China Update: “Small is beautiful” – the potential need for additional focused claims


In our news alert of March 16, 2017 we reported on the recent changes in the Guidelines for Examination. In one paragraph we speculated that there is a need for “including narrow claims, as a reservoir for amendments in case the patent is later challenged in invalidation proceedings” even though the new guidelines offered more freedom to make amendments during invalidation. A recent decision of the People’s Supreme Court in the case of the Patent Reexamination Board of SIPO (PRB) v. Beijing Winsunny Harmony Science & Technology with regard to the limitations of amending Markush claims during invalidation confirms this.

Markush claims are widely used in the field of chemistry and related arts to claim compounds as one genus by a chemical formula wherein certain substituents can have various alternatives. The Supreme Court has now put strict limitations on amending claims that use Markush type claims. The court considers such claims to not necessarily represent a set of different technical solutions or a set of various individual compounds claimed in an economic way, but sees them potentially as a single technical solution covered by the broad formula. In the above mentioned case it was found that deleting elements of the Markush claim creates a new group of compounds which has different technical effects based on their properties. Focusing on a newly created group of compounds by the amendment in certain parts of the Markush formula is not in line with the allowed “deletion of a technical solution from a claim” foreseen in the revised Guidelines for Examination.

This further stresses the need to structure the patent to survive an invalidation attack by using focused dependent claims. As such amendments may not be possible in invalidation proceedings it must be done during prosecution.

The invalidation environment in China

Invalidations in China are a serious threat to owners of valuable patent rights. Often the invalidation request is made anonymously by a so called “straw man”. Usually various grounds are put forward in parallel relating mostly to the following arguments for claiming invalidity: added subject matter during prosecution, insufficient disclosure, lack of claim support, lack of clarity of the claims, lack of essential technical features, double patenting as well as non-patentable subject matter and lack of inventive step and/or novelty.

In view of the strict examination standards in China in some of these areas amendments by the patentee may be desired during an invalidation attack to prevent a situation where the whole patent is at stake, if such an argument prevails. As witnessed there is a trend from the Supreme Court to limit amendments to the claims during invalidation. It is extremely problematic when an amendment is refused when the amendment focuses on the relevant commercial core of the invention.

There are requests for invalidation that seek out weaknesses of broad claims. Examples of requests that threaten patentees of high value patent demanding reverse royalties or cash payments to agree to withdraw their request for invalidation are known.

In such a situation it is usually a comfort to the patentee that there is at least certainty that the core parts of the invention can survive the invalidation with the form of narrow claims. Therefore it is highly recommended to draft such narrow claims when making voluntary amendments during the prosecution of the patent cases.

The importance of focused dependent claims

As a broad claim can be more easily attacked by newly found prior art documents or a potential support issue it is recommended to spend time on adding focused claims in view of the commercial value.

When drafting a patent application subgroups of the invention should have been formed or can be deduced from the specification based on high potential commercial value (e.g. individually disclosing a commercially relevant element such as a development compound in the pharmaceutical art) or best mode (e.g. subgroups based on structure-activity-relationship in the chemical art). These should be made the subject of dependent claims when filing voluntary amendments in China during patent prosecution.

Such claims not only help in invalidation, but also during patent enforcement. It is much easier to enforce a patent in administrative proceedings in China, such as tradefair enforcements, if a dependent claim closely mirrors the commercial product which may have been infringed. It has to be considered that the acting enforcement official is more willing to take action, if the infringement is more easily understood.

While all patent attorneys often focus their efforts on getting broad claims allowed (“bigger is better”), the Chinese system requires us to also spend time on prosecuting narrower claims (“small is beautiful”) focused on the core of the invention to minimize risk in invalidation proceedings.

Should you have any questions in regard to this update, please don’t hesitate to contact us.

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