Immunotherapeutic Agents in Non-small-cell Lung Cancer Finally Coming to the Front Lines

Non-small-cell lung cancer usually carries a dismal prognosis. Novel treatment approaches are clearly warranted. Immunotherapy has emerged as a promising area of research developing agents that manipulate the immune system to induce antitumor responses while avoiding major toxicity. New vaccines and checkpoint inhibitors are currently undergoing investigation in phase II and phase III clinical trials. In advanced non-small-cell lung cancer (NSCLC), belagenpumatucel-L, an allogeneic cell vaccine directed against transforming growth factor beta in the tumor microenvironment, knocks down the immune suppression caused by the tumor and has demonstrated a doseand time-dependent efficacy in some subgroups of patients. L-BLP25 and TG4010 are both antigenic vaccines that target mucin 1, whose encoding proto-oncogene is commonly mutated in solid tumors. The L-BLP25 vaccine achieved a significant improvement in overall survival in the subgroup of patients with stage IIIB NSCLC treated with chemoradiotherapy. TG4010 vaccination resulted in better progression-free survival when added to cisplatin-gemcitabine chemotherapy. These results are being addressed in the currently ongoing phase III TIME trial. In the adjuvant setting, MAGE-A3, an antigen-based vaccine, showed promising results in melanoma-associated antigen A3 positive lung cancer patients who underwent resection in the phase II study; however, no improvement in progressionfree survival was observed in the phase III MAGRIT study. CIMAVax is a recombinant human epidermal growth factor (EGF) vaccine that induces anti-EGF antibody production and prevents EGF from binding to its receptor. It has improved overall survival in patients with advanced NSCLC who achieve seroconversion. Ipilimumab, an immune checkpoint inhibitor that targets cytotoxic T-lymphocyte antigen 4, demonstrated improved progression-free survival in advanced NSCLC patients who received the drug after chemotherapy in a phased regimen. Finally, anti-programmed death receptor 1 agents have achieved durable response rates in phase I studies. This review gives an overview of the current data and the most promissory immunotherapeutic agents for NSCLC.