AEs adverse events CI confidence intervals CR complete response CTCAE Common Terminology Criteria for Adverse Events DCR disease control rate DOR duration of response ECOG Eastern Cooperative Oncology Group ES-SCLC extensive-stage small cell lung cancer HR hazard ratios ICIs immune checkpoint inhibitors irAEs immune-related adverse events NE neuroendocrine ORR objective response rate OS overall survival PD progressive disease PD-1 programmed cell death protein 1 PD-L1 programmed cell death...