[Edaily Reporter NA EUN-KYUNG ] MedPacto, Inc.(235980)announced on the 28th that it had confirmed tumor growth inhibition and improved survival rates in preclinical studies combining its anticancer drug candidate “Bactosetip” with a dendritic cell (DC)-based cancer vaccine developed by its affiliate, Celoram. The research results were published in the international academic journal *Nature Communications*.

This study was conducted jointly by MedPacto, Inc. and Celoram. Celoram is developing “PROTEXI,” a dendritic cell (DC) vaccine platform that enhances the immune response against tumors by leveraging existing antiviral immune memory. DC vaccines are immunotherapeutics that utilize the patient’s own immune cells—dendritic cells—to recognize cancer cells and induce an attack by T cells. However, they have traditionally been considered to have limited efficacy against cancers with weak immune responses.

In the study, PROTEC Co., Ltd. demonstrated the ability to suppress tumor growth by increasing T-cell infiltration even in an “immune-cold tumor” environment. Furthermore, when combined with the TGF-β inhibitor Bactosetip, the immune status of the tumor microenvironment improved, further enhancing the antitumor effect. TGF-β is a signaling protein that cancer cells use to evade attack by immune cells. Bactosetip is a candidate compound that works by blocking this signal, thereby transforming the tumor microenvironment into a state where immune cells can more easily attack the cancer.

Since TGF-β inhibitors facilitate the infiltration of immune cells into tumors and DC vaccines induce activated T cells, combining these two mechanisms is expected to enhance therapeutic efficacy even in tumors with low immune responses. According to the paper, in animal studies, the combination therapy reduced tumor size to 25% or less compared to PROTEC Co., Ltd. monotherapy, and the 25-day survival rate increased from approximately 50% with monotherapy to over 75% with the combination therapy.

The research team assessed that Protexi transforms the tumor microenvironment into an immune-friendly state and, when used in combination with Bactosetip or anti-PD-1 immune checkpoint inhibitors, has the potential to enhance therapeutic efficacy even in highly treatment-resistant tumors.

A MedPacto, Inc. representative stated, “This study confirms the potential for a new treatment strategy in cancers with low immune responses,” adding, “Based on the efficacy observed in combination with Bactosetip, we plan to proceed with future clinical development.”