The Evolving Role of Bispecific Antibodies in Oncogene-Driven NSCLC

Bispecific antibodies (bsAbs) have emerged as a novel therapeutic class in oncogene-driven non-small-cell lung cancer (NSCLC), designed to simultaneously target multiple signaling pathways and overcome resistance mechanisms associated with tyrosine kinase inhibitors (TKIs). Unlike small-molecule TKIs, bsAbs enable dual receptor blockade and immune effector engagement, offering a mechanistically distinct advantage in the context of tumor heterogeneity and bypass signaling. This review summarizes the structural and biological principles underlying bsAb design, with a focus on clinically approved agents such as amivantamab (EGFR/MET) and zenocutuzumab (HER2/HER3) and a growing pipeline of investigational agents. We evaluate key clinical evidence from Phase I-III trials including CHRYSALIS, PAPILLON, MARIPOSA, MARIPOSA-2 and eNRGy, and compare the efficacy, toxicity, and CNS penetration profile of bsAbs relative to TKIs and antibody–drug conjugates (ADCs). While bsAbs demonstrate meaningful clinical activity, particularly in TKI-resistant disease and molecularly defined subsets such as EGFR exon 20 insertions and NRG1 fusions, their limitations, including intravenous administration, increased immune-mediated and thromboembolic toxicity, currently preclude replacement of TKIs in most settings. Collectively, available evidence supports a complementary role for bsAbs within evolving multimodal treatment paradigms, particularly in combination strategies. Future directions include biomarker-driven patient selection, improved drug engineering and integration into adaptive therapeutic sequencing frameworks.