#ESMO2026 abstract: 🇨🇳Innovent’s EGFR/B7-H3 Bispecific ADC IBI3001 Posts 28% ORR in Phase 1, Reaches 87.5% in Biomarker-Positive Patients (1001O) IBI3001 carries exatecan, a topoisomerase I inhibitor, as its payload. The first-in-human study is registered as NCT06349408. Phase 1a: As of March 31, 2026, 57 patients had enrolled in the Phase Ia study, including 40 in China and 17 in Australia. - Main dose cohorts: 6 mg/kg (n=28) and 8 mg/kg (n=22) - Median follow-up was 6.4 months (range, 0.1–13.7), and median treatment duration was 18 weeks (range, 3–62). - At the data cutoff, 24 patients (42.1%) remained on treatment. ORR and DCR - ORR 28.0%, DCR 88.0%. - 6 mg/kg: ORR 26.9%, DCR 80.8% - 8 mg/kg: ORR 38.9%, DCR 100% Efficacy signals across tumor types • EGFR-mutated NSCLC (n=16): ORR 31.3%; mPFS 7.0 months, with a 62.5% event rate. • SCLC (n=6): ORR 66.7%; PFS data remained immature, with a 12.5% event rate. • ESCC & HNSCC (n=5): ORR 60.0%. • PDAC (n=13): mPFS 7.0 months across the 6 and 8 mg/kg dose cohorts, with a 46.2% event rate. • Biomarker-positive population (n=8): Among patients with EGFR and/or B7-H3 membrane H-score ≥100, ORR 87.5%, DCR 100%. Safety 2 DLTs: 1/3 at 10 mg/kg and 1/6 at 8 mg/kg. - TRAEs: 91.2%; Grade ≥3 TRAEs: 47.4% • TRAEs leading to treatment discontinuation: 1 patient • TRAE-related deaths: None • Grade 2 pneumonitis: 1 patient The most common TRAEs, each occurring in ≥40% of patients, were: • Anemia: 61.4% (Grade ≥3: 22.8%) • Decreased white blood cell count: 49.1% (Grade ≥3: 10.5%) • Decreased neutrophil count: 47.4% (Grade ≥3: 19.3%)