Akeso Enrolls First Patient in HER3 ADC Breast Cancer Trial

The clinical trial, designated AK138D1-202, evaluates the drug both as a monotherapy and in combination with ivonescimab. By refining the molecular design to reduce uptake in healthy tissue and prevent the clustering of ADC molecules on tumor surfaces, Akeso aims to bypass the dose-limiting toxicities that have historically hampered traditional HER3 therapies. Early-stage data from trials in China and Australia suggest the drug maintains robust anti-tumor activity while avoiding common complications like interstitial lung disease.

This study specifically targets the two breast cancer subtypes with the highest unmet clinical needs: hormone receptor-positive, HER2-negative disease and triple-negative breast cancer. These categories account for a significant majority of breast cancer cases globally. By integrating AK138D1 with ivonescimab, Akeso is positioning the regimen as a cornerstone of its IO2.0 plus ADC2.0 strategy. As the company continues to leverage its bispecific antibody platforms, this trial serves as a critical test for whether these next-generation combinations can effectively penetrate deep tumor tissue while maintaining a manageable safety profile for patients across multiple treatment lines.