SINO BIOPHARM (01177): TQB2102 "HER2 dual antibody ADC" Phase III clinical trial for low-expressing HER2 breast cancer completed subject enrollment.

SINO BIOPHARM (01177) announced that their independently developed national first-class innovative drug TQB2102 "HER2 dual antibody ADC" is currently undergoing a randomized, open-label, parallel-controlled Phase III clinical trial (TQB2102-III-01) to evaluate the effectiveness and safety of TQB2102 compared to chemotherapy selected by researchers in patients with HER2 low-expressing recurrent/metastatic breast cancer. Recently, all enrolled subjects have completed the trial. TQB2102 is a new generation HER2 dual epitope bispecific antibody-drug conjugate (ADC) independently developed by the group, which achieves an optimal balance of efficacy and safety through three core technological innovations: 1. Dual epitope targeting design: The antibody end adopts an asymmetric structure design, simultaneously binding to the ECD II/IV domains of HER2, significantly enhancing selectivity and drug internalization efficiency towards tumor cells, thereby enhancing anti-tumor activity. 2. Cleavable linker: Using an enzyme-cleavable linker, it can efficiently cleave and release toxins, and has a bystander effect, clearing surrounding heterogeneous tumor cells and expanding the killing range. 3. Optimized Drug Antibody Ratio (DAR): The DAR value is stably controlled at 5.8-6.0, combined with a Topoisomerase I (Topo I) inhibitor toxin, to enhance efficacy while reducing side effects. The combination of these core technologies breaks through the limitations of traditional HER2 monoclonal antibodies and single-target ADCs, showing significant potential for TQB2102 in the treatment of HER2 low-expressing tumors. At the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, the group presented the Phase Ib clinical study results of TQB2102 in patients with HER2 low-expressing advanced breast cancer, demonstrating good efficacy and safety: Efficacy data: In HER2 low-expressing patients who had previously received multiple lines of treatment (median of 4 lines of systemic therapy and 2 lines of palliative chemotherapy), the overall objective response rate (ORR) was 53.4% (39/73), with the ORR reaching 58.3% (21/36) in the 7.5mg/kg group. It is worth noting that even in patients who had previously received ADC treatment and progressed, 44.4% of patients achieved remission after treatment with TQB2102. Safety data: Grade 3 or higher treatment-related adverse events (TRAEs) mainly included neutropenia (23.3%), leukopenia (20.6%), anemia (8.2%), and hypokalemia (6.9%), with overall good tolerability. In the field of breast cancer treatment, the group has established a comprehensive molecular subtyping layout including HER2+, HER2 low-expressing, HR+/HER2-, and triple-negative breast cancer, covering the entire treatment course from neoadjuvant to adjuvant treatment phases, aiming to provide new treatment options for more patients.