Long-term effectiveness and treatment sequences in patients with extensive stage small cell lung cancer receiving atezolizumab plus chemotherapy: Results of the IFCT-1905 CLINATEZO real-world study

International audienceBackground: Small cell lung cancer (SCLC) has a tendency towards recurrence and limited survival. Standard-of-care in 1st-line is platinum-etoposide chemotherapy plus atezolizumab or durvalumab, based on landmark clinical trials. Methods: IFCT-1905 CLINATEZO is a nationwide, non-interventional, retrospective study of patients with extensive-SCLC receiving atezolizumab plus chemotherapy as part of French Early Access Program. Objectives were to analyse effectiveness, safety and subsequent treatments. Results: The population analyzed included 518 patients who received atezolizumab in 65 participating centers. There were 66.2% male, mean age was 65.7 years; 89.1% had a performance status (PS) 0/1 and 26.6% brain metastases. Almost all (95.9%) were smokers. Fifty-five (10.6%) received at least 1 previous treatment. Median number of atezolizumab injections was 7.0 (range [1.0–48.0]) for a median duration of 4.9 months (95% CI 4.5–5.1). Atezolizumab was continued beyond progression in 122 patients (23.6%) for a median duration of 1.9 months (95% CI: [1.4–2.3]). Best objective response was complete and partial in 19 (3.9%) and 378 (77.1%) patients. Stable disease was observed in 50 patients (10.2%). Median follow-up was 30.8 months (95% CI: [29.9–31.5]). Median overall survival (OS), 12-, 24-month OS rates were 11.3 months (95% CI: [10.1–12.4]), 46.7% (95% CI [42.3–50.9]) and 21.2% (95% CI [17.7–24.8]). Median real-world progression-free survival, 6-, 12-month rates were 5.2 months (95% CI [5.0–5.4]), 37.5% (95% CI [33.3–41.7]) and 15.2% (95% CI [12.2–18.6]). For patients with PS 0/1, median OS was 12.2 months (95% CI [11.0–13.5]). For patients with previous treatment, median OS was 14.9 months (95% CI [10.1–21.5]). Three-hundred-and-twenty-six patients (66.4%) received subsequent treatment and 27 (5.2%) were still under atezolizumab at date of last news. Conclusions: IFCT-1905 CLINATEZO shows reproductibility, in real-life, of IMpower-133 survival outcomes, possibly attributed to selection of patients fit for this regimen, adoption of pragmatic approaches, including concurrent radiotherapy and treatment beyond progression