THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR THE PURPOSES OF ARTICLE 7 OF THE MARKET ABUSE REGULATION (EU) 596/2014 AS IT FORMS PART OF UK DOMESTIC LAW BY VIRTUE OF THE EUROPEAN UNION (WITHDRAWAL) ACT 2018.

10 February 2026

4basebio PLC

("4basebio" or the "Company")

Leadership Changes

Cambridge, UK, 10 February 2026  – 4basebio PLC (AIM: 4BB), an innovation driven biotechnology company enabling and accelerating development of advanced therapy medicinal products (ATMPs) through its high performant GMP-grade synthetic DNA products , announces that Dr Amy Walker has been appointed as Chief Executive Officer, succeeding Dr Heikki Lanckriet, Founder of the Company.

After six years in the role, Heikki has stepped down as CEO in order to lead a newly formed entity which will be focussed on advancing the Hermes nanoparticle platform into the clinic. The Board and Executive Leadership team determined that Amy, with her deep knowledge of the company and commercially-focussed skillset and experience, is the right candidate to succeed Heikki as the Company prepares for accelerated commercial growth. Heikki will remain on the Board and will also continue to support the Company’s scientific and technical leadership. David Roth will join Heikki in the newly formed entity and will step down as Chief Financial Officer and as a Director, following an orderly handover period.

Amy has been with the Company for more than five years most recently serving as Chief Operating Officer. She has played a key role in scaling 4basebio’s GMP manufacturing capabilities, strengthening direct engagement with top-tier biopharma customers and supporting the Company’s growth operationally and strategically. As Chief Executive Officer, Amy will lead an accelerated commercial growth strategy, focusing on deepening penetration of the synthetic DNA market as customers increasingly seek alternatives to plasmid DNA, and building on the Company’s recent GMP milestone to support clinical programmes in cell and gene therapy and vaccine development.

Since the Company’s formation in 2020, Heikki has been responsible for leading 4basebio as it scaled its synthetic DNA technology from concept to clinic, built a global customer base and stewarded 4basebio in building its high-quality investor base.

This leadership change comes at a time when the Company enters an expected period of accelerated commercial growth in 2026 following a successful 2025. 4basebio has top tier pharma clients in the clinic and a strong and growing pipeline. The trend of drug development companies transitioning from plasmid DNA to synthetic DNA and RNA continues to gain traction and supports the Company’s commercial momentum, and we are pleased to have Amy at the helm of this exciting phase of the Company’s development.

Dr Manja Boerman, Executive Chair of 4basebio, commented : “4basebio’s GMP synthetic DNA manufacturing services help accelerate development timelines for cell and gene therapies and vaccines and offer superior safety and efficacy compared with plasmid DNA, two critical factors for clinical success. With GMP certification for its facility, the Company is now accelerating its focus on commercial delivery. Amy has invaluable commercial, scientific and technical expertise and has spearheaded building out the GMP infrastructure to enable 4basebio to lead this dynamic market. I’m delighted that she will lead the Company through this critical next phase of development and I look forward to leveraging my extensive CDMO experience in helping drive the business forward.

“On behalf of the Board and Executive Management Team, I’d like to thank Heikki for the leadership and vision that has brought the Company to a global market leadership position. We wish him the best with his new venture and are pleased he will continue to provide his valued strategic insights and technical support as he continues to serve on the Board as a technical expert. We will continue to build out the commercial and operational expertise of the Company and strengthen the team at this extremely exciting time . The Company would also like to thank David for his stewardship.”

Dr Amy Walker commented : “I am honoured to be appointed Chief Executive Officer at a time when 4basebio is poised for significant commercial traction. I look forward to leading the exceptional 4basebio team, accelerating our commercial momentum and scaling our GMP grade synthetic DNA offering to support our customers, while continuing to build long-term value for all stakeholders and, ultimately, patients.”

Dr Heikki Lanckriet added : “Leading 4basebio has been an exceptional privilege. Having founded the Company over six years ago and built it to where it is today, I feel the time is right to hand over the reigns as the Company moves into its next phase of commercial and operational development. Amy and I have worked closely together over the past years and she has been instrumental in the growth and success of 4basebio. Her expertise and judgement will lead the Company to commercial success and I am delighted that she will succeed me as Chief Executive Officer. With the Company under excellent stewardship, I am excited to be able to focus on my passion for entrepreneurship and business creation but I will continue to support Amy, the Board and the wider team to deliver on the Company’s goals. Finally, I would like to thank the 4basebio team for their commitment to the Company. It has been a genuine honour for which I am very grateful.”

Michael Wasserman, COO of Elevage Medical Technologies, commented: "We are extremely excited about 4basebio's move into GMP-grade drug substance manufacturing and the significant opportunity ahead for synthetic DNA in cell and gene therapy. Amy has been instrumental in positioning the company to capture this market inflection—her commercial vision, operational rigour and deep customer relationships make her the ideal leader to accelerate 4basebio's next phase of growth. We look forward to supporting the company as it scales its differentiated synthetic DNA platform to serve our partners' innovative programmes in the clinic."

This announcement contains inside information for the purposes of Article 7 of EU Regulation 596/2014 as amended by regulation 11 of the Market Abuse (Amendment) (EU Exit) Regulations 2019/310.

For further enquiries, please contact:

        4basebio PLC                                     +44 (0)12 2396 7943

Dr Amy Walker, CEO

Cairn Financial Advisers LLP (Nominated Adviser) +44 (0)20 7213 0880

Jo Turner / Sandy Jamieson / Ed Downes

Cavendish Capital Markets Limited (Joint Broker) +44 (0)20 7220 0500

Geoff Nash / Nigel BirksRBC Capital Markets (Joint Broker)               +44 (0)20 7653 4000
Kathryn Deegan / Matthew CoakesICR Healthcare (Media and Investor Relations     +44 (0)203 707 5700
Mary-Jane Elliott / Jessica Hodgson

Notes to Editors

About 4basebio

4basebio (AIM: 4BB) is an innovation driven life biotechnology company focused on accelerating the development of advanced therapy medicinal products (ATMPs) through its high-performance synthetic DNA products and non-viral, cell targeting nucleic acid delivery platform. The Company’s objective is to become a market leader in the manufacture and supply of high-quality synthetic DNA products for research, therapeutic and pharmacological use as well as development of target specific non-viral vectors for the efficient delivery of payloads in patients.

About Elevage Medical Technologies

Elevage Medical Technologies is a platform established by Patient Square Capital and is dedicated to supporting medical technology companies that can meaningfully improve health outcomes and quality of life for patients. Elevage provides capital along with deep technical, regulatory, and operational expertise to companies ranging from advanced clinical development to commercial acceleration stage. Elevage supports rapidly growing, highly differentiated companies with paradigm shifting technologies and strives to help build industry leading medical technologies. To learn more about Elevage, please visit  www.elevagemedical.com

Forward-looking statements

This announcement may contain certain statements about the future outlook for 4basebio.  Although the directors believe their expectations are based on reasonable assumptions, any statements about future outlook may be influenced by factors that could cause actual outcomes and results to be materially different.