Journal
CLINICAL CANCER RESEARCH
Volume 25, Issue 21, Pages 6406-6416Publisher
AMER ASSOC CANCER RESEARCH
DOI: 10.1158/1078-0432.CCR-19-1259
Keywords
-
Categories
Funding
- NCI [R01CA187076, P50CA093459, T32CA009666-21, P30CA016672]
- Melanoma Research Alliance Young Investigator Award [558998]
- Dr. Miriam and Sheldon G. Adelson Medical Research Foundation
- Aim at Melanoma Foundation
- Cancer Prevention and Research Institute of Texas [RP140106, RP170067]
- Miriam and Jim Mulva Research Fund
Ask authors/readers for more resources
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 PI3K beta 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 PI3K beta-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 IFN gamma, 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.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available