Gene Therapy最新文献

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.

Angelman syndrome (AS) is a severe neurodevelopmental disorder most often caused by deletion of the maternally inherited UBE3A allele (matUBE3A). In neurons, a long non-coding antisense RNA (Ube3a-ATS) silences the paternally-inherited UBE3A allele (patUBE3A). Here, we find that delivery of a zinc finger nuclease (ZFN) pair targeted to 86 Snord115 genes within Ube3a-ATS (ZFN17/18) using adeno-associated virus (AAV) can unsilence patUBE3A in primary neuron cultures and in the brain of a mouse model of AS for at least 9 weeks. The AAV vector genome integrated at ZFN17/18 on-target sites in cultured neurons and, as evidence of specificity, did not integrate at predicted off-target sites. AAV vectors carrying nickase and catalytically inactive ZFN17/18 variants failed to appreciably unsilence patUbe3a and did not integrate at on-target sites. In vivo, we observed significant knockdown of Ube3a-ATS in AS-model mice, resulting in some neurons reaching UBE3A levels like those of wild-type mice. ZFN17/18 did not downregulate Snrpn, Snord116, or IPW in vivo, genes that are associated with Prader-Willi syndrome. Overall, our findings demonstrate the potential use of multi-target ZFNs as therapeutics for AS.

Sporadic inclusion body myositis (IBM) is a highly debilitating muscle degenerative and rare disease of the middle aged and elderly. Because immunosuppressants fail to prevent muscle wasting in IBM patients and can even exacerbate it, drugs like AVGN7.2 are being developed to halt degeneration and to enhance muscle mass and function. AVGN7.2 is a novel gene therapeutic that attenuates activin receptors through muscle-specific human (h) SMAD7 expression and as part of its preclinical development, we performed a 91-day single-dose toxicology assessment of systemic safety, biodistribution and immunogenicity in accordance with Good Laboratory Practices. Standard physiological, ophthalmoscopic, hematological and serum chemistry examinations were performed and no adverse drug-related effects were detected at any dose (2.3E + 13, 7E + 13 and 2.1E + 14 vg/kg), resulting in a No Observed Adverse Effect Level of 2.1e14 vg/kg. Mice mounted early IgM and late IgG responses to the AAV6 capsid, but no response to the hSMAD7 protein. Vector biodistribution mirrored previously published patterns with liver followed by striated muscle having the highest levels, although overexpression of hSMAD7 and the S6RP biomarker only occurred in muscle. These data suggest that AVGN7.2 was well-tolerated even at doses known to elicit clinical toxicities with muscle-tropic AAV capsids other than AAV6.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease, with limited treatments. Gene therapy offers an alternative strategy for treating a large portion of ALS patients, however, the disparate genetic alterations in ALS complicate the development of gene therapies. Tyrosine receptor kinase B (TRKB) and Tyro3 receptors are highly expressed in mouse spinal cord motor neurons, suggesting that their ligands, brain-derived neurotrophic factor (BDNF) and growth arrest-specific 6 (GAS6), respectively, are crucial for neuronal survival. In this study, we tested whether genetically induced and muscle tissue-specific expression of such survival-enhancing ligands would ameliorate symptom development in the SOD1^G93A ALS mouse model. The therapeutic vectors (AAV-P_mus7-HuBDNF-teLuc or AAV-P_mus7-HuGAS6), or a control vector (AAV-P_mus7-teLuc) were injected intravenously via the retro-orbital route and intramuscularly into the hindlimb skeletal muscle of six-week-old mice. Treatment with the therapeutic vectors delayed disease onset and slowed progression in both male and female mice. Interestingly, a sex-specific response was observed, with female mice benefiting more from the treatments than males. Lumbar motor neuron survival was more sustained in the therapeutic vector-treated group compared to control vector group. No statistically significant extension of lifespan was observed in the treated groups.