Trastuzumab deruxtecan for previously treated HER2-positive metastatic breast cancer: updated survival results from DESTINY-Breast01

The multinational phase 2 DESTINY-Breast01 trial evaluated trastuzumab deruxtecan (T-DXd) in patients with HER2-positive metastatic breast cancer (mBC) previously treated with a median of six lines of therapy, among which trastuzumab emtansine (T-DM1). The primary analysis of the trial showed a confirmed objective response rate (cORR) of 60.9%, with median overall survival not reached after median 11.1 months follow-up. Updated results with median follow-up of 26.5 months have now been published. The updated cORR was 62.0%. The median duration of response was 18.2 months (95% CI 15.0-NE), the median progession-free survival was 19.4 months (14.1-25.0), and the median overall survival was 29.1 months (24.6-36.1). Treatment-emergent adverse events were seen in 99.5% of patients; grade 3 or higher TEAEs in 53.8%; and fatal TEAEs in 2.7%. The authors conclude that these updated results provide further evidence of sustained antitumor activity of T-DXd with a consistent safety profile in heavily pretreated patients with HER2-positive mBC.