Avantium N.V.

Regulatory Filings • Sep 4, 2025

THIS PRESS RELEASE IS RESTRICTED AND IS NOT FOR RELEASE, DISTRIBUTION OR PUBLICATION, WHETHER DIRECTLY OR INDIRECTLY AND WHETHER IN WHOLE OR IN PART, INTO OR IN THE UNITED STATES OF AMERICA, AUSTRALIA, JAPAN OR IN ANY OTHER JURISDICTION IN VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION.

ADVERTISEMENT. This announcement is an advertisement relating to the intention of the Company to proceed with the Offering and the admission to listing and trading of the Rights, the Offer Shares and the Additional Shares (each as defined below) (the Admission). This announcement does not constitute a prospectus. This announcement is for information purposes only and does not constitute, or form part of, an offer by, or invitation by or on behalf of, the Company or any representative of the Company to purchase any securities, or an offer to sell or issue, or the solicitation to buy, securities by any person in any jurisdiction where to do so would constitute a violation of the applicable laws or regulations of such jurisdiction. Further details about the Offering are included in the prospectus for the purposes of the Admission and is approved as such under the respective regulation by the Netherlands Authority for the Financial Markets (Stichting Autoriteit Financiële Markten, the AFM) on 4 September 2025 and available as of today (the Prospectus). The Prospectus has been published and made available at no cost through the website of the Company (20250904afmapprovedprospectus-avantiumn.v.rightsoffering2025.pdf), subject to securities law restrictions in certain jurisdictions. Potential investors should read the Prospectus before making an investment decision in order to fully understand the potential risks and rewards associated with the decision to invest in the Rights, the Offer Shares or the Additional Shares. The approval of the Prospectus by the AFM should not be understood as an endorsement of the quality of the Rights, the Offer Shares or the Additional Shares.

Avantium Announces the Launch of a fully Committed and Underwritten Rights Offering of €65 million

AMSTERDAM, 4 September 2025, 08:00 hrs CEST – Avantium N.V. (the "Company", "Avantium" or the "Group") today announces the launch of a capital increase by means of a fully committed and underwritten rights offering, for an amount of €65 million, which is expected to meet the conditions related to the comprehensive financing package as announced on 12 August 2025 (refer to Previous Announcements on page 12 of this press release) and aims to ensure that Avantium remains sufficiently financed until it reaches EBITDA break-even.

• 11 for 8 rights offering of 12,103,283 ordinary shares at an Issue Price of €5.40 per Offer Share
• Cornerstone investments and irrevocable shareholder commitments of €12.25 million, including from long-term shareholders VP Capital NV, Pieter Kooi Holding B.V. and Navitas B.V., representing 18.7% of the offering
• The balance of the Offering has been fully underwritten for an aggregate amount of €52.75 million (the "Underwriting")

• The Issue Price represents a discount of 40.0% to the theoretical ex-rights price based on the closing price of €13.95 on Euronext Amsterdam on 3 September 2025
• Ex-rights Date: 5 September 2025
• Rights trading period: from 9:00 CEST on 5 September 2025 to 17:36 CEST on 15 September 2025
• Record Time: 17:40 CEST on 8 September 2025
• Exercise Period: from 9:00 CEST on 5 September 2025 to 17:45 CEST on 17 September 2025

Tom van Aken, Chief Executive Officer of Avantium, comments: "Avantium has entered a pivotal phase in its journey. The successful start-up of the sugar dehydration unit - the largest part of our FDCA Flagship Plant – as announced on 29 August 2025 marks a key technical achievement in the phased commissioning and start-up of the facility. This unit converts plant sugars into MMF, a vital intermediate in the FDCA production process, and we are proud to report that MMF is now being produced successfully. With our utility systems already operational, we are now progressing with the commissioning and start-up of the final two units.

We anticipate commercial operations to begin in the first quarter of 2026, bringing us to the exciting moment when our 100% plant-based and circular material, PEF - branded as releaf® - will reach consumers and become a true commercial reality. This is backed by strong commercial traction, with 20 partners already committed through signed offtake agreements from our FDCA Flagship Plant. This progress is made possible by broad support from our longstanding shareholders, public partners and other stakeholders. Their support reflects deep confidence in our FDCA/PEF technology and our mission to lead the transition to renewable and circular chemistry.

This equity raise is a key part of the comprehensive funding package announced on 12 August 2025. Along with other funding initiatives, this equity raise is expected to cover Avantium's financial needs and help keep the Company well-funded until it reaches group-level EBITDA break-even, which is expected in 2027. We are grateful for the continued trust of our longstanding shareholders and are especially pleased with the continued support of Invest-NL as well as the support of the Dutch State, represented by the Ministry of Climate Policy and Green Growth (Ministerie van Klimaat en Groene Groei), which has committed to act as one of the underwriters for this equity raise and has agreed to subscribe via private placement for any portion of the €15 million underwriting not used in the offering. We warmly welcome both our existing shareholders and new investors who share our ambition to build a more sustainable future through innovation."

