Combination Therapy With Reovirus and Anti-PD-1 Blockade Controls Tumor Growth Through Innate and Adaptive Immune Responses.
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Embargo End Date
ICR Authors
Authors
Rajani, K
Parrish, C
Kottke, T
Thompson, J
Zaidi, S
Ilett, L
Shim, KG
Diaz, R-M
Pandha, H
Harrington, K
Coffey, M
Melcher, A
Vile, R
Parrish, C
Kottke, T
Thompson, J
Zaidi, S
Ilett, L
Shim, KG
Diaz, R-M
Pandha, H
Harrington, K
Coffey, M
Melcher, A
Vile, R
Document Type
Journal Article
Date
2016-01-01
Date Accepted
2015-08-23
Abstract
Oncolytic reovirus can be delivered both systemically and intratumorally, in both preclinical models and in early phase clinical trials. Reovirus has direct oncolytic activity against a variety of tumor types and antitumor activity is directly associated with immune activation by virus replication in tumors. Immune mechanisms of therapy include both innate immune activation against virally infected tumor cells, and the generation of adaptive antitumor immune responses as a result of in vivo priming against tumor-associated antigens. We tested the combination of local oncolytic reovirus therapy with systemic immune checkpoint inhibition. We show that treatment of subcutaneous B16 melanomas with a combination of intravenous (i.v.) anti-PD-1 antibody and intratumoral (i.t.) reovirus significantly enhanced survival of mice compared to i.t. reovirus (P < 0.01) or anti-PD-1 therapy alone. In vitro immune analysis demonstrated that checkpoint inhibition improved the ability of NK cells to kill reovirus-infected tumor cells, reduced T(reg) activity, and increased the adaptive CD8(+) T-cell-dependent antitumor T-cell response. PD-1 blockade also enhanced the antiviral immune response but through effector mechanisms which overlapped with but also differed from those affecting the antitumor response. Therefore, combination with checkpoint inhibition represents a readily translatable next step in the clinical development of reovirus viroimmunotherapy.
Citation
Molecular therapy : the journal of the American Society of Gene Therapy, 2016, 24 (1), pp. 166 - 174
Source Title
Publisher
CELL PRESS
ISSN
1525-0016
eISSN
1525-0024
Research Team
Targeted Therapy
Translational Immunotherapy
Translational Immunotherapy