“MARKUSH CLAIM” AND DISPUTE OF PATENT INVALIDITY

◆ Docket: (2016) ZuiGaoFaXingZai No. 41

CASE 17 :

City of Beijing

[Headnotes]

The nature of a Markush claim is a generalized, rather than a congregation of compounds, subject matter. Amendment of a Markush claim should be limited to a group or a compound producing no new character or effect. Markush claim drafting should followthe “tripartite” in forming inventiveness for compound claims.

[Synopsis]

Plaintiff: Beijing Winsunny Harmony Science & Technology Co., Ltd. (Winsunny)

Defendant: State Intellectual Property Office, Patent Reexamination Board(PRB, or the Board) 

The third party: Daiichi Sankyo Company Ltd. (Daiichi Sankyo)

Daiichi Sankyo is the patentee of a patent for “Process for preparing pharmaceutical composition for treatment or prevention hypertension” (the Patent) which was drafted withMarkush claims. Winsunny requests invalidation of the patent with SIPO, Patent Reexamination Board (PRB) for lack of inventiveness. On August 30, 2010, Daiichi Sankyo made amendment to the claim, including: deletion from claim 1 “… salt or ester that may be used as medicine” of the words “or ester;” deletion of “alkyl having 1-6 carbon atoms” under claim 1 R4 definition; deletion of all subject matters other than carboxyl and formula COOR5a under claim 1 R5 definition. In the oral examination, the PRB informed Daiichi Sankyo that the amendment of deleting “or ester” is acceptable, but all the others are not for being inconsistent with Article 68 under the Implementing Regulations under the Patent Law. Neither Daiichi Sankyo nor Winsunny objects to it. On January 14, 2011, Daiichi Sankyo submitted the amended claim substituting a page deleting “or ester” from claim 1. The Board allowed the patent as amended with Decision No. 16266 because claim 1 in light of reference 1 is nonobvious under Article 22(3) of the Patent Law.

Winsunny is not satisfied, and files for judicial review. The court of first instance finds that the Board’s rejection of the amendment of August 30, 2010 on basis of Article 68 of the Regulations is not inappropriate. Claim 1 is nonobvious over reference 1, and therefore possesses inventiveness.It then upholds No. 16266 decision. Winsunny is still not satisfied, and appeals. The court of second instance finds that Markush claim is a unique type that carries parallel subject matters; the Daiichi Sankyo amendment of August 30, 2010 narrows the scope of the patent protection, in line with Article 68(1) of the Regulations; the patent claim at issue contains one embodiment whose technical effect is compatible with that of embodiment 329 in reference 1 of the prior art, hence achieving no unexpected result, possessing no inventiveness. The court therefore vacated the decision below and Decision No. 16266, remanding the case to PRB for a new decision. 

The Board is not satisfied and requests for reconsideration with the Supreme People’s Court, which upon certiorari vacated the second instance decision and reinstalled the first instance decision, finding that the compound claim of Markush type should be taken as a generalized subject matter, rather than as congregation of multiple compounds; the principle for allowing amendment to Markush claim should be that it may not produce new property or effect of a category or a single compound by the amendment, but the consideration must be made on case-by-case basis; the inventiveness of a Markush claim compound should be determined following the “tripartite” method delineated by the Patent Examining Guidelines. The unexpected result is a secondary consideration for inventiveness. Generally, it would be inappropriate to bypass the “tripartite” test by applying the unexpected result test for inventiveness.

[Judge’s Comment]

This case relates to the nature of Markush claim, rules for making amendment in invalidity proceedings and determination of inventiveness. Markush claim is a relatively unique way of drafting for chemical or pharmaceutical inventions. Because of its generalized function, it has become widely used. Its nature, rules for making amendments and its inventiveness standard will directly affect large number of chemical and pharmaceutical applications for patents, attracting wide attention in the practicing and academic circles. The Supreme People’s Court clarifies in this case that amendment to Markush claim should be premised on the basic condition that it may not introduce a category or a single compound with new property or effect; determination of inventiveness must follow the “tripartite” test. This case has clarified several important legal principles and has important guiding influence for drafting patent claims in the field of chemical and pharmaceutical inventions.