Key terms of the Offering

• 11 for 8 rights offering of 12,103,283 new ordinary shares (the "Offer Shares") at the issue price of €5.40 per Offer Share (the "Issue Price") (the "Rights Offering"), for an amount of €65 million of gross proceeds.
• The Issue Price represents a discount of 40.0% to the theoretical ex-rights price ("TERP"), based on the closing price of €13.95 on Euronext Amsterdam on 3 September 2025.

• Shareholders are being granted transferable subscription entitlements (the "Rights") in the Rights Offering, which will entitle to subscribe in cash, on an irreducible basis, for Offer Shares. In addition, holders of Rights will be entitled to subscribe, on a reducible basis, for an additional number of Offer Shares, at the Issue Price (the "Excess Application").
• The Offer Shares that were issuable upon the exercise of Rights but that have not been subscribed for during the Exercise Period (the "Rump Shares") will be offered for sale at the Issue Price through (i) a public offering in the Netherlands and Belgium via ABN AMRO and in France via PrimaryBid SA and (ii) private placements to certain institutional investors in certain other eligible jurisdictions (the "Rump Offering", and together with the Rights Offering, the "Offering").
• Cornerstone investors (the "Cornerstone Investors") have irrevocably undertaken to subscribe for Offer Shares (the "Cornerstone Shares") and for an aggregate amount of €8.5 million, or 13.0% of the Offering (the "Cornerstone Commitment").
• Several existing long-term shareholders of Avantium (the "Committed Shareholders") have irrevocably undertaken to exercise their Rights for an aggregate amount of €3.75 million, or 5.7% of the Rights Offering (the "Shareholders Commitments"). The Cornerstone Investors and Committed Shareholders include Pieter Kooi, Navitas B.V. and VP Capital NV.
• The balance of €53.11 million, or 81.3% of the Rights Offering, is underwritten, subject to customary conditions, by ABN AMRO Bank N.V. ("ABN AMRO"), BNP PARIBAS ("BNPP"), and Stifel Europe Limited and Stifel Europe Securities SAS (together, "Stifel Europe"), also acting as Joint Global Coordinators, as well as by the State of the Netherlands, represented by the Ministry of Climate Policy and Green Growth (Ministerie van Klimaat en Groene Groei), funding an investment through INNL Publiek-Private Product Structurering B.V. (jointly, "KGG") and Invest-NL Capital N.V. ("Invest-NL") (altogether the "Underwriters").
• In addition to its role as Underwriter, KGG has agreed that, to the extent the underwriting of KGG for an amount of €15 million is not fully used in connection with the Offering, KGG will subscribe for any such remaining unused amount in a private placement (the "Additional KGG Placement"), thereby supporting the success of the Offering.
• ABN AMRO will act as the Subscription, Listing and Paying Agent for the Rights Offering.

Indicative timetable

• The record time for allocation of the Rights is set at 17:40 CEST on 5 September 2025 (the "Record Time"). Holders of Rights wishing to subscribe for Offer Shares must exercise their Rights during the Exercise Period, running from 9:00 CEST on 5 September 2025 through 17:45 CEST on 17 September 2025.
• The Company expects that the Rights will be admitted to listing and trading on Euronext and that trading will commence at 09:00 CEST on 5 September 2025 and will end at 17:36 CEST on 15 September 2025, barring unforeseen circumstances. The Rights will be traded under the symbol "AVTRI" and ISIN code NL0015002ND2.
• The Excess Application will be open from 9:00 CEST on 5 September 2025 through 17:45 CEST on 17 September 2025.

• Settlement is expected to take place on 22 September 2025.

Reasons for the Offering

The reason for the Offering is to enable the Company to, in the following order of priority: (1) remedy Avantium's acute working capital shortfall, and (2) fund any costs associated with the commissioning, start-up and ramp-up of the FDCA Flagship Plant, the market introduction of the FDCA, PEF (under the brand name releaf®), humins, including supporting regulatory activities and public affairs and (3) transforming the Company and its subsidiaries (the "Group") from a production company to a business focused on selling licenses for its YXY® Technology, including implementing strategic alternatives for its non-core business activities and investing in accelerating the sale of licenses for Avantium's YXY® Technology.

Use of proceeds

The Company expects the net proceeds of the Offering to amount to approximately €59 million, after deducting all expenses related to the Offering. These expenses are estimated at approximately €6 million and include administrative and legal fees and fees and commissions payable to the Underwriters.

