AAV Gene Therapy Research Articles

Preclinical evaluation of NG101, a potential AAV gene therapy for wet age-related macular degeneration

Preclinical evaluation of NG101, a potential AAV gene therapy for wet age-related macular degeneration

AAV gene therapy for Duchenne Muscular Dystrophy: lessons learned from a phase 3 trial.

AAV gene therapy for Duchenne Muscular Dystrophy: lessons learned from a phase 3 trial.

656P AAV gene therapy in the Pompe canine model demonstrates correction of the muscle and CNS disorder with immune tolerance to human GAA.

656P AAV gene therapy in the Pompe canine model demonstrates correction of the muscle and CNS disorder with immune tolerance to human GAA.

37P TreatMYPN: In vivo mouse characterization and in vitro 3D muscle studies followed by 15P AAV gene therapy for the ultrarare myopalladin-related congenital myopathy

37P TreatMYPN: In vivo mouse characterization and in vitro 3D muscle studies followed by 15P AAV gene therapy for the ultrarare myopalladin-related congenital myopathy

Early Intervention with Intravenous AAV9 Gene Therapy Significantly Improves Biomarkers and Phenotypes in a Floxed Mouse Model of X-linked Alport Syndrome

Early Intervention with Intravenous AAV9 Gene Therapy Significantly Improves Biomarkers and Phenotypes in a Floxed Mouse Model of X-linked Alport Syndrome

AAV gene therapy for hereditary spastic paraplegia type 50: a phase 1 trial in a single patient

There are more than 10,000 individual rare diseases and most are without therapy. Personalized genetic therapy represents one promising approach for their treatment. We present a road map for individualized treatment of an ultra-rare disease by establishing a gene replacement therapy developed for a single patient with hereditary spastic paraplegia type 50 (SPG50). Through a multicenter collaboration, an adeno-associated virus-based gene therapy product carrying the AP4M1 gene was created and successfully administered intrathecally to a 4-year-old patient within 3 years of diagnosis as part of a single-patient phase 1 trial. Primary endpoints were safety and tolerability, and secondary endpoints evaluated efficacy. At 12 months after dosing, the therapy was well tolerated. No serious adverse events were observed, with minor events, including transient neutropenia and Clostridioides difficile gastroenteritis, experienced but resolved. Preliminary efficacy measures suggest a stabilization of the disease course. Longer follow-up is needed to confirm the safety and provide additional insights on the efficacy of the therapy. Overall, this report supports the safety of gene therapy for SPG50 and provides insights into precision therapy development for rare diseases. Clinical trial registration: NCT06069687.

Optimization of systemic AAV9 gene therapy in Niemann-Pick disease type C1 mice.

Niemann-Pick disease, type C1 (NPC1) is a rare, fatal neurodegenerative disorder caused by pathological variants in NPC1, which encodes a lysosomal cholesterol transport protein. There are no FDA approved treatments for this disorder. Both systemic and central nervous system delivery of AAV9-hNPC1 have shown significant disease amelioration in NPC1 murine models. To assess the impact of dose and window of therapeutic efficacy in Npc1 m1N mice, we systemically administered three different doses of AAV9-hNPC1 at 4 weeks old and the medium dose at pre-, early, and post-symptomatic timepoints. Higher vector doses and treatment earlier in life were associated with enhanced transduction in the nervous system and resulted in significantly increased lifespan. Similar beneficial effects were noted after gene therapy in Npc1 I1061T mice, a model that recapitulates a common human hypomorphic variant. Our findings help define dose ranges, treatment ages, and efficacy in severe and hypomorphic models of NPC1 deficiency and suggest that earlier delivery of AAV9-hNPC1 in a pre-symptomatic disease state is likely to yield optimal outcomes in individuals with NPC1.

Synergism of dual AAV gene therapy and rapamycin rescues GSDIII phenotype in muscle and liver.

