[Comparison of the efficacy, safety, and cost-effectiveness of trastuzumab biosimilar HLX02 and the originator combined with pertuzumab and chemotherapy in the neoadjuvant treatment of patients with HER-2-positive breast cancer].

Objective: To compare the efficacy, safety, and cost-effectiveness of the trastuzumab originator (HST) versus its biosimilar (HLX02) combined with pertuzumab and chemotherapy as neoadjuvant treatment in patients with HER-2-positive breast cancer. Methods: This retrospective cohort study included 175 patients with HER-2-positive breast cancer who received neoadjuvant therapy followed by curative surgery at the Cancer Hospital Chinese Academy of Medical Sciences between October 2020 and January 2024. Patients were divided into two groups based on the trastuzumab formulation used: the HST group (n=89) and the HLX02 group (n=86).The efficacy, safety, and trastuzumab-related treatment costs were compared between the two groups. Moreover, using Logistic regression model to identify the factors influencing total pathological complete response (tpCR) rates. Results: There were statistically significant differences in clinical T stage and surgical approach between the HST and HLX02 groups (P＜0.05). Other clinicopathological characteristics, such as age and histological grade, showed no statistically significant differences (P＞0.05), with most baseline characteristics remaining balanced between the two groups. There were no significant differences in tpCR rates (P=0.957) or Miller-Payne (MP) grading rates (P=0.991) between the HST and HLX02 groups. The tpCR rates for the two groups were 55.1% (49/89) and 54.7% (47/86), respectively. The rates of achieving grade 5 (G5) in the postoperative MP pathological grading system were 55.1% (49/89) and 55.8% (48/86), respectively, with no statistically significant difference (P=0.991). Univariate and multivariate Logistic regression analyses showed that hormone receptor status is an independent risk factor affecting tpCR (OR=0.31, 95% CI; 0.16-0.61, P＜0.001). The incidence of adverse event during neoadjuvant therapy was similar between the groups, with no occurrences of trastuzumab-related cardiac toxicity. The HLX02 regimen showed a lower cost-effectiveness ratio (586.48 vs. 604.96) and reduced trastuzumab treatment costs during neoadjuvant therapy compared to HST [tpCR:(31 208.37±2 191.00) CNY vs. (33 224.49±2 741.00) CNY; non-tpCR: 33 030.05±5 787.00) CNY vs. (33 412.50±4 203.00) CNY, P＜0.05]. Conclusions: In the neoadjuvant treatment of early-stage HER-2-positive breast cancer, HLX02 combined with pertuzumab and chemotherapy demonstrates similar efficacy and safety to the trastuzumab originator, while offering a significant cost advantage.