# Gene Editing for Hemophilia A Treatment Using Lipid Nanoparticles

> **NIH NIH R01** · SEATTLE CHILDREN'S HOSPITAL · 2024 · $758,254

## Abstract

PROJECT SUMMARY
The goal of this project is to combine the technology of lipid nanoparticles (LNPs) and CRISPR/Cas9 gene editing
tools to correct the mutant factor VIII (FVIII) genes and rescue hemophilia A (HemA) phenotype. HemA is a
bleeding disorder resulting from a deficiency of the X-linked FVIII gene. Current treatment of frequent infusions
of FVIII protein is costly, inconvenient, short-term, and incompletely effective. Gene therapy represents a highly
promising alternative method to treat HemA patients. Recent hepatocyte-directed adeno-associated viral (AAV)
gene therapy trials for HemA yielded very promising results, however, FVIII levels dropped precipitously over
time in treated patients due to yet unidentified reasons. Ectopic FVIII expression and misfolding in hepatocytes
may induce cellular stress responses and toxicity. On the other hand, a nonviral in vivo gene editing approach
can provide permanent correction of FVIII gene without using viral vectors. LSECs are the primary natural cellular
source of FVIII biosynthesis. Recently, advancement of biocompatible LNP technology enabled delivery of
nucleic acids safely into target organs. We propose to develop LSEC-targeting LNPs to deliver gene editing tools
for hemophilia treatment. We will synthesize and improve LSEC-targeting LNPs via screening of different lipid
components, optimizing lipid formulations and attaching endothelial-targeting ligands to LNPs, enabling
enhancement of targeting and delivery efficiency into LSECs. In this project, we propose to permanently correct
mutated FVIII gene and regain FVIII expression using a combination of LNPs and Clustered regularly interspaced
short palindromic repeats (CRISPR)/Cas9 endonuclease (Cas9) gene editing tools. We will first investigate
correction of small deletions/insertions in a unique immunodeficient NSG HemA mice. We will use the optimal
LSEC-targeting LNPs to deliver Cas9 mRNA, sgRNAs and DNA templates at different dosages and ratios to
maximize the in vivo gene editing efficacy and examine the correction via indel and/or precision repair. In addition,
in order to facilitate the clinical translation, we will investigate if safe and highly efficient gene editing of small
deletion/insertions derived from HemA patients can be achieved in PBMCs isolated from HemA patients.
Furthermore, we propose to employ the newly developed base editor (BE) to correct single base mutations. BE
can achieve efficient precision editing without double strand breaks (DSBs) for enhanced safety. For selected
point mutations from HemA patients, we will test in vivo gene editing using specific BE in mutant FVIII plasmid
treated HemA mice. Next, we will use the optimal LSEC-targeting LNPs to deliver BE to restore FVIII gene
expression in the corresponding specific transgenic mouse model harboring a human FVIII exon with the
mutation site. Furthermore, we will investigate if the corresponding point mutations can be corrected using the
specific BE in PBMCs...

## Key facts

- **NIH application ID:** 10881530
- **Project number:** 1R01HL169793-01A1
- **Recipient organization:** SEATTLE CHILDREN'S HOSPITAL
- **Principal Investigator:** Carol H Miao
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $758,254
- **Award type:** 1
- **Project period:** 2024-08-15 → 2028-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10881530

## Citation

> US National Institutes of Health, RePORTER application 10881530, Gene Editing for Hemophilia A Treatment Using Lipid Nanoparticles (1R01HL169793-01A1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10881530. Licensed CC0.

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