Long-Term Response and Survival in Extensive-Stage SCLC Receiving Atezolizumab Plus Chemotherapy in a Real-World Setting: IFCT-1905 CLINATEZO.

[INTRODUCTION] Extensive-stage SCLC (ES-SCLC) is a highly aggressive type of lung cancer with a high risk of early progression and limited survival. Standard of care for first-line treatment is platinum-etoposide chemotherapy plus anti-PD-L1 immune checkpoint inhibitors.

[METHODS] Intergroupe Francophone de Cancérologie Thoracique-1905 CLINATEZO is a nationwide, non-interventional, retrospective study of consecutive patients with ES-SCLC who received atezolizumab plus platinum-based chemotherapy as part of the French Early Access Program that ran from May 2019 to March 2020. In this analysis, predictors of long-term response (defined by a real-world progression-free survival [rwPFS] > 12 mo) and long-term survival (defined by an overall survival [OS] > 24 mo) were assessed.

[RESULTS] A total of 517 patients were enrolled from 65 centers. After a median follow-up of 53.8 months, median, 12-month, and 48-month rwPFS rates were 5.2 (95% confidence interval [CI]: 5.0-5.4) months, 14.6% (95% CI: 11.6-17.9), and 6.8% (95% CI: 4.7-9.4), respectively. Median, 24-month, and 48-month OS rates were 11.3 (95% CI: 10.1-12.4) months, 21.1% (95% CI: 17.7-24.8), and 11.4% (95% CI: 8.8-14.4), respectively.Long-term response was observed in 12.6% patients. Median OS was 9.7 months in patients with rwPFS less than or equal to 12 months and 53.7 months in patients with rwPFS more than 12 months. Baseline characteristics associated with rwPFS more than 12 months were being a former smoker (versus current smoker, = 0.003) and having an Eastern Cooperative Oncology Group performance status of 0 to 1 (versus 2, = 0.048).Long-term survival was observed in 20.5% patients. Median OS was 8.8 months in patients with OS less than or equal to 24 months and 52.9 months in patients with OS more than 24 months. Predictors of long-term survival were younger age ( = 0.030), limited stage at initial diagnosis of SCLC ( = 0.022), and previous line of platinum-based chemotherapy ( = 0.01).

[CONCLUSIONS] CLINATEZO demonstrates the reproducibility of the key survival outcomes of landmark trials, in a real-life setting, for patients with ES-SCLC. Only low smoking history and performance status were associated with long-term response in our cohort.