ANNEX 3 27 ANNEX 3 STATUTORY AUDITOR’S REPORT ON THE COMPANY’S ANNUAL FINANCIAL STATEMENTS (FRENCH GAAP) FOR THE FISCAL YEAR ENDING DECEMBER 31, 2017 This is a translation into English of the Statutory Auditors’ Report on the financial statements of the Company issued in French and it is provided solely for the convenience of English speaking users. This Statutory Auditors’ Report includes information specifically required by French law, such as information about the appointment of the Statutory Auditors or verification of the Management Report and other documents provided to Shareholders. This Report should be read in conjunction with, and construed in accordance with French law and professional auditing standards applicable in France. To the Shareholders’ Meeting, OPINION In compliance with the engagement entrusted to us by your bylaws and your Shareholders’ Meeting, we have audited the accompanying financial statements of GENSIGHT BIOLOGICS S.A. for the year ended December 31, 2017. In our opinion, the financial statements give a true and fair view of the assets and liabilities, and of the financial position of the Company as at December 31, 2017 and of the results of its operations for the year then ended in accordance with the accounting rules and principles applicable in France. The audit opinion expressed above is consistent with our Report to the Audit Committee. BASIS FOR OPINION Audit framework We conducted our audit in accordance with professional standards applicable in France. We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our opinion. Our responsibilities under those standards are further described in the “Statutory Auditors’ Responsibilities for the Audit of the Financial Statements” section of our report. Independence We conducted our audit in compliance with independence rules applicable to us, for the period from January 1, 2017 to the issue date of our Report and in particular we did not provide any prohibited non-audit services referred to in Article 5, paragraph 1, of Regulation (EU) No 537/2014 or in the French Code of ethics for Statutory Auditors. Furthermore, the non-audit services that we provided to your Company during the fiscal year are the following: • Procedures provided for in the French Commercial Code relating to transactions involving the share capital (capital decreases and increases, issue of marketable securities), • Third-party independent review of CSR information in the Management Report. JUSTIFICATION OF ASSESSMENTS - KEY AUDIT MATTERS In accordance with the requirements of articles L.823-9 and R.823-7 of the French Commercial Code (Code de commerce) relating to the justification of our assessments, we bring your attention to the key audit matters relating to risks of material misstatement that, in our professional judgment, were of most significance in the audit of the financial statements of the current period, as well as our responses to those risks. These matters were addressed in the context of our audit of the financial statements as a whole, and in forming our opinion thereon. We do not provide a separate opinion on specific elements, accounts or items of the financial statements. Recording of research and development costs Identified risk Research and development costs represent a significant component of the Company’ financial statements, considering Company’ activity and its current development phase, as they account for 75% of total operating expenses. These expenses mainly include external subcontracting costs (including preclinical and clinical studies in particular) or product manufacturing as well as personnel costs. 258 – GENSIGHT BIOLOGICS – 2017 Registration Document