TransCode Therapeutics, Inc. (NASDAQ:RNAZ) announced Wednesday that it has successfully completed the Phase 1a dose-escalation clinical trial of its lead cancer therapeutic candidate, TTX-MC138.

It met its primary safety objectives and demonstrated durable disease stabilization in patients with advanced metastatic cancer.

The Boston-based clinical-stage company announced Wednesday that the drug candidate was well-tolerated, showing a complete absence of dose-limiting toxicities across all tested patient cohorts.

The positive data support advancing the therapeutic into Phase 2a clinical development.

Key Trial Findings & Patient Demographics

The Phase 1a trial evaluated the safety, tolerability, and pharmacokinetics of TTX-MC138 across a heavily pre-treated patient population.

  • Dosing and Duration: A total of 16 patients received 86 doses of the therapeutic candidate. The median treatment duration was 11.3 weeks, spanning a range of four to 52.4 weeks, which represents 2 to 20 treatment cycles.
  • Patient Retention: Three patients remain on the trial and continue to receive daily treatment, reaching 21, 16, and 14 cycles, respectively.
  • Bioavailability: Analysis of patient plasma confirmed a pharmacokinetics profile showing drug bioavailability that is consistent with the company’s earlier preclinical studies.

Dose Escalation and Safety Profile

The dose-escalation study evaluated patients across four distinct cohorts, with zero dose-limiting toxicities reported:

  • Cohort 1 (0.8 mg/kg): 3 patients enrolled; 0 toxicities reported.
  • Cohort 2 (1.6 mg/kg): 3 patients enrolled; 0 toxicities reported (1 patient remains active on study).
  • Cohort 3 (3.2 mg/kg): 7 patients enrolled via an optional backfill; 0 toxicities reported (1 patient remains active on study).
  • Cohort 4 (4.8 mg/kg): 3 patients enrolled; 0 toxicities reported (1 patient remains active on study).

Following the successful completion of these cohorts, TransCode has selected 4.8 mg/kg as its recommended Phase 2a dose (RP2D).

Evidence of Disease Stabilization

Assessments using Response Evaluation Criteria in Solid Tumors (RECIST) standardized imaging criteria underscored the drug’s potential to achieve durable disease control in highly advanced populations.

Out of 14 evaluable patients, nine (64%) achieved stable disease lasting at least six months. Notably, one patient diagnosed with metastatic thyroid cancer experienced a dramatic decrease in thyroglobulin levels—a primary tumor marker associated with cancer progression. This patient has maintained stable disease for the past 12 months and continues to participate in the ongoing study.

“From a clinical perspective, it is quite encouraging to see how well tolerated this agent has been at the exposures achieved through the Phase 1a dose-escalation study, without any dose-limiting toxicities,” said Dr. Keith Flaherty, Director of Clinical Research at the Massachusetts General Hospital Cancer Center, Professor of Medicine at Harvard Medical School, and TransCode Advisory Board member. “That, combined with the observation of disease stabilization in a population with such advanced disease supports continued clinical development”.

Next Steps: Phase 2a Development

TTX-MC138 is designed as a first-in-class RNA therapeutic candidate to inhibit microRNA-10b (miR-10b), a biomarker and critical driver of many metastatic cancers.

TransCode plans to transition the drug into a recently initiated Phase 2a clinical trial.

The upcoming phase will evaluate the efficacy of TTX-MC138 in patients who have circulating tumor DNA (ctDNA) positive colorectal cancer following curative-intent therapy.

Dr. Daniel Vlock, TransCode Consulting Clinician, said, “We continue to believe that TTX-MC138 may offer a promising therapeutic option for patients with metastatic disease who have limited treatment alternatives”.

TransCode said that a full clinical study report is currently in progress, and the company plans to share data presentations at future scientific congresses.

RNAZ Price Action: TransCode Therapeutics shares were up 20.91% at $6.39 during premarket trading on Wednesday. The stock is trading near its 52-week low of $5.01, according to Benzinga Pro data.

Photo via Shutterstock