Press release
May 16, 2018

Notice of Change of Auditor

Tokyo, Japan and London, UK, 16 May 2018 – Sosei Group Corporation (“Sosei” or the “Company”; TSE Mothers Index: 4565), the world leader in GPCR medicine design and development, today announced that at a meeting of its Board of Directors held on 15 May 2018, it was resolved to change its certified public accountant responsible for audit certification in accordance with Article 193-2, Paragraphs 1 and 2 of the Financial Instruments and Exchange Act. The details are as follows. 
1. Expected Date of Change 22 June 2018
    (scheduled date of the 28th Annual General Meeting of Shareholders)

2. Overview of the Incoming and Outgoing Auditors
    2.1. Overview of the incoming auditor
           Name: Ernst & Young ShinNihon LLC
           Location: Hibiya Kokusai Building, 2-2-3 Uchisaiwai-cho, Chiyoda-ku, Tokyo
           Names of engagement partners: Hironao Yazaki and Yutaka Mishima
           Registration status under the registration system for listed company audit firms of the Japanese Institute of Certified Public Accountants: Registered
    2.2. Overview of the outgoing auditor Name: Deloitte Touche Tohmatsu LLC Location: Shinagawa Intercity Tower, 2-15-3 Konan, Minato-ku, Tokyo
           Names of engagement partners: Shuichi Momoki and Masanori Toyoizumi
3. Reason for Nominating Auditor Stated in 2.1
    The Audit Committee has selected Ernst & Young ShinNihon LLC as the candidate for Accounting Auditor, as it concluded that Ernst & Young ShinNihon LLC is qualified for the
     role based on a comprehensive review of its auditing systems, including its plans to conduct auditing of the consolidated financial statements on a global basis. Ernst & Young
     ShinNihon LLC demonstrated significant expertise in quality control systems and has assured independence, and according to our judgment, is well qualified for the position of
     Accounting Auditor.
4. Most Recent Date of Appointment of Outgoing Auditor
    22 June 2017

5. Opinions etc. Stated in Audit Reports, etc. Prepared by the Outgoing Certified Public Accountant in the Immediately Preceding Three Years
    Not applicable

6. Reasons For and Background to Decision to Make the Change
    Deloitte Touche Tohmatsu LLC, the Accounting Auditor of the Company, will retire at the conclusion of this Ordinary General Meeting of Shareholders. Therefore, the Company
    would like to propose that the shareholders approve the election of Ernst & Young ShinNihon LLC as Accounting Auditor based on the decision of the Audit Committee.

7. Opinions of the Outgoing Auditor Concerning the Particulars Stated in Audit Reports and Other Documents Regarding the Reason and Background Described in 6.  
    The Company received a reply to the effect that there is no particular opinion.