人表皮生长因子受体-2 (HER2) 的抗体药物结合物 (ADC) 对HER2阳性非小细胞肺癌 (NSCLC) 患者提供了有效的治疗。外显子20插入突变是HER2突变中最常见的一种。这种突变亚型极度耐药，接受传统治疗的患者通常预后不佳。依据多项研究和报道的结果，靶向授时佐单抗（T-DXd）这种新型抗HER2 ADC 已出现作为HER2阳性（突变、表达、扩增、变异）NSCLC的一种新治疗选择。在这里，我们报告了一个52岁男性患者的Ⅳ期NSCLC病例，该患者在经过肺癌根治术后肿瘤复发，无法耐受化疗，且出现了骨转移。在接受T-DXd治疗后，肿瘤明显缩小，骨转移得到改善，保持了21个月无进展的状态。本个案报告证明了T-DXd在治疗HER2外显子20插入突变的NSCLC中的应用。版权所有 © 2023 作者。 Wolters Kluwer Health, Inc. 发表。

An antibody-drug conjugate (ADC) of human epidermal growth factor receptor-2 (HER2) provides effective treatment for patients with HER2-positive non-small cell lung cancer (NSCLC). Exon 20 insertion mutations are the most common among HER2 mutations. This mutant subtype is highly drug-resistant, and patients receiving conventional treatment often have a poor prognosis. Trastuzumab deruxtecan (T-DXd), a novel anti-HER2 ADC, has emerged as a novel treatment option for HER2-positive (mutated, expressed, amplified, alternated) NSCLC, based on several studies and reported results. Herein, we report a case of stage IV NSCLC with HER2 exon 20 mutation in a 52-year-old male patient whose tumor recurred after radical resection of pulmonary carcinoma, who could not tolerate chemotherapy, and presented with bone metastasis. After treatment with T-DXd, the tumor significantly regressed and bone metastasis improved, maintaining a state of no progression for 21 months. This case report evidences the use of T-DXd in the treatment of NSCLC with HER2 exon 20 insertion mutation.Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc.