BOSTON, Massachusetts, October 14, 2025 — TransCode Therapeutics, Inc. (NASDAQ: RNAZ) today announced encouraging preliminary data from its completed Phase 1a clinical trial of TTX-MC138, a first-in-class RNA therapeutic designed to inhibit microRNA-10b (miR-10b), a master regulator of metastasis. The data, presented at the ESMO Congress 2025 in Berlin, demonstrated that the study met its primary safety endpoint, identified a recommended Phase 2 dose, and showed early clinical signals supporting further development.
Science Significance
TTX-MC138 targets miR-10b, a microRNA widely implicated in the initiation and persistence of metastatic disease. Acting as a “genetic switch” for tumor invasiveness, miR-10b promotes cancer cell migration and survival. Inhibiting miR-10b may disrupt metastatic progression across multiple tumor types, offering a unifying therapeutic strategy for advanced cancers. In the Phase 1a trial, 16 patients received 77 total doses of TTX-MC138 across four escalating dose levels. No dose-limiting toxicities or significant treatment-related adverse events were reported. Forty-four percent of patients (7 of 16) achieved stable disease lasting four months or longer, and one patient with thyroid cancer showed reversal of rising thyroglobulin levels to undetectable status during therapy. The median treatment duration was four months, with some patients remaining on therapy for up to 12 months. “The clinical benefit we are observing is compelling given the preclinical evidence and the durability of the drug within tumor cells,” said Dr. William McKean, principal investigator at The START Center for Cancer Research. The pharmacodynamic results confirmed active target engagement across all doses, consistent with prior preclinical and Phase 0 findings.
Regulatory Significance
The completion of Phase 1a marks a key regulatory milestone for TransCode’s first-in-human RNA oncology program. The study met its primary safety and tolerability objectives while establishing a recommended Phase 2 dose (RP2D), paving the way for advancement into a Phase 2a efficacy trial. The trial was conducted under U.S. FDA oversight and registered under ClinicalTrials.gov Identifier NCT06260774. According to Dr. Daniel Vlock, Consulting Clinician at TransCode, “The observed safety profile and durability of anti-tumor effects are particularly encouraging. These findings, consistent with our mechanism of action, provide a clear basis for rigorous efficacy evaluation.” The results position TransCode to move toward an efficacy-driven Phase 2a study that could explore broader indications in solid tumors and potentially seek regulatory acceleration pathways if confirmed efficacy emerges.
Business Significance
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For TransCode Therapeutics, these results validate its TTX nanoparticle delivery platform, which is engineered to deliver RNA-based therapeutics precisely to tumor sites while minimizing systemic toxicity. Achieving Phase 1a safety and durability objectives enhances investor confidence and supports recent strategic initiatives, including the acquisition of Polynoma LLC and a $25 million strategic investment from CK Life Sciences. The company’s expanding pipeline—spanning RNA-based therapeutics and immune-oncology vaccine programs—positions it as a multifaceted player in metastatic disease intervention. These positive clinical data bolster its prospects for partnerships and funding continuity as it transitions to later-stage trials.
Patients’ Significance
Metastasis remains the leading cause of cancer-related mortality, with limited treatment options once the disease spreads beyond the primary site. TTX-MC138 offers hope for patients with few alternatives by directly targeting a genetic driver of metastasis rather than tumor-specific mutations. The Phase 1a findings of sustained disease stabilization and minimal toxicity suggest a potentially safer and more durable approach to managing advanced malignancy. “These data support the opportunity to intervene earlier in a patient’s disease course,” noted Dr. Vlock, “potentially preventing metastatic progression before it becomes irreversible.” For patients, the implications are profound—a therapy that may control or prevent metastasis across multiple cancer types, with the promise of maintaining quality of life during long-term treatment.
Policy Significance
The trial’s success underscores the growing importance of RNA-based oncology innovation within national cancer research priorities. By demonstrating translational progress from preclinical to human proof-of-concept, TransCode aligns with federal initiatives promoting precision medicine and biotech innovation, such as the Cancer Moonshot and FDA’s RNA-therapy regulatory frameworks. Moreover, the company’s strategy to use platform-based modular design supports policy goals encouraging adaptable technologies that can be repurposed rapidly for different cancer indications, improving the efficiency of drug development pipelines.
Transaction Highlights
The completion of the Phase 1a clinical trial for TTX-MC138 represents a defining milestone for TransCode Therapeutics, marking its transition from early discovery to a clinically validated stage in RNA oncology. The announcement follows the company’s strategic acquisition of Polynoma LLC, which added a Phase 3–ready melanoma vaccine, seviprotimut-L, to its expanding pipeline, and a $25 million strategic investment from CK Life Sciences, providing financial strength to support continued clinical development. Together, these transactions reinforce TransCode’s ability to execute a diversified development strategy that integrates RNA-based therapeutics and immuno-oncology platforms under one clinical framework. The favorable safety and pharmacodynamic outcomes of TTX-MC138 not only validate the company’s TTX delivery platform but also create a foundation for future collaboration, licensing, and partnership opportunities. With this solid combination of clinical progress, financial support, and strategic assets, TransCode is well positioned to advance into Phase 2a trials and establish a leading position in metastatic cancer therapeutics.
Source: TransCode Therapeutics, Inc. Press Release
