# [18F]-AraG -PET imaging to evaluate immunological response to checkpoint inhibitor therapy (CKI) in patients with advanced solid tumors

> **NIH NIH R01** · OREGON HEALTH & SCIENCE UNIVERSITY · 2024 · $1

## Abstract

Contact PD/PI: Kummar, Shivaani
PROJECT SUMMARY/ABSTRACT
Immunotherapy, specifically checkpoint inhibitor (CKI) therapy, has resulted in dramatic and
sustained tumor responses in patients with a variety of advanced cancers, such as melanoma,
non-small cell lung cancer, head and neck cancer and others. However, only a subset of patients
with advanced solid tumors derive clinical benefit, and of those a substantial portion progress over
time. The ability to better select patients likely to respond to CKI therapy would optimize delivery;
and reduce the number of patients exposed to agents not likely to work on their disease. There
are multiple ongoing efforts focusing on blood or tissue based biomarkers; and number of immune
cells, especially T cells, in the tumor lesions has correlated with tumor response to CKI treatment.
However, it remains difficult and risky to biopsy solid tumor lesions repeatedly in a given patient.
Since imaging can be safely performed at multiple time points, and multiple disease sites can be
assessed simultaneously, it presents an attractive strategy for patient selection. [18F]F-AraG, a
18F-labeled analog of arabinofuranosylguanine (AraG), has been shown to be selectively taken
up by T cells in laboratory models and in initial human studies. We hypothesize that [18F]F-AraG
signal will increase in patients who develop T-cell immune responses in tumor following CKI
therapy, and this will correlate with subsequent clinical benefit. In aim 1, we will correlate changes
in [18F]F-AraG signal to number of T cells in tumor biopsies obtained pre and post-treatment with
CKI. In our second aim, we will correlate the change in [18F]F-AraG signal following treatment to
observed clinical benefit, defined as either tumor stabilization or shrinkage. In the third aim,
correlate change in [18F]-AraG signal in lung and GI tract with the subsequent occurrence of higher
grade immune related adverse events. Data generated from the proposed study will inform
development of a novel imaging biomarker of response to immunotherapies, optimizing patient
selection and outcome. In addition, our ability to predict which patients will go on to develop more
severe toxicities will inform institution of therapies earlier to mitigate these side effects, as well as
personalize management of adverse events.

## Key facts

- **NIH application ID:** 10380906
- **Project number:** 5R01CA240638-03
- **Recipient organization:** OREGON HEALTH & SCIENCE UNIVERSITY
- **Principal Investigator:** Shivaani Kummar
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $1
- **Award type:** 5
- **Project period:** 2021-04-01 → 2026-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10380906

## Citation

> US National Institutes of Health, RePORTER application 10380906, [18F]-AraG -PET imaging to evaluate immunological response to checkpoint inhibitor therapy (CKI) in patients with advanced solid tumors (5R01CA240638-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10380906. Licensed CC0.

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