目的 研究维迪西妥单抗（RC48）在晚期胃癌三线及三线以上治疗中的临床疗效及其安全性。 方法 回顾性分析2020年8月至2022年8月南通市肿瘤医院收治的既往至少接受过两次系统化疗失败的30例晚期胃癌患者的临床资料。根据不同的治疗方案分为RC48组（n = 15）和对照组（化疗/靶向/免疫单药）（n = 15）。观察两组患者的客观缓解率（ORR）疾病控制率（DCR）、无进展生存期（PFS）、总生存期（OS）和治疗相关不良反应。 结果 中位随访7.5个月，RC48组和对照组的ORR为20% vs. 0%（P = 0.224），DCR为53.3% vs. 20%（P = 0.128），中位PFS为4个月 vs. 3个月（P = 0.479），中位OS为18个月vs. 5个月（P = 0.043）。安全性方面，RC48组和对照组最常见的不良反应为均白细胞减少和中性粒细胞减少，两组整体不良反应发生率相当，无致死性不良事件。 结论 RC48在晚期胃癌三线及三线以上治疗中具有一定的疗效，患者耐受性良好。

Objective To study the clinical efficacy and safety of disitamab vedotin （RC48） in the third-line and above third-line treatment of advanced gastric cancer. Methods The clinical data of 30 patients with advanced gastric cancer who had previously failed to receive at least two systemic chemotherapy regimens from August 2020 to August 2022 in Nantong Tumor Hospital were retrospectively analyzed. According to different treatment regimens， they were divided into RC48 group （n = 15） and control group （chemotherapy/targeted/immune monotherapy） （n = 15）. The objective response rate （ORR）， disease control rate （DCR）， progression-free survival （PFS）， overall survival （OS） and treatment-related adverse reactions were observed in the two groups. Results The median follow-up time was 7.5 months. The ORR of RC48 group and control group was 20% vs. 0% （P = 0.224）， DCR was 53.3% vs. 20% （P = 0.128）， mPFS was 4 months vs. 3 months （P = 0.479）， mOS was 18 months vs. 5 months （P = 0.043）. In terms of safety， the most common adverse reactions in the RC48 group and the control group were leukopenia and neutropenia.The overall incidence of adverse reactions in the two groups was comparable， and there were no fatal adverse events. Conclusion RC48 has a certain effect in the third-line and above third-line treatment of advanced gastric cancer， and patients are well tolerated.