A retrospective cohort study of sintilimab and pembrolizumab as first-line treatments for advanced non-small cell lung cancer.

Background: Pembrolizumab and sintilimab have both been approved by the China National Medical Products Administration (NMPA) for the first-line treatment of advanced non-small cell lung cancer (NSCLC). These two drugs have several differences in biological characteristics and population in clinical trials. The current retrospective study was conducted to compare the efficacy and safety of sintilimab and pembrolizumab as first-line treatments in patients with advanced NSCLC. Methods: Consecutive patients with advanced NSCLC who received sintilimab or pembrolizumab as first-line therapy, with or without chemotherapy, from November 2018 to October 2021 in the First Affiliated Hospital of Soochow University and Dushu Lake Hospital Affiliated to Soochow University were retrospectively reviewed. Clinical data and treatment response were collected and survival was followed up. Kaplan-Meier method was used to estimate survival curves. The patients were divided into the sintilimab group and the pembrolizumab group according to the PD-1 inhibitors they received during treatment. The primary objective was to compare objective response rate (ORR) and progression-free survival (PFS) between the two groups. The secondary objectives were to compare disease control rate (DCR) and analyze adverse events (AEs) of the two groups. Results: A total of 124 patients were enrolled, including 68 patients (54.8%) in the sintilimab group and 56 patients (45.2%) in the pembrolizumab group. The baseline characteristics of the patients were comparable between the two groups. The ORR was 50% in the sintilimab group and 46.4% in the pembrolizumab group (P=0.69). The DCR was 89.7% and 89.3% in the sintilimab group and the pembrolizumab group, respectively (P=0.94). The median PFS time was 9.9 months in patients treated with sintilimab compared to 10.8 months in patients on pembrolizumab treatment [hazard ratio (HR) =0.960; 95% confidence interval (CI): 0.574-1.606; P=0.875]. The median OS time was not reached in either group of patients. The incidence of grade 3-4 treatment-related adverse events (TRAEs) was 25% (17/68) in the sintilimab group and 21.4% (12/56) in the pembrolizumab group. Conclusions: Sintilimab has similar efficacy to pembrolizumab as a first-line treatment option for patients with advanced NSCLC in clinical practice, with manageable AEs.