Format

Send to

Choose Destination
Clin Cancer Res. 2019 Nov 1;25(21):6406-6416. doi: 10.1158/1078-0432.CCR-19-1259. Epub 2019 Aug 1.

Anti-OX40 Antibody Directly Enhances The Function of Tumor-Reactive CD8+ T Cells and Synergizes with PI3Kβ Inhibition in PTEN Loss Melanoma.

Author information

1
Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas. phwu@mdanderson.org Niranjan.x.yanamandra@gsk.com Wpeng2@central.uh.edu.
2
Department of Melanoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
3
Oncology R&D, Immuno-Oncology and Combinations RU, GlaxoSmithKline, Collegeville, Pennsylvania.
4
Department of Oncology Research for Biologics and Immunotherapy Translation Platform, The University of Texas MD Anderson Cancer Center, Houston, Texas.
5
Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas.
6
Oncology R&D, Immuno-Oncology and Combinations RU, GlaxoSmithKline, Collegeville, Pennsylvania. phwu@mdanderson.org Niranjan.x.yanamandra@gsk.com Wpeng2@central.uh.edu.

Abstract

PURPOSE:

OX40 agonist-based combinations are emerging as a novel avenue to improve the effectiveness of cancer immunotherapy. To better guide its clinical development, we characterized the role of the OX40 pathway in tumor-reactive immune cells. We also evaluated combining OX40 agonists with targeted therapy to combat resistance to cancer immunotherapy.Experimental Design: We utilized patient-derived tumor-infiltrating lymphocytes (TILs) and multiple preclinical models to determine the direct effect of anti-OX40 agonistic antibodies on tumor-reactive CD8+ T cells. We also evaluated the antitumor activity of an anti-OX40 antibody plus PI3Kβ inhibition in a transgenic murine melanoma model (Braf mutant, PTEN null), which spontaneously develops immunotherapy-resistant melanomas.

RESULTS:

We observed elevated expression of OX40 in tumor-reactive CD8+ TILs upon encountering tumors; activation of OX40 signaling enhanced their cytotoxic function. OX40 agonist antibody improved the antitumor activity of CD8+ T cells and the generation of tumor-specific T-cell memory in vivo. Furthermore, combining anti-OX40 with GSK2636771, a PI3Kβ-selective inhibitor, delayed tumor growth and extended the survival of mice with PTEN-null melanomas. This combination treatment did not increase the number of TILs, but it instead significantly enhanced proliferation of CD8+ TILs and elevated the serum levels of CCL4, CXCL10, and IFNγ, which are mainly produced by memory and/or effector T cells.

CONCLUSIONS:

These results highlight a critical role of OX40 activation in potentiating the effector function of tumor-reactive CD8+ T cells and suggest further evaluation of OX40 agonist-based combinations in patients with immune-resistant tumors.

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center