Assuming €59 million in net proceeds from the Offering, the Company currently anticipates that it will use the net proceeds of the Offering as follows and in the following order of priority:

• €11.0 million to repay the outstanding Bridge Loan to Invest-NL, consisting of €10.0 million principal and €1.0 million in fees;
• For the remaining €48 million in net proceeds:
• o approximately 60% will be used to remedy the Group's acute working capital shortfall, thereby providing the necessary liquidity to fund operating expenses and working capital needs. This includes, but is not limited to, raw materials and finished goods, and other costs required to maintain the Group's operations and financial stability. Of these working capital needs, approximately:
  • 20% relates to the commissioning and start-up of the FDCA Flagship Plant, which are not distinct, isolated events, but rather interconnected steps that occur sequentially. These proceeds may for example be used to (i) solve quality issues in the piping of the FDCA Flagship Plant, (ii) replace electrical components as well as fix bugs in the plant's software, (iii) seal leaks in the plant, (iv) repair any faulty equipment discovered during the plant's functional testing or during cold or hot commissioning (e.g. pumps, instruments or control valves) and (v) repair or replace other components that cause performance issues, all to realise a safe start-up of all the plant's units;
  • 70% relates to the ramp-up of the FDCA Flagship Plant. These proceeds may for example be used to (i) cover the working capital necessary to keep the ramp-up process of the FDCA Flagship Plant going, (ii) address process

instabilities or product quality failures that arise and require action, which may involve troubleshooting and debottlenecking activities, and (iii) any other issues or challenges that arise during the ramp-up similar to the ones set out above for the commissioning and start-up of the FDCA Flagship Plant; and

• 10% relates to investments in strengthening the commercial, technology, and engineering activities within the Renewable Polymers business unit, such as marketing costs, business travel and commercial personnel costs, to facilitate and potentially accelerate the sale and execution of the YXY® Technology Licenses to third parties, transforming the Group from a production company to a business focused on selling licenses for the YXY® Technology;
• o approximately 25% will be used to fund general corporate expenses related to the day-to-day management of the Company, executing the strategic portfolio review process of the non-core activities and providing overhead services (including finance, human resources, legal, marketing and communications, intellectual property, information technology and quality, safety, health and environment), including those related to Avantium's Corporate Technology team which incorporates the Dawn Technology™ for textile waste recycling; and
• o approximately 15% will be used to fund the Company's financing costs (cash interest costs related to the facility granted by the lenders to the Company (the "Debt Financing")) and forecasted capital expenditures.

The amounts and timing of the Company's actual expenditures will depend upon numerous factors, including (1) progress, costs, and timing in relation to the commissioning, start-up and ramp-up of the FDCA Flagship Plant and the build-up of related working capital such as inventories and accounts receivable, (2) progress, costs, timing and results of its R&D, regulatory or competitive developments, (3) the net proceeds actually raised in the Offering, (4) any amounts received by way of grants and (5) the Group's operating costs and expenditures.

Working capital measures

As per 1 September 2025, the Group had a cash balance of approximately €3 million. In its liquidity forecast for the period between the date of the Prospectus and 30 September 2026, the Group forecasts (i) a cash-out of approximately €96 million, and (ii) a cash-in of approximately €29 million.

As a result, the Company faces a working capital shortfall for the next 12 months following the date of the Prospectus of approximately €64 million. If the Offering is successful, the working capital shortfall for the next 12 months following the date of the Prospectus will decline to €5 million (after deducting the €59 million in net proceeds of the Offering).

In addition to the Offering, in order to remedy the working capital shortfall of approximately €64 million, the Group has initiated the following measures:

• Government-related investment initiative funding: If the Offering is successful, the Group expects to receive funding of €20 million from a government-related investment initiative,

which can be by means of a subsidy, grant, (convertible) subordinated loan, or private placement. This funding is subject to completion of the Offering, the Group's commitment to the Groningen region, and customary governmental approvals. The Group currently anticipates that the funding will be received in November 2025 and is confident, based on ongoing discussions and strong governmental support, that the investment will be completed in the last quarter of 2025.

• Strategic review and divestment of non-core technology assets: The Group has completed a strategic review to focus on its FDCA/PEF platform within the Renewable Polymers business unit and is in advanced discussions to divest non-core activities, including R&D Solutions, Volta Technology, and Ray Technology™. These transactions are expected to generate €10–50 million in net proceeds and reduce future cash outflows. The Group is confident it will realise at least €10 million in net proceeds in or before April 2026.
• The Groningen Consortium 2025 Subordinated Loan: BPIG, a minority shareholder of Avantium Renewable Polymers, has committed to provide a €2.5 million subordinated shareholder loan. Disbursement is subject to completion of the Offering, and the Group expects the funds to be available shortly after settlement of the Offering in September 2025.

