Yuhan Corporation, a leading South Korean pharmaceutical company, has announced positive interim results from the Phase 1 clinical trial of its innovative immuno-oncology drug candidate YH32367 (ABL105) at the American Association for Cancer Research (AACR) Annual Meeting 2025 in Chicago. The company also presented research findings on resistance mechanisms observed in Phase 3 clinical studies of its approved lung cancer treatment Lekraza (lazertinib) when used as first-line therapy.
Developed in collaboration with ABL Bio, YH32367 represents a bispecific antibody designed to target HER2-expressing tumor cells while simultaneously activating the 4-1BB co-stimulatory receptor on T-cells. This dual mechanism of action aims to enhance the body’s natural immune response against cancer while directly suppressing tumor growth. The therapeutic approach combines tumor-specific immunity with direct anticancer effects.
The ongoing Phase 1/2 clinical trial represents the first human study of YH32367, evaluating its safety profile, tolerability, pharmacokinetic properties, and preliminary efficacy in patients with HER2-positive locally advanced or metastatic solid tumors. The trial consists of sequential dose-escalation and dose-expansion phases to establish optimal dosing parameters.
Initial data from the dose-escalation phase, conducted at multiple sites in South Korea and Australia since October 2022, involved 32 patients across various cancer types. The study population included 14 patients with cholangiocarcinoma, 9 with gastric cancer, and 9 with other solid tumors. Researchers tested eight different dose levels ranging from 0.3 mg/kg to 30 mg/kg administered triweekly.
Preliminary results indicate a favorable safety profile with no reported dose-limiting toxicities and no identified maximum tolerated dose within the tested range. Treatment-related adverse events occurred in 10 patients (31%), primarily manifesting as low-grade fever and chills. Among 31 evaluable patients, the therapy demonstrated promising antitumor activity with 7 patients achieving partial responses and 10 maintaining stable disease, yielding an objective response rate of 23% and disease control rate of 55%.
Dr. Yeol Hong Kim, Yuhan’s Head of Research and Development, commented on the findings: “The Phase 1 data presented at AACR underscore YH32367’s excellent safety characteristics and clinically meaningful antitumor activity. Based on these results, we have identified two optimal dose levels for further investigation in the expansion phase, focusing on HER2-positive cholangiocarcinoma and other solid tumors across international sites. We are optimistic about YH32367’s potential to address significant unmet medical needs in difficult-to-treat cancers.” The company plans to advance the clinical development program with expanded studies in South Korea, Australia, and the United States.
