TransCode Achieves Phase 1a Safety Milestone For TTX-MC138, Advancing To Phase 2a After Durability And Disease Control In Cancer Patients

Author: Benzinga Newsdesk | October 14, 2025 07:09am

• Safety primary endpoint achieved
• Median treatment duration of 4 months with a range of 2 to 12 months and three patients remain on trial
• RECIST data with apparent stable disease lasting over 4 months in 44% of patients (7 out of 16)
• Safety and durability profile consistent with known mechanism of action
• Early signals support advancement to a Phase 2a clinical trial with established treatment dose

BOSTON, Oct. 14, 2025 /PRNewswire/ -- TransCode Therapeutics, Inc. (NASDAQ:RNAZ) announces completion of Phase 1a clinical trial with TTX-MC138, an investigational inhibitor of microRNA-10b, or miR-10b. By meeting its primary safety endpoint and defining a recommended Phase 2 dose, TTX-MC138 is moving forward into the next stage of clinical evaluation to assess its efficacy across selected metastatic diseases and for multiple indications.

Primary objectives of the trial focused on safety, tolerability, pharmacokinetics ("PK") and establishment of a Phase 2 dose (RP2D). A total of sixteen patients were treated across four escalating dose levels. No significant treatment-related safety events or dose limiting toxicities were observed.

TTX-MC138 was administered to 16 patients (77 total doses to date) with positive pharmacodynamic effects over all four administered dose range levels. Currently three patients remain on trial receiving TTX-MC138. The median treatment duration was four months. Importantly, the duration of treatment for all patients ranged from two to 12 cycles, indicative of tolerability and disease control. Forty-four per cent or seven out of sixteen patients were classified as having stable disease lasting 4 months or longer. Preliminary data in 16 patients showed positive pharmacodynamic effects over a wide dose range, consistent with preclinical models and TransCode's Phase 0 clinical trial. Of note, one patient diagnosed with thyroid cancer and historic evidence of an increase in thyroglobulin levels, demonstrated a reversal of the trend during treatment and presented at the most recent measurement with undetectable thyroglobulin levels.

Study investigator William McKean, MD, PhD (The START Center for Cancer Research) stated, "The clinical benefit we are observing in patients treated with TTX-MC138 is compelling given the pre-clinical data and length of time the drug remains in the tumor cells".

Data analysis and monitoring are ongoing.  A final clinical study report, scientific presentations and publications are planned.

The treatment response, safety and durability profile provides the basis for TransCode's decision to proceed with the TTX-MC138 program in a Phase 2a clinical trial. TransCode's Daniel Vlock, MD, Consulting Clinician noted "the observed safety profile, coupled with the durability of TTX-MC138's anti-tumor effects, is particularly encouraging. These findings are consistent with the drug's mechanism of action and provide a basis for a more rigorous efficacy evaluation. This positions us to potentially intervene earlier in the patient's disease, offering a new therapeutic option for patients at risk of developing metastatic disease."

Further information about the trial is available at www.clinicaltrials.gov  NCT Identifier: (NCT06260774).

Preliminary data to be presented in a poster session at ESMO Congress October 17-21, 2025, taking place in Berlin, Germany. (FPN: 983P)

Posted In: RNAZ