Correspondence authors comment on the results of the HARMONi-6 study by Zhiwei Chen and colleagues, which showed improved progression-free survival in patients with advanced squamous non-small cell lung cancer (NSCLC) treated with ivonescimab plus chemotherapy compared with tislelizumab plus chemotherapy. Subgroup results by PD-L1 tumor proportion score (TPS) reveal a significant stratification signal. In patients with PD-L1 TPS below 50%, dual blockade achieved a significant benefit with a hazard ratio (HR) of 0.63 (95% CI 0.41–0.98). In patients with PD-L1 TPS of 50% or more, the improvement was numerical but not significant (HR 0.371; 10). The HARMONi-6 study compared ivonescimab plus chemotherapy with tislelizumab plus chemotherapy as first-line treatment. Overall, ivonescimab plus chemotherapy significantly improved progression-free survival regardless of PD-L1 status.