CRISPR Gene Editing Newsletter
Issue #48August 3, 20267 studies

CRISPR base editors delivered to rat brains reduced Huntington's protein fragments and improved movement

CRISPR gene editing had a genuinely big week — in the clinic, the lab, and the field.

From a Huntington's disease rodent breakthrough to drug-controllable T-cell therapies, the tools are getting sharper and the problems are getting harder to ignore.

A CRISPR base editor took on Huntington's disease — in a living brain 🧠

  • Researchers delivered CRISPR base editors directly into the striatum of a rodent Huntington's disease model, targeting a splice site in the huntingtin gene to block production of toxic protein fragments.
  • The result: reduced fragment formation, less protein aggregation, measurable improvement in movement deficits, and slowed brain atrophy — all from a single editing intervention.
  • The approach sidesteps full gene deletion by generating a proteolysis-resistant huntingtin version instead, which is a meaningfully different strategy than silencing the gene outright.

Why it matters: Huntington's has no disease-modifying treatment. Showing that base editing can reach the right brain region, hit the right target, and produce functional improvement in an animal model moves the field past proof-of-concept into something more urgent.

🥇 Top 1% journal 🔗 Nature biomedical engineering Journal Article 🗓️ Jul 29

Key Findings

Prime editing gave T-cells a drug-resistance upgrade — then let doctors dial them back ⚙️

  • A multiplex prime-editing platform engineered human T-cells to resist common immunosuppressive drugs, allowing therapeutic cells to survive and expand in patients who can't stop immunosuppression — like transplant recipients.
  • In humanized mouse models, corrected T-cells from lymphoma patients selectively expanded under drug pressure, and a different drug could rapidly suppress them when needed.
💡 Drug-controllable T-cell therapy now has a working proof-of-concept in mice.
🥇 Top 1% journal 🔗 Blood Journal Article 🗓️ Jul 29

The first in-vivo CRISPR therapy for a swelling disorder just got a close look 💉

  • Lonvoguran ziclumeran (NTLA-2002) is a systemically administered CRISPR/Cas9 therapy designed to permanently disrupt the gene driving hereditary angioedema — a rare condition causing unpredictable, potentially life-threatening swelling attacks.
  • Unlike current treatments that require lifelong dosing, a single in-vivo edit is designed to durably suppress the plasma enzyme responsible for triggering attacks.
💡 One-and-done CRISPR dosing for a rare swelling disorder is now under investigation.
Top 20% journal 🔗 Expert opinion on investigational drugs Review 🗓️ Jul 27

An analysis of 32 cancer trials shows CRISPR's clearest wins — and its clearest wall 🎯

  • Across 32 registered clinical trials, CRISPR-edited immune cell therapies targeting blood cancers produced objective responses and showed edited cells persisting in patients over time.
  • Solid tumors remain a different story: delivery barriers, tumor heterogeneity, and immunosuppressive tumor environments have kept clinical translation limited.
💡 CRISPR is working in blood cancers; solid tumors are still a different problem entirely.
Top 20% journal 🔗 Frontiers in oncology Review 🗓️ Aug 1

Monkey genomes are a poor stand-in for human CRISPR safety testing 🐒

  • A large computational study designed over 7 million CRISPR spacer sequences and predicted off-target sites across humans and five common nonhuman primate species used in preclinical safety studies.
  • Only 7–21% of predicted human off-target sites were recapitulated in primate genomes — meaning animal safety data may systematically miss the human-specific risks that matter most.
💡 Primate safety studies for CRISPR therapies may miss most human-relevant off-target sites.
Top 20% journal 🔗 Human gene therapy Journal Article 🗓️ Aug 1

The repair templates used in gene editing carry their own hidden errors 🔬

  • Deep sequencing of single-stranded DNA donor templates from three manufacturers revealed synthesis errors present in every batch tested, with error rates varying more than two-fold between suppliers.
  • Those errors were propagated into the genome via the editing process itself — in a sickle cell correction protocol, some errors were predicted to generate a thalassemia-like outcome.
💡 Synthesis errors in editing templates can sneak into the genome; standard QC doesn't catch them.
Top 20% journal 🔗 Genes Journal Article 🗓️ Jul 28

A CRISPR screen inside tumors fingered a metabolism enzyme as an immunotherapy blocker 🔍

  • An in-vivo CRISPR screen in mouse tumor models identified leukotriene A4 hydrolase (LTA4H) as a regulator of resistance to PD-1 checkpoint blockade — a widely used cancer immunotherapy.
  • Removing the gene was associated with more immune cell infiltration and better tumor control; blocking its downstream signaling with an existing drug compound improved outcomes when combined with PD-1 blockade.
💡 A metabolic enzyme linked to immunotherapy resistance now has a pharmacological workaround in mice.
🔗 International immunopharmacology Journal Article 🗓️ Jul 31

Implications

CRISPR is simultaneously treating patients, rebuilding immune cells, and mapping its own blind spots — all in the same week. The unresolved tension: off-target prediction tools still miss a substantial fraction of true editing events, and the animal models used to catch those errors may not reflect human genomes closely enough to matter.

Studies in this issue

Primary sources used for this newsletter.

  1. Using gene editing inside the body to treat Huntington's disease
    main storyNature biomedical engineering2026-07-29PMID 42527584
  2. Errors in DNA Building Blocks Cause Unwanted Variation in Precise Gene Editing
    key findingGenes2026-07-28PMID 42510769
  3. Gene therapy using CRISPR-Cas9 to treat hereditary angioedema
    key findingExpert opinion on investigational drugs2026-07-27PMID 42504735
  4. Monkey Genomes Are Poor Models for Predicting Human CRISPR Off-Target Effects
    key findingHuman gene therapy2026-08-01PMID 42541388
  5. Prime editing allows drug-controlled T-cell therapies during immune suppression
    key findingBlood2026-07-29PMID 42523019
  6. Using CRISPR/Cas9 gene editing in cancer treatment: clinical applications, underlying methods, and future approaches
    key findingFrontiers in oncology2026-08-01PMID 42539480
  7. Live CRISPR screening finds LTA4H may boost immunotherapy by affecting LTB4-driven neutrophil response
    key findingInternational immunopharmacology2026-07-31PMID 42537346

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