Efficacy and safety of immune checkpoint inhibitor nivolumab and radiotherapy combination in advanced NSCLC

Abstract

In the last decade the discovery of immune checkpoint inhibitors such as PD-1 inhibitor Nivolumab had revolutionized the treatment of advanced NSCLC. The combination with radiotherapy is of particular interest, due to some preliminary observations reporting additive o synergist effect in some tumors. The purpose of this study was to retrospectively evaluate the role of radiotherapy on the effect of an immune checkpoint inhibitor (Nivolumab) in terms of activity and toxicity in pretreated locally advanced or metastatic lung cancer patients. From March 2015 to December 2016, 35 consecutive patients (15 men and 5 women) received Nivolumab for a advanced NSCLC. Fifteen received an hypofractionated radiotherapy as palliative measure, and in these patients Nivolumab was administered at least one week from radiotherapy end. The median age was 69 years, 23 patients (65.7%) had an ECOG score 0-1. All patients had received, previously at least one systemic regimen, for only 3 (8.6%), nivolumab was a third treatment line. The two groups of treatment (radiotherapy-nivolumab and nivolumab alone) were well matched for baseline characteristics. At a median follow-up of 7.4 months, the 1-year overall survival rates were 57.8% for patients treated with radiotherapy-Nivolumab and 27.4% for patients treated with Nivolumab alone (p=0.043). The 1 year progression free survival was 57.8% in the radiotherapy-nivolumab group and 20.6% in the Nivolumab alone group (p=0.040). No difference in adverse event was detected. In conclusion, radiotherapy and Nivolumab can be combined in advanced, pretreated NSCLC patients, with potential benefit in overall survival and progression free survival, without significant increase in acute toxicities. Prospective studies are needed to confirm these results.