RT Journal Article
SR Electronic
T1 A novel antibody targeting ICOS increases intratumoural cytotoxic to regulatory T cell ratio and induces tumour regression
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 771493
DO 10.1101/771493
A1 Richard C.A. Sainson
A1 Anil K. Thotakura
A1 Miha Kosmac
A1 Gwenoline Borhis
A1 Nahida Parveen
A1 Rachael Kimber
A1 Joana Carvalho
A1 Simon Henderson
A1 Kerstin Pryke
A1 Tracey Okell
A1 Siobhan O’Leary
A1 Stuart Ball
A1 Lauriane Gamand
A1 Emma Taggart
A1 Eleanor Pring
A1 Hanif Ali
A1 Hannah Craig
A1 Vivian W. Y. Wong
A1 Qi Liang
A1 Robert J. Rowlands
A1 Morgane Lecointre
A1 Jamie Campbell
A1 Ian Kirby
A1 David Melvin
A1 Volker Germaschewski
A1 Elisabeth Oelmann
A1 Sonia Quaratino
A1 Matthew McCourt
YR 2019
UL http://biorxiv.org/content/early/2019/09/16/771493.abstract
AB The immunosuppressive tumour microenvironment constitutes a significant hurdle to the response to immune checkpoint inhibitors. Both soluble factors and specialised immune cells such as regulatory T cells (TReg) are key components of active intratumoural immunosuppression. Previous studies have shown that Inducible Co-Stimulatory receptor (ICOS) is highly expressed in the tumour microenvironment, especially on TReg, suggesting that it represents a relevant target for preferential depletion of these cells. Here, we used immune profiling of samples from tumour bearing mice and cancer patients to characterise the expression of ICOS in different tissues and solid tumours. By immunizing an Icos knockout transgenic mouse line expressing antibodies with human variable domains, we selected a fully human IgG1 antibody called KY1044 that binds ICOS from different species. Using KY1044, we demonstrated that we can exploit the differential expression of ICOS on T cell subtypes to modify the tumour microenvironment and thereby improve the anti-tumour immune response. We showed that KY1044 induces sustained depletion of ICOShigh TReg cells in mouse tumours and depletion of ICOShigh T cells in the blood of non-human primates, but was also associated with secretion of pro-inflammatory cytokines from ICOSlow TEFF cells. Altogether, KY1044 improved the intratumoural TEFF:TReg ratio and increased activation of TEFF cells, resulting in monotherapy efficacy or in synergistic combinatorial efficacy when administered with the immune checkpoint blocker anti-PD-L1. In summary, our data demonstrate that targeting ICOS with KY1044 can favourably alter the intratumoural immune contexture, promoting an anti-tumour response.