APAA e-Newsletter (Issue No. 34, April 2023)

Narrow Interpretation of Incorporation by Reference in Korea

Syhoon Kim, Kim & Chang (Korea)

A recent decision by the Patent Court of Korea (Patent Court Decision 2021Huh3994 decided on June 9, 2022) sheds light on how one should carefully use incorporation by reference in a Korean patent application.

The patent application at issue described an invention titled “Treatment of Cancer with TOR[1] Kinase Inhibitors.”  Korean Intellectual Property Office (KIPO) rejected the application under Article 42(3) of the Korean Patent Act (KPA) for failing to describe pharmacological effects of an active ingredient[2] (referred to as chemical compound IV).  The applicant has appealed the decision by KIPO to the Intellectual Property Trial and Appeals Board (IPTAB) and ultimately to the Patent Court after affirmation by the IPTAB.  The applicant essentially argued to the Patent Court that pharmacological effects of the compound IV is described in the specification based on incorporation by reference of U.S. Patent Publication No. US 2011/0137028 in its entirety (because the pharmacological effect is allegedly described in another U.S. patent publication (US 2010/0216781[3]) which is incorporated in US 2011/0137028 by reference in its entirety).

Incorporation by reference, in general, refers to including a first document within a second document by only mentioning the first document.  For a PCT application, missing parts (description or drawing) to a specification of the PCT application claiming the priority may be added based on incorporation by reference, so long as the missing parts are disclosed in the priority application[4].  Accordingly, accidentally omitted parts that are contained in the priority application can be included in the PCT application without affecting the international filing date.  Patent Law Treaty[5] (PLT) has similar provisions allowing missing parts to be added or parts to be replaced in an application based on the disclosure of the priority application[6].

The U.S. has adopted the incorporation by reference provisions of both PCT and PLT[7].  In addition to the priority application, “essential material” and “other (nonessential) material” may be incorporated by reference as well[8].  The essential material is material necessary to satisfy description requirements of 35 U.S.C. 112(a), (b) or (f) and may be incorporated by reference; however, the incorporated document should not itself incorporate such essential material by reference[9].

In Korea, there is no clear guideline on the incorporation by reference in the Patent Examination Guidelines of KIPO.  Korea has reserved adopting the PCT rules on the incorporation by reference and did not participate in the PLT.  In such a situation, the Patent Court made a decision that would give an impact to the practice of incorporation by reference (Patent Court Decision 2005Huh5693).  The case involved Article 42(3) rejection of an application (Korean Patent Application No. 10-2000-7005110) of an invention for a new substance (retinoid antagonists) containing chemical compounds I to XVI.  The specification stated that the compounds (chemical compounds XV and XVI) are “described in EP Patent Application No. 97 107 843.1 and references [J. Med. Chem. 1996, 39, 3229] and [Nature 1996, 383, 450].”  In affirming the rejection under Article 42(3) of the KPA, the Patent Court found that a person of ordinary skill in the art could not have easily practiced the invention in view of J. Med. Chem publication, which does not disclose the method for manufacturing compound XV even if the publication discloses the manufacturing method of compound XVI.

In the recent decision 2021Huh3994, the Patent Court further clarified its position on the incorporation by reference.  The Korean application (Korean Patent Application No. 10-2019-7014135) at issue is a divisional application of another Korean application which has entered the national phase in Korea based on a PCT application (PCT/US2013/031202).  The application at issue stated that “the method for manufacturing chemical compound IV … is disclosed in … US 2011/0137028, which is incorporated herein by reference in its entirety.”  Because the decision hinged on whether the pharmacological effect of the chemical compound IV (the active ingredient) was disclosed in the specification, the Patent Court reviewed whether the incorporation by reference should be recognized based on the above statement and if so, then how the incorporation by reference should be interpreted.  Accordingly, the two main issues related to the incorporation by reference were (i) whether the statement “incorporated herein by reference in its entirety” should be given weight and (ii) whether the pharmacological effect should be deemed to be disclosed based on the incorporation by reference statement.

Regarding the first issue, the Patent Court held that even if the specification of the application at issue includes the statement indicating that the entire content of another patent application is incorporated, it cannot be deemed that the entire content of the referenced application is stated in the specification of the application at issue.  The Patent Court addressed the second issue by finding that the person of ordinary skill in the art would not likely have known the pharmacological effect from the specification of the application at issue because the specification merely states “the method for manufacturing chemical compound IV … is disclosed in … US 2011/0137028” and even if US 2011/0137028 incorporates US 2010/0216781 by reference in its entirety, it cannot be regarded that the application at issue incorporates the disclosure of US 2010/0216781 in which the applicant asserted the pharmacological effect is disclosed.  The Patent Court’s position on the secondary incorporation by reference (i.e., the incorporation by reference in US 2011/0137028) is similar to the practice in the U.S., which clearly indicates that for essential materials, the incorporated document should not itself incorporate the material by reference.

In view of the recent decision, the Patent Court of Korea appears to be applying strict and narrow interpretation of the incorporation by reference.  Accordingly, when filing a patent application in Korea, especially when claiming the priority from a PCT application or an application filed in another country that has a more lenient standard on the incorporation by reference, applicants should carefully consider possible limitations in applying the incorporation by reference as intended.


[1] Target of Rapamycin

[2] Under Article 42(3) of the KPA, an invention must be clearly and specifically described in the written description of the specification such that a person of ordinary skill in the art can easily practice the invention.  For a medicinal use invention, KIPO strictly requires that the original specification contains quantitative pharmacological data for specific active ingredients showing pharmacological effects, unless the pharmacological mechanism was already known prior to the filing date of the application.  See Supreme Court decision 2013Hu730 Decision decided on April 23, 2015.

[3] US 2010/0216781 is a publication of U.S. Patent Application No. 12/605,791, which is stated in US 2011/0137028.

[4] See, e.g., PCT Rules 4.18, 20.5, and 20.8.

[5] The PLT aims to harmonize and streamline formal procedures with respect to national and regional patent applications and patents and make such procedures more user friendly.

[6] See, e.g., PLT Articles 5(6)(b) and 5(7)(a).

[7] See 35 U.S.C. §111(c) and 37 CFR 1.57(b).

[8] See 37 CFR 1.57(d) and (e).

[9] See 37 CFR 1.57(d).