RNA oncology company TransCode Therapeutics Inc (NASDAQ:RNAZ) on Thursday reported further progress in its Phase 1a clinical trial of TTX-MC138 in patients with metastatic cancer.

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. To date, 13 patients have received at least one dose of TTX-MC138 at four separate dose levels ranging from 0.8 mg/kg to 4.8 mg/kg. Two patients have been treated in the expanded enrolment.

Eight patients remain on study for continued treatment, receiving an additional dose of TTX-MC138 during each 28-day treatment cycle, and may remain on study absent any significant safety observations or disease progression. To date, the two patients who have remained on study the longest have received seven doses of TTX-MC138 over the course of approximately seven months and have demonstrated stable disease. No significant safety or dose limiting toxicities have been reported to date in any of the trial's 13 patients.

The observed tolerability profile and the available PK/PD results thus far supports advancement of the clinical trial to further evaluate safety and potential anti-tumour activity of TTX-MC138 in the planned dose expansion (Phase 1b) portion of the trial, TransCode said. At the highest dose administered, TTX-MC138 was well tolerated with no significant toxicities noted.

TransCode's Phase 1 clinical trial is a multicentre, 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-tumour activity of TTX-MC138 will be further evaluated in certain tumour types selected based on preliminary results from the dose-escalation phase.