Based on this action plan, the Group expects to fully address the working capital shortfall of €64 million and secure sufficient working capital for the twelve months following the date of the Prospectus. If the Company cannot successfully implement the above action plan, it will be unable to address its working capital shortfall, and may not be able to continue as a going concern. Please see for further details the Prospectus.

EBITDA and revenue outlook

Avantium expects to reach EBITDA break-even at the Group level in 2027, provided it achieves its targeted revenue of approximately €90 million. Of this targeted revenue, approximately 35% is anticipated to come from technology license sales and approximately 45% from the operations of the FDCA Flagship Plant. The remainder, approximately 20%, is expected to be generated by R&D Solutions. The ambition for the Revenue and EBITDA Outlook is driven by the FDCA Flagship Plant sales and milestone payments from license agreements the Company plans to enter into.

The strategic business activities or any additional cost-saving measures will not adversely affect funding requirements, except for potential one-off restructuring costs (if any), which are estimated to be approximately €1 million, if incurred.

Additional Placement

Avantium has obtained shareholder approval to issue up to the statutory maximum of the authorised share capital at the Annual General Meeting of Shareholders (AGM) held on 14 May 2025. In addition to its role as Underwriter, KGG has agreed that, to the extent the underwriting of KGG for an amount of €15 million is not fully used in connection with the Offering, KGG will subscribe for any such remaining unused amount in the Additional KGG Placement, thereby further supporting the success of the Offering and the Company. The subscription price per Share subscribed for by KGG in connection with the Additional KGG Placement will be equal to the Issue Price.

The Company entered into Cornerstone Commitments, raising aggregate proceeds of €8.5 million. Each Cornerstone Investor has been guaranteed its respective allocation of Cornerstone Shares under the Offering and/or the Additional Cornerstone Placement (as defined below), subject to the terms and conditions of the respective Cornerstone Investment Agreement. The Cornerstone Commitments will be satisfied by the Cornerstone Investors irrevocably exercising their rights as shareholders in the Rights Offering and, to the extent not fully allocated, by subscribing for the remainder as part of the Rump Offering (the Cornerstone Placement). If the full allocation of Cornerstone Shares cannot be satisfied through the Rights Offering and the Rump Offering, the Cornerstone Investors will participate in an additional placement for any remaining amount of their commitment (the "Additional Cornerstone Placement" and together with the Additional KGG Placement, the "Additional Placement"). Any shares issued under the Additional Placement are referred to as the "Additional Shares". The aggregate amount of the Additional Placement shall not exceed €19.78 million. The subscription price for each Cornerstone Share is equal to the Issue Price.

Depending on the allocation of Cornerstone Shares under the Offering and the extent to which the underwriting by KGG is fully utilised in connection with the Offering, Avantium may raise up to €19.78 million by issuing Additional Shares under the Additional Placement. For any gross proceeds above €65 million, Avantium will have broad discretion over how to use such proceeds, but anticipates to use the additional net proceeds to further strengthen the financial profile of the Company, increasing its available working capital allowing covering of additional unexpected general corporate costs and to demonstrate its long-term financial viability to the Group's stakeholders, such as its customers, prospective licensees, debt holders, the shareholders and employees. The issuance of any Additional Shares, to the extent required, was agreed with the Cornerstone Investors and KGG to ensure allocation and placement of the Shares to which the Cornerstone Investors and KGG have irrevocably subscribed and/or provided an underwriting commitment, respectively, to ensure successful completion of the Offering.

Terms of the Offering

Details of the Rights Offering are set forth in the Prospectus that has been approved by the Netherlands Authority for the Financial Markets (the "AFM") and has been published today on prospectusavantiumrightsoffering2025.pdf.

Rights Offering ratio and Issue Price

11 for 8 Rights Offering of 12,103,283 Offer Shares at an Issue Price of €5.40 per Offer Share. The Issue Price represents a discount of 40.0% to the TERP, based on the closing price of €13.95 on Euronext Amsterdam on 3 September 2025. The Issue Price represents a discount of 61.3% to the closing price of the shares on 3 September 2025.

Record Time, Exercise Period and Excess Application

Each ordinary share held on the Record Time will entitle its holder to one (1) Right. Eligible Persons (as defined in the Prospectus) holding Rights, will be entitled to subscribe in cash, on an irreducible basis, for 11 Offer Shares for every 8 Rights held and, via the Excess Application on a reducible basis, for an additional number of Offer Shares they wish to acquire, at the Issue Price, from 9:00 CEST on 5 September 2025 until 17:45 CEST on 17 September 2025 (the "Exercise Period").

The last date and/or time before which notification of Rights exercise and Excess Application instructions must be given in order to be valid may be earlier, depending on the financial institution through which the Rights are held. Rights can only be exercised in multiples of the Subscription Ratio (as defined in the Prospectus). No fractions of Offer Shares will be issued. Except as otherwise set out in the Prospectus, once an Eligible Person has exercised his or her Rights, he or she may not revoke or modify that exercise. Any Rights that have not been validly exercised by the end of the Exercise Period will expire and can no longer be exercised.

