Gene Therapy最新文献

This study explores the potential of adeno-associated virus serotype 9 (AAV9) to deliver therapeutic genes directly into the memory circuit throughout the olfactory bulb (OB), a critical memory and sensory processing region. Using convection-enhanced delivery (CED) of AAV9 encoding green fluorescent protein (GFP), we mapped the extensive neural connectivity from the OB to key memory-related brain regions, including the entorhinal cortex (EC) and hippocampus. Our findings reveal significant transduction of neural pathways and underscore the potential of targeting the OB connectome for therapeutic interventions in progressive neurodegenerative disorders such as Alzheimer's disease or mild cognitive impairment. Targeting the OB connectome will pave the way for new therapeutic strategies to preserve neuronal function and slow the progression, offering a promising avenue beyond symptomatic relief to address the underlying mechanisms of the disease.

Preexisting anti-AAV antibodies pose a significant challenge to the success of Adeno-associated Virus (AAV) mediated gene therapies, as they can diminish therapeutic effectiveness, restrict patient eligibility for treatment, and cause serious health issues during treatment. This study introduces the first point-of-care (POC) test for the rapid, quantitative detection of AAV8 binding antibodies in patients' plasma, serum, and blood, leveraging Chembio's Dual Path Platform (DPP) technology. The DPP AAV8 Total Antibody (TAb) assay delivers results within 20 min from sample addition, with a dynamic range of 0-32 µg/ml when evaluated with purified human polyclonal antibodies that bind to AAV8, with reasonable specificity and sensitivity relative to Chembio's AAV8 TAb ELISA (R² = 0.90). Moreover, the assay demonstrated strong correlations with Chembio's AAV8 neutralizing antibody (NAb) ELISA and cell-based NAb assays (R² = 0.97 in plasma) (Cell-based assay adapted from BioAgilytix EU protocol). This rapid and reliable test can facilitate the screening of potential gene therapy patients for pre-existing antibodies that bind to AAV8 and assess their suitability for AAV8-mediated gene therapy.

Onasemnogene abeparvovec (OA) is the first gene replacement therapy (GT) approved for 5q spinal muscular atrophy (SMA). While effective, it can cause severe side effects, including thrombotic microangiopathy (TMA). The pathophysiology, risk factors, and management of viral-vector-related TMA remain unclear. This study aimed to evaluate TMA frequency among Brazilian patients treated with OA and characterize their clinical and laboratory profiles. This retrospective, multicenter study analyzed 294 Brazilian patients with 5q SMA treated with OA between October 2020 and September 2024, of whom seven (2.4%) developed TMA. The average age at OA administration was 20.4 months, and the average weight was 11.5 kg. Three patients had documented infections before OA administration. TMA symptoms appeared within 6-10 days post-infusion. All patients showed hemolytic anemia, thrombocytopenia, and at least one organ dysfunction. Treatment included plasmapheresis in two cases and increased corticosteroid doses in four cases. One patient died from TMA complications. Whole exome sequencing in five patients identified no pathogenic variants linked to TMA. TMA is a rare but severe complication of OA therapy for SMA. Prompt recognition and management, often with corticosteroids, are crucial for improving outcomes.

Gaucher disease (GD) is a rare genetically inherited illness caused by loss of lysosomal acid β-glucosidase (β-GCase) that leads to progressive accumulation of substrates, sphingolipid glucosylceramide (GL1) and glucosylsphingosine (lyso-GL1). The protein-based enzyme replacement therapy (ERT) requires frequent dosing due to short drug half-life causing challenges in long-term patient compliance. JCXH-301 is a lipid nanoparticle (LNP) encapsulated messenger RNA (mRNA) encoding β-GCase. Intravenous administration of JCXH-301 delivered the target mRNA to various tissues in mice with intracellular expression of β-GCase predominantly in macrophages and dendritic cells in the spleen and bone marrow. In GBA1 D427V homozygous mice treated with JCXH-301, the dose-dependent in vivo production of functional β-GCase resulted in reduction of serum lyso-GL1, a key biomarker of GD. The therapeutic effect of JCXH-301 was sustained for a duration significantly longer than that of protein-based ERT Cerezyme. JCXH-301 administration induced minimal pro-inflammatory cytokines in the liver and spleen. Taken together, these results provide proof-of-concept for using LNP-delivered mRNA as a new drug modality to restore the β-GCase genetic deficiency for GD treatment.

