Abstract
BACKGROUND: HLX02 (Zercepac®) is the first trastuzumab biosimilar manufactured in China. This study presents the first real-world comparison of HLX02 with reference trastuzumab (RTZ) plus pertuzumab and chemotherapy as the first-line treatment for HER2-positive metastatic breast cancer (MBC) patients. METHODS: Medical data of patients with HER2-positive MBC who received HLX02 or RTZ, both combined with pertuzumab and various chemotherapies as the first-line therapy at Beijing Cancer Hospital from January 2019 to August 2023 were reviewed retrospectively. The survival outcomes, efficacy, and adverse events were analyzed. RESULTS: In total, 118 patients were included in this study retrospectively, among whom 66 patients received RTZ and 52 received HLX02. No significant difference was observed in progression-free survival (PFS) between the groups (median PFS: 22.0 months for RTZ vs. 19.0 months for HLX02, P = .832). Additionally, the objective response rate, disease control rate, and safety profiles were similar across both groups. Of all 118 patients, 20 (16.9%) patients experienced progression in the central nervous system (CNS), with a median time to CNS progression of 15.0 months (95% confidence interval, CI, 12.8-17.2). CONCLUSION: The real-world data suggested that both HLX02 and RTZ, when combined with pertuzumab and various chemotherapy regimens, offer comparable efficacy and safety as first-line treatments for HER2-positive advanced breast cancer patients in China.