6P - Circulating low-density neutrophils (LDNs) are associated with resistance to immunotherapy as frontline treatment for non-small cell lung cancer (NSCLC): Updated results and proteomic characterization

Background

Immune checkpoint inhibitors (ICI) have become positioned as frontline treatments for NSCLC when tumour PD-L1 expression is > 50%. However, no accurate biomarkers have been discovered yet. Our group found an association between the expansion of circulating LDNs (>7.09%), an immunosuppressive myeloid subpopulation, and resistance to ICI monotherapy. We present the updated results of the extended cohort, as well as the comparison between LDNs and conventional neutrophils (CN) by quantitative proteomics.

Methods

A total of 45 patients with NSCLC receiving ICI monotherapy were recruited. Peripheral blood mononuclear cells (PBMCs) were purified from fresh blood by Ficoll gradient. Baseline LDNs were quantified by flow cytometry (CD66b+, CD116+). The association between LDNs and outcomes was evaluated. LDNs and CN were isolated using CD15 magnetic beads and compared using quantitative proteomics.

Results

LDNs above 7.09% were found in 45% of patients. A weak although significant correlation between LDNs and neutrophils quantified by conventional blood test was observed (r=0.236, p=0.002). A trend towards higher LDNs was detected in patients with adverse prognostic scores including LIPI and GRIm. High LDNs were associated with lower ORR, (13.6% vs 57.1%, p=0.003), lower disease control at 6 months (18.1% vs 85.7%, p<0.001) and higher incidence of fast progressive disease (death within 12 weeks), 85% vs 21% (p=0.003), shorter mPFS (21.8 mo vs 1.4 mo, p < 0.001) and shorter mOS (28.1 mo vs 3.8 mo, p=0.002). A total of 178 proteins were upregulated and 187 downregulated. LDNs exhibited a distinct proteomic profile compared with CN, upregulating genes associated with immune-suppressive activities (MMRN1, SHP1, KHSRP), neutrophil extracellular traps (NET) production (FLNA9, PF4, H1-1), survival (WDR1, CSRP1), mitochondrial metabolism and chemotaxis (CORO1A, ERM family, HMGB2, MYO9, TLN1, THBS1).

Conclusions

High baseline LDNs are associated with resistance to ICI monotherapy in patients with NSCLC. LDNs have specific characteristics compared with CN, upregulating cell functions including survival, cell migration and immunosuppression.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Navarrabiomed-Fundación Miguel Servet.

Funding

SEOM grant for translational research projects in immuno-oncology.

Disclosure

N. Castro Unanua: Financial Interests, Personal, Invited Speaker: Pierre Fabre, Roche; Financial Interests, Personal, Other, Traveling/accommodation expenses: Lilly, Roche, Pierre Fabre, MSD, Merck, Pfizer, BMS. M. Martínez-Aguillo: Financial Interests, Advisory Board: Pfizer, Boehringer Ingelheim. A. Lecumberri: Financial Interests, Personal, Invited Speaker: Pierre Fabre; Other, Travel, accommodation and registration support to attend conferences or workshops: Pierre Fabre, Merck, Lilly, PharmaMar; Other, Registration support to attend conferences or workshops: GSK, Advanced Accelerator Applications, Merck, Sharp & Dohme (MSD), Pfizer. M. Alsina Maqueda: Financial Interests, Personal, Advisory Board: MSD, BMS, AstraZeneca, BeiGene; Non-Financial Interests, Principal Investigator, Investigator initiated trial: Merck Serono. R. Vera: Financial Interests, Advisory Board: Servier, Roche, MSD; Financial Interests, Invited Speaker: Amgen, MSD, AstraZeneca, Roche. H. Arasanz: Financial Interests, Advisory Board: AstraZeneca; Financial Interests, Coordinating PI: Ferrer Farma; Financial Interests, Invited Speaker: Takeda; Financial Interests, Other, Traveling/accommodation expenses: Angelini, BMS, MSD, Roche, Takeda. All other authors have declared no conflicts of interest.