REGISTRATION DOCUMENT 2019 This Registration Document was filed with the French Financial Markets Authority (AMF) on 29 April 2019 as required by Article 212-13 of the AMF’s General Regulation. This Registration Document may only be used in support of a financial transaction when supplemented by a transaction note approved by the AMF. It was prepared by the issuer and is binding on its signatories. Copies of this Registration Document are available free of charge from the Company at 5 rue de la Baume, 75008 Paris, France, as well as electronically on the Company’s website (www.abivax.com) and on the AMF’s website (www.amf- france.org). 1 | 2019 REGISTRATION DOCUMENT CONTENTS 1. PERSONS RESPONSIBLE ........................................................................................................................................... 7 1.1. Person responsible for the Registration Document .......................................................................................... 7 1.2. Statement by the Responsible Person .............................................................................................................. 7 1.3. Person responsible for financial reporting ........................................................................................................ 7 2. STATUTORY AUDITORS ........................................................................................................................................... 8 2.1. Principal statutory auditors .............................................................................................................................. 8 2.2. Alternate statutory auditor .............................................................................................................................. 8 3. SELECTED FINANCIAL INFORMATION ...................................................................................................................... 9 4. RISK FACTORS ....................................................................................................................................................... 12 4.1 Risks related to the Company’s business ........................................................................................................ 12 4.2 Risks related to the Company’s organisation .................................................................................................. 16 4.3 Regulatory and legal risks ............................................................................................................................... 17 4.4 Industrial risks ................................................................................................................................................ 23 4.5 Financial risks ................................................................................................................................................. 23 4.6 Market risks ................................................................................................................................................... 27 4.7 Insurance and risk coverage ........................................................................................................................... 29 4.8 Exceptional events and litigation .................................................................................................................... 31 5. INFORMATION ABOUT THE COMPANY ................................................................................................................. 32 5.1 History and development of the Company ..................................................................................................... 32 5.2 Investments .................................................................................................................................................... 35 6. OVERVIEW OF ACTIVITIES ..................................................................................................................................... 36 6.1 General presentation of ABIVAX, a biotech company specialised in viral diseases ......................................... 36 6.2 Overview of ABIVAX’s main scientific assets .................................................................................................. 39 6.3 Detailed presentation of the main ABIVAX products ...................................................................................... 46 6.4 Organisation of ABIVAX .................................................................................................................................. 66 6.5 Legal situation of the Company during the past financial year ....................................................................... 70 7. ORGANISATIONAL CHART ..................................................................................................................................... 72 7.1 Organisation of the Company ......................................................................................................................... 72 7.2 List of subsidiaries, branches and secondary establishments ......................................................................... 72 8. PROPERTY, PLANT AND EQUIPMENT .................................................................................................................... 73 8.1 Description of real property ........................................................................................................................... 73 8.2 Environmental matters ................................................................................................................................... 73 9. REVIEW OF RESULTS AND FINANCIAL POSITION ................................................................................................... 74 9.1 General presentation ..................................................................................................................................... 74 9.2 Review of the financial position at 31 December 2018 ................................................................................... 74 10. CASH AND CAPITAL ............................................................................................................................................. 83 10.1 Information on the Company’s capital ........................................................................................................... 83 10.2 Cash flow ........................................................................................................................................................ 85 2 | 2019 REGISTRATION DOCUMENT 10.3 Borrowing conditions and financing structure ................................................................................................ 86 10.4 Restrictions on the use of capital which have materially affected or may materially affect the Company’s operations directly or indirectly ..................................................................................................................... 87 10.5 Expected sources of funding ........................................................................................................................... 87 11. INVENTIONS, PATENTS, LICENCES, TRADEMARKS AND DOMAIN NAMES ............................................................ 89 11.1 Innovation policy ............................................................................................................................................ 89 11.2 Patents and patent applications ..................................................................................................................... 89 11.3 Collaboration, research, service provision and licensing contracts granted by or to the Company ............... 102 11.4 Trademarks, trademark applications and domain names ............................................................................. 104 12. TRENDS ............................................................................................................................................................. 106 12.1 Outlook for 2019 .......................................................................................................................................... 106 12.2 Known trends, uncertainties, request for commitment or events that are reasonably likely to affect the Company’s outlook ....................................................................................................................................... 106 13. PROFIT FORECASTS OR ESTIMATES ................................................................................................................... 107 14. ADMINISTRATIVE, MANAGEMENT, SUPERVISORY AND EXECUTIVE BODIES ..................................................... 108 14.1 Executives, directors and non-voting directors ............................................................................................. 108 14.2 Non-voting directors .................................................................................................................................... 116 14.3 Conflicts of interest of administrative and executive bodies ........................................................................ 116 15. COMPENSATION AND BENEFITS ........................................................................................................................ 117 15.1 Corporate officers’ compensation ................................................................................................................ 117