An Overview of Amendment of Invention Patent Applications Under Chinese Patent Law

22 April 2011 Publication


By Xiaomin Ni, Scihead Patent Agent Co. Ltd., and Alex Nie, Foley & Lardner LLP

This article is part of our Spring 2011 edition of Legal News: China Quarterly Newsletter, Eye on China.

The General Principle

As a general rule, Article 33 of China’s patent law prohibits amendments that go beyond the scope of the original disclosure of the application as filed. This is similar to the law in most other countries.

Timing and Restrictions of Claim Amendments

The applicant is allowed to amend the application voluntarily at the time a request for substantive examination is filed, or within three months upon receipt of a notice from the patent office of entry into the substantive examination phase. For a national phase patent application of a PCT application, the applicant also may voluntarily amend the application under PCT Article 28/41 when entering into the Chinese national phase. In a voluntary amendment, no additional restriction is applied other than those set forth in Article 33.

The applicant also is allowed to amend the application when responding to any office actions. The amendment submitted in such a response, however, is governed by additional strict limitations.

First, new claims, whether independent claims or dependent claims, cannot be added. In view of such limitation, the applicant is advised to carefully review the claims and ensure that what the applicant desires to protect is included in the claims before the application enters substantive examination.

Moreover, at this stage, no amendment is allowed to broaden the scope of a claim. For example, an amendment may not delete or change claim limitations, even if the amendment finds support in the original specification. This rule is based on the so called "procedure saving" principle adopted by the patent office. This principle is designed to reduce search burden once an original search has been concluded and to speed up examination. In this context, it is reasoned that a broadened claim scope would necessitate a new search.

Amendments to the Specification

Amendments to the specification also are very restricted. For example, during the prosecution, the applicant may wish to add new experimental data obtained after the application was filed in order to satisfy the requirements for support. However, this type of amendment is generally not allowed.

In limited situations, the applicant may be able to introduce such data in a response to an office action. In this case, the new data can only be used to counter an objection based on obviousness or lack of novelty, such as with comparative experiments. The new data, even if entered, cannot be used to provide support for the claims. In sum, post-filing data cannot be used to remedy a deficiency.

Amendments During an Invalidation Proceeding

Under the current Chinese patent law, a patent may be challenged by any party after grant by filing a petition for invalidation before the Re-examination Board. When the validity of a patent is challenged, the patent owner is allowed to amend the claims by way of (i) cancellation of one or more claims, (ii) deletion of one or more Markush group members in a claim, and/or (iii) combination of claims.

Applicants should pay special attention to the timing of such amendments. Cancellation of claims and deletion of Markush group members, for instance, can be done anytime during the entire invalidation procedure. Incorporation of claims, however, is only allowed (i) when replying to a petition for invalidation, (ii) when the petitioner introduces new arguments and/or evidence, or (iii) when the Board introduces new evidence and/or arguments that have not been presented by the petitioner. Moreover, when combining claims, the claims to be combined should depend from the same independent claim and should not depend from each other.

Special Issues Relating to Claim Drafting in the Biotechnology Field

Because certain claims relating to biological sequences are not allowable under Chinese patent law, it is recommended that adequate disclosure be provided in the specification when the application is drafted. This will ensure that appropriate claim amendments in compliance with the patent law will have the necessary support. By way of illustration, please consider the following examples:

Nucleic Acid Sequence Homologues
Claims reciting nucleic acid sequences having a certain identity, e.g., 90 percent, to a specific nucleic acid sequence, are not allowable in China. An allowable claim may read as follows:

Claim 1. A nucleotide sequence that hybridizes, under stringent conditions, to sequence X and encodes a protein having an activity Y.

Claim 1 may be allowable provided: (i) the stringent conditions are described in the specification and (ii) at least one exemplary Sequence X is provided in the specification.

Amino Acid Sequence Homologues
Like nucleic acid homologues, a claim reciting an identity percentage is not allowable under Chinese patent law. An allowable claim may read as follows:

Claim 2. A polypeptide that has activity X and is derived, by way of one or more amino acid substitutions, deletions or insertions, from the polypeptide sequence Y.

Claim 2 may be allowable provided: (i) sequence Y is exemplified in the specification, (ii) preparation of the polypeptide Y is provided in the specification, and (iii) activity of polypeptide Y is demonstrated in the specification.

Therefore, an applicant should include claim 1 and/or 2 shown above in the disclosure when preparing the priority application. Without such disclosure, the applicant would not be allowed to make the appropriate amendments to comply with Chinese patent law.

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