Abivax Announces Repurchase of Royalty Certificates and Pricing of $45M (€38.5M) Offering of American Depositary Shares

Abivax Announces Repurchase of Royalty Certificates and Pricing of $45M (€38.5M) Offering of American Depositary Shares

• Cash runway remains into Q4 2027, supporting continued funding of clinical programs and pre-commercial planning activities
• Royalty overhang materially reduced, enhancing financial flexibility to support future commercialization efforts

PARIS, France – May 5, 2026 – 8:00 am CEST – Abivax SA (Euronext Paris: FR0012333284 – ABVX) (“Abivax” or the “Company”), a clinical-stage biotechnology company focused on developing therapeutics that harness the body’s natural regulatory mechanisms to modulate the immune response in patients with chronic inflammatory diseases, today announces (i) the execution of a purchase agreement (the “Purchase Agreement”) for the royalty certificates issued by the Company in September 2022 (the “Royalty Certificates”), to be partially paid in shares, and (ii) consequently, the pricing of a $45 million offering of 403,347 ordinary shares (“Ordinary Shares”) represented by American Depositary Shares (“ADSs”), each representing one Ordinary Share, €0.01 nominal value per share, of the Company, to the benefit of the Royalty Certificates’ holders (the “Holders”) at an offering price of $111.57 per ADS (the “Offering”).

The offering price of $111.57 per ADS (corresponding to €95.34 per Ordinary Share), based on the exchange rate of €1.00 = $1.1702 as published by the European Central Bank on April 30, 2026, is equal to the volume-weighted average trading price of the ADSs on the Nasdaq Global Market over the five consecutive trading days ending on and including the trading day immediately preceding the pricing of the Offering (i.e., from April 27, 2026 to May 1, 2026) and has been determined by the Board of Directors pursuant to the 26th resolution of the Company’s combined shareholders’ meeting held on June 6, 2025 (the “General Meeting”).

Didier Blondel, Chief Financial Officer of Abivax, said: “Strengthening our balance sheet remains a core priority as we continue to reduce legacy obligations. The current market environment presents a compelling opportunity to proactively repurchase these royalty certificates on attractive terms, allowing us to simplify our capital structure and enhance long-term shareholder value.”

Purchase of the Royalty Certificates

The Royalty Certificates have been issued to TCG Crossover Fund I, L.P., VHCP ABVX Holdings, LLC, Deep Track Biotechnology Master Fund, Ltd., Sofinnova Crossover I SLP, Invus Public Equities, L.P., FPCI BioMedTech and Santé Holdings Srl pursuant to a decision of the Board of Directors of the Company held on August 31, 2022.

Pursuant to the Purchase Agreement entered into between the Company and the Holders on May 4, 2026, the Holders have agreed to sell, and the Company has agreed to purchase, all of the Royalty Certificates for a purchase price equal to $90 million, of which $45 million shall be paid in cash on the closing date, expected on or about May 7, 2026.

The Holders have agreed to grant an interest-free vendor’s loan (crédit vendeur) in a total amount equal to the remaining $45 million, to be reinvested in the Company’s securities and such loan will be set off against the subscription price of the ADSs to be issued by the Company to the Holders in the Offering. Such set-off, and the corresponding issuance and delivery of the ADSs to the Holders, is expected to occur on the closing date of the Offering, expected on or about May 7, 2026, at which time the vendor's loan will be fully extinguished.

The Royalty Certificates repurchased by the Company will be immediately cancelled by the Company.

Type of Offering

The Ordinary Shares (in the form of ADSs) being issued in the Offering are being issued by way of a capital increase with cancellation of the preferential subscription rights of existing shareholders to the benefit of the Holders, pursuant to the 26th resolution of the General Meeting.

Expected Closing

The Offering is expected to close on or about May 7, 2026, subject to the satisfaction of customary closing conditions.

