Immune checkpoint inhibitors for non-small cell lung cancer – review
The aim of this review was to evaluate the efficacy of immune checkpoint inhibitors (ICIs) for non-small cell lung cancer (NSCLC). NSCLC is the most common lung malignancy (85% of all lung cancers) and has a poor prognosis. Though chemotherapy is an effective therapeutic option, factors such as drug resistance, drug toxicity, and adverse side-effects cause poor response rate and ~10-20% survival within 2 years in metastatic NSCLC patients. The efficacy of ICIs in NSCLC has been widely studied as an alternative treatment option. This review discusses the role of ICIs in tumorigenesis, recent clinical trials, clinically available ICIs, including their efficacy, toxicity, and application as a single agent and in combination with other agents. Currently, ICIs such as Nivolumab and Pembrolizumab have been approved as effective therapeutic options for NSCLC. Durable response rate, improved overall survival, and tolerable safety profiles have been recorded in clinical trials for these ICIs. Combination treatments with ICIs such as Nivolumab + Ipilimumab and Durvalumab + Tremelimumab have been shown in clinical trials to provide better safety and efficacy profiles than single ICI treatment. However, further research is required to study different ICI combination therapies in treating metastatic NSCLC and variations in efficacy among smokers and non-smokers. It is recommended that future research should consider combination therapy with other conventional therapies including chemotherapy, radiotherapy, and personalized targeted therapy; the efficacy of ICIs for early-stage cancer; and identification of predictive biomarkers.