Adenosine deaminase type 2 deficiency (DADA2) is caused by bi-allelic loss-of-function mutations in ADA2. While anti-TNF therapy is effective for the autoinflamatory and vasculitic components of the disease it does not correct marrow failure or immunodeficiency. Allogeneic stem cell transplantation (HSCT) offers a potential cure but is limited by challenges such as graft-versus-host-disease and donor availability. We previously demonstrated that lentiviral-mediated ADA2 gene therapy could restore ADA2 enzyme activity in patient-derived cells, correct macrophage inflammatory activation and reduce endothelial activation in vitro. Here, we evaluated the biodistribution and engraftment potential of lentivirally transduced healthy donor and patient-derived haematopoietic stem cells (HSC) in vivo using a humanised NBSGW mouse model. Transduced healthy HSC retained multilineage differentiation and engraftment capacity, without functional impairment. PCR analysis confirmed the absence of viral integration in non-haematopoietic organs, and histology showed no abnormal tissue changes, underscoring the safety and precision of this approach. In DADA2 patient-derived HSC, ADA2 transduction restored protein expression and enzyme activity, supporting improved cellular function and enhanced engraftment potential. These findings provide a strong foundation for advancing ADA2 gene therapy as a therapeutic strategy for DADA2, bringing it closer to clinical application.

Duchenne Muscular Dystrophy is a rare, X-linked neuromuscular disorder that leads to progressive muscle degeneration, loss of ambulation, and premature mortality due to respiratory and cardiac failure. Historically, Duchennke Muscular Dystrophy has been managed through supportive and symptomatic treatments, with limited options for disease modification. However, advancements in gene therapy have introduced promising interventions aimed at addressing the underlying dystrophin deficiency. Delandistrogene moxeparvovec (Elevidys) received accelerated approval from the U.S. Food and Drug Administration in June 2023 for ambulatory children aged 4-5 years with a confirmed diagnosis of Duchenne Muscular Dystrophy. This approval represented an advancement, offering a disease-modifying therapy at an early stage when muscle function remains relatively preserved. The Food and Drug Administration expanded its approval in June 2024 to include both ambulatory and non-ambulatory children aged 4 years and older. This study provides a retrospective real-world analysis of eight Duchenne Muscular Dystrophy patients who received Elevidys gene therapy at our center in Qatar. Recognizing the complexities involved in treating older Duchenne Muscular Dystrophy patients, a standardized protocol for pre- and post-infusion care was implemented. Our findings highlight the positive clinical outcomes of gene therapy for Duchenne Muscular Dystrophy patients in Qatar.

Commercial development of gene therapeutics often requires transitioning to human payload genes as initial proof-of-concept studies in animal models often use taxa-specific orthologs. Such transitions also provide opportunities to address potential secondary structure and immune-related subsequences as with human Smad7 cDNA, which was optimized by removing several repeats, potential hairpins and negative cis elements. Thermodynamic modeling at or above minimal free energy states revealed substantial improvements in secondary structure with fewer hairpins and improved diversity scores. Serotype 6 adeno-associated viral vectors with optimized human Smad7 (AVGN7.2) expression constructs were equally or more effective than those with wild-type mouse Smad7 in stimulating skeletal muscle hypertrophy and enhancing isometric torque of hind-limb dorsiflexor muscles in vivo. In murine models of Duchenne Muscular dystrophy, where deficits in muscle mass and disproportionate declines in force are pathognomonic, AVGN7.2 proportionally increased muscle mass and isometric torque while normalizing contractile kinetics. Such improvements occurred without deleterious impacts on serum creatine kinase, fibrosis or myofiber central nucleation. These data suggest that AVGN7.2 is capable of enhancing dystrophic muscle function without exacerbating muscle degeneration. Although these functional effects were partial, they resembled those of several dystrophin-targeting drugs and suggest that combinatorial approaches may safely yield further benefit.