Possible immunologic predictors of the PD-1/PD-L1 checkpoint inhibitors' efficiency in lung cancer patients.

Abstract

e21035 Background: Immunotherapy with PD-1/PD-L1 check-point inhibitors (CPI) is a new trend in oncology. Their effect significantly depends on the patients` immune status. The aim of the study was to search the immunologic parameters of lung cancer (LC) patients receiving immunotherapy as factors that could predict their effect. Methods: 20 patients (12 male and 8 female) with LC had adenocarcinoma – 15 (75%), squamous cell carcinoma – 5 (25%). PD-1/PD-L1 CPI were used: 9 patients received atezolizumab (43%), 9 (43%) – pembrolizumab and 3 (14%) – nivolumab. The effect of therapy was evaluated according to imRECIST v.1.1. Factors of cell-mediated immunity were assessed by flow cytometry before treatment including immunotherapy. CD8+CD279+, CD4+CD279+, TLR2, TLR4, TLR3, TLR8 were studied. Results: Complete response was observed in 2 (9%) patients, partial response in 5 (24%), stabilization in 4 (19%) and progression in 8 (38%). In one patient the treatment was cancelled due to the development of immune-mediated complication (Guillain-Barre syndrome). The factors studied varied depending on different effect. In cases of LC stabilization/progression the initial amount of CD8+CD279+ cells were twice lower than in cases with complete/partial response. In the first group CD8+CD279+ cells` level before the treatment was 0,1-3,4%, while in the other group 4,1-9% (7,0±1,16%). In patients with stabilization/progression CD4+CD279+ cells` level before the immunotherapy was 0,1-3,3 and in patients with response to treatment 1,4-7,8% (3,4±0,8%) of total CD4+ lymphocytes. Besides, the LC patients with different effect of treatment had different initial amount of CD4+ Tem cells: stable response to CPI developed in patients with their higher levels (40,8±3,9%) vs 15,3±3,9% in cases of tumor progression (p < 0.05). Initial high expression of TLR2 and TLR4 as well as low expression of TLR3 and TLR8 on monocytes in patients with response to immunotherapy suggests the contribution of innate immunity to its effect. Conclusions: Complete or partial response should be expected in cases of initially high per cent of T lymphocytes (CD4+, CD8+) CD4+ Tem cells and TLR2+, TLR4+ as well as low amount of TLR3+ and TLR8+ monocytes. These factors should be studied in future as predictive factors for effectiveness of CPI.