TransCode Therapeutics Successfully Completes Initial Dosing of Patients in Cohort 4 of Phase 1a Clinical Trial; No Dose Limiting Toxicities Reported

BOSTON,May 8, 2025/PRNewswire/ -- 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 (Phase1b) portion of the trial.

TTX-MC138 is a first-in-class therapeutic candidate designed to inhibit microRNA-10b, or miR-10b, a microRNA widely believed to be critical to the emergence and progression of many metastatic cancers. TransCode's Phase 0 clinical trial produced evidence of delivery of a radiolabeled version of TTX-MC138 to metastatic lesions and pharmacodynamic activity, even at a microdose of the drug candidate, suggesting a broad therapeutic window for TTX-MC138.

TransCode's Phase 1 clinical trial is a multicenter, open-label, dose-escalation and dose-expansion study designed to generate critical data to support evaluation of the safety and tolerability of TTX-MC138 in patients with a variety of metastatic solid cancers.  While not an endpoint, the trial may provide early evidence of clinical activity of TTX-MC138. The trial comprises an initial dose-escalation stage followed by a dose-expansion stage. The primary objective of the dose-escalation stage is to evaluate the safety and tolerability of escalating dose levels of TTX-MC138. In the dose-expansion stage, the safety, tolerability and anti-tumor activity of TTX-MC138 will be further evaluated in certain tumor types and at a certain dose level selected based on preliminary results from the dose-escalation phase.

Further information is available atwww.clinicaltrials.govNCT Identifier: (NCT06260774).

TransCode is a clinical-stage oncology company focused on treating metastatic disease. The company is committed to defeating cancer through the intelligent design and effective delivery of RNA therapeutics based on its proprietary TTX nanoparticle platform. The company's lead therapeutic candidate, TTX-MC138, is focused on treating metastatic tumors which overexpress microRNA-10b, a unique, well-documented biomarker of metastasis. In addition, TransCode has a portfolio of other first-in-class RNA therapeutic candidates designed to overcome the challenges of RNA delivery and thus unlock therapeutic access to a variety of novel genetic targets that could be relevant to treating a variety of cancers.

This release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including, without limitation, statements concerning the timing, conduct and results of TransCode's Phase 1 clinical trial, statements about microRNAs and their involvement in cancer, and statements concerning the therapeutic potential of TransCode's TTX-MC138 and other therapeutic candidates. Any forward-looking statements in this press release are based on management's current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: the risks associated with drug discovery and development; the risk that the results of clinical trials will not be consistent with TransCode's preclinical studies or expectations or with results from previous clinical trials; risks associated with the conduct of clinical trials; risks associated with TransCode's financial condition and its need to obtain additional funding to support its business activities, including TransCode's ability to continue as a going concern; risks associated with the timing and outcome of TransCode's planned regulatory submissions; risks associated with obtaining, maintaining and protecting intellectual property; risks associated with TransCode's ability to enforce its patents against infringers and defend its patent portfolio against challenges from third parties; risks of competition from other companies developing products for similar uses; risks associated with TransCode's dependence on third parties; and risks associated with geopolitical events and pandemics, including the COVID-19 coronavirus and military actions. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause TransCode's actual results to differ from those contained in or implied by the forward-looking statements, see the section entitled "Risk Factors" in TransCode's Annual Report on Form 10-K for the year endedDecember 31, 2024, as well as discussions of potential risks, uncertainties and other important factors in any subsequent TransCode filings with the Securities and Exchange Commission. All information in this press release is as of the date of this release; TransCode undertakes no duty to update this information unless required by law.