosecution, invalidation or administrative litigation proceedings has been long debated for pharmaceutical patent applicants. In an effort to strengthen the protection of intellectual property rights and actively respond to the demands of the rapid economic and technological development, several effective administrative and judicial measures are coming into force in China to lower the threshold for submitting and considering "post-filing experimental data" in a more reasonable manner. 

This change will be welcomed by patent applicants in the chemical/pharmaceutical field in China, particularly those originating from international jurisdictions, with a more liberal approach to allowing the inclusion of post-filing data during examination. However, it is still unclear to the applicant or patentee exactly what type of "post-filing experimental data" would be acceptable.

Recently, a Richter Geodeon CN patent related to the drug product Cariprazine holds the validity relying on post-filing data, while a Boehringer Ingelheim (BI) CN patent related to the drug product Empagliflozin relate was invalidated for lack of inventive step. The decision made by the CNIPA gives a clear explanation to the supplemental data issue where inventive step is involved.


1. Experimental data submitted after the filing date to address sufficiency objections and inventiveness objections shall be analyzed by the examiners.

Both the judicial interpretation and the amended Patent Examination Guideline seemed to provide some principles for the supplemental data issue. According to these provisions, experimental data submitted after the filing date to address sufficiency and inventiveness issues shall be analyzed by the examiners. 

−     Article 10 of “Provisions of the Supreme People's Court on Several Issues Concerning the Application of Law in the Trial of Administrative Cases for Patent authorization and Confirmation (1)” that came into effect on September 12, 2020 stipulates: “Where the medicament patent applicant submits supplementary experimental data after the filling date, claims that the demonstration of the patent application in conformity with the provisions of the Article 22, Paragraph 3 and Article 26, Paragraph 3 of the Chinese Patent Law is to rely on this data, the data shall be reviewed by the court.”

−     The amended Patent Examination Guideline, which came into effect on January 15, 2021, also clarified that “For the experimental data supplemented by the applicant after the filling date for meeting the requirements of Article 22, paragraph 3 and Article 26, paragraph 3 of the Chinese Patent Law, the examiner shall examine the data.”

2. The amended Guideline clarified the examining criteria of supplementary experimental data for pharmaceutical patent applications.

According to section 3.5.2 of the amended Guidelines, the technical effects to be elucidated by the supplemented experimental data should be such that they can be derived by a person skilled in the art from the disclosure of the patent application.

For pharmaceutical patent application, the Guideline adds section 3.5.2 including two typical examples, to show what the technical effect derivable from the disclosure of the patent application means exactly.

According to Example 1 in section 3.5.2, when the specification involves literal description of the effect and the experimental method but with no result data, the corresponding technical effect should be considered as derivable from the original disclosure, and the post-filing activity data proving such effect should be taken into consideration for patentability evaluation. 

According to Example 2 in section 3.5.2, it is acceptable to submit specific numbers (for example, “15nM”) for inventiveness examination if the “binned” data (for example, “10-100 nM”) is described in the specification.


Facts of Richter Geodeon invalidation case (related to Cariprazine)

The CNIPA issued Invalidation Decision No. 47087 regarding the Richter Geodeon patent (200880015627.7) on January 05, 2021, holding the patent effective by taking supplementary experimental data into consideration. During the invalidation proceeding, Richter Geodeon submitted part of the response document for the prosecution in Europe as evidence. The document showed that the hydrobromide pursued by the patent manifested significant higher purity than other cariprazine salts, and higher solubility than the free base of cariprazine.

In the decision, the panel stated the following:
i) Any technical effect recorded in the description is the factual basis for evaluating inventiveness. 
ii) For the technical effect recited in the specification but with no specific data to support, if combined with the overall content of the specification, it can be determined that the patentee has paid attention to the technical effect and conducted research before the application date, and that the technical effect has been described in the specification, then the supplemented data could be regarded as the evidence to prove the inventiveness of the invention.
iii) The panel accepts the supplementary experimental data, and recognizes the purity effect as un-expectable. For the solubility effect, it is regarded as expectable in light of the prior art.
iv) Regarding purity, the specification describes "the hydrochloride salt is particularly preferred, as it may be prepared in the highest yield and highest purity”, and those skilled in the art can conceive from the specification that the higher purity of hydrochloride salt compared to other salts is a technical effect that the patentee has paid attention to and should have been researched before the filling date. The panel thus takes the corresponding experimental data into consideration. 

Facts of Boehringer Ingelheim(BI) invalidation case (related to Empagliflozin)
The CNIPA issued an invalidation decision regarding the BI patent (200680011591.6) on January 04, 2021 for lack of inventive step. In the Decision, the panel holds that supplementary experimental data should not be considered as the basis for proving the claimed high selectivity towards SGLT-2 over SGLT-1 because said low inhibitory effect on SGLT-1 is not mentioned in the original specification. 

In the decision, the panel asserted the following:
i) The technical effects proved by the supplementary experimental data should be obtainable by those skilled in the art from the disclosure of the original specification.
ii) If those skilled in the art are not able to derive or read out the technical effects to be proved by the supplementary experimental data from the original specification, the supplementary data cannot be regarded as the evidence to prove the inventiveness of the invention.
iii) The patent at issue describes by incorporating other documents for reference that the compound has an inhibitory effect on SGLT, especially SGLT-2. And no other experimental data is recorded in the original specification. 


The inadmissibility of the post-filing experimental data during the Chinese patent examination has been a decade-long headache for many applicants from the pharma/chemical field. In the last decade, the principle of “any embodiment and experimental data submitted after the date of filing shall not be taken into consideration” was adopted, although controversially, to avoid the potential scenario under a background of very uneven IP abilities between the domestic and the foreign applicants. 

In the past, due to the weak research and development capabilities of pharmaceutical companies in China, the requirements for supplementary data on pharma patents are stricter. This means that pharmaceutical patents are less likely to be allowed or have questionable stability. However, China’s share of the global pharmaceutical market is gradually increasing recently. Innovative pharmaceutical companies are developing rapidly, the interests of both innovative and generic pharmaceutical companies should be weighed. Compared with the previous concern that foreign patent monopolies will damage domestic competitiveness, requirement for stricter patent protection indicates that the adjustment of the review of supplementary data is an objective demand of China's industrial development currently.

Patent examination guidelines of 2017 finally allowed patentees to submit post-filing data to the patent office. From judicial interpretation and new guidelines of 2021, a more tolerant judicial policy shall be adopted for the submission of experimental data in the field of pharma/chemical. Decision No. 47087 made waves in the industry with an eye-opening finding: the change in CNIPA examination standards – not just on rules but on practice. Although it is unclear what the change means exactly, it may lead to a more liberal standard to be consistent with other jurisdictions standard.