An investigational EGFR x HER3 antibody-drug conjugate demonstrated promising efficacy with a tolerable safety profile in patients with previously treated EGFR-mutated non-small cell lung cancer (NSCLC), supporting selection of the 2.5 mg/kg dose for evaluation in the global Phase 3 IZABRIGHT-Lung01 registrational study.

These results will be presented at the International Association for the Study of Lung Cancer (IASLC) 2026 World Conference on Lung Cancer (WCLC) in Seoul, Republic of Korea.

Results from the randomised dose-expansion cohort of the global Phase 1 study showed increasing clinical activity with higher dose levels.

At the recommended Phase 3 dose of 2.5 mg/kg, the objective response rate reached 33.3%, the confirmed objective response rate was 29.6%, and median progression-free survival was 6.9 months.

All enrolled patients had previously progressed on a third-generation EGFR inhibitor, and nearly two-thirds had also received platinum-based chemotherapy.

Mandatory primary G-CSF prophylaxis was associated with an improved hematologic safety profile compared with previously reported experience.

Overall, the investigational therapy demonstrated a manageable safety profile.

No treatment-related deaths were observed, and only one patient discontinued treatment because of a treatment-related adverse event.

“These findings support continued development of iza-bren and provide the rationale for advancing the 2.5 mg/kg regimen into the global Phase 3 IZABRIGHT-Lung01 trial for patients with previously treated EGFR-mutated NSCLC,” said Alexander Spira, M.D.,  NEXT Oncology Virginia and Virginia Cancer Specialists, Fairfax, Va.

Source: International Association for the Study of Lung Cancer