Complete Response to Disitamab Vedotin (RC48) in HER2-low Metastatic Endometrial Carcinoma: A Case Report and Review of the Literature

10:22Endometrial cancer (EC) is one of the most common gynecologic malignancies with increasing morbidity. The prognosis for patients diagnosed with early-stage EC remains favorable; however, for patients with recurrent or metastatic EC, the prognosis is poor and treatment options, until recently, are limited. Antibody drug conjugates (ADCs) represent innovative strategies in cancer treatment; however, there are less investigations regarding their efficacy in EC. This report describes an EC case with low human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) expression score (IHC 2+) that experienced recurrent metastasis in the abdominal and peritoneal following post surgical chemotherapy and radiotherapy. Subsequently, the commencement of HER2 targeted ADC, disitamab vedotin (RC48; 2.5 mg/kg), administered intravenously every two weeks, was initiated. The tumor lesions shrunk markedly after three cycles of treatment and disappeared by the completion of ten cycles of therapy. The patient is still in remission at present. The current findings imply the potential efficacy of HER2 targeted ADCs for patients with HER2 low metastatic EC.

子宫内膜癌（Endometrial cancer, EC）是最常见的妇科恶性肿瘤之一，发病率呈逐年上升趋势。早期诊断的子宫内膜癌患者预后良好，但复发或转移性子宫内膜癌患者的预后较差，且直至近年治疗选择仍十分有限。抗体偶联药物（Antibody drug conjugates, ADCs）是癌症治疗领域的创新策略，但针对其在子宫内膜癌中疗效的相关研究仍较少。本报告报道1例人类表皮生长因子受体2（human epidermal growth factor receptor 2, HER2）免疫组化（immunohistochemistry, IHC）表达评分为2+的低表达患者，该患者在接受手术治疗后辅以化疗及放疗，出现腹部及腹膜复发转移。随后患者启动HER2靶向抗体偶联药物维迪西妥单抗（disitamab vedotin, RC48；2.5 mg/kg）治疗，给药方案为每两周静脉输注1次。经3个周期治疗后，肿瘤病灶显著缩小；完成10个周期治疗后，病灶完全消失。截至目前，患者仍处于临床缓解状态。本研究结果提示，HER2靶向抗体偶联药物对HER2低表达转移性子宫内膜癌患者具有潜在治疗疗效。