Partial response to trastuzumab deruxtecan (DS8201) following progression in HER2-amplified breast cancer with pulmonary metastases managed with disitamab vedotin (RC48): a comprehensive case report and literature review

• Published in: Frontiers in oncology Vol. 14; p. 1338661
• Main Authors: Lan, Yanfang, Zhao, Jiahui, Zhao, Fangrui, Li, Juanjuan, Li, Xiangpan
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 17.06.2024
• Subjects: antibody-drug conjugate; disitamab vedotin; Her2-amplified breast cancer; Oncology; tislelizumab; trastuzumab deruxtecan; disitamab vedotin; antibody-drug conjugate; tislelizumab; Her2-amplified breast cancer; trastuzumab deruxtecan
• ISSN: 2234-943X; 2234-943X
• DOI: 10.3389/fonc.2024.1338661

Breast cancer remains one of the predominant malignancies worldwide. In the context of inoperable advanced or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer, systemic management primarily relies on HER2-targeting monoclonal antibodies. With the successful development of anti-HER2 antibody-drug conjugates (ADCs), these agents have been increasingly integrated into therapeutic regimens for metastatic breast cancer. Here, we present the case of a 42-year-old female patient with HER2-positive pulmonary metastatic breast cancer who underwent an extensive treatment protocol. This protocol included chemotherapy, radiation therapy, hormonal therapy, surgical intervention on the breast, and anti-HER2 therapies. The anti-HER2 therapies involved both singular and dual targeting strategies using trastuzumab and the ADC disitamab vedotin (RC48) over an 8-year period. After experiencing disease progression following HER2-targeted therapy with RC48, the patient achieved noticeable partial remission through a therapeutic regimen that combined trastuzumab deruxtecan (DS8201) and tislelizumab. The data suggest a promising role for DS8201 in managing advanced stages of HER2-amplified metastatic breast cancer, especially in cases that demonstrate progression after initial HER2-directed therapies using ADCs. Furthermore, its combination with anti-PD-1 agents enhances therapeutic efficacy by augmenting the anti-tumoral immune response.