15 September 2026

Thalia Therapeutics plc

("Thalia" or the "Company")

Business Update and Notice of Results

Progress across clinical-stage oncology, cardiovascular and RNA delivery programmes

Thalia Therapeutics plc (AIM: THAT), a clinical-stage biotechnology company developing innovative RNA-based therapeutics and delivery technologies in oncology and cardiovascular disease, today provides an update on its strategy execution and progress across its development portfolio.

Furthermore, the Company will announce its interim results for the six months ended 30 June 2026 on Wednesday, 30 September 2026, with an analyst briefing and Investor Meet Company presentation to be held the same day.  Details are outlined below.

Highlights

·      Strategic transformation into a clinical-stage RNA therapeutics company completed following the Company's rebrand from N4 Pharma plc and the acquisition of Sanmirna Therapeutics Inc. ("Sanmirna") in July 2026.

·      THAT-001 - miRisten: Phase 1 dose-escalation clinical trial in patients with relapsed or refractory Acute Myeloid Leukaemia ("AML") is continuing at City of Hope in the United States. The trial is on schedule, with an interim status update expected shortly and top-line data targeted for H1 2027.

·      THAT-002 - PCSK9/Lp(a): preclinical development work commenced with WuXi AppTec (Hong Kong) Limited ("WuXi"), a global provider of biology services and solutions, progressing stage one of the Company's long-duration bispecific siRNA cardiovascular programme.

·      THAT-003 - Nuvec®: ongoing development programme increasingly focused on targeted RNA delivery to the liver, via GalNAc, with ex-vivo work underway with the University of Strathclyde to confirm delivery of payload from Nuvec® to the target.

·      Luke Cairns, currently Executive Director, appointed Chief Financial Officer of the Company.

Dr David Solomon, Chief Executive Officer of Thalia Therapeutics, commented:

"The transformation of Thalia over the past six months has established the foundations of the business we set out to build - a clinical-stage RNA therapeutics company with a diversified portfolio spanning oncology, cardiovascular disease and RNA delivery.

"Following the acquisition of Sanmirna and our successful £2.75 million fundraise, our focus is now firmly on execution. We are advancing our assets in valuable therapeutic areas, and I am delighted to welcome Luke Cairns as our Chief Financial Officer. Luke's strong financial and capital markets expertise will continue to drive progress in implementing our strategy.

"miRisten is our most important asset, with near-term clinical milestones and the Phase 1 clinical trial well underway. Work has commenced to advance THAT-002, our bispecific cardiovascular gene-silencing medicine to reduce cardiovascular risk, which is now in preclinical development. We also continue to advance Nuvec®'s potential as a differentiated, targeted, RNA-delivery platform.

"We are making progress across each of our three programmes and look forward to providing shareholders with further details in due course."

Overview

Since Dr David Solomon's appointment as Chief Executive Officer in February 2026, Thalia has made significant progress implementing its strategy to build a differentiated RNA therapeutics business, now comprising three distinct and exciting assets, with an update on each below.

THAT-001 - miRisten: AML

miRisten is an anti-microRNA-126 therapeutic being developed initially for the treatment of relapsed or refractory AML, an aggressive blood cancer where there remains significant unmet medical need, particularly for patients whose disease has returned or failed to respond to existing treatments. AML affects over 22,000 new US patients annually, with a global market opportunity of US$3.9 billion, projected to grow to US$9.8 billion by 2035^¹.

miRisten is designed to selectively inhibit microRNA-126 ("miR-126"), which has been shown to play an important role in the survival and maintenance of leukaemia stem cells ("LSCs"), a key contributor to treatment resistance and disease relapse in AML. Preclinical studies have shown that miRisten inhibition of miR-126 can deplete LSC activity and improve survival.

Further preclinical research in March 2026, published in Blood², the leading peer-reviewed haematology journal, showed that miRisten, when combined with venetoclax, enhanced anti-leukaemic activity in preclinical models, including reducing LSC burden and restoring sensitivity to venetoclax. These findings provide further scientific support for targeting miR-126 as a potential therapeutic approach in AML. Venetoclax is the market-leading targeted prescription medication to treat specific types of blood cancers, including AML. In 2025, Venetoclax had global net sales of US$2.79 billion³.

The summary results from preclinical studies on miRisten, together with the research published in the leading haematology/oncology journal Blood, are available in Thalia's corporate presentation at https://investors.thaliatx.com/aim-rule-26.

miRisten is currently being evaluated in a Phase 1 dose-escalation clinical trial in patients with relapsed or refractory AML at City of Hope in the United States. The trial is on track, has completed several patient cohorts, and the Company expects to provide an interim update after completing a Clinical Trial Agreement with City of Hope reflecting Sanmina's financial commitment to conclude the trial.

Top-line data from the Phase 1 study remain targeted for H1 2027 and, if successful in reaching the study's clinical endpoints, will enable the Company to swiftly prepare for a Phase 2 pivotal trial with the FDA.

The Company's immediate priority is to complete the study and, once the Phase 1 data are available, determine the appropriate clinical and regulatory development pathway for miRisten.

THAT-002 - Bispecific PCSK9/Lp(a) siRNA cardiovascular programme

Thalia is developing THAT-002 as a potentially long-duration, dual-acting siRNA therapeutic designed to address cardiovascular risk through simultaneous targeting of PCSK9 and lipoprotein(a) ("Lp(a)"). PCSK9 is a clinically validated target for lowering low-density lipoprotein cholesterol caused through lifestyle factors and is an established therapeutic approach to reducing cardiovascular risk. Lp(a) represents a separate, genetically determined and independent cardiovascular risk factor for which there remain limited treatment options. The global PCSK9 inhibitor market worth US$3.14 billion in 2025 is forecast to reach US$7.71 billion by 2030, whilst there continues to be significant investment from big pharma in Lp(a)⁴.

