Notice of Absorption-Type Merger of a Wholly-Owned Subsidiary, Renalys Pharma, Inc.

TOKYO, November 18, 2025 -- Chugai Pharmaceutical Co., Ltd. announced that it has resolved, at a meeting of the Board of Directors held today, to conduct an absorption-type merger (hereinafter “Merger”) with Renalys Pharma, Inc. (Headquarters: Tokyo; Representative Director: Brian Taylor Slingsby; hereinafter “Renalys Pharma”), which Chugai is scheduled to acquire as a wholly-owned subsidiary on November 27, 2025.
The Merger will become effective following the completion of Renalys Pharma’s conversion into a wholly-owned subsidiary. Also, since it will be a simplified absorption-type merger with a wholly-owned subsidiary, disclosure of certain items and details has been omitted.

1. Purpose of the Merger
As announced in the “Notice Concerning Making Renalys Pharma, Inc. a Wholly-Owned Subsidiary” dated October 24, 2025, Chugai resolved to acquire Renalys Pharma as a wholly-owned subsidiary by purchasing all shares and share acquisition rights of Renalys Pharma (hereinafter “Share Acquisition”). Renalys Pharma was established for the purpose of developing and commercializing sparsentan (U.S. product name: FILSPARI^®), which is being developed mainly for IgA nephropathy, in Asia. Through the complete acquisition of Renalys Pharma, Chugai will obtain exclusive development and commercialization rights of sparsentan in Japan, South Korea, and Taiwan.

The absorption-type merger of Renalys Pharma, which is scheduled to become a wholly-owned subsidiary upon completion of the Share Acquisition on November 27, 2025, is intended to accelerate the development of sparsentan obtained through Renalys Pharma and maximize corporate value. Through the Merger, Chugai will establish an integrated and efficient operational structure by consolidating management resources. Furthermore, as the ultimate Marketing Authorization Holder, Chugai will consistently and proactively manage the entire process from clinical development to the filing for regulatory approval, thereby streamlining and accelerating the development.

Through the Merger, Chugai aims to deliver new treatment options for patients with kidney diseases including IgA nephropathy as quickly as possible.

2. Summary of the Merger
(1) Schedule of the Merger

Note: The Merger is a simplified absorption-type merger under Article 796, Paragraph 2 of the Companies Act for Chugai, and a short-form absorption-type merger under Article 784, Paragraph 1 of the Companies Act for Renalys Pharma. Therefore, no approval by the general meeting of shareholders of either company is required.

(2) Form of the Merger

The Merger will be conducted as an absorption-type merger, in which Chugai is the surviving company and Renalys Pharma is the dissolving company.

(3) Details of allotment related to the Merger

Since this is a merger with a wholly-owned subsidiary, no shares will be allotted and no other consideration will be paid or delivered in connection with the Merger.

(4) Handling of share acquisition rights and bonds with share acquisition rights in connection with the Merger

The share acquisition rights issued by Renalys Pharma will be extinguished on the effective date of the Merger.