IP High Court Revokes JPO Decision, Upholding Validity of Priority Claims for Broad Institute’s CRISPR-Cas9 Patent

On March 24, 2026, the Intellectual Property High Court of Japan rendered a judgment revoking the trial decision of the Japan Patent Office (JPO), which had invalidated a patent related to CRISPR-Cas9 jointly owned by The Broad Institute, Inc. (“Broad”), Massachusetts Institute of Technology (“MIT”), and the President and Fellows of Harvard College (“Harvard”, collectively referred to as the “Patentees”).  This judgment recognized a lawful assignment of the right to claim priority from the first and second basic applications.  This case appears to be the world’s first judgment at the high court level regarding the validity of the priority claims for Broad’s CRISPR-Cas9 related patents. (IP High Court Judgment of March 24, 2026, Case No. 2025 (Gyo-Ke) 10019 https://www.courts.go.jp/assets/hanrei/hanrei-pdf-95826.pdf).

1. Overview

The subject patent is Japanese Patent No. 6203879 (the “Patent”), which entered the national phase in Japan from an international application, PCT/US2013/074819 (the “Application”), and was subsequently registered.  The Application was filed on December 12, 2013, with the USPTO as the receiving office, claiming priority from a total of twelve (12) US provisional applications, including US Provisional Application No. 61/736,527 as the first basic application filed on December 12, 2012, and US Provisional Application No. 61/748,427 as the second basic application filed on January 2, 2013.  ToolGen Inc. (“ToolGen”), a South Korean company and the demandant, filed a trial for patent invalidation against the Patent.  The JPO determined that the priority claims based on the first and second basic applications in the Application were unlawful, thereby declaring the Patent invalid.

2. The JPO’s Decision

The JPO reasoned that for the priority claims based on the first and second basic applications to be valid, the applicants of the Application must qualify as “successors” in title under Article 4A(1) of the Paris Convention, which requires the aplicants of the Application to have succeeded to the priority rights from all applicants of the basic applications.  The JPO found no objective proof establishing an assignment of priority rights from Rockefeller University, which had acquired the rights from Dr. X, one of the co-inventors of the first and second basic applications, to either the applicants of the Application or Broad.  Consequently, the JPO concluded that the applicants of the Application were not lawful successors in title under Article 4A(1) of the Paris Convention, rendering the priority claims invalid.

Due to the invalidation of these priority claims, the JPO held that the inventions lacked novelty or an inventive step over prior art references, specifically D1 and D2, which were published after the filing of the first and second basic applications but prior to the third basic application.

<<Timeline>>

• The first basic application               – filed on December 12, 2012
• The second basic application        – filed on January 2, 2013
• D1                                                           – disclosed on January 3, 2013
• D2                                                          – disclosed on January 29, 2013
• The third basic application             – filed on January 30, 2013

Dissatisfied with this decision, the Patentees filed a lawsuit with the IP High Court to revoke the trial decision.

3. Issues

As described above, the central issue in this case was whether the applicants of the Application constituted “successors” under Article 4A(1) of the Paris Convention.  Specifically, while it was uncontested that Dr. X, a co-inventor listed on the first and second basic US provisional applications, had assigned his rights to Rockefeller University, the dispute centered on whether an agreement existed prior to the PCT filing to further transfer the right to claim priority from Rockefeller University to either Broad or the other applicants of the Application.

ToolGen argued that the priority claim was unlawful due to the absence of objective written evidence, such as an assignment deed, demonstrating this transfer.  The JPO basically adopted a rationale aligned with ToolGen’s assertions.

4. The Judgment

In contrast, the IP High Court revoked the JPO’s trial decision based on declarations submitted by Broad and Rockefeller University.  The Court made factual findings indicating that the transferring party, Rockefeller University, and the transferee, Broad, shared a consistent understanding that the transfer had occurred prior to the PCT filing.  Furthermore, the Court found that an inventorship investigation had been conducted by external patent counsel with the consent of all involved institutions regarding the basic applications and the related PCT Applications where priority claims were expected.  The applicants for the related PCT Applications were determined based on this investigation.  Although Dr. X and Rockefeller University were dissatisfied with the outcome of the investigation, namely Dr. X’s contributions regarding eukaryotic cells, they did not express this dissatisfaction in any form at the time the related PCT Applications, including the Application, were filed.  The Court concluded that this dissatisfaction did not affect the assignment of the priority rights, thereby ruling that the priority claims were valid.