# The Study of Immune Effects in Gliomas Treated with Oncolytic Viruses in Combination with IDO Inhibitors

> **NIH NIH F31** · UNIVERSITY OF TX MD ANDERSON CAN CTR · 2020 · $33,010

## Abstract

Project Summary/Abstract
With current treatment options, the five year survival rate of patients with glioblastoma (GB) is only 5%. Thus,
different therapies should be developed. One promising alternative therapy is the use of the oncolytic virus,
Delta-24-RGD, which has resulted in complete responses in up to 15% of GB patients. Delta-24-RGD causes
death by cancer cell lysis and immunogenic cell death. Our preliminary data show that mice with GB can be
cured with treatment of the armed oncolytic adenoviruses, named Delta-24-RGDOX, which expresses immune
agonist, OX40L. The OX40 signaling pathway can enhance effector T-cell responses against cancer cells.
Conversely, the tumor microenvironment of GB can employ immunosuppressive and anergic mechanisms to
halt immune responses directed against the tumor. For example, the activation of indoleamine-2,3-dioxygenase
(IDO), which has been reported to be upregulated in GB, can activate immunosuppressive regulatory T-cells.
Thus, we hypothesize that the combination treatment of Delta-24-RGDOX and IDO inhibitors will
immunomodulate the tumor microenvironment towards a more cytotoxic and less immunosuppressive
nature and be effective in the treatment of GB. To test this hypothesis, we aim to 1) Compare the therapeutic
efficacy of using Delta-24-RGDOX with and without IDO inhibitors in murine GB and 2) Analyze the effectiveness
of Delta-24-RGDOX in combination with IDO inhibitors to overcome T-cell anergy in mouse models of GB.
Completing this study will provide a greater understanding of the immune tumor evasion mechanisms that occur
after treatment with Delta-24-RGDOX and/or IDO inhibitors leading to better therapeutic targets for GB.

## Key facts

- **NIH application ID:** 9850848
- **Project number:** 5F31CA228207-02
- **Recipient organization:** UNIVERSITY OF TX MD ANDERSON CAN CTR
- **Principal Investigator:** Teresa T Nguyen
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $33,010
- **Award type:** 5
- **Project period:** 2019-01-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9850848

## Citation

> US National Institutes of Health, RePORTER application 9850848, The Study of Immune Effects in Gliomas Treated with Oncolytic Viruses in Combination with IDO Inhibitors (5F31CA228207-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9850848. Licensed CC0.

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