Abstract
Atezolizumab is a monoclonal antibody targeting the programmed death ligand 1 (PD-L1) that was approved in 2017 in the USA and Europe for the second-line treatment of advanced or metastatic non-small cell lung cancer (NSCLC). This review article describes the practical clinical issues associated with atezolizumab treatment in NSCLC using a combination of four illustrative cases and a narrative literature review. The first two cases highlight the importance of tumor mutational status when making treatment decisions. A 62-year-old man with epidermal growth factor receptor (EGFR)-mutated, PD-L1-positive, stage IV lung adenocarcinoma received treatment with second-line atezolizumab + bevacizumab, carboplatin, and paclitaxel (BCP) after first-line osimertinib. In the second case, a 63-year-old man with stage IVb lung adenocarcinoma with anaplastic lymphoma kinase (ALK) translocation received sixth-line treatment with atezolizumab + BCP. The two final cases both had extensive metastases. A 55-year-old woman with EGFR-mutated lung adenocarcinoma received second-line treatment with atezolizumab + BCP after development of multiple metastases, followed by atezolizumab + bevacizumab until last follow-up. A 42-year-old man with PD-L1-positive pulmonary adenocarcinoma (negative for EGFR mutations) developed liver and brain metastases after several lines of therapy. He underwent holocranial radiation and received atezolizumab + BCP, which resulted in a decrease in all measurable and evaluable tumoral lesions. These illustrative cases indicate that the type and number of mutations may influence treatment response to atezolizumab, and that atezolizumab may provide clinical benefit in patients with high disease burden.