Antibody-drug conjugates (ADCs), such as trastuzumab deruxtecan (T-DXd) and sacituzumab govitecan (SG) offer new and potent options for curing for curing hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 (HER2)-low advanced breast cancer; however, comparisons in terms of their relative effectiveness and safety concerns are lacking. Compared with other ADC drugs, T-DXd showed relatively better treatment characteristics, better PFS benefit, and relatively low incidence of serious AEs (SAEs). Combined with RCTs and real-world data, T-DXd has potential advantages in this population.

Postoperatively, he received adjuvant stereotactic radiosurgery (30-35 Gy in five fractions) to the resection cavity and was transitioned from tamoxifen to trastuzumab deruxtecan (T-DXd) for improved CNS-directed systemic therapy. Surveillance imaging at 6 months demonstrated no intracranial recurrence, and systemic restaging showed no extracranial disease progression. This case highlights the importance of prompt neuroimaging for new neurological symptoms in male breast cancer patients and supports a multimodal strategy, including surgical resection, focal radiation, and CNS-penetrant HER2-targeted therapy, for achieving durable intracranial control in select patients with isolated brain metastasis.

Three ADCs are currently approved for previously treated gynaecological cancers: mirvetuximab soravtansine for folate receptor-α-positive ovarian cancer, trastuzumab deruxtecan for solid tumours expressing HER2 (defined as a staining intensity on immunohistochemistry of 3+) and tisotumab vedotin for cervical cancer (independent of tissue factor expression). Moreover, rational combinations could reinforce and extend the clinical potential of these agents, as has already been demonstrated with the addition of ADCs to immune checkpoint inhibitors in an effort to amplify antitumour immunity and prolong the durability of clinical responses. In this Review, we provide an overview of the current landscape of ADCs in gynaecological malignancies, highlighting key advances and future opportunities.

ADCs against TROP2 (Sacituzumab govitecan) or HER2 (T-DXd) have demonstrated efficacy in metastatic breast cancer, yet paradoxically, outside of HER2-amplified breast cancers, expression levels of these breast cancer-enriched epitopes in tumor biopsies have not been strongly correlated with clinical response. Thus, while CTC burden is correlated with response to these ADCs, the level of TROP2 or HER2 expression is poorly predictive. These findings point to sensitivity to the drug payload as a potential driver of clinical response to currently approved ADCs in breast cancer.

P2, N=124, Recruiting, The First Affiliated Hospital of Soochow University

P3, N=412, Active, not recruiting, Seagen, a wholly owned subsidiary of Pfizer | Trial primary completion date: Jun 2026 --> Jan 2027

With the expanding use of trastuzumab deruxtecan (T-DXd), sacituzumab govitecan (SG), and datopotamab deruxtecan (Dato-DXd) across HER2-positive, HER2-low, and hormone-receptor-positive disease, management of treatment-related toxicities has become a critical determinant of outcomes. Integrating these findings, we propose practical algorithms for managing pulmonary, gastrointestinal, hematologic, ocular, and mucosal adverse events. This review consolidates evidence into a clinician-oriented reference for ADC toxicity management, emphasizing multidisciplinary coordination, early recognition, and system-specific mitigation strategies to enhance treatment safety and adherence.

SMP-70067-X demonstrates potent cytotoxicity in HER2-positive tumor cells (sub-nanomolar IC50 values) and significantly enhanced antitumor efficacy compared to DS-8201a in HER2-moderate and HER2-low xenograft models. These results highlight the critical role of rational linker engineering in expanding the therapeutic window of hydrophobic topoisomerase I inhibitor-based ADCs.

A cross-tumor perspective contrasts GC/GEJ testing and biology with the breast cancer paradigm and summarizes the importance of HER2-low expression in non-gastric malignancies. Finally, we discuss the therapeutic strategies in HER2-low GC/GEJ and highlight key safety and monitoring considerations for HER2-directed ADCs.

T-DXd represents an emerging therapeutic option for HER2-positive gynecological malignancies after prior treatment, especially in advanced lines of therapy. Further studies focusing on biomarker refinement, sequencing approaches, and toxicity mitigation will be key to establishing its place in clinical practice.

Treatment response was the main determinant of progression, while baseline inflammatory markers offered modest complementary prognostic value. These findings may aid patient selection for T-DM1, particularly in settings with limited access to trastuzumab deruxtecan.