Abstract 4480: Circulating and tumor associated neutrophil subtypes correlate with hyperprogressive disease (HPD) upon immunecheckpoint inhibitors (ICI) in advanced non-small cell lung cancer (aNSCLC) patients (pts) and in vivo models
Authors: Ferrara Roberto , Proto Claudia , Lo Russo Giuseppe , Signorelli Diego , Prelaj Arsela , Galli Giulia , Zilembo Nicoletta , De Toma Alessandro , Viscardi Giuseppe , Lobefaro Riccardo , Brambilla Marta , Ganzinelli Monica , Molino Giuliano , Talarico Giovanna , Garassino Marina Chiara , Colombo Mario , Sangaletti Sabina 
Published: September 2020

Abstract
Background: HPD was described in ≃10-25% of NSCLC pts upon single-agent ICI and correlated with poor prognosis. High circulating neutrophil count and neutrophils/lymphocytes ratio were associated with shorter survival and HPD in aNSCLC pts. In mouse lung cancer models, interleukin-17 (IL-17) promoted tumor growth upon ICI through increased intratumoral neutrophils. The role of specific circulating and/or tumor-associated neutrophil populations in driving HPD is unknown.
Methods: aNSCLC pts treated with ICI and enrolled in a prospective monocentric study were assessed for HPD and circulating neutrophils' phenotype. HPD required 3 tumor measurements (2 before ICI, 1 upon ICI) and was defined as delta tumor growth rate (TGR) TGR (TGR upon ICI - TGR before ICI) &gt;50% and/or TGR ratio (TGR upon ICI/ TGR before ICI) ≥2. Survival curves were estimated by Kaplan Meier and compared by log-rank, correlations with categorical/continuous variables were performed by Fisher/Mann-Whitney tests. The phenotype of circulating low density neutrophils (LDNs) was assessed by flow cytometry (FC) on peripheral blood mononuclear cells from fresh blood samples. Mature and immature LDNs were defined according to the expression of CD10 on CD66b+CD15+ cells, being immature the CD10− neutrophil population. The capacity of immune competent mice to undergo HPD upon anti-PD-1 treatment was further tested in C57BL/6 mice bearing Lewis Lung Carcinoma and treated with anti-murine PD-1. Tumor associated neutrophils' phenotype was assessed by FC analysis.
Results: Of 46 aNSCLC, 85% were &gt;65 years, 72% had adenocarcinoma histology, 89% stage IV, 22% had PD-L1 on tumor cells ≥50%, 72% received 1st line ICI. 19 (41%) pts had progression (PD) by RECIST, 4 (9%) pts were HPD by TGR ratio and/or delta-TGR. HPD [4.1 (95% CI 3.1-5) months] correlated with poorer median overall survival compared to non-HPD [6.9 (95% CI 6.1-7.8) months, p=0.03] and to PD pts [4.7 (95% CI 3.2-6.1) months, p=0.8]. Before ICI initiation, the median percentage of circulating immature CD10− CD15+ CD66b+ LDNs was significantly higher in HPD [36.6 (min 29.2; max 64.5)] compared to both non-HPD [8.9 (min 0; max 70.4); p=0.01] and PD non-HPD pts [10.1 (min 0; max 70.4), p=0.04]. HPD defined by TGR ratio and/or delta-TGR occurred in 3 (12.5%) out of 24 immune competent mice treated with anti-murine PD-1. The mean of Gr1highLy6Clow IL-17+ tumor associated neutrophils was significantly higher in HPD compared to non-HPD mice [0.25 (min 0.14; max 0.63) vs 0.06 (min 0.02; max 0.32), p=0.03].
Conclusions: Circulating immature CD10− LDNs and tumor associated IL-17+ neutrophils correlate with HPD upon ICI in aNSCLC pts and in vivo models, respectively. Characterization of neutrophils' functional properties in HPD pts and in vivo models is currently ongoing.
Citation Format: Roberto Ferrara, Claudia Proto, Giuseppe Lo Russo, Diego Signorelli, Arsela Prelaj, Giulia Galli, Nicoletta Zilembo, Alessandro De Toma, Giuseppe Viscardi, Riccardo Lobefaro, Marta Brambilla, Monica Ganzinelli, Giuliano Molino, Giovanna Talarico, Marina Chiara Garassino, Mario Colombo, Sabina Sangaletti. Circulating and tumor associated neutrophil subtypes correlate with hyperprogressive disease (HPD) upon immunecheckpoint inhibitors (ICI) in advanced non-small cell lung cancer (aNSCLC) patients (pts) and in vivo models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4480.