CMN Weekly (21 March 2025) - Your Weekly CRISPR Medicine News

Top picks

• The new Tapestri single-cell sequencing platform can analyse CRISPR-Cas-edited cells at over 100 loci, revealing distinct genotypic profiles in nearly every cell. The Israelian study underscores the limitations of bulk sequencing and emphasises the need for single-cell resolution to assess zygosity, structural variants, and clonality accurately – key for ensuring safety in gene-edited therapeutic products.
• Researchers used CRISPR-Cas9 homology-directed repair to generate gluten-reactive, HLA-DQ2.5–restricted CD4⁺ engineered Tregs, which suppressed pathogenic T cell responses in a celiac disease mouse model. The epitope-specific eTregs showed bystander suppression and required antigen-specific activation, demonstrating therapeutic potential for targeting gluten-driven immunity in celiac disease beyond a gluten-free diet.

Research

• Researchers have created a humanised knock-in mouse model of autosomal dominant retinitis pigmentosa carrying the RHO T17M mutation, recapitulating key clinical features, including retinal dysfunction and structural abnormalities. Using AAV-delivered adenine base editing, they achieved 39.7% RNA-level correction and improved retinal function. The CRISPR-based intervention validated therapeutic efficacy in vivo, establishing the hT17M model as a valuable translational platform for base editing in retinal diseases.
• Optimising locked nucleic acid (LNA) placement in ssODNs significantly enhanced CRISPR-Cas-mediated genome editing efficiency in HEK293T cells, achieving up to 18-fold improvement in precise base deletions. Strategic LNA positioning also boosted editing with longer ssODNs and enabled efficient base substitutions, though some configurations reduced efficacy, highlighting the importance of modification site selection for therapeutic applications.
• A bibliometric analysis of CRISPR-Cas9 research in age-related diseases highlights growing interest in gene repair and molecular interventions for conditions like Alzheimer's and cardiovascular disease. Despite promising advances, key challenges remain, including off-target effects, delivery inefficiencies, and ethical concerns. The study underscores the need for precision tools, improved delivery, and global regulatory coordination to advance clinical applications in ageing-related health.
• Spanish researchers have demonstrated an in vivo CRISPR-based gene therapy approach for Ewing sarcoma that reduces tumour growth in mice with no detectable activity in normal tissues. The researchers targeted the disease-causing fusion protein EWSR1::FLI1 using CRISPR-Cas9 under the control of a GGAA repeat-based promoter (GGAAprom), which is selectively activated by the fusion protein. This approach ensured that Cas9 was only expressed in Ewing sarcoma cells.
• Using CRISPR-Cas9, researchers mimicked BRD4 focal deletions identified in ovarian and other cancers, showing these deletions alleviate toxicity from BRD4 overexpression. Despite BRD4 copy number gain, the deletions disrupt regulatory regions, reducing isoform expression. The findings suggest cancer cells selectively delete BRD4 elements to fine-tune expression, marking the first recurrent deletion shown to reduce gene toxicity and support tumour growth.
• Researchers have used CRISPRa to activate regulatory elements near Gata6 and Cdx2, inducing embryonic stem cells to self-organise into 3D structures mimicking pre-gastrulation mouse embryos. These CRISPRa-programmed embryo models (CPEMs) show coordinated cell movement and morphological accuracy and enable precise perturbations to study lineage differentiation and tissue remodelling. The work demonstrates that targeted epigenome editing can drive autonomous embryonic patterning in vitro.
• Researchers have optimised mitochondria-targeted TALENs to precisely edit m.3243A>G heteroplasmy in patient-derived iPSCs. Using non-conventional repeat-variable di-residues (ncRVD) and obligate FokI heterodimers, the modified mpTALENs improved specificity and preserved mtDNA copy number. Depending on the target, mutant loads could be increased or reduced without affecting pluripotency, offering a refined tool for disease modelling and a potential therapeutic approach for m.3243A>G-related mitochondrial disorders.
• Using CRISPR-Cas9, researchers achieved allele-specific editing of age-related macular degeneration (AMD)-associated SNPs in the CFH and CFB genes in heterozygous ARPE-19 cells. Targeting efficiencies varied by guide RNA, with up to 36.7% editing and allele-specific activity reaching 52%. The study supports CRISPR-mediated modulation of the complement system as a therapeutic strategy in AMD.
• Knock-in mice constitutively or conditionally expressing Cas12a or enhanced AsCas12a from the Rosa26 locus enabled efficient, multiplexed genome editing without pathology. Using CRISPR RNA arrays, researchers achieved in vivo editing via AAVs and lipid nanoparticles, as well as immune-cell engineering ex vivo. The system supports dual-gene activation and knockout, offering a robust platform for disease modelling and gene interaction studies.

