TransCode Therapeutics, Inc. (NASDAQ: RNAZ), the RNA oncology company committed to more effectively treating cancer using RNA therapeutics, today announced that the third patient in Cohort 4 of its Phase 1a clinical trial has received their initial dose of TTX-MC138. All cohorts have enrolled at least three patients who have been dosed with TTX-MC138 at least once. The Safety Review Committee monitoring the clinical trial unanimously approved opening the fourth cohort based on its review of available safety and pharmacokinetic (PK) data. Additionally, the Safety Review Committee approved expanded enrollment in Cohort 3 to obtain additional safety data. To date, 15 patients have received at least one dose of TTX-MC138 at 4 separate dose levels ranging from 0.8 mg/kg to 4.8 mg/kg. Three patients have been treated in the expanded enrollment.

Ten patients remain on study for continued treatment, receiving an additional dose of TTX-MC138 during each treatment cycle every 28 days, and may remain on study absent any significant safety observations or disease progression. Two patients who have remained on study the longest have received so far seven doses of TTX-MC138 over approximately seven months and have demonstrated stable disease. The 10 patients currently on study have shown no disease progression. Further, no significant safety or dose limiting toxicities have been reported in any of the trial’s 15 patients. Analysis of PK activity from Cohorts 1, 2 and 3 is ongoing and suggests that TTX-MC138 demonstrates a PK/PD profile consistent with preclinical results and results from TransCode’s Phase 0 clinical trial. Specifically, preliminary PK and pharmacodynamic (PD) data follow a predictable dose-response relationship. Analysis of PD activity from cycle 1 treatments in Cohorts 1 and 2, treated with doses of 0.8 mg/kg and 1.6 mg/kg, respectively, demonstrates miR-10b target engagement at 24 hours post-infusion.

The observed tolerability profile and the available PK/PD results thus far support advancement of the clinical trial to further evaluate safety and potential anti-tumor activity of TTX-MC138 in the planned dose expansion (Phase 1b) portion of the trial.