Listing of and trading of the Rights

Trading in the Rights on Euronext Amsterdam is expected to commence at 9:00 CEST on 5 September 2025 and will continue until 17:36 CEST on 15 September 2025, barring unforeseen circumstances. The Rights will be listed and traded on Euronext Amsterdam under the symbol "AVTRI" and ISIN NL0015002ND2.

Rump Shares

After the Exercise Period has ended, the Offer Shares that were issuable upon the exercise of Rights but that have not been validly subscribed for during the Exercise Period, will be offered for sale at the Issue Price through (i) a public offering in the Netherlands, Belgium and France and (ii) private placements to certain institutional investors in certain other eligible jurisdictions, subject to the terms and conditions of the Underwriting Agreement and subject to applicable securities laws. PrimaryBid SA has been engaged as retail placement agent in the Netherlands, Belgium and France. The subscription price of the Rump Shares will be equal to the Issue Price.

The allocation of the Rump Shares will be made as follows: (i) first, the Cornerstone Investors will receive their guaranteed allocation of Offer Shares, which will be satisfied by the Rump Shares to the extent available; (ii) second, the Eligible Persons (as defined in the Prospectus) who have validly submitted an Excess Application will receive a proportionate allocation of any remaining Rump Shares, subject to the discretion of the Company and the Joint Global Coordinators; (iii) third, the new investors who have validly subscribed for the Rump Shares will receive an allocation of any remaining Rump Shares, subject to the discretion of the Company and the Joint Global Coordinators.

The Company and the Joint Global Coordinators may, at their sole discretion determine the allocation of the Rump Shares among the Eligible Persons and new investors, and may, give preference to certain new investors over Eligible Persons who have validly submitted an Excess Application.

Risk Factors

The following is a summary of the key risks that, alone or in combination with other events or circumstances, could have a material adverse effect on Avantium's business, financial condition, results of operations or prospects, the Offering, the Admission or the Offer Shares:

• The Group is in financial distress and faces a working capital shortfall for the next 12 months following the date of the Prospectus of approximately €64 million. If the Offering is successful, the working capital shortfall for the next 12 months is €5 million, after deducting the net proceeds of €59 million of the Offering. If the Group does not rectify its working capital shortfall, it will likely become insolvent;

• Even if the Group is able to resolve its working capital shortfall, no assurance can be given that the Group will be able to continue as a going concern, as the Group may continue to face liquidity challenges;
• The Group has incurred losses and negative operating cash flow and has an accumulated deficit. The Group anticipates that it will continue to incur losses for the foreseeable future and the Group may never achieve or sustain profitability;
• No assurance can be given that the commercial production of the FDCA Flagship Plant will begin on schedule, within budget or at all, and if the commissioning, start-up and ramp-up of the FDCA Flagship Plant take longer than expected, the Group will face additional operational costs and there is no assurance that the Group will have sufficient funds available to fund such additional costs;
• The commercial success of the YXY® Technology depends on the market acceptance of FDCA, PEF and PEF products and the Group's ability to sell FDCA, PEF and Licenses, which may only become clear after the FDCA Flagship Plant becomes operational;
• The YXY® Technology may not perform as expected at the planned scale at the FDCA Flagship Plant and FDCA produced at the FDCA Flagship Plant or PEF produced by third parties under License may not meet the required product quality standards, performance tests or specifications;
• The Group may not be able to identify and pursue adequate strategic alternatives for its non-core business activities;
• The Group may not be able to successfully develop its technologies;
• The Group may not be able to repay and/or refinance the Debt Financing facility for the FDCA Flagship Plant; and
• An increase in interest rates may increase the Group's financing costs and may adversely affect its business.

For a full overview of the key risks, please refer to the Prospectus.

Lock-up undertakings

The Company has agreed to a lock-up period expiring 180 calendar days following the date of settlement of the Rights Offering. The Joint Global Coordinators may waive the lock-up restrictions under the Underwriting Agreement. In addition, KGG has agreed to a lock-up period expiring 180 calendar days following the date of settlement of the Offering with respect to any ordinary shares subscribed for by KGG. The lock-up arrangements are subject to certain customary exceptions.

Dilution

Shareholders who transfer, or who do not or are not permitted to exercise any of their Rights granted under the Rights Offering will suffer a dilution of their proportionate ownership and voting rights of approximately 57.9% as a result of the issue of the Offer Shares. Furthermore, to the extent that the Additional Placement is completed, Shareholders will experience additional dilution of their

proportionate ownership and voting rights as a result of the issue of further new Ordinary Shares to KGG and the relevant Cornerstone Investors. The maximum additional dilution resulting from the Additional Placement would be approximately 14.9%.

