# Project 1

> **NIH NIH P20** · WAYNE STATE UNIVERSITY · 2024 · $244,657

## Abstract

PROJECT SUMMARY/ABSTRACT
For multiple subtypes of breast cancer, Black patients endure poorer outcomes than White patients. There are
many contributing factors, including socioeconomic inequality, stage at diagnosis, and access to quality care. In
addition, there may be biologic, genetic drivers that disproportionally affect Black patients. Black patients with
HER2+ breast cancer have lower response rates and experience higher off-target toxicities than their white
counterparts, even when stage and age at diagnosis are considered. Trastuzumab is a monoclonal antibody
(mAb) designed to bind the HER2 receptor and block growth factor signaling, and the mAb Fc region is also able
to engage innate effector immune cells through Fc receptors. Due to this immune involvement, trastuzumab and
similar TAA-binding mAbs are classified as targeted immunotherapies (ITx). Importantly, patients who develop
endogenous anti-tumor immunity after targeted ITx have a predilection for improved long-term benefit, but it
remains unclear what mechanisms regulate durable response. Our preliminary data in a novel genetically diverse
mouse model support the hypothesis that host genetic background influences endogenous immune priming after
anti-HER2/neu targeted ITx. Importantly, in our model all mice receive genetically identical tumors, which
controls for tumor heterogeneity. Genetic linkage analysis in these mice pinpoints specific genomic loci that are
associated with treatment outcomes. The leading candidate locus was validated, and mechanistic studies
identified differences in the efficiency of macrophages to conduct antibody-dependent phagocytosis (ADCP).
These results suggest that host genetics, and potentially genetic ancestry, may regulate the method by which
macrophages engulf, process, and/or present tumor antigens to T cells. ADCP and other genetically-regulated
immune mechanisms may contribute to the biologic underpinnings of healthcare disparities in immuno-oncology.
We have assembled a team of population scientists and tumor immunologists to investigate this hypothesis using
patient samples collected in Detroit. We will utilize cutting-edge spatial transcriptomics and imaging mass
cytometry technologies to characterize the immune landscape in 184 HER2+ breast cancer tumor sections from
patients (~50:50 Black:White) exhibiting response to or recurrence after trastuzumab neoadjuvant therapy. Aim
1 will evaluate immune infiltration patterns, which will be compared by race and association with therapeutic
outcomes. In Aim 2, single nucleotide polymorphisms (SNPs) associated with known immune genes and novel
candidate genes identified in our preclinical model will also be probed for correlation with trastuzumab response,
by race. Collectively, we strive to unveil biologic contributors to healthcare disparities in immuno-oncology, and
identify novel actionable genes/pathways to improve targeted ITx outcomes, in addition to key biomarkers to
guide clinical decision-m...

## Key facts

- **NIH application ID:** 10879549
- **Project number:** 1P20CA290450-01
- **Recipient organization:** WAYNE STATE UNIVERSITY
- **Principal Investigator:** Heather Marie Gibson
- **Activity code:** P20 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $244,657
- **Award type:** 1
- **Project period:** 2024-09-05 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10879549

## Citation

> US National Institutes of Health, RePORTER application 10879549, Project 1 (1P20CA290450-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10879549. Licensed CC0.

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