Henlius Expands Clinical Program for AC101 HER2 Antibody in Breast Cancer

According to a recent LinkedIn post from BioSpectator Inc, Chinese biopharma company Henlius is reportedly expanding clinical development of AC101 (HLX22), a HER2 epitope antibody originally acquired from AbClon. The post indicates that Henlius has initiated a Phase 2/3 trial combining AC101 with a HER2 antibody-drug conjugate (ADC) in first-line breast cancer treatment.

The LinkedIn post highlights that Henlius previously began a Phase 2 trial in China (HLX22-BC201), combining AC101 with the standard-of-care HER2 ADC Enhertu (T-DXd) in HER2-low breast cancer, with patient enrollment now said to be complete. It further notes that the new Phase 2/3 study will pair AC101 with HLX87, a HER2 ADC asset acquired from GeneQuantum that, like Enhertu, incorporates a TOP1 inhibitor payload.

According to the post, Henlius appears to be positioning itself aggressively in the HER2 treatment segment and is also advancing clinical development of a HER2xHER2 ADC that includes the AC101 sequence. For investors tracking AbClon’s partnering economics, this expanded clinical activity could signal rising option value for AC101-related milestones and royalties, though regulatory and clinical risk remain substantial.

The post also suggests that broader progress in HER2-targeted ADC combinations could increase competitive intensity in the global HER2 oncology market, potentially affecting incumbents focused on Enhertu and similar assets. If successful, Henlius’s strategy may create new licensing or co-development benchmarks for epitope-specific HER2 antibodies, which could be relevant to companies with comparable targets or platforms.