Full text

Turn on search term navigation

© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

Background/Objectives: Breast cancer is the most common malignant neoplasm in women and the leading cause of cancer-related death. Approximately 50% of HER2-negative breast cancers exhibit low expression of this protein (HER2-low). Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate targeting the HER2 receptor which has shown benefit in patients with HER2-low metastatic breast cancer in the DESTINY-Breast04 study. However, few data are available on its efficacy in real-world practice. Methods: We conducted a retrospective multicenter national study (eight centers) including patients with advanced HER2-low breast cancer (immunohistochemistry 1+ or 2+/ in situ hybridization negative) who started T-DXd treatment between January 2022 and March 2024. Patients had received at least one previous line of treatment. The primary endpoint was real-world progression-free survival (rwPFS) in patients with metastatic HER2-low breast cancer treated with T-DXd. The secondary endpoints were real-world overall survival (OS) and objective response rate (ORR). Results: The study included 35 patients (34 female and 1 male patient), with a median age of 54 years at the start of T-DXd. All patients had an ECOG-PS 0–1, and 26 patients (74%) had hormone receptor (HR)-positive disease. The median number of prior lines of treatment was 4 [1–7], and 23 patients (65.8%) had metastases in three or more sites. With a median follow-up of 7.8 months, rwPFS was 6 months (95% CI, 2.3–9.7), and OS was 15 months (95% CI, 4.7–25.3). In HR-positive patients, the median rwPFS was 6 months (95% CI, 1.2–10.7), compared to 4 months (95% CI, 2.1–5.9) in HR-negative patients. The overall ORR was 52.9%. Adverse events of grade 3 or higher were neutropenia (2.9%) and fatigue (2.9%). Conclusions: This study provides real-world data on T-DXd in the treatment of advanced HER2-low breast cancer. It is noteworthy that the population was heavily pre-treated and had a higher proportion of HR-negative patients, which may explain the lower efficacy compared to the DESTINY-Breast04 study.

Details

Title
Trastuzumab Deruxtecan in Previously Treated HER2-Low Metastatic Breast Cancer: Real-World Multicentric Study in the Portuguese Population
Author
Soares, Miranda Luísa 1   VIAFID ORCID Logo  ; Sousa, Maria João 2 ; Martins Braga Miguel 2   VIAFID ORCID Logo  ; Couto Marisa 3 ; Vieira, Fernandes Isabel 4 ; Abreu Francisca 5 ; Eiriz Inês 6   VIAFID ORCID Logo  ; Lopes Fernandes Catarina 7   VIAFID ORCID Logo  ; Fonseca, Marques Alice 8 ; Marques, Maria Teresa 9 ; Romão Raquel 2   VIAFID ORCID Logo  ; Gonçalves, Fernando 2 ; Simões Joana 2   VIAFID ORCID Logo  ; Araújo António 1   VIAFID ORCID Logo 

 Serviço de Oncologia Médica, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, 4099-001 Porto, Portugal; [email protected] (M.J.S.); [email protected] (M.M.B.); [email protected] (R.R.); [email protected] (F.G.); [email protected] (J.S.); [email protected] (A.A.), Oncology Research UMIB-Unit for Multidisciplinary Research in Biomedicine, ICBAS-School of Medicine and Biomedical Sciences, University of Porto, 4050-313 Porto, Portugal, Laboratório para a Investigação Integrativa e Translacional em Saúde Populacional (ITR), University of Porto, 4050-600 Porto, Portugal 
 Serviço de Oncologia Médica, Centro Hospitalar Universitário de Santo António, Unidade Local de Saúde de Santo António, 4099-001 Porto, Portugal; [email protected] (M.J.S.); [email protected] (M.M.B.); [email protected] (R.R.); [email protected] (F.G.); [email protected] (J.S.); [email protected] (A.A.) 
 Serviço de Oncologia Médica, Unidade Local de Saúdo de São João, 4200-319 Porto, Portugal; [email protected] 
 Serviço de Oncologia Médica, Instituto Português de Oncologia de Coimbra Francisco Gentil, 3000-075 Coimbra, Portugal; [email protected] 
 Serviço de Oncologia Médica, Hospital Senhora de Oliveira, Unidade Local de Saúde Alto Ave, 4835-044 Guimaraes, Portugal; [email protected] 
 Serviço de Oncologia Médica, Hospital Prof. Dr. Fernando Fonseca, Unidade Local de Saúde Amadora-Sintra, 2720-276 Amadora, Portugal; [email protected] 
 Serviço de Oncologia Médica, Hospital Pedro Hispano, Unidade Local de Saúde de Matosinhos, 4464-513 Matosinhos, Portugal; [email protected] 
 Serviço de Oncologia Médica, Unidade Local de Saúde de Coimbra, 3004-561 Coimbra, Portugal; [email protected] 
 Serviço de Oncologia Médica, Hospital de São Bernardo, Unidade Local de Saúde da Arrábida, 2910-446 Setúbal, Portugal; [email protected] 
First page
1911
Publication year
2025
Publication date
2025
Publisher
MDPI AG
e-ISSN
20726694
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
3223880264
Copyright
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.