Advisors

ABN AMRO, BNPP and Stifel Europe are acting as Joint Global Coordinators for the Rights Offering.

ABN AMRO will act as the Subscription, Listing and Paying Agent for the Rights Offering.

PrimaryBid SA has been engaged as advisor to the Company in relation to the public offering in France and to cooperate with the Joint Global Coordinators in the Netherlands and Belgium.

Point Partners B.V. is acting as advisor to KGG and Invest-NL.

Underwriting

The Company has secured gross proceeds of €65 million from the Rights Offering by: (i) the Cornerstone Commitments and the Shareholder Commitments, and (ii) underwriting on a firm committed basis of any Rump Shares not covered by the Shareholders Commitments and the Cornerstone Commitments, pursuant to an underwriting agreement entered into on 4 September 2025 with a syndicate of underwriters including ABN AMRO, BNPP, Stifel Europe, Invest-NL and KGG (the "Underwriters"). Avantium has made a number of commitments in connection with KGG's role as Underwriter, including a right to appoint a Supervisory Board Observer. The commitments are further outlined in the Prospectus.

Indicative timetable

Subject to acceleration or extension of the timetable for, or withdrawal of the Offering, the timetable below sets forth certain expected key dates for the Offering.

Event	Time and Date
Launch of the Offering and publication of the Prospectus	4 September 2025
Ex-rights date and start of trading in the Rights on	09:00 hours CEST on 5 September
Euronext	2025
	09:00 hours CEST on 5 September
Start of the Offering period	2025
	09:00 hours CEST on 5 September
Start of the Exercise Period	2025
	17:40 hours CEST on 8 September
Record Time	2025
	17:36 hours CEST on 15 September
End of trading in the Rights on Euronext	2025
End of the Exercise Period and Excess Application for	17:45 hours CEST on 17 September
retail investors	2025

Event	Time and Date
	17:45 hours CEST on 17 September
End of Exercise Period for institutional investors	2025
	After 17:45 hrs CEST 17 September
Start Rump Offering	2025
	Before 09:00 hours CEST 18
End of Rump Offering	September 2025
Allotment and issue of the Offer Shares and publication of	Before 09:00 hours CEST 18
a press release by the Company announcing the results of	September 2025
the Offering
Settlement Date	22 September 2025
Listing of and start of trading in the Offer Shares on	09:00 hours CEST on 22 September
Euronext	2025

Availability of the Prospectus

The Rights Offering is being made only by means of the Prospectus, approved by, and filed with, the AFM on 4 September 2025 as competent authority under the Prospectus Regulation. The Prospectus has been notified to the Belgian Financial Services and Markets Authority and to the French Autorité des Marchés Financiers for passporting in accordance with article 25 of the Prospectus Regulation. The Prospectus is available electronically, free of charge, via the website of the Company 20250904afmapprovedprospectus-avantiumn.v.rightsoffering2025.pdf and the AFM website Register goedgekeurde prospectussen, subject to securities law restrictions in certain jurisdictions.

Information for Retail Investors

The Company has made available a Frequently Asked Questions document, in the Dutch language, on the Company website: https://newsroom.avantium.com/rights-offering-2025/

Prospective investors should carefully read and review the entire Prospectus and should form their own views before making an investment decision with respect to the Rights, the Offer Shares and the Additional Shares. Furthermore, before making an investment decision with respect to the Rights, the Offer and the Additional Shares, prospective investors should consult their own professional adviser and carefully review the risks associated with an investment in the Rights, the Offer Shares and the Additional Shares and consider such an investment decision in light of their personal circumstances.

Half-year 2025 results

The summary of financial information in the Prospectus contains HY 2025 financial statements. The half-year 2025 press release is published on 4 September 2025 and is available on the website of the Company: https://newsroom.avantium.com/avantium-announces-half-year-2025-results/

Previous announcements

On 12 August 2025, Avantium announced it had entered into a comprehensive financing package and reached a conditional agreement with its lenders ABN AMRO (and its subsidiaries), ING Sustainable Investments B.V., Invest-NL, ASN Bank, and Coöperatieve Rabobank U.A. to extend and amend its existing senior debt financing agreement, subject to a successful equity raise.

On 29 August 2025, Avantium announced the successful start-up of the sugar dehydration (SDH) unit and all auxiliary systems and utilities at its FDCA Flagship Plant in Delfzijl. This achievement marks a key technical achievement in the phased commissioning and start-up of the of the FDCA Flagship Plant. With the SDH unit now operational, the next steps include the finalization of commissioning and sequential start-up of the remaining units that handle oxidation and purification. Avantium has identified quality issues in the piping and certain electrical components. These will be repaired or replaced to ensure a safe and reliable start-up of the remaining units. Avantium now expects to begin commercial sales under its existing offtake agreements in the first quarter of 2026.