Glycogen storage disease type III (GSDIII) is a rare metabolic disorder due to glycogen debranching enzyme (GDE) deficiency. Reduced GDE activity leads to pathological glycogen accumulation responsible for impaired hepatic metabolism and muscle weakness. To date, there is no curative treatment for GSDIII. We previously reported that 2 distinct dual AAV vectors encoding for GDE were needed to correct liver and muscle in a GSDIII mouse model. Here, we evaluated the efficacy of rapamycin in combination with AAV gene therapy. Simultaneous treatment with rapamycin and a potentially novel dual AAV vector expressing GDE in the liver and muscle resulted in a synergic effect demonstrated at biochemical and functional levels. Transcriptomic analysis confirmed synergy and suggested a putative mechanism based on the correction of lysosomal impairment. In GSDIII mice livers, dual AAV gene therapy combined with rapamycin reduced the effect of the immune response to AAV observed in this disease model. These data provide proof of concept of an approach exploiting the combination of gene therapy and rapamycin to improve efficacy and safety and to support clinical translation.

ACADVL−/−/ACADL−/− mice demonstrate symptoms of very long chain acyl-CoA dehydrogenase deficiency that are rescued by AAV9 gene therapy

ACADVL−/−/ACADL−/− mice demonstrate symptoms of very long chain acyl-CoA dehydrogenase deficiency that are rescued by AAV9 gene therapy

Platform Processes May Reduce AAV Gene Therapy Costs

Platform Processes May Reduce AAV Gene Therapy Costs

The presence of CpGs in AAV gene therapy vectors induces a plasmacytoid dendritic cell-like population very early after administration

AAV-mediated gene transfer is a promising platform still plagued by potential host-derived, antagonistic immune responses to therapeutic components. CpG-mediated TLR9 stimulation activates innate immune cells and leads to cognate T cell activation and suppression of transgene expression. Here, we demonstrate that CpG depletion increased expression of an antibody transgene product by 2–3-fold as early as 24 h post-vector administration in mice. No significant differences were noted in anti-transgene product/ anti-AAV capsid antibody production or cytotoxic gene induction. Instead, CpG depletion significantly reduced the presence of a pDC-like myeloid cell population, which was able to directly bind the antibody transgene product via Fc-FcγR interactions. Thus, we extend the mechanisms of TLR9-mediated antagonism of transgene expression in AAV gene therapy to include the actions of a previously unreported pDC-like cell population.

Evaluation of safety and early efficacy of AAV gene therapy in mouse models of vanishing white matter disease

Leukoencephalopathy with vanishing white matter (VWM) is a progressive incurable white matter disease that most commonly occurs in childhood and presents with ataxia, spasticity, neurological degeneration, seizures, and premature death. A distinctive feature is episodes of rapid neurological deterioration provoked by stressors such as infection, seizures, or trauma. VWM is caused by autosomal recessive mutations in one of five genes that encode the eukaryotic initiation factor 2B complex, which is necessary for protein translation and regulation of the integrated stress response. The majority of mutations are in EIF2B5. Astrocytic dysfunction is central to pathophysiology, thereby constituting a potential therapeutic target. Herein we characterize two VWM murine models and investigate astrocyte-targeted adeno-associated virus serotype 9 (AAV9)-mediated EIF2B5 gene supplementation therapy asa therapeutic option for VWM. Our results demonstrate significant rescue in body weight, motor function, gait normalization, life extension, and finally, evidence that gene supplementation attenuates demyelination. Last, the greatest rescue results from a vector using a modified glial fibrillary acidic protein (GFAP) promoter-AAV9-gfaABC(1)D-EIF2B5-thereby supporting that astrocytic targeting is critical for disease correction. In conclusion, we demonstrate safety and early efficacy through treatment with a translatable astrocyte-targeted gene supplementation therapy for a disease that has no cure.

