Immunological markers for predicting the response to immunotherapy in non-small cell lung cancer

Itroduction. Immune checkpoint inhibitors have become the standard of care for patients with advanced non-small cell lung cancer. However, despite the determination of programmed death-ligand 1 expression in clinical practice, which determines the effectiveness of therapy, up to 80 % of patients with non-small cell lung cancer do not respond to treatment.

The study objective – investigation of the prognostic role of clinical and immunological markers during immune checkpoint inhibitor monotherapy in ≥2 lines in patients with advanced non-small cell lung cancer.

Materials and methods. The study included 45 patients with advanced non-small cell lung cancer receiving programmed cell death 1 / programmed death-ligand 1 inhibitors in monotherapy in 2 and subsequent lines (Group 1), as well as 30 patients with advanced non-small cell lung cancer receiving first-line chemotherapy (Group 2). All patients from 2 groups did not have autoimmune diseases before starting treatment. The determination of autoantibodies, β-2-microglobulin, neopterin, interleukin 6, interleukin 18 and the allelic variant of HLA-DRB1 in patients in the Group 1 was carried out 2 months after the start of therapy, and in the Group 2 – before the start of the next chemotherapy cycle.

Results. In Group 1, the presence of EGFR / ALK mutations is an independent predictor of shorter progression-free survival (p = 0.018). Also, in the univariate analysis, neutrophil-lymphocyte ratio <5 before immune checkpoint inhibitors (p = 0.009) and the appearance of immune-related adverse events (p = 0.038) are associated with long-term progressionfree survival. In Group 1, β-2-microglobulin was lower in patients with a response duration of ≥6 months than with a progression <6 months: 1.7 mg / L and 2.9 mg / L, respectively (p <0.0001). Patients receiving immune checkpoint inhibitors with a β-2-microglobulin level ≥2.5 mg / L have a shorter progression-free survival than patients with a marker value <2.5 mg / L: 168 days and the value is not reached, respectively (p = 0.017). In response duration ≥6 months neopterin value was lower than in disease progression: 8.6 nmol / l and 13.4 nmol / L, respectively (p <0,0001). Progression-free survival was lower in patients with neopterin ≥12 nmol / L than patients with neopterin <12 nmol / L: median was 164 days and the value was not reached, respectively (p = 0.0007). Based on the results of multivariate analysis, β-2-microglobulin ≥2.5 mg / L (p = 0.006) and neopterin ≥12 nmol / L (p = 0.027) were independent predictors of shorter progression-free survival. Low levels of interleukin 6 and interleukin 18, as well as antibodies to thyroperoxidase, are associated with a response of ≥6 months. HLA-DRB1*03 was associated with a duration of response of ≥6 months, as well as a longer progression-free survival compared with other allelic variants. The levels of β-2-microglobulin, neopterin, interleukin 6, interleukin 18 were higher in patients in Group 1 than in patients in Group 2 (p <0.0001).

Conclusion. Immunological markers can serve as promising prognosis markers in patients with advanced non-small cell lung cancer during immunotherapy.