About Avantium

Avantium is a pioneering commercial-stage company focused on renewable & circular polymer materials. Avantium develops and commercialises innovative technologies for the production of materials based on sustainable carbon feedstocks, i.e. carbon from biomass or carbon from the air (CO2). The most advanced technology is the YXY® Technology that catalytically converts plantbased sugars into FDCA (furandicarboxylic acid), the key building block for the sustainable plastic PEF (polyethylene furanoate). PEF is known under the brand name releaf®, an EU registered trademark of Avantium. Avantium has successfully demonstrated the YXY® Technology at its pilot plant in Geleen, the Netherlands, and is in the process of starting the world's first commercial plant for FDCA in Delfzijl, the Netherlands. Avantium works in partnership with like-minded companies around the globe to develop revolutionary renewable chemistry solutions from invention to commercial scale.

Avantium's shares are listed on Euronext Amsterdam and Euronext Brussels (symbol: AVTX). Avantium is incorporated in the Euronext Amsterdam SmallCap Index (AScX). Its offices and headquarters are in Amsterdam, the Netherlands.

This press release by Avantium N.V. contains information that qualifies as inside information within the meaning of section 7(1) of Regulation (EU) No 596/2014 on market abuse.

Forward-looking information / disclaimer

This press release may include forward-looking statements. Other than reported financial results and historical information, all statements included in this press release, including, without limitation, those regarding our financial position, business strategy and management plans and objectives for future operations, are forward-looking statements. These forward-looking statements are based

on our current expectations and projections about future events and are subject to risks and uncertainties that could cause actual results to differ materially from those expressed in the forward-looking statements. Many of these risks and uncertainties relate to factors that are beyond Avantium's ability to control or estimate precisely, such as future market conditions, the behaviour of other market participants and the actions of governmental regulators. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this press release and are subject to change without notice. Other than as required by applicable law or the applicable rules of any exchange on which our securities may be traded, we have no intention or obligation to update forward-looking statements.

Any securities mentioned herein are not and will not be registered under the U.S. Securities Act of 1933, as amended (the Securities Act), and may not be offered or sold in the United States absent registration or unless pursuant to an applicable exemption from the registration requirements of the Securities Act. The Company has no intention to register any part of the offering in the United States or make a public offering of securities in the United States.

For more information:

Caroline van Reedt Dortland, Director Communications +31-20-5860110 / +31-613400179 mediarelations@avantium.com

Aarne Luten, Head of Investor Relations +31-625687714 ir@avantium.com

DISCLAIMER

These materials are not for release, distribution or publication, whether directly or indirectly and whether in whole or in part, in or into the United States, Canada, Australia or Japan or any other jurisdiction where to do so would constitute a violation of the relevant laws of such jurisdiction.

These materials are for information purposes only and are not intended to constitute, and should not be construed as, an offer to sell or a solicitation of any offer to buy the securities of Avantium N.V. (the Company, and such securities, the Securities) in the United States, Canada, Australia or Japan or in any other jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration, exemption from registration or qualification under the securities laws of such jurisdiction.

This announcement is not for publication or distribution, directly or indirectly, in or into the United States. This announcement is not an offer of securities for sale into the United States. The Securities have not been and will not be registered under the U.S. Securities Act of 1933, as amended, and may not be offered or sold in the United States. No public offering of securities is being made in the United States.

The Company has not authorised any offer to the public of Securities in any Member State of the European Economic Area and the United Kingdom other than the Netherlands. With respect to any Member State of the European Economic Area and the United Kingdom, other than the Netherlands (each a Relevant Member State), no action has been undertaken or will be undertaken to make an offer to the public of Securities requiring publication of a prospectus in any Relevant Member State. As a result, the Securities may only be offered in Relevant Member States (i) to any legal entity which is a qualified investor as defined in section 2(e) of the Prospectus Regulation; or (ii) in any other circumstances falling within section 1(4) of the Prospectus Regulation. For the purpose of this paragraph, the expression "offer of securities to the public" means the communication in any form and by any means of sufficient information on the terms of the offer and the Securities to be offered so as to enable the investor to decide to purchase or subscribe for the Securities and the expression "Prospectus Regulation" means Regulation (EU) 2017/1129 and includes any relevant delegated regulations.

No action has been taken by the Company that would permit an offer of Securities or the possession or distribution of these materials or any other offering or publicity material relating to such Securities in any jurisdiction where action for that purpose is required.

The release, publication or distribution of these materials in certain jurisdictions may be restricted by law and therefore persons in such jurisdictions into which they are released, published or distributed, should inform themselves about, and observe, such restrictions.

