Clinical outcome and tolerability of DS-8201 in patients with advanced HER2-positive breast cancer: a retrospective study.

[OBJECTIVE] There are limited data about DS-8201 (trastuzumab deruxtecan) in Chinese patients with advanced human epidermal growth factor receptor 2 (HER2)-positive breast cancer previously treated with trastuzumab emtansine (T-DM1). This study aimed to evaluate the efficacy and safety of DS-8201 compared to the treatment of physician's choice (TPC) in this population.

[METHODS] In this retrospective cohort study, 185 eligible patients treated between December 2022 and March 2025 were assigned to either the DS-8201 group (n=83) or the TPC group (n=102), which received regimens such as capecitabine combined with anti-HER2 therapy. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), duration of response (DoR), disease control rate (DCR), quality of life (QoL), and safety were assessed.

[RESULTS] The DS-8201 group demonstrated significantly superior 12- and 24-month PFS (62.65% vs. 42.16%; 50.60% vs. 23.53%) and OS (90.36% vs. 60.78%; 75.90% vs. 54.90%) compared to the TPC group (all P<0.05). ORR (72.29% vs. 45.10%), median DoR (20.00 vs. 9.00 months), and DCR (80.72% vs. 60.78%) were also significantly improved (all P<0.05). Patients receiving DS-8201 reported better QoL and delayed time to first hospitalization (all P<0.05). The overall incidence of treatment-emergent adverse events (TEAEs) was similar between groups (P>0.05). However, DS-8201 was associated with higher rates of nausea, alopecia, and drug-induced interstitial lung disease, while the TPC group had more diarrhea and palmar-plantar erythrodysesthesia (all P<0.05).

[CONCLUSION] DS-8201 showed significantly better efficacy and similar overall safety compared to TPC in patients with T-DM1-pretreated HER2-positive advanced breast cancer, supporting its use as a treatment option in this setting.