Yuhan Corp.’s combination of chemotherapy with immunotherapy YH24931 has stronger efficacy than a single use of programmed death-ligand 1 (PD-L1) inhibitors, according to the result of a non-clinical trial.

YH24931, currently at the non-clinical trial stage, is expected to enter a phase 1 clinical trial next year.

YH24931 works as an anti-tumor therapy as it prompts the movement of dendritic cells, activated in lymph nodes, and promotes infiltration of T-cells into tumor cells.

Based on the results of the latest study, the company will push for a clinical trial and aims at overseas license-out deal with a phase 2 clinical trial. At the same time, the company hopes to conduct a local phase 3 clinical trial and enter the domestic market first.

According to the results of the study, which was commissioned by the Ministry of Science and ICT as a project under the “Development Project of YH24931 as Radiation Immunotherapy Combination,” the combo therapy YH24931 was more effective in lung cancer than the single treatment of immunotherapy.

The animal testing on the mouse, through allotransplantation, was carried out on five groups – negative control group, radiation-only group, YH24931-radiation combination group, control antibody group, and PD-L1 antibody group.

The study measured the volume of the tumor twice a week, and among the five groups of the mouse, YH24931-radiation combination group showed the smallest tumor on average.

The optimal concentration was mentioned as 10mg/kg. In an early stage of tumor growth in liver cancer, YH24931 had efficacy in suppressing tumor growth in combination with radiation, regardless of the concentration of YH24931. At the last stage of tumor growth, however, 10mg/kg concentration of YH24931 had a sustainable efficacy in suppressing tumor growth.

In the test on the mouse with colorectal cancer through allotransplantation, the higher the concentration, the stronger efficacy the combo therapy showed. There was no difference between YH24931 in 10mg/kg and that in 20mg/kg, though.

In chemotherapy combination, a single radiation was more effective than multiple low-dose radiations.

Yuhan is to consider YH24931’s mechanism, the current status of immunotherapies market, and receive experts’ consultations to decide on the final target cancer of YH24931. Solid cancer and cancer that requires lots of chemotherapy are likely to be the ultimate target, observers said.