Thalia Acquires Sanmirna, Secures £2.75M to Advance Anti-miRNA Therapy for AML
Key Insights
Thalia Therapeutics (search) has acquired Sanmirna Therapeutics (search), transforming into a clinical-stage RNA company with the anti-miRNA asset miRisten targeting acute myeloid leukemia (search).
The acquisition is valued at £3.675 million upfront with up to £13 million in milestone payments, alongside an oversubscribed £2.75 million fundraise.
MiRisten inhibits microRNA-126 (search), a molecule implicated in leukemia stem cell survival, and is currently in a Phase 1 trial for relapsed/refractory AML.
Thalia Therapeutics (search) plc has acquired Sanmirna Therapeutics (search) in a deal that transforms the AIM-listed company from a drug delivery and preclinical business into a clinical-stage RNA therapeutics company. The acquisition, announced alongside an oversubscribed £2.75 million (€2.4m) financing round, sent Thalia shares up 20% to 0.69p.
The deal carries an initial consideration of £3.675 million, with deferred milestone payments worth up to a further £13 million. The fundraise, conducted through a placing and subscription of new shares at 0.6p each, saw directors subscribe for £1.1175 million — representing 40% of the total — with additional support from investors including Premier Miton.
"This is an exciting and transformative opportunity to accelerate our clinical-stage oncology pipeline and diversify our RNA therapeutics pipeline," said CEO Dr. David Solomon. "The Sanmirna acquisition is value accretive for Thalia shareholders, as it transforms Thalia into a clinical-stage company developing a promising novel therapeutic approach to treat AML."
MiRisten: Targeting microRNA-126 (search) in AML
The centerpiece of the acquisition is miRisten, an anti-miRNA therapy that selectively inhibits microRNA-126 (search). This RNA molecule is believed to play a critical role in the survival of leukemia stem cells in acute myeloid leukemia (search) (AML), a rare and aggressive blood cancer affecting more than 22,000 new patients annually in the United States.
Unlike siRNA therapies that silence messenger RNA targets, anti-miRNA therapies aim to block disease-associated microRNAs that can regulate multiple downstream pathways. The candidate was originally discovered at City of Hope (search), a leading US cancer research center, which licensed the rights to Sanmirna.
Thalia estimates the global market opportunity for AML at $3.9 billion, projected to grow to $9.8 billion by 2035.
Phase 1 Trial and Timeline
An ongoing Phase 1 trial is currently evaluating miRisten's safety and early signs of efficacy in patients with relapsed or refractory AML. The study is primarily designed to assess safety and generate initial efficacy signals. Topline data are expected in the first half of 2027.
The company stated that the proceeds from the fundraise should support operations through mid-2027, including completion of the ongoing Phase 1 study.
A Challenging Field for microRNA Therapeutics
The acquisition positions Thalia in a field that has seen significant setbacks. While several siRNA drugs have reached the market, microRNA therapeutics have faced a more difficult path, with early programs encountering safety and delivery challenges.
MRX34 from Mirna Therapeutics, the first microRNA therapy to enter clinical testing, showed early signs of activity in cancer but had its Phase 1 trial halted after severe immune-related adverse events, including several treatment-related deaths. Regulus Therapeutics' RG-101, an anti-miR-122 therapy for hepatitis C, initially produced promising antiviral responses but was later discontinued following FDA intervention after cases of severe hyperbilirubinemia. Miragen Therapeutics' cobomarsen, an anti-miR-155 therapy, advanced into Phase 2 studies in hematological cancers but was ultimately discontinued after results were deemed not compelling for the study's primary endpoint.
MiRisten remains an early-stage programme, and clinical proof-of-concept is still some distance away. The ongoing Phase 1 trial represents the first step in determining whether targeting microRNA-126 (search) can offer a viable therapeutic approach for patients with relapsed or refractory AML.