Atezolizumab plus carboplatin and etoposide in small cell lung cancer patients previously treated with platinum-based chemotherapy.

Although immune checkpoint inhibitors have improved the survival of small cell lung cancer (SCLC) patients, their efficacy in SCLC patients who relapsed after systemic chemotherapy is unclear. This retrospective study aimed to investigate the utility of treatment with atezolizumab plus carboplatin and etoposide in SCLC patients previously treated with platinum-based chemotherapy. We retrospectively screened consecutive eight SCLC patients who received atezolizumab plus carboplatin and etoposide after platinum-based chemotherapy. We evaluated the efficacy of this treatment and its association with programmed cell death-ligand 1 (PD-L1) expression. Three and five patients had sensitive relapse and refractory relapse for first-line platinum-based chemotherapy, respectively. The overall response rate and disease control rate was 37.5% and 75.0%, respectively. Median progression-free survival was 4.0 months. Out of three patients who achieved clinical response, two patients had refractory relapse for first-line platinum-based chemotherapy. No patient exhibited PD-L1 expression. Atezolizumab plus carboplatin and etoposide therapy was effective in SCLC patients with sensitive and refractory relapse and might be a second-line treatment option for SCLC patients previously treated with platinum-based chemotherapy.