HEALER Phase 3 Trial Shows Annitumumab Plus HB1801 Improves First-Line PFS in HER2-Positive Advanced Breast Cancer

The HEALER randomized phase 3 results, presented at ESMO 2026, showed that annitumumab plus HB1801 significantly improved PFS over THP as first-line treatment for HER2-positive advanced breast cancer. The study enrolled 885 patients at 76 centers in China who had received no chemotherapy or anti-HER2 targeted therapy in the advanced setting. The 24-month PFS rate was 58.5% versus 34.4%, HR=0.46 (95% CI 0.37-0.56, P=6.37*10^-15), and ORR was 87.6% versus 73.4%.