Improved gene therapy for spinal muscular atrophy in mice using codon-optimized hSMN1 transgene and hSMN1 gene-derived promotor

Physiological regulation of transgene expression is a major challenge in gene therapy. Onasemnogene abeparvovec (Zolgensma®) is an approved adeno-associated virus (AAV) vector gene therapy for infants with spinal muscular atrophy (SMA), however, adverse events have been observed in both animals and patients following treatment. The construct contains a native human survival motor neuron 1 (hSMN1) transgene driven by a strong, cytomegalovirus enhancer/chicken β-actin (CMVen/CB) promoter providing high, ubiquitous tissue expression of SMN. We developed a second-generation AAV9 gene therapy expressing a codon-optimized hSMN1 transgene driven by a promoter derived from the native hSMN1 gene. This vector restored SMN expression close to physiological levels in the central nervous system and major systemic organs of a severe SMA mouse model. In a head-to-head comparison between the second-generation vector and a benchmark vector, identical in design to onasemnogene abeparvovec, the 2nd-generation vector showed better safety and improved efficacy in SMA mouse model.

Autosomal Recessive Non-Syndromic Deafness: Is AAV Gene Therapy a Real Chance?

The etiology of sensorineural hearing loss is heavily influenced by genetic mutations, with approximately 80% of cases attributed to genetic causes and only 20% to environmental factors. Over 100 non-syndromic deafness genes have been identified in humans thus far. In non-syndromic sensorineural hearing impairment, around 75-85% of cases follow an autosomal recessive inheritance pattern. In recent years, groundbreaking advancements in molecular gene therapy for inner-ear disorders have shown promising results. Experimental studies have demonstrated improvements in hearing following a single local injection of adeno-associated virus-derived vectors carrying an additional normal gene or using ribozymes to modify the genome. These pioneering approaches have opened new possibilities for potential therapeutic interventions. Following the PRISMA criteria, we summarized the AAV gene therapy experiments showing hearing improvement in the preclinical phases of development in different animal models of DFNB deafness and the AAV gene therapy programs currently in clinical phases targeting autosomal recessive non syndromic hearing loss. A total of 17 preclinical studies and 3 clinical studies were found and listed. Despite the hurdles, there have been significant breakthroughs in the path of HL gene therapy, holding great potential for providing patients with novel and effective treatment.

Development and validation of a novel AAV gene therapy for mucopolysaccharidosis type IIIB in large animal

Development and validation of a novel AAV gene therapy for mucopolysaccharidosis type IIIB in large animal

First in-human, intracisternal dosing of RGX-111, an investigational AAV gene therapy, for a 21-month-old child with mucopolysaccharidosis type I (MPS I): 3.5 year follow-up

First in-human, intracisternal dosing of RGX-111, an investigational AAV gene therapy, for a 21-month-old child with mucopolysaccharidosis type I (MPS I): 3.5 year follow-up

Optimized dual promoter AAV gene therapy for lysosomal β-glucocerebrosidase with high M6P content for treatment of neuronopathic Gaucher disease

Optimized dual promoter AAV gene therapy for lysosomal β-glucocerebrosidase with high M6P content for treatment of neuronopathic Gaucher disease

Immune tolerance to GALNS enhances the therapeutic efficacy of AAV gene therapy

Immune tolerance to GALNS enhances the therapeutic efficacy of AAV gene therapy

Liver-directed AAV gene therapy corrects disease symptoms in a murine model of lysosomal acid lipase deficiency

Liver-directed AAV gene therapy corrects disease symptoms in a murine model of lysosomal acid lipase deficiency

Interim results from the first-in-human intracisternal dosing of RGX-181 investigational AAV9 gene therapy in a child with late infantile neuronal ceroid lipofuscinosis type 2 (CLN2)

Interim results from the first-in-human intracisternal dosing of RGX-181 investigational AAV9 gene therapy in a child with late infantile neuronal ceroid lipofuscinosis type 2 (CLN2)