ASCO 2026: HARMONi-6 Phase 3 — Ivonescimab Dual PD-1/VEGF Bispecific Achieves 11.1 vs. 6.9 Months PFS in First-Line Squamous NSCLC

At ASCO 2026, HARMONi-6 Phase 3 data for ivonescimab (AK112/SMT112) demonstrated a clinically meaningful and statistically significant improvement in progression-free survival versus a PD-1 inhibitor alone in previously untreated squamous non-small cell lung cancer (NSCLC). The trial showed a median PFS of 11.1 months with ivonescimab versus 6.9 months with anti-PD-1 monotherapy (HR approximately 0.55). Ivonescimab is a first-in-class bispecific antibody simultaneously targeting PD-1 (blocking T-cell exhaustion) and VEGF (blocking tumor angiogenesis) — a rational dual-mechanism combination designed to enhance both immune activation and vascular normalization in the tumor microenvironment. Squamous NSCLC, which represents approximately 25% of all lung cancers and predominantly affects current and former smokers, has historically had worse outcomes with targeted therapies than adenocarcinoma subtypes. The bispecific antibody strategy avoids the pharmacokinetic complexity and scheduling challenges of separate anti-PD-1 plus bevacizumab combinations. Ivonescimab is being developed in multiple additional NSCLC and solid tumor settings, with the HARMONi program representing a potential platform shift away from chemotherapy-immunotherapy backbone toward bispecific antibody approaches in first-line lung cancer. Regulatory submissions in squamous NSCLC are expected to follow rapidly given the clinical significance of these results, consistent with the accelerating pace of bispecific antibody development across oncology in 2025-2026.