Immune checkpoint inhibitors in lung cancer: the holy grail has not yet been found…

Abstract

Lung cancer is rich in molecular complexities and driven by different abnormal molecular pathways. Personalised medicine has begun to bring new hope for the treatment of patients with lung cancer, especially non-small cell lung cancer (NSCLC). The development of molecularly targeted therapy (small molecules and monoclonal antibodies) has significantly improved outcomes in the metastatic setting for patients with NSCLC whose tumours harbour activated oncogenes such as epidermal growth factor receptor (EGFR) and translocated genes like anaplastic lymphoma kinase (ALK). In addition, immune checkpoint inhibitors have also dramatically changed the therapeutic landscape of NSCLC. In particular, monoclonal antibodies targeting the programmed death-1 receptor (PD-1) /PD ligand 1 (PD-L1) pathway have emerged as powerful new therapeutic tools in several clinical trials, and some of them are already approved by the Food and Drug Administration (FDA) and American Medical Association (AMA). Immunotherapy is a novel type of treatment that has been tested in patients with metastatic NSCLC. Two anti-PD-1 drugs (nivolumab and pembrolizumab) and one anti-PD-L1 drug (atezolizumab) have been approved as monotherapy for second-line treatment for NSCLC. Recent trials in first-line treatment of advanced or metastatic NSCLC with nivolumab and pembrolizumab have shown promising and also controversial results. The FDA has approved pembrolizumab as a first-line treatment for patients with NSCLC whose tumours express PD-L1 in more than 50% cells based on Keynote-024 trial.1 This high PD-L1 presence is only observed on about 30% of patients with NSCLC, limiting the use of the newly approved drug in less than one-third newly diagnosed patients. The results of nivolumab activity, in Checkmate-26 study, compared with chemotherapy were disappointing.2 We are still trying to understand the possible reasons for the disappointing progression-free survival (PFS) data and trying to find out how to improve survival with first-line immunotherapy. Either combination with chemotherapy, …