# CHIPP-PrEP: Cabotegravir-Hormone Interrogation of Pharmacokinetics/Pharmacodynamics for HIV Prevention in Cisgender and Transgender Persons

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2024 · $616,760

## Abstract

PROJECT SUMMARY____________________________________________________________________
The goal of CHIPP-PrEP: Cabotegravir-Hormone Interrogation of Pharmacokinetics/Pharmacodynamics for
HIV Prevention in Cisgender and Transgender Persons is to improve the medical care of transgender women
(TGW) and gender diverse persons assigned male at birth who are accessing estrogen-based gender affirming
hormone therapy (GAHT) through characterizing the relationship between GAHT and long-acting cabotegravir
(CAB-LA) for HIV pre-exposure prophylaxis (PrEP). A key strategy to improve the quality of life among
transgender and gender diverse (TGD) persons is the provision of gender affirming care, including GAHT.
However, a persistent concern among persons who access GAHT is the potential impact of other medications
on exogenous hormone regimens. HIV infection remains a public health priority, and TGW are
disproportionately affected by HIV, with a global prevalence of 19.9%. The HIV Prevention Trials Network
(HPTN) 083 trial showed that CAB-LA was more effective than emtricitabine/tenofovir disoproxil fumarate
(F/TDF) in preventing HIV in cisgender men and TGW who have sex with men. CAB-LA pharmacokinetics
(PK) were evaluated in a subset of TGW who reported or denied GAHT-use; while drug concentrations were
similar, steady state trough (Ctau-SS) CAB-LA concentrations were modestly higher among TGW who reported
GAHT use. Further, CAB-LA PK parameters, including absorption rate constant (Ka), are influenced by sex
assigned at birth, body mass index (BMI) and needle length (indicator of injection site fat distribution); of note,
CAB-LA maximal concentrations (Cmax-SS) are lower and Ctau-SS are higher in cisgender women as compared to
cisgender men, which may result in protective pharmacologic advantages in women. However, the impact of
GAHT on CAB-LA Ka among TGW and gender diverse persons assigned male at birth has not been evaluated,
and it is unknown if hormone concentrations or GAHT use are significant covariates on CAB-LA PK. Based
on the complex interactions of estrogens on body composition and fat distribution, absence of CAB-LA
pharmacologic correlates of protection, and the paucity of data detailing drug interactions between GAHT and
CAB-LA, additional data are needed to understand the PK and PD interactions between GAHT and CAB-LA for
an understudied and at-risk population. The proposed work will address these gaps through the following: a)
evaluation of the multi-compartment CAB-LA PK in cisgender persons and TGW and gender diverse persons
assigned male at birth who are on a stable regimen of estrogen-based GAHT; b) development of a CAB-LA
PK/PD model using ex vivo HIV susceptibility assays; and c) generation of a popPK model inclusive of PK and
PD data from TGW and gender diverse persons and subsequent simulations to evaluate the contribution of
estrogen-based GAHT on CAB-LA PK parameters. The proposed research provides a critical next step in our
underst...

## Key facts

- **NIH application ID:** 11002040
- **Project number:** 1R01AI186440-01
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Mark A Marzinke
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $616,760
- **Award type:** 1
- **Project period:** 2024-08-01 → 2029-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11002040

## Citation

> US National Institutes of Health, RePORTER application 11002040, CHIPP-PrEP: Cabotegravir-Hormone Interrogation of Pharmacokinetics/Pharmacodynamics for HIV Prevention in Cisgender and Transgender Persons (1R01AI186440-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/11002040. Licensed CC0.

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