TransCode Therapeutics Unveils Promising Phase 1a Results for TTX-MC138 at ESMO Congress

On October 14, 2025, TransCode Therapeutics, Inc. (NASDAQ: RNAZ) announced the completion of its Phase 1a clinical trial of TTX-MC138, a groundbreaking inhibitor of microRNA-10b, or miR-10b, which plays a significant role in metastatic cancer development. The findings were shared during the ESMO Congress, taking place in Berlin, Germany, from October 17-21, 2025.

The primary focus of this trial was to assess safety and tolerability, pharmacokinetics, and to define a recommended Phase 2 dose (RP2D). The study involved a total of 16 patients who were treated across four escalating dose levels to ascertain the treatment's impact on metastatic diseases.

Key Findings

The trial reached its primary safety endpoint without any significant treatment-related adverse events or dose-limiting toxicities. Patients were administered a median treatment duration of four months, with durations ranging between two and twelve months. Notably, three patients are still on trial, while 44% of the 16 participants (seven patients) experienced stable disease for four months or more—a promising indicator of the treatment's effectiveness.

Furthermore, the pharmacodynamic effects displayed by TTX-MC138 across all administered dose levels showed consistency with preclinical findings. One particular case highlighted involved a patient with thyroid cancer, who exhibited a notable reversal in thyroglobulin levels during treatment, illustrating the candidate's therapeutic potential.

Dr. William McKean, an investigator from The START Center for Cancer Research, emphasized the compelling nature of clinical benefits observed with TTX-MC138, which aligns with earlier preclinical research. This points to the drug's capability to remain effective within tumor cells over extended periods, making it a potential game-changer for patients who are battling metastatic diseases.

Next Steps

TransCode’s strategic decision to advance TTX-MC138 into a Phase 2a clinical trial stems from its favorable safety profile and the durability of observed anti-tumor effects. Dr. Daniel Vlock, Consulting Clinician, expressed optimism regarding these promising findings, highlighting the potential for intervening earlier in the disease progression for patients susceptible to metastatic cancer.

The ongoing data analysis and vigilance in monitoring patient responses indicate robust interest in further investigating TTX-MC138’s efficacy in subsequent trials. Plans for a final clinical study report alongside scientific presentations and publications are underway, ensuring that all stakeholders are kept informed of larger developments in the program.

In summary, TransCode Therapeutics is poised to transition TTX-MC138 into crucial stages of evaluation with expectations for broader clinical applications across several metastatic conditions. The preliminary results signify a vital step in cancer treatment, demonstrating how innovative approaches can pave the way for novel therapeutic options in an ever-evolving field.

For more information about the trial, visit Clinical Trials.gov under the NCT Identifier NCT06260774.