Industry

• Arbor Biotechnologies has raised $73.9M to advance CRISPR-Cas-based therapies, including ABO-101, which uses Cas12i2 to inactivate HAO1 in liver cells for treating primary hyperoxaluria type 1. Now in Phase 1/2 trials, the therapy is delivered via lipid nanoparticles. Funding will also support IND filings for additional programmes, including CRISPR-based candidates targeting CNS and rare liver diseases.
• Prime Medicine has announced preclinical in vivo data for its CRISPR-based prime editing therapy targeting alpha-1 antitrypsin deficiency (AATD). Using GalNAc-LNPs for liver-specific delivery, the approach precisely corrected the E342K mutation in SERPINA1 in up to 72% of hepatocytes in humanised mice, restoring over 95% of serum AAT to wild-type. An IND/CTA filing is planned for mid-2026.
• Precision BioSciences has presented preclinical data showing that PBGENE-DMD, using dual ARCUS nucleases delivered via a single AAV, excises exons 45–55 of the dystrophin gene in an in vivo DMD mouse model. This CRISPR-Cas-based approach restored near-normal dystrophin in muscle and satellite stem cells, yielding up to 93% of normal force output and suggesting durable, functional benefits for a broad subset of DMD patients.
• ElevateBio has partnered with AWS to accelerate CRISPR-Cas therapeutic discovery using generative AI. The partnership will apply AWS's protein language models and cloud infrastructure to ElevateBio's large CRISPR dataset to accelerate the discovery and design of both naturally occurring and synthetic custom CRISPR systems. The collaboration aims to reduce development costs and expand CRISPR's applicability beyond rare monogenic diseases to more complex genetic conditions.

Full-Year 2024 Financial Results

• Vor Bio has announced full-year 2024 financial results with a net loss of $117 million and $92 million in cash.
• Sangamo Therapeutics has announced its full-year 2024 financial results, which show a net loss of $98 million and $42 million in cash.
• Lenz Therapeutics has announced its full-year 2024 financial results, which show a net loss of $258 million and $209 million in cash.
• Allogene Therapeutics has announced its full-year 2024 financial results, which show a net loss of $50 million and $373 million in cash.
• Korro Bio has announced its full-year 2024 financial results, which show a net loss of $84 million and $163 million in cash.

Clinical

• Anocca reports that regulators in four EU countries have approved its Clinical Trial Application for VIDAR-1, the first European study of a non-viral CRISPR-Cas-edited TCR-T therapy. ANOC-001, the trial's lead candidate, uses gene-edited T cells to target KRAS G12V mutations in pancreatic cancer. Phase I is set to begin in Q2 2025 across Sweden, Denmark, Germany and the Netherlands.
• Precision BioSciences reports clearance from the FDA for the US enrolment of its Phase 1 ELIMINATE-B trial, marking the first IND clearance for a curative CRISPR-based hepatitis B therapy. The clearance comes following promising early safety and efficacy data of the in vivo gene editing therapy PBGENE-HBV. It is delivered via lipid nanoparticles and uses CRISPR-Cas to eliminate cccDNA and inactivate integrated HBV DNA in hepatocytes. See also our news coverage here.
• Wugen has dosed the first patients in its pivotal Phase 2 trial of WU-CART-007, an off-the-shelf anti-CD7 CAR-T therapy for relapsed or refractory T-ALL/LBL. The allogeneic cells are CRISPR-Cas9-edited to delete CD7 and TRAC, preventing fratricide and GvHD. Early data showed high remission rates, and the therapy has received multiple expedited regulatory designations in the US and EU.

Delivery

• A comparative study using CRISPR-Cas9 in mouse embryos shows that while pronuclear injection yields higher knock-in efficiency at the tyrosinase locus, electroporation offers a simpler alternative for generating indel-based knockouts. Both methods employed identical reagents, highlighting electroporation's suitability for routine gene disruption despite lower knock-in rates.
• Researchers have used spatial genomics to demonstrate that transcriptional crosstalk between AAV genomes enables cell-type-specific expression of large cargos, such as a 3.2 kb Cas9, by separating enhancers and promoters across distinct vectors. This concatemer-dependent strategy allowed minimally invasive, systemic AAV delivery for precise CRISPR-Cas9 editing in specific brain cell types, enabling disease modelling in wild-type mice.
• A hybrid delivery system combining lipid nanoparticles with cell-derived vesicles, such as nano plasma membrane vesicles, achieved up to a tenfold increase in endosomal escape efficiency and an 18-fold rise in gene expression compared to standard LNPs. Tested in vitro and in vivo, this CRISPR-compatible platform enhances nucleic acid delivery potency while maintaining scalability and biocompatibility. (Note: This news is from last year and does not specifically address CRISPR, but we came across it and found it interesting.)

News from CRISPR Medicine News

• On Monday, we published an interview with two Chinese scientists who used lipid nanoparticles to deliver CRISPR-Cas9 targeting Hao1 for the treatment of primary hyperoxaluria type 1. Proof-of-concept studies in mouse models showed that a single administration of the LNP-CRISPR-Cas9 system achieved sustained therapeutic effects for up to 12 months, with minimal off-target effects and no significant toxicity.
• On Wednesday, we reported that Precision BioSciences has received IND clearance for PBGENE-HBV, making it the first investigational in vivo gene-editing therapy to enter a clinical trial for chronic hepatitis B virus (HBV) in the United States. PBGENE-HBV is designed to eliminate cccDNA and inactivate integrated HBV DNA that current treatments cannot effectively address.