High-Density of FcγRIIIA+ (CD16+) Tumor-Associated Neutrophils in Metastases Improves the Therapeutic Response of Cetuximab in Metastatic Colorectal Cancer Patients, Independently of the HLA-E/CD94-NKG2A Axis.

Marie Denis Musquer,François-Xavier Caroli Bosc,Céline Bossard,Morgane Pere,Nicolas Jouand,Nadine Gervois,Tamara Matysiak,Juliette Eugène Lamer,Jean-François Mosnier,Marie-Christine Rousselet,Roger Faroux,Stéphane Bézieau,François Leclair,Claire Toquet

doi:10.3389/fonc.2021.684478

Abstract

Antibody-dependent cellular cytotoxicity (ADCC) in the anti-tumor effect of cetuximab in metastatic colorectal cancer (mCRC) is only based on the impact of FcγRIIIA (CD16) polymorphisms as predictive of therapeutic response. However, nature, density and therapeutic impact of FcγRIIIA+ (CD16) effector cells in tumor remain poorly documented. Moreover, the inhibition of cetuximab-mediated ADCC induced by NK cells by the engagement of the new inhibitory CD94-NKG2A immune checkpoint has only been demonstrated in vitro. This multicentric study aimed to determine, on paired primary and metastatic tissue samples from a cohort of mCRC patients treated with cetuximab: 1) the nature and density of FcγRIIIA+ (CD16) immune cells, 2) the expression profile of HLA-E/β2m by tumor cells as well as the density of CD94+ immune cells and 3) their impact on both objective response to cetuximab and survival. We demonstrated that FcγRIIIA+ (CD16) intraepithelial immune cells mainly correspond to tumor-associated neutrophils (TAN), and their high density in metastases was significantly associated with a better response to cetuximab, independently of the expression of the CD94/NKG2A inhibitory immune checkpoint. However, HLA-E/β2m, preferentially overexpressed in metastases compared with primary tumors and associated with CD94+ tumor infiltrating lymphocytes (TILs), was associated with a poor overall survival. Altogether, these results strongly support the use of bispecific antibodies directed against both EGFR and FcγRIIIA (CD16) in mCRC patients, to boost cetuximab-mediated ADCC in RAS wild-type mCRC patients. The preferential overexpression of HLA-E/β2m in metastases, associated with CD94+ TILs and responsible for a poor prognosis, provides convincing arguments to inhibit this new immune checkpoint with monalizumab, a humanized anti-NKG2A antibody, in combination with anti- FcγRIIIA/EGFR bispecific antibodies as a promising therapeutic perspective in RAS wild-type mCRC patients.

Highlights

The introduction of targeted therapies, especially monoclonal antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, a human-mouse chimeric IgG1 antibody, in the treatment of patients with metastatic colorectal cancer, has led to a consistent improvement in survival
These results prompted us to address for the first time in a cohort of RAS wild-type metastatic colorectal cancer (mCRC) patients treated with cetuximab, on paired primary and metastatic tissue samples: 1) the nature and density of FcgRIIIA+ (CD16) immune cells, 2) the expression profile of human leucocyte antigen E (HLA-E)/b2m by tumor cells as well as the density of intra-tumor CD94+ immune cells and 3) their impact on both objective response to cetuximab and overall survival
We demonstrated for the first time, in wild-type RAS mCRC patients, a significant relationship between the density of FcgRIIIa+ (FcgRIIIA+ (CD16) intraepithelial TAN in close contact with tumor cells in metastases and the objective response to cetuximab

Summary

INTRODUCTION

The introduction of targeted therapies, especially monoclonal antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, a human-mouse chimeric IgG1 antibody, in the treatment of patients with metastatic colorectal cancer (mCRC), has led to a consistent improvement in survival. The CD94/NKG2A receptor, recently considered as a new inhibitory immune checkpoint that blocks the terminal cytolytic tumor-attack in the tumor microenvironment, can be blocked by the anti-NKG2A antibody, monalizumab, a therapy associated with promising clinical responses in gynecologic and head and neck refractory cancers [12] These results prompted us to address for the first time in a cohort of RAS wild-type mCRC patients treated with cetuximab, on paired primary and metastatic tissue samples: 1) the nature and density of FcgRIIIA+ (CD16) immune cells, 2) the expression profile of HLA-E/b2m by tumor cells as well as the density of intra-tumor CD94+ immune cells and 3) their impact on both objective response to cetuximab and overall survival.

RESULTS

DISCUSSION

ETHICS STATEMENT