Three-Year Follow-Up of Neoadjuvant Programmed Cell Death Protein-1 Inhibitor (Sintilimab) in NSCLC

INTRODUCTION: Programmed cell death protein-1 (PD-1) inhibitors have been proved to be feasible and to have efficacy in multiple cancers, including NSCLC. But few studies have evaluated the effectiveness of PD-1 inhibitor as neoadjuvant therapy with a long-term follow-up. Here, in this phase 1b study with a 3-year follow-up, we reported the clinical outcomes of patients who received the PD-1 inhibitor as neoadjuvant therapy. METHODS: Two doses of sintilimab (intravenously, 200 mg) were used for patients with stages IA to IIIB NSCLC (registration number: ChiCTR-OIC-17013726). Then, surgery was performed within 29 to 43 days after the first dose. All patients underwent positron emission tomography-computed tomography at enrolment and before surgery to evaluate tumor metabolism after administration of PD-1 inhibitor. We also evaluated the expression of programmed death-ligand 1 (PD-L1) as an exploratory analysis in 32 eligible patients. Safety was the primary end point. Overall survival (OS), disease-free survival (DFS), event-free survival, and major pathologic response were the key secondary end points. RESULTS: With the mean follow-up of 37.8 months, 3-year OS rate was 88.5% and the 3-year DFS rate was 75.0% among patients who underwent R0 resection. In patients with positive PD-L1 expression, 3-year OS and DFS rates were 95.5% and 81.8%, respectively. Eight patients had recurrent tumors, including local recurrence, lung metastasis, brain metastasis, and bone metastasis. Patients with PD-L1 greater than or equal to 1% had more favorable clinical outcomes than the other subgroup (hazard ratio = 0.275, 95% confidence interval: 0.078-0.976). No more new adverse events have occurred in the 3-year follow-up because we first reported them in the former publication. CONCLUSIONS: This is the first study to report the long-term survival probability of patients with NSCLC receiving PD-1 inhibitors as the neoadjuvant treatment. The 3-year follow-up results revealed that patients with positive PD-L1 expression and high tumor mutation burden have favorable clinical outcomes.