Abivax S.A.

initial public offering as well as ordinary shares in Europe (including France) and countries outside of the United States in a private placement in October 2023, 637.5 million of gross proceeds were from the offering of our ordinary shares in the form of ADS on the Nasdaq Global Market in July 2025 ("the Offering"), bank borrowings and structured loans for 175.0 million, reimbursements of CIR in an amount of 41.3 million , subsidies received from Bpifrance (including 21.3 million of subsidies and 1.8 million of conditional advances) and royalty certificates in an amount of 2.9 million.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

Following these share issuances, we no longer hold any debt with Heights Capital Management.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

As of June 30, 2025 , our contractual obligations and loans were 319.1 million, comprising financial debt obligations of 101.3 milli on (i n turn, comprising 45.7 million with respect to the second and third tranches of senior secured non-convertible bonds in the Kreos / Claret Financing, 24.8 million with respect to Heights Convertible Notes, 29.5 million with respect of the Kreos / Claret OCABSA and 1.3 million with respect to the PGE ) and off-balance sheet obligations of 215.0 million with respect to purchase obligations.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

Following the conversion of all the Heights Convertible Notes and the Kreos / Claret OCABSA in July 2025 and August 2025, financial debt obligations amounting to 54.3 million as of June 30, 2025 were extinct.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

As a result, the Group is, and expects to continue to be, in the short to mid-term, financed through the issuance of new equity or debt instruments.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

All statements other than present and historical facts and conditions contained in this half-year report, including statements regarding our future results of operations and financial positions, business strategy, plans and our objectives for future operations, are forward-looking statements.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

8 OPERATING RESULTS Overview We are a clinical-stage biotechnology company focused on developing therapeutics that harness the body s natural regulatory mechanisms to stabilize the immune response in patients with chronic inflammatory diseases.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

This increase was primarily due to a 6.5 million increase in expenses related to our CD program , resulting from the progression of our Phase 2b trials in CD, and a 5.7 million increase in transversal activities related to the overall expansion of the research and development headcount to support our organizational growth and the issuance of new equity awards to officers and employees in research and development.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

Bpifrance CARENA Contract As part of the development of therapeutic and diagnostic solutions targeting alternative splicing and RNA interference in the fields of virology (HIV-AIDS, HTLV-1) and metabolism (obesity), SPLICOS, which we acquired in October 2014, entered into a Master Support Agreement and a conditional advance contract in December 2013 for the CARENA Strategic Industrial Innovation Project ( CARENA project ), with Bpifrance.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

Bpifrance RNP-VIR Contract As part of the CARENA project, focused on the clinical development of a drug molecule and demonstrating the validity of an innovative therapeutic approach targeting viral RNPs, we entered into a Master Support Agreement with Bpifrance, as well as a beneficiary agreement dated March 21, 2017, with conditional advances for the RNP-VIR structuring research and development project for competitiveness.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

D Risk Factors for a more complete understanding of the risks and uncertainties material to our business, including important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025

In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame or at all.

SEC original ↗Abivax S.A. — Earnings release (6-K report)6-KSep 8, 2025