29 September 2026

Thalia Therapeutics plc

("Thalia" or the "Company")

New Patent Granted for miRisten in China

Extends intellectual property protection for Thalia’s clinical-stage AML programme

Thalia Therapeutics plc (AIM: THAT), a clinical-stage biotechnology company developing innovative RNA-based therapeutics and delivery technologies in oncology and cardiovascular disease, announces the granting and issue of a Chinese patent relating to miRisten (THAT-001), its lead clinical-stage programme for acute myeloid leukaemia (“AML”).

The patent covers the use of miRisten in the highly valuable Chinese market. It further enhances the intellectual property exclusively licensed from City of Hope, one of the largest and most advanced cancer research and treatment organizations in the U.S., to Sanmirna Therapeutics Inc.*, which Thalia acquired in July 2026, with patents granted in the US, UK, Germany, France, Japan, EPO (European Patent Organisation) countries, and now in China.

miRisten is an anti-microRNA-126 therapeutic being developed initially for patients with AML, an aggressive blood cancer with significant unmet medical need. It 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. Thalia is targeting top-line data from the trial in the first half of 2027.

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

“We are pleased to see further patent protection granted for miRisten in China. Strengthening the intellectual property supporting our lead clinical programme is an important part of its development as we work towards the next clinical milestones.

“AML remains an area of significant unmet medical need, including in China. Our immediate focus is on completing the Phase 1 trial and assessing the data to inform the next stage of miRisten’s development.  The Phase 1 trial continues to accrue patients, and we currently anticipate reporting results in H1 2027. 

China represents a potentially significant patient population for AML therapies. The Company estimates that approximately 30,400 people will be newly diagnosed with AML in China in 2026. This figure represents the overall incidence of AML and does not reflect the smaller population who may be eligible for miRisten, which is currently being developed for patients with relapsed or refractory disease.

A population-based study published in The Lancet Haematology in 2025 estimated 43,275 new cases of acute leukaemia across all subtypes in China in 2019. https://pubmed.ncbi.nlm.nih.gov/41062205/

*City of Hope has a financial interest in Thalia Therapeutics plc, which owns Sanmirna Therapeutics Inc.

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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 (THAT-001) is a microRNA therapeutic in development for Acute Myeloid Leukaemia (AML). Alongside this, our preclinical bispecific siRNA (THAT-002) is being developed as a potential long-acting treatment for atherosclerotic cardiovascular disease by addressing two independent drivers of cardiovascular risk. Our proprietary delivery technology, Nuvec® (THAT-003), offers the potential to overcome the fundamental challenges of RNA delivery, enabling targeted, scalable RNA therapeutics.

For further information visit www.thaliatx.com