Anti-cancer activity of dose-fractioned mPE +/- bevacizumab regimen is paralleled by immune-modulation in advanced squamous NSLC patients

Background: Results from the BEVA2007 trial, suggest that the metronomic chemotherapy regimen with dose-fractioned cisplatin and oral etoposide (mPE) +/- bevacizumab, a monoclonal antibody to the vascular endothelial growth factor (VEGF), shows anti-angiogenic and immunological effects and is a safe and active treatment for metastatic non-small cell lung cancer (mNSCLC) patients. We carried out a retrospective analysis aimed to evaluate the antitumor effects of this treatment in a subset of patients with squamous histology. Methods: Retrospective analysis was carried out in a subset of 31 patients with squamous histology enrolled in the study between September 2007 and September 2015. All of the patients received chemotherapy with cisplatin (30 mg/sqm, days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE) and 14 of them also received bevacizumab 5 mg/kg on the day 3q21 (mPEBev regimen). Results: This treatment showed a disease control rate of 71% with a mean progression free survival (PFS) and overall survival (OS) of 13.6 and 17 months respectively. After 4 treatment courses, 6 patients showing a remarkable tumor shrinkage, underwent to radical surgery, attaining a significant advantage in term of survival (P=0.048). Kaplan-Meier and log-rank test identified the longest survival in patients presenting low baseline levels in neutrophil-to-lymphocyte ratio (NLR) (P=0.05), interleukin (IL) 17A (P=0.036), regulatory-T-cells (T_regs) (P=0.020), and activated CD83+ dendritic cells (DCs) (P=0.03). Conclusions: These results suggest that the mPE +/- bevacizumab regimen is feasible and should be tested in comparative trials in advanced squamous-NSCLC (sqNSCLC). Moreover, its immune-biological effects strongly suggest the investigation in sequential combinations with immune check-point inhibitors.