Neoadjuvant PD-1 and PD-L1 Blockade With Chemotherapy for Borderline Resectable and Unresectable Stage III Non–Small Cell Lung Cancer

Importance Patients with borderline resectable or unresectable stage III non–small cell lung cancer (NSCLC) with T4 and/or N2-N3 involvement face limited treatment options and poor outcomes. Neoadjuvant chemoimmunotherapy has shown promise in improving resectability and pathological responses. Objective To evaluate the efficacy of neoadjuvant programmed cell death 1 protein (PD-1) or programmed cell death 1 ligand 1 (PD-L1) blockade combined with chemotherapy in enhancing surgical outcomes and pathological responses in patients with T4 and/or N2-N3 stage III NSCLC. Design, Setting, and Participants This multicenter cohort study analyzed data from patients treated between February 2018 and January 2024 with neoadjuvant PD-1/PD-L1 inhibitors plus chemotherapy at academic and tertiary care centers across the US and Italy. Pathological and survival outcomes were assessed. Patients with stage III NSCLC and T4 and/or N2-N3 involvement were included. Data were collected from February 2018 to January 2024. Exposures Neoadjuvant PD-1/PD-L1 blockade combined with platinum-based chemotherapy. Main Outcomes and Measures Pathological complete response (pCR), major pathological response, surgical resectability, and event-free survival (EFS). Results Of 112 patients, 58 (51.8%) were female, and the median (range) age was 66 (41-84) years. A total of 84(75.0%) underwent surgical resection, achieving a pCR rate of 29.0% (24 of 83 with available final pathology) and a major pathological response rate of 42.2% (35 of 83). Patients with both PD-L1 expression of 50% or more and high tumor mutational burden achieved the highest pCR rate (4 of 9 [44.4%]; P = .03). Conversely, covariants in KRAS / STK11 or KRAS / KEAP1 were associated with lack of pCR. Patients with single-station or multistation N2/N3 disease exhibited comparable pathological outcomes. The median EFS for all resected patients was 52.6 months (95% CI, 27.8 to not reached), and this was significantly longer in patients with pCR (not reached vs 27.8 months [95% CI, 19.5 to not reached]; P < .001). Conclusions and Relevance In this study, neoadjuvant PD-1/PD-L1 blockade combined with chemotherapy resulted in high pathological response rates and surgical resectability in patients with T4 and/or N2-N3 stage III NSCLC. This approach offers a viable treatment option for patients with borderline resectable or unresectable NSCLC but requires further validation through prospective studies.