Atezolizumab in the first-line treatment of metastatic non-small cell lung cancer. Clinical experience of the drug application. Case report

Abstract

Background. Lung cancer is still the leading cause of cancer morbidity and mortality among both men and women. At the same time, non-small cell lung cancer (NSCLC) accounts for 85% of all cases of malignant tumors. Historically, the treatment for locally advanced and metastatic lung cancer was consisted of systemic cytotoxic therapy. The main aim was to destroy tumor cells, to reduce the severity of the disease manifestations, to improve the quality of life and to prolong survival. Recent discovery of mutations in the epidermal growth factor receptor (EGFR) gene and ALK translocations or proto-oncogene 1 (ROS1) has led to a paradigm shift and the development of molecularly oriented therapeutic agents and options, such as targeted therapy as well as immunotherapy using immune checkpoint inhibitors.
 Aim. Present the efficacy of atezolizumab application in the first-line treatment of metastatic non-small cell lung cancer associated with high PD-L1 expression.
 Clinical case report. A 64-year-old patient with T1N3M1 stage IV right lung cancer, brain and right adrenal metastases was under observation. Right supraclavicular lymph node biopsy was performed. The histological examination showed the metastases of squamous cell carcinoma. EGFR-activating mutations, ALK translocations and ROS1 were not detected (wild-type). The immunohistochemical analysis showed a high expression of programmed cell death ligand (PD-L1) 90%. The patient was treated using atezolizumab 1200 mg every 21 days in monoregimen. The patient was receiving 50 injections of the drug for almost 3 years. The effect of the therapy was evaluated using hybrid 18-F-fluorodeoxyglucose PET/CT. The complete metabolic regression of the tumor was obtained after 14 cycles of treatment and was persisting throughout the treatment period for 36 months. Grade 2 neutropenia after 6,7 and 30 cycles of therapy was noted among the adverse effects. Immune-mediated adverse events were not described.
 Conclusion. The application of atezolizumab in monoregimen can provide long-term overall survival in patients with untreated metastatic EGFR-negative, ALK-negative NSCLC associated with high PD-L1 expression, as well as a favorable safety profile and quality of life.