EGFR and lung cancer: As the outcome of immunotherapy can be improved when concurrently or sequentially combined with cytotoxic chemotherapy or radiotherapy, we investigated the efficacy of immunotherapy maintenance following platinum‐based chemotherapy in epidermal growth factor receptor (EGFR)‐mutant non‐small cell lung cancer (NSCLC) after EGFR‐tyrosine kinase inhibitor (EGFR‐TKI) failure.