A multicenter real-world study comparing the clinical equivalence of trastuzumab biosimilar HLX02 and reference trastuzumab in the treatment of HER-2-positive breast cancer.

As the first trastuzumab biosimilar introduced in China, there are few studies on the clinical application of HLX02, especially in combination with other antitumour drugs, for the treatment of HER-2-positive breast cancer. A multicenter retrospective study was conducted in three hospitals in China to select patients with HER-2-positive breast cancer who met the inclusion criteria and received HLX02 or the reference trastuzumab. Ninety-six patients diagnosed with HER-2-positive breast cancer were finally included and divided into two groups and treated with HLX02 or the reference trastuzumab. The results showed no significant differences in pathological complete response (70.0% vs. 76.2%; P=1.000) and overall response rate (91.9% vs. 94.9%; P=0.673) between the two groups. Kaplan-Meier survival curves also showed no significant difference in time-to-event variables between the two groups (log-rank P=0.48). Safety was also comparable in both groups. In conclusion, among patients with HER2-positive breast cancer, HLX02 demonstrated equivalent efficacy and safety to its reference trastuzumab, both in neoadjuvant chemotherapy and in postoperative adjuvant therapy. However, clinical equivalence studies between HLX02 and the original trastuzumab drug remain challenging. Future research should focus on the clinical exchange between biosimilars and original drugs, as well as the extrapolation of biosimilars' indications.