Background and importance The high cost of immunotherapy makes it necessary to assess health outcomes in real life, which can help in decision-making.

Aim and objectives The current study aimed to analyse the effectiveness and safety of immunotherapy in second-line treatment in adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) in real life.

Material and methods Retrospective and observational study. All patients with locally advanced or metastatic NSCLC treated with nivolumab, pembrolizumab and atezolizumab monotherapy as second-line treatment between April 2017 and April 2020 were included.

Outcomes collected were: demographic variables: age and sex and clinical variables: diagnosis, stage, performance status score according to Eastern Cooperative Oncology Group (ECOG), PD-L1 expression and treatment variables: treatment start and end date and administered doses.

The primary endpoints were: overall survival (OS) and progression-free survival (PFS). All adverse effects (AE) were recorded according to CTCEA v4.3 criteria.

Data were collected from the electronic clinical history and electronic prescribing software. The Kaplan−Meier method was used to calculate PFS and OS. SPSS v17 was used to perform statistical calculations.

Results 104 patients were included in this study: N=40 nivolumab, N=29 pembrolizumab and N=35 atezolizumab. Median age was 62.93±9.20, 64.92±11.69 and 59.86±11.60 years, respectively. 74.7% were men and 67.8% were ECOG-1.

Nivolumab showed an OS of 6.4 months (95% CI 2.81 to 9.98) and a PFS of 3 months (95% CI 1.14 to 4.25), pembrolizumab-treated patients had a median OS of 8 months (95% CI 3.05 to 12.94) and median PFS of 3.5 months (95% CI 2.4 to 4.6). The use of atezolizumab demonstrated an OS of 6.33 months (95% CI 4.4 to 9.1) with a PFS of 3.2 months (95% CI 2.6 to 7.2).

82.5% of patients suffered from some AE to nivolumab, 76.9% to pembrolizumab and 80.9% to atezolizumab. Asthenia was the AE that occurred most frequently and was common to all three drugs.

Conclusion and relevance Safety was similar for all drugs, and the effectiveness in terms of OS was a little higher for pembrolizumab, which could be related to the fact that patients treated with this antibody had PD-L1 expression >1%. However, it will be necessary to expand the sample size to generate quality information that can help in decision-making in real-life clinical practice.

Conflict of interest No conflict of interest