Markush claims in China - what can be arbitrarily deleted during invalidation?
Since 2010, the China Patent Re-examination Board (PRB) has published the top 10 patent invalidation cases of the year in April of each year. The selection criteria are high social concern, significant impact on the related industry, or involve difficult legal issues and important examination criteria. Below is one of the top 10 cases that discusses post filing data in China patents.
This case (Beijing Winsunny Harmony Science & Technology Co., Ltd. v. Daiichi Sankyo Co., Ltd) describes an invalidation request of Daiichi Sankyo’s Chinese invention patent 97126347.7 related to processes of preparing pharmaceutical compositions for treating or preventing hypertension. The patent covered the marketed hypertension drug Olmesartan medoxomil.
During the invalidation, the patentee made select amendments to multiple Markush groups, deleting particular individual components from several different R groups of a molecule. The issue at hand is whether these amendments are allowable during an invalidation proceeding, which typically has very strict rules regarding amendments.
Courts Differ on Markush Claims in China
In short, it boils down to how the courts interpret a Markush claim. Does it refers to a general technical solution or parallel embodiments of several technical solutions? If it is one general solution, should you really be able to pick and carve away at its scope? Does doing so create a new scope that has a different technical effect than the original invention? If so, is that allowable?
The Patent Re-examination Board (PRB) and the Beijing High People’s Court (BHPC) disagreed on how to interpret Markush claims in China. The PRB felt that arbitrary amendments should not be allowed because a Markush claim is directed towards a general technical solution. Arbitrarily deleting elements during invalidation would thus create new scopes of protection that could have different technical solutions.
The BHPC thought that Markush groups represented alternate parallel technical solutions, and thus deleting one or more options just narrowed the scope of the claim. The Supreme People’s Court (SPC) ruled that the amendments were allowable. Additionally, the SPC indicated that such types of amendments may be allowed during invalidation as long as the amendments did not generate a scope that possessed a new function or technical effect.
Markush Claims in China Drafting Tips
Applicants should be aware that amendments which carve out a new scope with improved technical effect (as compared to the original scope) may not be allowable. During an invalidation proceeding, it will be difficult to amend claims to a narrower scope with improved technical results to overcome inventive step. Instead, at the time of drafting, applicants should draft several dependent claims directed towards alternate scopes with varying qualities of efficacy, including very narrow claims covering the best, most efficacious compounds. It is risky to rely on being able to carve out scope from broader claims during an invalidation challenge.
A side note on inventive step . . .
Interestingly, this case also briefly discussed inventive step. The petitioners argued that the patent lacked inventive step because a specific embodiment in the patent had equivalent technical effect as a prior art compound. The PRB disagreed and emphasized that inventiveness is actually a three-step determination, and it is inappropriate to directly apply just the “unexpected technical effect” test to see if claims are inventive or not.
Sources: Lexology, Sanyou IP Group
China Releases Draft Implementation Guidelines for the Drug Administration Law
2022年6月2日
The latest draft implementation guidelines for China’s Drug Administration Law (“Guidelines”) are out and open for comment. Previously, the new implementation measures for early dispute resolution mechanisms for drug patents (“Patent Linkage Measures”) came into effect on July 4, 2021. The Guidelines indicate that the final approval of generic chemical drug applications for marketing approval […]
閱讀更多 >
Can Post Filing Data Overcome Inventive Step in China?
2018年11月19日
Since 2010, the Patent Re-examination Board (PRB) has published the top 10 patent invalidation cases of the year in April of each year. The selection criteria are high social concern, significant impact on the related industry, or involve difficult legal issues and important examination criteria. Below is one of the top 10 cases that discusses […]
閱讀更多 >
Introducing the New USPTO Cancer Moonshot Expedited Examination Pilot Program
2023年1月10日
Starting from February 1, 2023, the USPTO will begin the new Cancer Moonshot Expedited Examination Pilot Program that advances out-of-turn applications that are directed to oncology or smoking cessation. This new program will replace the Cancer Immunotherapy Pilot Program that has been in place since 2016, and covers more technologies than only cancer immunotherapies. Applications […]
閱讀更多 >
Can I transfer priority rights in China without the consent of other applicants? Insights from the Broad Institute’s CRISPR patent
2025年2月4日
The high-profile disputes surrounding an important CRISPR patent belonging to The Broad Institute, MIT and Harvard (hereinafter “the proprietors”) has attracted a lot of attention in recent years, particularly regarding the validity of priority rights that were challenged worldwide. In Europe, the patent was famously revoked by the European Patent Office (hereinafter “EPO”) due to […]
閱讀更多 >
我們過去活動
Dr. Jacqueline Lui, Ms. Pauli Wong, and Mr. Eddie Ho Named Patent Stars by ManagingIP
2025年6月13日
Eagle IP Ranked Among Top Tier Firms in IAM Patent 1000
2025年6月12日
Jennifer Che from Eagle IP to Attend BIO 2025 in Boston!
2025年6月11日
Insights from HKSTP Market Discovery - BIO Connect
2025年5月28日
HKMHDIA Medical Fair Forum
2025年5月27日
Celebrating Innovation at the Asia Summit for Global Health
