Real‐world efficacy of atezolizumab in non‐small cell lung cancer: A multicenter cohort study focused on performance status and retreatment after failure of anti‐PD‐1 antibody

BACKGROUND: Atezolizumab is a programmed death‐ligand 1 (PD‐L1) targeted monoclonal antibody that inhibits PD‐L1 interacting with its receptors PD‐1 and B7‐1, thereby enhancing anticancer immunity. Some real‐world efficacy and safety studies of anti‐PD‐1 antibody have been previously reported. However, there have been no reports investigating the efficacy of atezolizumab monotherapy in clinical practice which have focused on performance status and previous anti‐PD‐1 antibody treatment. METHODS: We retrospectively reviewed consecutive advanced NSCLC patients who received atezolizumab monotherapy between April 2018 and February 2019 at eight institutions. A total of 152 patients with NSCLC were enrolled in this study. RESULTS: A total of 38 patients (25%) had already been treated with anti‐PD‐1 treatment (nivolumab or pembrolizumab) before atezolizumab. The median OS and TTF was 384 days (12.8 months) (95% confidence interval [CI]: 206–424), and 42 days (1.4 months) (95% CI: 27–56) in all patients, respectively. ECOG PS 0 had significantly longer OS (median OS; not reached, p < 0.0001) and TTF (median TTF; 63 days, p = 0.012) compared with PS 1 or 2–3. Most retreated patients were unable to continue atezolizumab for a longer period, but seven patients (18.4%) were able to continue atezolizumab over four months as an ICI retreatment. CONCLUSIONS: In previously treated advanced NSCLC patients, atezolizumab monotherapy demonstrated good efficacy and safety regardless of heavily treated patients in real‐world clinical practice, and ECOG PS 0 was a favorable predictive factor. The efficacy of retreatment with atezolizumab was limited but was well tolerated in patients treated with prior anti‐PD‐1 antibody.