Targeting the PD-1/PD-L1 axis in non-small cell lung cancer

The last decade has witnessed rapid advances in the discovery and development of immune checkpoint inhibitors in cancer medicine, particularly drugs targeting programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC). The proven antitumor efficacy coupled with low rates of drug-related toxicities observed, albeit idiosyncratic, with these novel immunotherapeutics have led to the registration of multiple PD-1 and PD-L1 inhibitors, such as nivolumab, pembrolizumab, and atezolizumab, in second-line advanced NSCLC, whereas durvalumab and avelumab are in late-phase clinical testing. Moreover, pembrolizumab has shown a survival advantage in the first-line setting; however, nivolumab failed to show a survival benefit possibly relating to patient selection based on PD-L1 expression. Current patient selection is based on PD-L1 expression, using the relevant companion diagnostic test, where patients with strong PD-L1 expression being more likely to respond to these novel agents. Ongoing clinical research focuses on the development of PD-1 and PD-L1 inhibitor monotherapy in neoadjuvant and adjuvant NSCLC. There is also much interest in using these drugs as a therapeutic backbone for rational combinations with other treatment modalities including cytotoxic chemotherapies in the first-line NSCLC, other immunotherapies such as cytotoxic T-lymphocyte-associated protein 4 antagonists, molecularly targeted agents including EGFR and ALK inhibitors, and radiotherapy. Concurrent treatment with radiotherapy is of particular interest owing to the potential for the abscopal effect, using radiotherapy to facilitate systemic treatment.

Focus on Nivolumab in NSCLC

Immunotherapy is changing the treatment of non-small cell lung cancer (NSCLC). The PD-1 inhibitor nivolumab has demonstrated meaningful results in terms of efficacy with a good safety profile. The novel approach to treating NSCLC using immunotherapy still has unsolved questions and challenging issues. The main doubts regarding the optimal selection of the patient are the role of this drug in first line of treatment, the individualization of the correct methodology of radiologic assessment and efficacy analysis, the best management of immune-mediated adverse events, and how to overcome the immunoresistance. The aim of this review is to analyze literature data on nivolumab in lung cancer with a focus on critical aspects related to the drug in terms of safety, the use in clinical practice, and possible placement in the treatment algorithm.

Emerging challenges of advanced squamous cell lung cancer

Squamous cell lung cancer (SQCLC) is an aggressive type of lung cancer and most are diagnosed at advanced stage. Patients with advanced SQCLC tend to be older, current or former smoker, with central type tumour located near large blood vessels and seldom with druggable genetic alternations. Consequently, progress of targeted therapy and antivascular agents available in lung adenocarcinoma could not be duplicated in this subset of patients. The treatment paradigms have long been dominant by cytotoxic agents and posed many therapeutic challenges. Until recent years, immune checkpoint inhibitors, other monoclonal antibodies and afatinib have been approved for treatment of advanced SQCLC, presenting a novel treatment landscape and initiating the era of precision medicine in this subset of patients. This review will summarise the recent treatment progresses in advanced SQCLC with a focus on checkpoint inhibitors of programmed cell death-1 receptor or its ligand, and discuss the emerging challenges in this new era.