REGISTRATION DOCUMENT 2018 In application of its General Regulations, specifically Article 212-13, the Autorité des marchés financiers (the “AMF”) registered this document on 27 April 2018 under number R.18-038. This Registration Document may only be used in support of a financial transaction if it is accompanied by a prospectus approved by the AMF. It was prepared by the issuer under the responsibility of its signatories. The registration, pursuant to the provisions of Article L. 621-8-1-I of the French Monetary and Financial Code, was performed after the AMF verified “whether the document is complete and comprehensible and the information it contains is consistent”. It does not imply that the accounting and financial information presented was authenticated by the AMF. 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 | 2018 REGISTRATION DOCUMENT CONTENTS GENERAL REMARKS ..................................................................................................................................................... 5 1. RESPONSIBLE PERSONS .................................................................................................................................... 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 ............................................................................................................................... 18 4.4 Industrial risks ................................................................................................................................................ 23 4.5 Financial risks ................................................................................................................................................. 24 4.6 Market risks ................................................................................................................................................... 28 4.7 Insurance and risk coverage ........................................................................................................................... 29 4.8 Exceptional events and litigation .................................................................................................................... 33 5. INFORMATION ABOUT THE COMPANY .......................................................................................................... 34 5.1 History and development of the company ...................................................................................................... 34 5.2 Investments .................................................................................................................................................... 36 6. OVERVIEW OF ACTIVITIES .............................................................................................................................. 38 6.1 General presentation of ABIVAX, a biotech company specialised in viral diseases ......................................... 38 6.2 Overview of ABIVAX’s main scientific assets .................................................................................................. 40 6.3 Detailed presentation of the main ABIVAX products ...................................................................................... 47 6.4 Organisation of ABIVAX .................................................................................................................................. 67 6.5 Legal situation of the company during the past financial year ........................................................................ 72 6.6 Company policy regarding environmental, social and societal responsibility ................................................. 73 7. ORGANISATIONAL CHART .............................................................................................................................. 85 7.1 Organisation of the Company ......................................................................................................................... 85 7.2 List of subsidiaries, branches and secondary establishments ......................................................................... 85 8. PROPERTY, PLANT AND EQUIPMENT ............................................................................................................. 86 8.1 Description of properties ................................................................................................................................ 86 8.2 Environmental matters ................................................................................................................................... 86 9. REVIEW OF RESULTS AND FINANCIAL POSITION ............................................................................................ 87 9.1 General presentation ..................................................................................................................................... 87 9.2 Review of the financial position at 31 December 2017 ................................................................................... 87 2 | 2018 REGISTRATION DOCUMENT 10. CASH AND CAPITAL ........................................................................................................................................ 95 10.1 Information on the Company’s capital ........................................................................................................... 95 10.2 Cash flow ........................................................................................................................................................ 97 10.3 Borrowing conditions and financing structure ................................................................................................ 98 10.4 Restrictions on the use of capital which have materially affected or may materially affect the Company’s operations directly or indirectly ..................................................................................................................... 99 10.5 Expected sources of funding ........................................................................................................................... 99 11. INVENTIONS, PATENTS, LICENCES, TRADEMARKS AND DOMAIN NAMES ..................................................... 101 11.1 Innovation policy .......................................................................................................................................... 101 11.2 Patents and patent applications ................................................................................................................... 102 11.3 Collaboration, research, service provision and licence contracts granted by or to the Company .................. 113 11.4 Trademarks, trademark applications and domain names ............................................................................. 116 12. TRENDS ........................................................................................................................................................ 118 12.1 Outlook for 2018 .......................................................................................................................................... 118 12.2 Known trend, uncertainty, request for commitment or event that is reasonably likely to affect the Company’s outlook ......................................................................................................................................................... 118 13. PROFIT FORECASTS OR ESTIMATES .............................................................................................................. 119 14. ADMINISTRATIVE, MANAGEMENT, SUPERVISORY AND EXECUTIVE BODIES ................................................ 120 14.1 Executives, directors and non-voting directors ............................................................................................. 120 14.2 Non-voting