EXCLUSIVE: TransCode's RNA Therapeutic Achieves 64% Stable Disease Rate In Colorectal Cancer Phase 1 Stud

TransCode Therapeutics delivered a meaningful data point Wednesday for the emerging field of RNA-based cancer treatment, reporting that its lead candidate TTX-MC138 achieved stable disease in 64% of evaluable patients in a Phase 1a clinical trial — with zero dose-limiting toxicities across all tested cohorts.

The results, announced June 3, come from a dose-escalation study in heavily pre-treated patients with advanced metastatic cancer. Out of 14 evaluable patients, nine achieved stable disease lasting at least six months. One patient with metastatic thyroid cancer experienced a dramatic decrease in thyroglobulin levels — a primary tumor marker — and has maintained stable disease for 12 months, continuing to participate in the ongoing study.

TTX-MC138 is designed as a first-in-class RNA therapeutic that inhibits microRNA-10b (miR-10b), a biomarker and critical driver of metastasis in multiple cancer types. The approach targets the RNA mechanisms that allow cancer to spread rather than attacking the tumor itself, which represents a fundamentally different therapeutic strategy from traditional chemotherapy or even most targeted therapies.

The safety profile is particularly notable. Across four dose cohorts ranging up to the recommended Phase 2a dose of 4.8 mg/kg, not a single dose-limiting toxicity was observed. For a cancer drug in patients who have already exhausted standard treatment options, that clean safety signal matters as much as the efficacy data — it means the drug can potentially be dosed at therapeutic levels without adding meaningful burden to patients who are already suffering.

The trial met its primary safety objectives and demonstrated durable disease stabilization, supporting the therapeutic's advancement into Phase 2a development. TransCode has already initiated the next phase, which will evaluate TTX-MC138 in patients with circulating tumor DNA (ctDNA) positive colorectal cancer following curative-intent therapy — a more focused population that could yield clearer efficacy signals.

TransCode's stock jumped 20.91% to $6.39 in premarket trading on the news, though it remains near its 52-week low of $5.01. That disparity between the clinical promise and the stock price reflects a brother truth about RNA therapeutics: the field is still early, and investors have been burned before by promising Phase 1 data that doesn't translate into Phase 2 or 3 success.

The RNA therapeutics space has been gaining momentum across multiple modalities — mRNA vaccines proved the platform during COVID, and RNA interference drugs like Alnylam's patisiran have achieved regulatory approval. But cancer applications remain the hardest frontier, because solid tumors present delivery challenges that blood disorders and liver targets do not. TransCode's data suggests that at least some of those delivery challenges are surmountable.

Dr. Daniel Vlock, TransCode Consulting Clinician, noted: "We continue to believe that TTX-MC138 may offer a promising therapeutic option for patients with metastatic disease who have limited treatment alternatives." For patients who have run out of options, a drug that stabilizes disease for six months or more without significant toxicity isn't a cure — but it's something real.

What This Means For You: If you or a loved one is dealing with advanced metastatic cancer, this is an early-stage but genuine signal of progress in RNA-based treatment. It will likely be 2-3 years before TTX-MC138 could reach the market, assuming Phase 2 and 3 trials confirm these results. If you're an investor, understand that Phase 1 data in oncology is exciting but far from definitive — the stock's proximity to its 52-week low tells you the market is pricing in significant execution risk. And if you're watching the RNA therapeutics space broadly, this data adds to the growing evidence that RNA-based drugs can work outside the liver and blood — the delivery problem in solid tumors is being chipped away, even if it isn't fully solved yet.