Second Draft”) was issued by the China National Intellectual Property Administration..." /> The Second Draft Patent Examination Guidelines

The Second Draft Patent Examination Guidelines on Patent Linkage Invalidation, PTE and PTA

Pharmaceuticals 4 min
November 3, 2022

TTThe second draft amendment to the Patent Examination Guidelines (the “Second Draft”) was issued by the China National Intellectual Property Administration (the “CNIPA”) on 31 October 2022 for public consultation until 15 December 2022. The Second Draft contains a number of changes which are different from the first draft amendment issued on 3 August 2021 (the “First Draft”), in particular on Patent Linkage Invalidation, Patent Term Extension (the “PTE”) and Patent Term Adjustment (the “PTA”). For details on the First Draft, please refer to Bird & Bird’s article – “China Pharma Update – Draft Patent Examination Guidelines contain proposals on Patent Linkage Invalidation, Patent Term Extension and Patent Term Adjustment”. This article highlights the proposed changes on patent linkage invalidation, PTE and PTA.

I. Patent Linkage Invalidation

A comparison of the main proposed changes in the First Draft and Second Draft is set out in the table below:

First Draft Second Draft
Definition A patent invalidation petition filed by a generic drug market authorization (“MA”) applicant against a patent registered on the China Marketed Drug Patent Information Registration Platform (the “Patent Platform”), after it has submitted a Category IV certification in accordance with Patent Linkage Implementing Measures.  A patent invalidation petition filed by a generic drug MA applicant against a patent registered on the Patent Platform.
Documentation The Petitioner must indicate in the invalidation petition:

  • the patent in dispute is registered on the Patent Platform;
  • the Petitioner is the generic drug MA applicant;
  • a Category IV certification has been submitted;
  • the generic MA application acceptance notice; and
  • a copy of the certification.
  1. If the invalidation petition is filed after the Category IV certification – the same documentation as set out in the First Draft must be filed.
  2. If the invalidation petition is filed before the Category IV certification is submitted, the Petitioner shall provide CNIPA with evidence that the invalidation petition is related to the patent linkage mechanism promptly, which shall not be later than (1) the end of the oral hearing on the invalidation proceedings or (2) the issuance of the invalidation decision if no oral hearing is held.


The proposed changes in the Second Draft, if adopted, make it clear that, a generic applicant can commence invalidation proceedings well in advance of the MA application for patent challenge purposes. The Second Draft provides that if the documentary evidence is not filed within the statutory timeline, the invalidation will not be applicable for patent linkage mechanism, namely, the patent challenge for market exclusivity purpose.


There are only minor changes between the First Draft and the Second Draft in respect of the PTE provisions. For instance, the proposed categories of drugs eligible for PTE. The conditions for PTE and the calculation of the PTE term remains generally the same.

The Second Draft clarifies that the 3-month timeline to request PTE is calculated upon MA approval in China. The documentation for the request includes the technical dossier to determine the patent protection scope for the PTE. It is not limited to the manufacturing process dossier for a process patent as provided in the First Draft. The Second Draft reinstates that the patent during the PTE term will have the same rights and obligation as the originally granted patent. This is in line with the draft Implementing Regulations of the PRC Patent Law (27 November 2020).


There is only a minor clarification contained in the Second Draft relating to the “date of request for substantive examination.” The application date of the substantive examination and after due payment of the examination fee. However, if the application date of the substantive examination is earlier than the ordinary patent publication date (namely 18 months upon patent application date or an earlier date as requested by the applicant), the three-year timeline will be calculated from the publication date.

Considering the minor changes in Second Draft, it appears that most of the proposals on PTE and PTA will likely be adopted by CNIPA.

Written by
Alison Wong
Alison Wong
As a partner in our Intellectual Property Group in Hong Kong and head of our Life Sciences & Healthcare Sector Group in Asia, I have 20 years' experience in advising clients in the life sciences, healthcare, food & beverage and retail & consumer sectors.
Martoe Xu
Martoe Xu
I am a Patent Agent in our Intellectual Property Group, based in our Hong Kong office. I advise clients on a broad range of IP matters covering patent, trademark, copyright, domain name and compliance. I have experience in dealing with patent prosecutions, analysis and invalidations, trademark availability searches and infringement analysis, IP and anti-trust litigations, and IP contract reviews etc. I also advise clients on drug, medical device and advertising regulatory matters in China.

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