Background and importance Atezolizumab as monotherapy is indicated for the treatment of adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) after prior chemotherapy. Patients with epidermal growth factor receptor (EGFR) mutant or anaplastic lymphoma kinase (ALK) positive NSCLC should also have received targeted therapies before receiving immunotherapy.

Aim and objectives To analyse the effectiveness and safety of treated patients with atezolizumab in usual clinical practice.

Material and methods An observational retrospective study was carried out between April 2018 and August 2020. Every patient with squamous and non-squamous NSCLC undergoing treatment with atezolizumab as monotherapy was included. Patient data were obtained from clinical records. Variables analysed were demographic variables (age and sex) and clinical variables (diagnosis, stage, treatment line, dose administered and performance status (PS) according to the ECOG scale). Efficacy endpoints were progression free survival (PFS) and overall survival (OS) assessed by iRECIST criteria and analysed by Kaplan–Meier curves. Adverse reactions were also assessed.

Results 35 patients were included, average age 63.52±11.25 years. 8.53% (n=3) had ECOG-PS 2 and the remainder had ECOG-PS 0–1 (n=32). NSCLC stage was IV in 100% (n=35) of patients. 68.57% of patients started therapy with atezolizumab as secondline, 14.29% as thirdline and 17.14% as fourth/fifth line. Only one patient had an EGFR positive mutation. The administered dose was 1200 mg 3 weekly. Four patients (11.43%) were still receiving treatment. Causes of treatment suspension in the remaining patients were disease progression (n=31), death (n=4) or toxicity (n=1). Median PFS was 3.2 months (95% CI 2.6 to 7.2). Median OS was 6.3 months (95% CI 4.4 to 9.1). 40% of patients received ≤3 cycles of treatment.

Adverse reactions were: grade 2–3, asthenia 31.43%, grade 1–2 arthralgia 14.29%, anorexia 14.29%, skin toxicity 17.14%, gastrointestinal toxicity 28.57%, pneumonitis 2.86%, hepatic toxicity 8.57%, rheumatological 14.29% and neurological 5.71%. One case of gastrointestinal toxicity caused treatment suspension. Neither renal nor endocrine toxicity was recorded.

Conclusion and relevance Median PFS in our study was similar to that found in the OAK phase III trial (2.8 months). Atezolizumab was safe and well tolerated; the safety profile was similar to that described in clinical trials. 40% of patients receiving ≤3 cycles could suggest hyperprogression in a high group of patients. Chemotherapy associated with immunotherapy needs to be studied in this no benefit subgroup of patients.

Conflict of interest No conflict of interest