4CPS-268 Nivolumab versus pembrolizumab in secondline treatment of metastatic non-small cell lung cancer in clinical practice

Background and importance Nivolumab and pembrolizumab are immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1). The introduction of these agents has significantly improved survival outcomes in metastatic non-small cell lung cancer (NSCLC). However, few studies have compared the efficacy of these two drugs in the secondline setting. Aim and objectives To compare the efficacy of nivolumab and pembrolizumab in secondline metastatic NSCLC. Material and methods A retrospective observational study was conducted. We included patients diagnosed with metastatic NSCLC treated with nivolumab and pembrolizumab as secondline treatment in a tertiary care hospital between March 2016 and March 2020. Selected variables were: age, sex, diagnosis, drug, treatment start/end date, disease progression and death. Data were collected using electronic prescription and medical records. Efficacy was measured using survival outcomes. Progression free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method, and the log rank test was used to assess differences between groups. A p value ≤0.05 was considered statistically significant. Statistical analyses were performed using SPSS V.19. Results 43 patients were analysed. Mean age was 64 years (±7.7) and 79.1% (n=34) were men. 26 patients (60.5%) were treated with nivolumab; mean age in this subgroup was 64±6.8 years, with 80% (n=21) men. The remaining 17 patients (39.5%) received pembrolizumab and mean age was 63 (±9.16), with 76.5% (n=13) men. Median time on treatment was 4 months (0.5–24.8): 3.5 (0.5–24.8) for nivolumab and 5.4 (0.5–20) for pembrolizumab. Median PFS for all treated patients was 5 months (95% CI 2.26 to 7.4). PFS was 4 months (95% CI 2.6 to 5.4) for nivolumab patients and 5 (95% CI 0 to 11.3) for those treated with pembrolizumab. Regarding OS, median time was 7 months (95% CI 2.5 to 11.5): 5 months for nivolumab (95% CI 2 to 8) and 11 for pembrolizumab (95% CI 6 to 16). There were no significant differences in PFS (p=0.741) or OS (p=0.615) between the subgroups. Conclusion and relevance According to our results, nivolumab and pembrolizumab showed similar PFS. OS, although not statistically significant, was considerably superior in pembrolizumab patients. These data might be clinically relevant. However, the small sample size makes it difficult to draw conclusions. Further studies should be conducted to confirm potential differences between both anti-PD-1 and could be helpful in supporting clinician decisions. References and/or acknowledgements Conflict of interest No conflict of interest