STCube Achieves 100% Disease Control Rate in Hard-to-Treat MSS Colorectal Cancer... "Innovative Indicator"

STCube has achieved excellent treatment results in MSS (microsatellite stable) metastatic colorectal cancer, a difficult-to-treat cancer. Among the various types of colorectal cancer, it demonstrated partial response (PR) in patients with 'MSS colorectal cancer with liver metastasis,' known to have the highest malignancy, achieving early outcomes beyond standard treatments.

On the 29th, STCube announced that interim results from the investigator-initiated phase 1b clinical trial of the anti-BTN1A1 immune checkpoint inhibitor Nelmastovat (hSTC810) combined with capecitabine (standard treatment) in metastatic colorectal cancer showed a disease control rate (DCR) of 100% and an objective response rate (ORR) of 16.7%.

The patients participating in the phase 1b trial were stage 4 or higher MSS colorectal cancer patients who were refractory to or relapsed after previous treatments. Among the 12 patients, 2 showed partial response (PR) and 10 showed stable disease (SD), resulting in a 100% disease control rate and a 16.7% objective response rate. Safety evaluation confirmed that Nelmastovat did not cause any drug-related adverse events (side effects) in any patient.

This result significantly surpasses the disease control rates of 41?69.51% and objective response rates of 1?6.1% of currently approved standard treatments, including ▲regorafenib ▲TAS-102 (trifluridine/tipiracil) ▲TAS-102 combined with bevacizumab ▲and fruquintinib. The progression-free survival (PFS) of most patients also already exceeded that of standard treatments (1.9?5.6 months).

Particularly noteworthy is the confirmation of partial response (PR) in MSS colorectal cancer patients with progressing liver metastasis.

Liver metastasis is one of the major causes of death in colorectal cancer patients. Approximately 70% of metastatic colorectal cancer patients develop liver metastasis, most of whom are either inoperable or experience recurrence after surgery. Since the response rate to immuno-oncology drugs decreases as liver metastasis progresses, the presence of liver metastasis is an important evaluation factor in the design and interpretation of colorectal cancer clinical trials.

Despite most colorectal cancer patients being MSS colorectal cancer patients with liver metastasis, no immuno-oncology drug has yet proven efficacy in MSS colorectal cancer. The global blockbuster immuno-oncology drug 'Keytruda' also showed an objective response rate of 0% and a disease control rate of 11% in monotherapy clinical trials targeting MSS colorectal cancer patients.

Jung Hyunjin, CEO of STCube, said, “In a situation where the development of treatments to improve the prognosis of MSS colorectal cancer patients is urgently needed, Nelmastovat has sufficiently demonstrated promising potential as a new immuno-oncology treatment option through this clinical trial. The progression-free survival in phase 1b is also confirmed to be better than existing treatments, and since patient treatment is still ongoing, survival time is expected to continue increasing.”

He added, “The treatment effect in liver metastatic colorectal cancer patients is the aspect most commonly noted by global big pharma companies with whom we are discussing technology transfer cooperation, as well as hospitals and the industry. We expect to further prove global competitiveness through follow-up observation in phase 1b and phase 2 clinical trials.”

STCube is conducting investigator-initiated phase 1b/2 clinical trials to evaluate the efficacy and safety of Nelmastovat combined with capecitabine as a third-line treatment for metastatic colorectal cancer. The phase 1b trial began in February this year, and patient dosing for phase 2 started at the end of last month. The phase 2 trial will recruit 35 MSS colorectal cancer patients.

This content was produced with the assistance of AI translation services.