Abstract 1669: Immunometabolism of circulating neutrophils in hyperprogressive disease (HPD) upon first-line PD-1/PD-L1 inhibitors (ICI) alone or in combination with platinum-based chemotherapy (PCT) in non-small cell lung cancer (NSCLC) patients (pts)
Authors: Ferrara Roberto , Jachetti Elena , Calareso Giuseppina , Brambilla Marta , Lo Russo Giuseppe , Proto Claudia , Prelaj Arsela , Signorelli Diego , Galli Giulia , De Toma Alessandro , Occhipinti Mario , Manglaviti Sara , Labianca Alice , Ganzinelli Monica , Spanò Sestina Maria , Molino Giuliano , Martinetti Antonia , Greco Francesca Gabriella , Bini Marta , Beninato Teresa , de Braud Filippo , Colombo Mario Paolo , Garassino Marina Chiara , Sangaletti Sabrina 
Published: July 2021

Abstract
Background: HPD has been described in 14-26% of NSCLC pts upon single agent ICI and correlates with poor survival. Currently, HPD occurrence has not been explored upon ICI-PCT and biomarkers of HPD are lacking. Although high circulating neutrophils (Ns) correlated with HPD in NSCLC pts, the role of specific Ns subsets is unknown.
Methods: NSCLC pts treated with 1st line ICI as single agent or in combination with PCT were assessed for HPD and circulating Ns' phenotype. Tumor response was evaluated by RECIST 1.1. HPD required 3 assessment (2 before ICI, 1 upon ICI) and was defined as delta tumor growth rate (TGR) (TGR upon ICI - TGR before ICI) &gt;50% and/or TGR ratio (TGR upon ICI/TGR before ICI) ≥2. Circulating low density Ns (LDNs) subtypes were assessed by flow cytometry (FC) on peripheral blood mononuclear cells (PBMCs). LDNs were defined as CD66b+CD15+ cells among CD11b+ PBMCs. Immature subtypes were defined as CD10- LDNs. Fatty acids (FA) (bodipy-palmitate) uptake was assessed by FC. T-cells of healthy donors were isolated and activated in vitro with CD3/CD28 beads in presence or not of pts' Ns to characterize their interplay.
Results: Of 63 NSCLC pts, 22% had PD-L1 on tumor cells ≥50%. In the ICI single agent cohort (N=46), PD and HPD occurred in 21 (41%) and 4 (9%) pts, respectively. Before ICI start, HPD pts had significantly higher median percentage (%) of circulating immature CD10- LDNs [43.5 (min 29.5; max 82.6) vs 10.3 (min 0.1; max 79.4), p=0.01] compared to PD pts. In the ICI-PCT cohort (N=17), PD occurred in 4 (23%) pts, no HPD was reported. 5 pts had baseline CD10- LDNs ≥ 43.5% (median % of CD10- LDNs in HPD pts upon single agent ICI), 2 of them had SD and 3 PD upon ICI-PCT. In these 5 pts, CD10- LDNs significantly decreased during ICI-PCT compared to what observed in HPD pts during single agent ICI [median variation -43.4 (min -67.6, max -31.6) vs +6.9 (min -33, max +44), p= 0.03]. CD10- LDNs did not impair T-cells proliferation and IFNγ production, measured after 7 days of coculture but significantly reduced T-cell survival compared to CD10+LDNs. Baseline metabolic profile assessment showed that immature CD10- LDNs had a predominant lipid metabolism with a higher FA uptake [bodipy-palmitate mean florescence intensity (MFI) ± standard deviation (SD): 46754±11562] compared to lymphocytes [bodipy-palmitate MFI ±SD: 11542±405].
Conclusion: Higher baseline immature CD10- LDNs is a circulating biomarker of HPD upon single agent ICI. The addition of PCT prevents HPD reducing the immature Ns subset. The FA metabolism of immature LDNs does not affect T-cells proliferation/activation but reduces T-cells survival, suggesting that these two processes are differently regulated and that immature Ns reduce T-cells life span by metabolic competition.
Citation Format: Roberto Ferrara, Elena Jachetti, Giuseppina Calareso, Marta Brambilla, Giuseppe Lo Russo, Claudia Proto, Arsela Prelaj, Diego Signorelli, Giulia Galli, Alessandro De Toma, Mario Occhipinti, Sara Manglaviti, Alice Labianca, Monica Ganzinelli, Sestina Maria Spanò, Giuliano Molino, Antonia Martinetti, Francesca Gabriella Greco, Marta Bini, Teresa Beninato, Filippo de Braud, Mario Paolo Colombo, Marina Chiara Garassino, Sabrina Sangaletti. Immunometabolism of circulating neutrophils in hyperprogressive disease (HPD) upon first-line PD-1/PD-L1 inhibitors (ICI) alone or in combination with platinum-based chemotherapy (PCT) in non-small cell lung cancer (NSCLC) patients (pts) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1669.