The Company's strategy is to develop a single therapeutic capable of addressing both targets simultaneously, with the potential to provide a differentiated approach to reducing cardiovascular risk be it caused by lifestyle or genetics.

Thalia has now commenced preclinical work on THAT-002 with WuXi.The scope of this first phase of work includes synthesising the siRNAs, followed by in vitro and then in vivo studies, which will determine the next phase of work, which could include advancement into IND-enabling non-human primate studies in early 2027.

In addition, data generated through the ongoing preclinical development programme will enhance the intellectual property around THAT-002.

Significant scientific and industry interest, and investment, continue in RNA therapeutics targeting cardiovascular risk factors, including both PCSK9 and Lp(a). Thalia believes THAT-002's potential differentiation lies in its bispecific siRNA approach within a single long-acting therapeutic and that this approach could interest major pharma operating in the space.

The Company's development strategy remains milestone-driven, with investment in THAT-002 determined by the data generated at each successive stage of development.

THAT-003 - Nuvec® RNA delivery platform

Nuvec® remains an important part of Thalia's portfolio and provides the Company with a proprietary and differentiated approach to nucleic acid delivery.

Work with the Centre for Continuous Manufacturing and Advanced Crystallisation ("CMAC") at the University of Strathclyde is continuing. Following encouraging results generated to date, ex vivo studies are now underway to demonstrate targeted delivery and release of a payload in the liver via GalNAc. GalNAc is a clinically validated liver-targeting mechanism with several GalNAc-mediated RNA therapies approved by the FDA.

The Company believes that generating robust scientific data demonstrating where Nuvec® can provide meaningful advantages will be important in determining its future development and commercial positioning, including potential partnerships. The ongoing programme at Strathclyde will provide opportunities for future scientific publication and external validation of the technology.

Chief Financial Officer appointment

Luke Cairns, currently an Executive Director of Thalia, has been appointed Chief Financial Officer. Luke will formally oversee the Company's finance function while continuing to work closely with David Solomon, Chief Executive Officer, in an executive capacity on implementing the Company's strategy and development plans.

Development priorities

After completing the Sanmirna acquisition and associated fundraising, Thalia is focused on disciplined execution against clearly defined clinical and preclinical milestones.

The Company's principal priorities for the remainder of 2026 and into 2027 are to:

·      complete the miRisten Phase 1 clinical trial towards top-line data in H1 2027;

·      advance THAT-002 towards IND-enabling development;

·      generate further data to establish the differentiation and potential applications of Nuvec®;

·      strengthen the intellectual property position across its therapeutic programmes; and

·      evaluate partnership and licensing opportunities that could accelerate development or enhance shareholder value.

Notice of interim results, analyst briefing and investor presentation

The Company will announce its unaudited interim results for the six months ended 30 June 2026 on Wednesday, 30 September 2026 and hold the following analyst briefing and investor presentation:

Analyst briefing

Dr David Solomon, Chief Executive Officer, will host an online briefing for analysts at 9.30 am BST on Wednesday, 30 September 2026. Analysts wishing to attend should contact Sarah Hollins at Northstar Communications at [email protected]

Investor presentation

An investor presentation to cover the interim results will be held at 2.00 pm BST on Wednesday, 30 September 2026.

The presentation is open to all existing and potential shareholders. Questions can be submitted pre-event via your Investor Meet Company dashboard up until 9 am on 29 September 2026 or at any time during the live presentation.

Investors can sign up to Investor Meet Company for free and add to meet Thalia Therapeutics plc via: https://www.investormeetcompany.com/thalia-therapeutics-plc/register

Investors who already follow Thalia Therapeutics plc on the Investor Meet Company platform will automatically be invited.

1.     https://www.fortunebusinessinsights.com/industry-reports/acute-myeloid-leukemia-treatment-market-100607

2.     Blood. March 2026;147(10):1083-1097 https://doi.org/10.1182/blood.2025029875

3.     Source: AbbVie Inc., Full-Year and Fourth-Quarter 2025 Financial Results, published 4 February 2026 https://investors.abbvie.com/news-releases/news-release-details/abbvie-reports-full-year-and-fourth-quarter-2025-financial

4.     https://www.mordorintelligence.com/industry-reports/pcsk9-inhibitor-market

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 which has been incorporated into UK law by the European Union (Withdrawal) Act 2018.  Upon the publication of this announcement via Regulatory Information Service, this inside information is now considered to be in the public domain. 

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About Thalia Therapeutics plc

Thalia Therapeutics is a clinical-stage biotechnology company developing innovative RNA-based therapeutics and delivery technologies across oncology and cardiovascular disease. With a growing, differentiated pipeline, de-risked by validated therapeutic targets, we aim to treat disease at its source by silencing or modifying the genes that cause or contribute to it.

Our clinical-stage programme miRisten is a microRNA therapeutic in development for Acute Myeloid Leukaemia (AML). Alongside this, our preclinical bispecific siRNA programme is being developed as a potentially long-acting treatment for atherosclerotic cardiovascular disease by addressing two independent drivers of cardiovascular risk. Our proprietary delivery technology, Nuvec®, offers the potential to overcome the fundamental challenges of RNA delivery, enabling targeted, scalable RNA therapeutics.

For further information visit www.thaliatx.com