These materials may include statements, including the Company's financial and operational medium-term objectives that are, or may be deemed to be, ''forward-looking statements''. These forward-looking statements may be identified by the use of forward-looking terminology, including the terms ''believes'', ''estimates'', ''plans'', ''projects'', ''anticipates'', ''expects'', ''intends'', ''may'', ''will'' or ''should'' or, in each case, their negative or other variations or comparable terminology, or by discussions of strategy, plans, objectives, goals, future events or intentions. Forward-looking statements may and often do differ materially from actual results. Any forward-looking statements reflect the Company's current view with respect to future events and are subject to risks relating to future events and other risks, uncertainties and assumptions relating to the Company's business, results of operations, financial position, liquidity, prospects, growth or strategies. Forward-looking statements speak only as of the date they are made.

Each of the Company, as well as the Underwriters, including Joint Global Coordinators and their respective affiliates expressly disclaims any obligation or undertaking to update, review or revise any forward-looking statement contained in these materials whether as a result of new information, future developments or otherwise.

The Underwriters, including the Joint Global Coordinators are acting exclusively for the Company and no one else in connection with any offering of Securities. They will not regard any other person as their respective clients in relation to any offering of Securities and will not be responsible to anyone other than the Company for providing the protections afforded to their respective clients nor for providing advice in relation to any offering of Securities, the contents of these materials or any transaction, arrangement or other matter referred to herein. None of the Underwriters or any of their respective subsidiary undertakings, affiliates or any of their respective directors, officers, employees, advisers, agents, alliance partners or any other entity or person accepts any

responsibility or liability whatsoever for, or makes any representation, warranty or undertaking, express or implied, as to the truth, accuracy, completeness or fairness of the information or opinions in these materials (or whether any information has been omitted from these materials) or any other information relating to the group, its subsidiaries or associated companies, whether written, oral or in a visual or electronic form, and howsoever transmitted or made available or for any loss howsoever arising from any use of these materials or its contents or otherwise arising in connection therewith. Accordingly, the Underwriters disclaim, to the fullest extent permitted by applicable law, all and any liability, whether arising in tort or contract or that they might otherwise be found to have in respect of these materials and/or any such statement.

This announcement does not constitute a prospectus. An offer to acquire Securities pursuant to the proposed offering will be made, and any investor should make his investment, solely on the basis of information that will be contained in the prospectus to be made generally available in the Netherlands in connection with such offering. When made generally available, copies of the prospectus may be obtained at no cost from the Company or through the website of the Company.

In connection with the Offering, each of the Underwriters and any of their affiliates, may take up a portion of the Securities in the Offering as a principal position and, in that capacity, may retain, purchase, sell, offer to sell for its own account such Securities and other securities of the Company or related investments in connection with the Offering or otherwise. In addition, each of the Underwiters and any of their affiliates may enter into financing arrangements (including swaps or contracts for differences) with investors in connection with which each of the Underwriters and any of their affiliates may from time to time acquire, hold or dispose of Securities. None of the Underwriters or their affiliates intends to disclose the extent of any such investment or transactions otherwise than in accordance with any legal or regulatory obligations to do so.

Information to distributors

Solely for the purposes of the product governance requirements contained within: (a) EU Directive 2014/65/EU on markets in financial instruments, as amended (MiFID II); (b) sections 9 and 10 of Commission Delegated Directive (EU) 2017/593 supplementing MiFID II; and (c) local implementing measures (together, the MiFID II Product Governance Requirements), and disclaiming all and any liability, whether arising in tort, contract or otherwise, which any "manufacturer" (for the purposes of the MiFID II Product Governance Requirements) may otherwise have with respect thereto, the Securities subject to the Offering have been subject to a product approval process, which has determined that such Securities are: (i) compatible with an end target market of retail investors and investors who meet the criteria of professional clients and eligible counterparties, each as defined in MiFID II; and (ii) eligible for distribution through all distribution channels as are permitted by MiFID II (the Target Market Assessment).

Notwithstanding the Target Market Assessment, "distributors" (for the purposes of the MiFID II Product Governance Requirements) should note that: the price of the Securities may decline and investors could lose all or part of their investment; the Securities offer no guaranteed income and no capital protection; and an investment in the Securities is compatible only with investors who do not need a guaranteed income or capital protection, who (either alone or in conjunction with an appropriate financial or other adviser) are capable of evaluating the merits and risks of such an investment and who have sufficient resources to be able to bear any losses that may result

therefrom. The Target Market Assessment is without prejudice to the requirements of any contractual, legal or regulatory selling restrictions in relation to the Offering.

For the avoidance of doubt, the Target Market Assessment does not constitute: (a) an assessment of suitability or appropriateness for the purposes of MiFID II; or (b) a recommendation to any investor or group of investors to invest in, or purchase, or take any other action whatsoever with respect to the Securities.

Each distributor is responsible for undertaking its own target market assessment in respect of the Securities and determining appropriate distribution channels.