 Pre-clinical studies support the proposed dosing schema to be tested and a potential benefit of the combination of inhaled DV281 with an approved anti-PD-1 inhibitor for subjects with advanced NSCLC. This study DV9-NSC-01 is designed for establishing an immunologically optimal RP2D for inhaled DV281 in combination with an approved anti-PD-1 inhibitor. This trial, studying the potential to enhance the efficacy of an approved anti-PD-1 inhibitor in subjects with advanced NSCLC, addresses an unmet need for NSCLC patients having tumors that do not respond or do not respond adequately to anti-PD-1 inhibitor monotherapy. 