Thalia Therapeutics plc (AIM: THAT), a clinical-stage RNA therapeutics company, has announced that its wholly-owned subsidiary Sanmirna Therapeutics Inc. has entered into a Clinical Trial Agreement with City of Hope in the United States for the ongoing Phase 1 trial of miRisten (THAT-001) in relapsed or refractory Acute Myeloid Leukaemia. The agreement formalises arrangements for trial completion, including access to data and budget confirmation, which the company states is in line with previously disclosed use of proceeds. An interim data readout is expected in Q4 2026, with topline results targeted for the first half of 2027, making the coming months a potentially significant period for investors.

Key Points

  • Thalia Therapeutics plc (AIM: THAT) is a clinical-stage biotechnology company developing RNA-based therapeutics in oncology and cardiovascular disease
  • Subsidiary Sanmirna Therapeutics Inc. has signed a Clinical Trial Agreement with City of Hope to support completion of the Phase 1 miRisten study in Acute Myeloid Leukaemia
  • Interim data expected Q4 2026; topline readout targeted for H1 2027; budget confirmed in line with the June 2026 fundraise of £2.75 million
  • Investors should watch for the Q4 2026 interim data release and any subsequent regulatory or clinical decisions regarding miRisten

Sanmirna Therapeutics Formalises Phase 1 miRisten Study Arrangements with City of Hope

The Clinical Trial Agreement between Sanmirna Therapeutics Inc. and City of Hope covers the completion of the ongoing Phase 1 dose-escalation study of miRisten, an anti-microRNA-126 therapeutic. The agreement defines access to trial results and trial-related information, and confirms the budget for the study. Thalia states the confirmed budget is consistent with the use of proceeds outlined at the time of its £2.75 million fundraise, announced on 24 June 2026. City of Hope is described as one of the world's leading cancer research and treatment centres and holds the intellectual property from which Sanmirna draws an exclusive licence covering miRisten and its applications.

miRisten Targets Relapsed or Refractory AML, a Disease Area of Significant Unmet Need

miRisten is being evaluated in patients with relapsed or refractory Acute Myeloid Leukaemia, a population with limited treatment options and historically poor outcomes. The Phase 1 trial is designed to assess the safety and tolerability of miRisten and explore initial signs of efficacy through a dose-escalation design. Chief Executive Officer Dr David Solomon noted in the announcement that AML remains an area of significant unmet medical need, particularly for patients whose disease has relapsed or not responded to existing treatments. The company's focus, the announcement states, is on supporting completion of the ongoing study and evaluating the resulting data to determine the programme's next clinical and regulatory steps.

City of Hope's 10.6% Shareholding Triggers AIM Related Party Transaction Rules

Because City of Hope holds a 10.6 per cent interest in Thalia Therapeutics — a stake acquired as part of the July 2026 Sanmirna acquisition — entering into the Clinical Trial Agreement is classified as a related party transaction under AIM Rules. The company's directors, having consulted with nominated adviser SP Angel Corporate Finance LLP, concluded that the terms are fair and reasonable so far as shareholders are concerned. Investors may note that City of Hope's dual role as scientific partner, licensor, and substantial shareholder creates a structural alignment of interests, though it also introduces governance considerations typical of such related-party arrangements in clinical-stage biotechnology.

Interim Data Expected Q4 2026 as Thalia Builds Its RNA Therapeutics Pipeline

Beyond miRisten, Thalia is developing a preclinical bispecific siRNA candidate, THAT-002, targeting atherosclerotic cardiovascular disease, alongside its proprietary Nuvec® RNA delivery technology platform, THAT-003. The upcoming interim data readout from the miRisten Phase 1 study, expected before the end of 2026, will represent the next major newsflow catalyst for Thalia. Topline data is targeted for the first half of 2027. The company's ability to advance miRisten through Phase 1 and generate compelling clinical data will be a key determinant of its pipeline value and future financing options in a competitive RNA therapeutics landscape.