# Research Project III: RNP-CRISPR to Treat Huntington's Disease

> **NIH NIH U19** · UNIVERSITY OF CALIFORNIA BERKELEY · 2024 · $574,283

## Abstract

PROJECT SUMMARY / ABSTRACT
The experiments in this proposal focus on developing a therapy for Huntington's disease based upon Cas9 RNP
formulations that are complexed to amphiphilic delivery peptides (ADPs) and conjugated to PEG. We have
chosen Huntington's disease as a disease target because it is a fatal disease with no treatment, caused by a
well-defined genetic mutation. CRISPR-based genome editing holds tremendous potential for treating
Huntington's disease but has been challenging to develop because of delivery limitations. Two key challenges
need to be solved before CRISPR-based genome editing can be used clinically. First, strategies for efficiently
and safely delivering Cas9 and gRNA into neurons, after an intracranial injection, need to be developed. Second,
strategies that can enable large volumes of brain tissue (>1 cm) to be transfected after an intracranial injection
of CRISPR reagents must also be developed. This is particularly important for genome editing in large animals
because charged macromolecules, such as Cas9 enzymes or viruses, typically only diffuse 1–2 mm away from
the injection site after an intracranial injection.
We have recently developed a new strategy for performing genome editing in the brain using a combination of
convection-enhanced delivery (CED) combined with the Cas9 RNP complexed to new rationally designed
amphiphilic delivery peptides (ADPs). This new strategy for Cas9 RNP delivery has shown remarkable promise,
and was able to edit as much as 40% of the neurons in the vicinity of the injection site, after an intracranial
injection, using the Ai9 mouse model. In addition, we have also demonstrated that conjugation of PEG to the
Cas9 RNP dramatically enhances its distribution through brain tissue. Our Cas9 RNP + ADP formulations have
much higher brain transfection ability than other strategies based upon just the Cas9 RNP fused to ADPs or
nanoparticle based delivery methods. In addition, our formulation is based upon the Cas9 RNP, PEG and a well-
defined peptide, and is anticipated to be significantly easier to manufacture than viral or nanoparticle-based
formulations, as all the components – protein, gRNA, PEG, and peptide – can readily be produced under GMP
conditions and have a robust clinical track record. In this proposal, we will build upon the momentum of our
ongoing studies and will develop a Cas9 RNP formulation that can edit >50% of the mutant Huntington's gene
after a single intracranial injection, administered via CED, using an RNP formulation that has the manufacturing
and toxicology properties needed for performing IND-enabling studies. We propose the following aims:
Specific Aim 1: Develop RNP monoparticles that efficiently transfect large volumes of brain tissue.
Specific Aim 2. Rescue mice and rats from HD via editing of HTT using Cas9 RNP monoparticles.
Specific Aim 3. Safety and process development of Cas9 RNP monoparticles.

## Key facts

- **NIH application ID:** 10840867
- **Project number:** 5U19NS132303-02
- **Recipient organization:** UNIVERSITY OF CALIFORNIA BERKELEY
- **Principal Investigator:** NIREN MURTHY
- **Activity code:** U19 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $574,283
- **Award type:** 5
- **Project period:** 2023-05-15 → 2028-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10840867

## Citation

> US National Institutes of Health, RePORTER application 10840867, Research Project III: RNP-CRISPR to Treat Huntington's Disease (5U19NS132303-02). Retrieved via AI Analytics 2026-05-30 from https://api.ai-analytics.org/grant/nih/10840867. Licensed CC0.

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