Intermittent administration of atezolizumab with combined carboplatin and etoposide therapy for patients with extensive­disease small cell lung cancer.

To the best of our knowledge, no published reports have examined the significance of additional immune checkpoint inhibitors in treating malignancies, including lung cancer. Therefore, the present study aimed to examine the efficacy and feasibility of adding atezolizumab to carboplatin and etoposide combination chemotherapy for small cell lung cancer with extensive disease (ED-SCLC). The present retrospective analysis examined 16 patients with ED-SCLC who received the addition of atezolizumab to carboplatin and etoposide therapy during treatment at four institutions between August 2019 and September 2020. The effectiveness of treatment was evaluated based on tumor response, survival time and adverse events. Within the study cohort, there were 14 males (87.5%) and 2 females (12.5%), with a median age of 73.5 years (range, 62-79 years); 7 patients had a performance status (PS) of 0-1 (43.8%) and 9 had a PS of 2-3 (56.3%). The median follow-up period was 12.1 months. The overall response rate, median progression-free survival time and median overall survival time were 75.0%, 5.3 and 13.0 months, respectively. Regarding the frequency of hematological adverse events, the occurrence of grade ≥3 adverse events was observed, including decreased neutrophil (56.3%), white blood cell (50.0%) and platelet (43.8%) counts, as well as febrile neutropenia (12.5%). Although 1 patient developed grade 3 pneumonitis as a serious adverse event, no treatment-related deaths were observed. Despite the aforementioned hematological toxicities, the addition of atezolizumab to carboplatin and etoposide therapy during treatment demonstrated favorable efficacy and acceptable toxicity in ED-SCLC. Thus, adding atezolizumab to carboplatin and etoposide combination chemotherapy may be a treatment option for ED-SCLC.