Initial Phase II data for Henlius Biotech's PD-L1 ADC drug candidate, HLX43, were disclosed at the ESMO Asia 2025 congress, marking the first public Phase II results for a PD-L1 ADC. The randomised, open-label, multicentre trial enrolled 30 patients with recurrent or metastatic cervical cancer who had failed prior therapy or were intolerant/unsuitable for standard first-line treatment. The study evaluated the efficacy and safety of HLX43 at three dose levels, with the primary endpoints being investigator-assessed objective response rate (ORR) and progression-free survival (PFS).

As of 28 July 2025, 29 patients were evaluable for efficacy. The ORR across all dose groups was 37.9%, with a disease control rate (DCR) of 72.4%. Notably, the 3mg/kg dose cohort showed particularly promising results, achieving an ORR of 70.0% and a DCR of 100%. Regarding safety, grade 3 or higher treatment-related adverse events occurred in 53.3% of patients, with neutropenia, anaemia and decreased lymphocyte count being the most common. Immune-related adverse events were reported in 10.0% of patients.

According to PharmCube's NextBiopharm® database, HLX43 was the global leader among PD-L1 ADCs until it got overtaken by PF-08046054 when Pfizer put it in Phase III earlier this year. Click here to request a free trial for NextBiopharm®.