1. In Japan, a product invention can be identified in a claim by its production process (product-by-process claim). In this case, the Supreme Court judged an interpretation of a technical scope of the product-by-process claim in patent-infringement litigation. Furthermore, the Supreme court decision had an important impact on the prosecution of the product-by-process claim.
2. Teva, a global generic company, filed a patent infringement lawsuit against Kyowa Hakko Kirin (KHK) as infringing Teva’s patent right (Patent No. 3737801), before the Tokyo district court.
Teva’s patent relates to a pravastatin composition, a cholesterol-lowering drug, with a reduced amount of impurities. Patented claim identifies the pravastatin composition by its production process and impurity concentration.
KHK’s product meets the requirement of the impurity concentration of the Teva’s patented claim. On the other hand, KHK’s product was produced by a production process that is different from the production process recited in Teva’s patented claim.
3. Since the district court dismissed Teva’s request, Teva appealed to the IP High Court. The IP High Court dismissed Teva’s request for the following reasons:
In terms of determining the technical scope of a product-by-process claim, the claim should be interpreted to cover only a product that is produced by the claimed production process, unless there are special circumstances existing at the filing date of an application where it was impossible or difficult to directly identify the product invention in the claim by its structure or property.
Since there are no special circumstances for Teva’s patented claim, the technical scope of the patent claim should be limited to a product produced by the claimed production process. Accordingly, KHK’s product produced by a production process that is different from the production process recited in the patented claim is not within the technical scope of Teva’s patented claim.
4. Since the IP High Court dismissed Teva’s request, Teva appealed to the Supreme Court. The Supreme Court reversed the IP High Court decision and remanded the case to the IP High Court for the following reasons:
(1) Even if a product invention is identified in a claim by its production process, the claim should be interpreted to cover a product having the same structure, property and etc. as those of the product produced by the claimed production process.
(2) Under such a claim interpretation, there is a concern that a third party cannot predict the technical scope of a product-by-process claim because it is unclear what structure or property of the claimed product is defined by the production process recited in the claim. On the other hand, there can be any circumstance in which it was technically impossible to analyze a structure or property of the product at the time of the filing of a patent application or it was impractical to do so for the reason that it requires considerably excessive time and cost.
(3) In view of said circumstances, when a product invention is identified in a claim by its production process, the claimed invention could meet the Clarity Description Requirement only if there are circumstances where it is impossible or utterly impractical to directly identify the product by its structure or property at the time a patent application for such product was filed.
5. Influence of the Supreme Court decision
In view of the Supreme Court decisions, the Japan Patent Office (JPO) revised the Examination Guidelines. (URL: http://www.jpo.go.jp/tetuzuki_e/t_tokkyo_e/1312-002_e.htm) Specifically, the Examination Guidelines state that when a product invention is identified in a claim by its production process (product-by-process claim), it is required to prove the existence of “impossible or impractical circumstances” where it is impossible or utterly impractical to directly identify the claimed product by its structure or property at the time a patent application for such product was filed, in order that the product-by-process claim meets the Clarity Description Requirement.
Furthermore, the JPO states that this handling of Clarity Description Requirement for the product-by-process claim is applied to not only the pending applications but also the opposition and trial for patents which have already been granted.
6. Our comments
(1) The Supreme Court judged that a product-by-process claim is interpreted as covering an accused product that is indistinguishable from the patented product as a product, although the accused product was produced by a production process that is different from the claimed production process.
It is worth noting that the Supreme Court newly judged the Clarity Description Requirement for the product-by-process claim, despite that the Clarity Description Requirement of the product-by-process claim was not the point in dispute in the past court procedures.
(2) The point at issue in this case is an interpretation of a technical scope of a product-by-process claim in patent-infringement litigation. In another case (Case No. 2012 (ju) 2658) relating to the validity of the same patent as that of the present case, the Supreme Court judged that, in terms of determining the validity of a product-by-process claim, the claim should be interpreted in the same manner as in determining the technical scope of the product-by-process claim.