# A novel CAR-T cell therapy for the one-time treatment of chronic HIV infection in patients who are not ART suppressed

> **NIH NIH R42** · MARPAM PHARMA, LLC · 2024 · $1,000,449

## Abstract

ABSTRACT
We aim to develop a one-time treatment for durable remission of human immunodeficiency virus (HIV) for
patients who are not suppressed by antiretroviral therapy (ART), including patients who are ART naïve or ART
non-compliant. Our treatment is an autologous HIV-specific chimeric antigen receptor (CAR)-T cell therapy that
employs the CXCR5 chemokine receptor as a homing device to direct anti-HIV killer T cells into immune-
protected “hidden” viral reservoirs in lymphoid B cell follicles, where most virus-producing cells are located during
chronic infections. Virus-specific CD8 T cells exert potent antiviral activity against HIV-1 and Simian
immunodeficiency virus (SIV), an animal model of HIV. Nevertheless, despite abundant CD8 T cell responses in
HIV-1-infected humans and SIV-infected macaques, these cells do not fully suppress virus replication, likely
because the majority of HIV-1 and SIV replication occurs in CD4+ T cells concentrated within B cell follicles in
secondary lymphoid tissues where few virus-specific CD8 T cells reside. In fact, we showed that the ratio of in
vivo effector virus-specific CD8 T cells to target SIV RNA+ cells is >40-fold lower inside compared to outside of
B cell follicles in lymphoid tissues in SIV-infected macaques. Furthermore, the majority of virus-specific CD8 T
cells fail to express the follicular homing molecule CXCR5, likely explaining low levels of virus-spcific CD8 T cells
localizing to and surveilling B cell follicles. These data suggest that the inability of HIV- and SIV-specific CD8 T
cells to fully suppress virus replication may be due to a deficiency of virus-specific CD8 T cells in B cell follicles.
As the vast majority of virus-producing cells are CD4 T cells located in secondary lymphoid tissue during chronic
HIV and SIV infections, we targeted lymphoid cells by autologously infusing anti-viral CAR (specifically
CAR/CXCR5) T cells into chronically SIV-infected rhesus macaques. The treated animals showed CAR/CXCR5-
T cell localization to B cell follicles and decreased virus replication in the follicles compared to control animals.
In addition, this product showed safety and efficacy in a pilot preclinical study of ART-suppressed SIV-infected
macaques. Based on these findings and the success of our preclinical studies in ART-suppressed macaques,
we propose to: (Phase 1, Aim 1) modify our current CAR/CXCR5 construct by producing and characterizing an
optimized (opt) CAR/CXCR5 construct that contains a tri-specific HIV binding domain, an alternate co-stimulatory
domain, and an HIV resistance domain; (Phase 2, Aim 2) develop a GMP-scalable method to produce CAR-T
cells using the optCAR/CXCR5 construct and PBMCs from a) SIV-infected non-ART-treated rhesus macaques
for use in an IND-enabling preclinical study; and b) HIV-infected non-ART treated individuals to prepare for the
first-in-human Phase 1 clinical trial; and (Phase 2, Aim 3) assess the safety and efficacy of CAR-T cells produced
with the...

## Key facts

- **NIH application ID:** 10948948
- **Project number:** 4R42AI167175-02
- **Recipient organization:** MARPAM PHARMA, LLC
- **Principal Investigator:** Maria Constance Athanasiou
- **Activity code:** R42 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $1,000,449
- **Award type:** 4N
- **Project period:** 2024-02-13 → 2026-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10948948

## Citation

> US National Institutes of Health, RePORTER application 10948948, A novel CAR-T cell therapy for the one-time treatment of chronic HIV infection in patients who are not ART suppressed (4R42AI167175-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10948948. Licensed CC0.

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