Estimated Proceeds from the Offering

As the subscription price of the Ordinary Shares (including in the form of ADSs) being issued in the Offering is to be paid by way of set-off against certain, liquid, and due claims against the Company, there will be no proceeds from the Offering.

Dilution

The 403,347 Ordinary Shares (including in the form of ADSs) to be issued in the Offering will result in a dilution of approximately 0.5% of the share capital of the Company (on a non-diluted basis). On an illustrative basis, a shareholder holding 1% of the Company’s share capital before the Offering would hold a stake of 0.99% after completion of the Offering.

Settlement and Delivery – Documentation

The Company’s ADSs are listed on the Nasdaq Global Market under the ticker symbol “ABVX.” The Company’s Ordinary Shares are listed on the regulated market of Euronext in Paris (“Euronext”) under the symbol “ABVX.”

The Ordinary Shares issued in the Offering are expected to be admitted to trading on Euronext on or about May 7, 2026. The ADSs representing the Ordinary Shares being issued in the Offering are expected to be admitted to trading on the Nasdaq Global Market on or about May 7, 2026.

The Ordinary Shares underlying the ADSs issued in the Offering will be subject to an application for admission to trading on Euronext on the same trading line as the existing Ordinary Shares of the Company currently listed on Euronext, under the same ISIN code FR0012333284.

An automatic shelf registration statement on Form F-3 (including a prospectus) relating to the Company’s securities was filed with the Securities and Exchange Commission (the “SEC”) on July 23, 2025, and became effective upon filing. The Company intends to file with the SEC a prospectus supplement (and accompanying prospectus) to register any potential resale of the ADSs (the “Prospectus Supplement”). These documents may be obtained free of charge by visiting EDGAR on the SEC’s website at www.sec.gov.

The Offering is not subject to a prospectus requiring an approval of the AMF.

Accounting Treatment

The Company accounted for the repayment of the Royalty Certificates in accordance with applicable accounting standards, recognizing the transaction upon settlement and derecognizing the associated liability from its balance sheet. Any difference between the carrying value of the Royalty Certificates and the consideration paid will be recorded as a gain or loss in the Company’s results of operations for quarter ended June 30, 2026.

Advisors

Leerink Partners is acting as exclusive financial advisor to the Company in connection with the Offering.

Dechert (Paris) LLP and Cooley LLP are acting as legal advisors to the Company in connection with the Offering.

Cash Position and Runway

The Company had cash, cash equivalents and short-term investments of €530.4 million as of December 31, 2025, providing a projected cash runway into Q4 2027 based on current operating assumptions.

After the repurchase of the Royalty Certificates, the Company’s projected cash runway remains unchanged (into Q4 2027).

Risk Factors

Potential investors should carefully consider the risks described under “Risk Factors” in the Prospectus Supplement, including the following risks:

• Future sales of ordinary shares or ADSs by existing shareholders could depress the market price of the ADSs and ordinary shares; and
• Raising additional capital, including as a result of this offering or of further offerings to finance the clinical programs or the commercialization of the Company’s drug candidates, may cause dilution to the Company’s shareholders, restrict its operations, or require it to relinquish rights to its drug candidates.

In addition, the Company draws attention to the risk factors related to the Company and its activities described under the caption “Risk Factors” in the Company’s Annual Report on Form 20-F filed with the U.S. Securities and Exchange Commission on March 23, 2026 and in Chapter 2 of the 2026 universal registration document filed with the French Financial Markets Authority (Autorité des Marchés Financiers – the “AMF”) under number D.26-0133 on March 23, 2026, which is available free of charge on the Company’s website at https://ir.abivax.com/fr, as well as on the AMF’s website at www.amf-france.org.

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About Abivax

Abivax is 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. Based in France and the United States, Abivax’s lead drug candidate, obefazimod (ABX464), is in Phase 3 clinical trials for the treatment of moderately to severely active ulcerative colitis.

Contacts

Abivax Investor Relations Patrick Malloy [email protected] +1 847 987 4878