The treatment landscape for hormone receptor-positive (HR+) metastatic breast cancer (mBC) in Switzerland has just broadened with two important Swissmedic approvals, offering new antibody-drug conjugate (ADC) options for patients after progression on endocrine therapy.
Trastuzumab deruxtecan
Following the DESTINY-Breast06 trial results, trastuzumab deruxtecan received Swissmedic approval in June for patients with HR+/HER2-low and—importantly—HER2-ultralow mBC. This marks the first approval extending beyond the HER2-low category. The compound can now be used directly after endocrine therapy, providing an earlier and broader treatment option for patients with disease progression.
According to the official label, trastuzumab deruxtecan is indicated as monotherapy for adults with inoperable or metastatic HR+ breast cancer expressing HER2-low (IHC 1+ or IHC 2+/ISH–) or HER2-ultralow (IHC 0 with membrane staining), whose disease has progressed on one or more lines of endocrine therapy and for whom further endocrine treatment is not suitable.
Datopotamab deruxtecan
In May, Swissmedic also approved datopotamab deruxtecan, a novel TROP2-directed ADC developed by the AstraZeneca/Daiichi Sankyo alliance. This marks its first authorization in Switzerland, based on the pivotal TROPION-Breast01 study.
Datopotamab deruxtecan is now indicated as monotherapy for adults with inoperable or metastatic HR+, HER2-negative breast cancer (IHC 0, IHC 1+ or IHC 2+/ISH–) who have received prior endocrine therapy and at least one chemotherapy line in the metastatic setting, with documented progression on their most recent therapy.
Implications for Practice
These back-to-back approvals highlight the rapidly evolving role of ADCs in HR+ breast cancer management. For clinicians in Switzerland, trastuzumab deruxtecan and datopotamab deruxtecan provide much-needed additional treatment strategies for patients progressing beyond endocrine therapy, with options tailored to both HER2 expression levels and prior chemotherapy exposure.
Watch the full e-learning course with Dr. Christian Kurzeder and Dr. Marcus Vetter to learn more about managing ADC-related adverse events in breast cancer.Â
References
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Modi S, Jacot W, Yamashita T, et al. Trastuzumab deruxtecan in hormone receptor–positive, HER2-low metastatic breast cancer. N Engl J Med. 2024;390:1234–1246. (DESTINY-Breast06)
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Cortes J, Rugo HS, Bardia A, et al. Datopotamab deruxtecan in hormone receptor–positive, HER2-negative metastatic breast cancer (TROPION-Breast01). J Clin Oncol. 2024;42:2015–2027.
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Swissmedic. Public summary of the Swissmedic-approved product information for trastuzumab deruxtecan. (Accessed September 2025).
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Swissmedic. Public summary of the Swissmedic-approved product information for datopotamab deruxtecan. (Accessed September 2025).
Sara De Dosso
