Table 1_Efficacy and safety of inetetamab-containing regimens in patients with HER2-positive metastatic breast cancer in first-line/second-line setting.docx

BackgroundInetetamab is a novel recombinant humanized anti-Human epidermal growth factor receptor 2 (HER2) monoclonal antibody. This real-world retrospective study assessed the efficacy and safety of inetetamab-containing regimens in first-line/second-line treatment of HER2-positive metastatic breast cancer (MBC).
MethodsThis study retrospectively recruited HER2-positive MBC patients who received inetetamab- containing regimens from June 2020 to May 2023. The outcomes included progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR).
ResultsA total of 329 patients were enrolled and included in the efficacy analysis. The most frequently used treatment strategy was contained inetetamab plus pyrotinib (205/329, 62.3%). Patients treated with first-line regimens benefited the most, with a median PFS of 15.0 versus (vs.) 10.0 months (first-line- vs. second-line inetetamab plus pyrotinib, p <0.001), 19.0 vs. 17.0 months (first-line- vs. second-line inetetamab plus pertuzumab, p=0.096), and 13.0 vs. not reached months (first-line- vs. second-line inetetamab plus chemotherapy, p=0.229). The complete response (CR) was observed in 16 (4.9%) patients of all cohort, with the ORR was 51.1% (95% confidence interval [CI], 45.7%-56.4%), and the DCR was 96.4% (95% CI, 93.7%-97.9%). The grade 3 or higher adverse events (AEs) were observed in 29.5% of the whole study cohort. Diarrhea (39.2%), white blood cell count decreased (33.0%), and myelosuppression (18.6%) as the most frequent ones.
ConclusionsFollowing the first- and second-line of treatment, inetetamab- containing combinations demonstrated promising clinical activity and a manageable safety profile in patients with HER2-positive MBC, especially in the first-line treatment.

背景：英妥木单抗（inetetamab）是一种新型重组人源化抗人表皮生长因子受体2（Human epidermal growth factor receptor 2, HER2）单克隆抗体。本项真实世界回顾性研究评估了含英妥木单抗方案在HER2阳性转移性乳腺癌（metastatic breast cancer, MBC）一线/二线治疗中的疗效与安全性。
方法：本研究回顾性招募了2020年6月至2023年5月期间接受含英妥木单抗方案治疗的HER2阳性转移性乳腺癌患者。研究终点包括无进展生存期（progression-free survival, PFS）、客观缓解率（objective response rate, ORR）及疾病控制率（disease control rate, DCR）。
结果：本研究共纳入329例患者并纳入疗效分析。最常用的治疗方案为英妥木单抗联合吡咯替尼（205/329，62.3%）。接受一线治疗的患者获益最为显著：英妥木单抗联合吡咯替尼亚组中，一线治疗患者的中位无进展生存期为15.0个月，二线治疗患者为10.0个月（一线vs二线，p<0.001）；英妥木单抗联合帕妥珠单抗亚组中，一线治疗患者中位PFS为19.0个月，二线为17.0个月（p=0.096）；英妥木单抗联合化疗亚组中，一线治疗患者中位PFS为13.0个月，二线患者未达到中位PFS（p=0.229）。全队列中共16例（4.9%）患者达到完全缓解（complete response, CR），客观缓解率为51.1%（95%置信区间[CI]：45.7%~56.4%），疾病控制率为96.4%（95%CI：93.7%~97.9%）。全队列中29.5%的患者发生3级及以上不良事件（adverse events, AEs），最常见的不良事件为腹泻（39.2%）、白细胞计数降低（33.0%）及骨髓抑制（18.6%）。
结论：在HER2阳性转移性乳腺癌患者的一线及二线治疗中，含英妥木单抗的联合方案展现出良好的临床活性与可控的安全性特征，尤其在一线治疗中获益更为显著。