TTX-MC138 - (PRE-I-SPY)

Sept. 28, 2026: TransCode Therapeutics (NASDAQ: RNAZ) reported updated data from the Phase 1a trial of TTX-MC138, an anti-miR-10b candidate, in relapsed/refractory, unresectable locally advanced, or metastatic solid tumors. In 14 efficacy-evaluable patients as of Sept. 1, 2026, 10/14 (71.4%) achieved stable disease as best overall response. Disease control rate was 57.1% at Cycle 3 Day 1 (95% CI 28.9%-82.3%) and 35.7% at Cycle 6 Day 1 (95% CI 12.8%-64.9%); three patients remained progression-free at 12 months. The company said the study’s primary safety endpoint was met.

Safety: 98 doses had been administered; no dose-limiting toxicities were reported, no treatment-emergent adverse events led to discontinuation, and treatment at the highest evaluated dose of 4.8 mg/kg and for over one year was reported as well tolerated.

Additional analyses: in a post-hoc Growth Modulation Index analysis, 6/15 evaluable patients (40%) had GMI >1.3. Exploratory blood RNA-sequencing showed treatment-associated immune activation, including antitumor cytokine signatures and dose-dependent immune effects; findings were described as hypothesis-generating.

Next steps: TransCode plans a clinical study report addendum, continued evaluation of safety/PK/PD/antitumor activity, and is assessing dose-expansion strategies. The release also states TTX-MC138 is being evaluated in a Phase 2a trial in ctDNA-positive colorectal cancer after curative-intent treatment.