Evaluation of pembrolizumab for the treatment of advanced non-small cell lung cancer: a retrospective, single-centre, single-arm study

Background: Immune checkpoint inhibitors (ICIs) provided a paradigm shift for advanced non-small cell lung cancer (NSCLC) treatment and improved the clinical prognosis of such patients. Pembrolizumab is a humanized anti-programmed death cell protein 1 (PD-1) monoclonal antibody, approved for the treatment of patients with advanced or metastatic NSCLC. This article investigated and reported on the efficacy and safety of pembrolizumab in the treatment of advanced NSCLC in our center since 2019.

Methods: Patients with clinical stage III-IV NSCLC treated with pembrolizumab for ≥4 cycles were enrolled as participants in this study. Pembrolizumab was administered intravenously at a dose of 2 mg/kg every 3 weeks. A cycle was defined as 3 weeks of treatment. We assessed the efficacy and safety of pembrolizumab through the collection of researcher-assessed tumor response, survival, and safety data.

Results: A total of 24 patients were included in this study. The median follow-up time was 9 months (3-20 months) and the median period of pembrolizumab therapy was 7 cycles (4-21 cycles). The objective response rate (ORR) was 45.8% and disease control rate (DCR) was 70.8%. The median overall survival (OS) and progression-free survival (PFS) times were not reached. A total of 2 programmed death-ligand 1 (PD-L1)-negative participants were treated with pembrolizumab combined with chemotherapy and there was no significant progression during the follow-up period. During the follow-up period, 8 patients underwent surgery. The major pathological response (MPR) was 75% and pathological complete response (pCR) was 50%. A case that was preoperatively diagnosed with clinical stage IV achieved pCR after 6 cycles of pembrolizumab combined with chemotherapy. The incidence of adverse effects (AEs) was 83.3%, and 16.7% of these were serious AEs (grade ≥3), which was similar to the incidence reported in previous studies.

Conclusions: This real-world data supports the use of pembrolizumab for advanced NSCLC, including those cases that are PD-L1 negative. More importantly, pembrolizumab immunotherapy can also provide the potential of local treatment for patients with advanced NSCLC, which has wide application prospects in the field of surgery.