T-DXd Delivers 58% ORR and 15.7-Month PFS in China HER2 IHC3+ Pan-Tumor Cohort

Trastuzumab deruxtecan is a HER2-directed ADC with a topoisomerase I payload, tested in DESTINY-PanTumor03 Part 1 (NCT06271837) in China among HER2 IHC3+ unresectable/metastatic solid tumors excluding breast and gastric cancer. Patients had received ≥1 prior systemic therapy (n=50; median 2 prior lines), and ICR-assessed ORR was 58%, median DOR 15.4 months, and median PFS 15.7 months at 9.9 months’ median follow-up. Grade ≥3 drug-related AEs occurred in 62%, and adjudicated drug-related ILD/pneumonitis occurred in 8% (grade 3 in 2%), consistent with the known T-DXd risk profile and broadly comparable to DESTINY-PanTumor02’s HER2 IHC3+ activity.