Chinese guidance for the clinical application of adeno-associated virus vector-based gene therapy for hemophilia B (2025)

The mainstay of treatment for hemophilia B is Factor Ⅸ or non-factor drug therapy; however, as the disease is incurable, lifelong treatment is required. In recent years, gene therapy for hemophilia B has advanced significantly, with three adeno-associated virus (AAV) vector-based gene therapy products receiving market authorization globally. Among these, Palbociclib was recently approved in China. AAV vector gene therapy is characterized by its irreversible post-treatment effects and potential for long-term efficacy; however, suboptimal efficacy or loss of efficacy has been observed in some cases during early clinical trials. Eligibility for AAV vector gene therapy primarily depends on several factors, including patient diagnostic subtype, age, inhibitor status, AAV capsid antibody titer, and the preferences of the patient and/or their family. Given that AAV vector-based gene therapy for hemophilia has become an accessible frontier treatment, the Thrombosis and Hemostasis Group of the Chinese Society of Hematology, Chinese Medical Association, and the Hemophilia Treatment Center Collaborative Network of China have jointly formulated this guidance. This guidance aims to standardize operational procedures and follow-up recommendations, ensuring that patients receive standardized management when undergoing this novel therapeutic approach.

Three Decades of Clinical Gene Therapy: From Experimental Technologies to Viable Treatments

Adeno-Associated Virus Vectors in Clinical Trials

Evidence for the Failure of Adeno-associated Virus Serotype 5 to Package a Viral Genome ≥8.2 kb

Adeno-associated virus (AAV) vector-based gene therapy is an innovative modality being increasingly investigated to treat diseases by modifying or replacing defective genes or expressing therapeutic entities. With its unique anatomic and physiological characteristics, the eye constitutes a very attractive target for gene therapy. Specifically, the ocular space is easily accessible and is generally considered "immune-privileged" with a low risk of systemic side effects following local drug administration. As retina cells have limited cellular turnover, a one-time gene delivery has the potential to provide long-term transgene expression. Despite the initial success with voretigene neparvovec (Luxturna), the first approved retina gene therapy, there are still challenges to be overcome for successful clinical development of these products and scientific questions to be answered. The current review paper aims to integrate published experience learned thus far for AAV-based retina gene therapy related to preclinical to clinical translation; first-in-human dose selection; relevant bioanalytical assays and strategies; clinical development considerations including trial design, biodistribution and vector shedding, immunogenicity, transgene expression, and pediatric populations; opportunities for model-informed drug development; and regulatory perspectives. The information presented herein is intended to serve as a guide to inform the clinical development strategy for retina gene therapy with a focus on clinical pharmacology.

My Pathway to Adeno-Associated Virus and Adeno-Associated Virus Gene Therapy: A Personal Perspective.

A Hybrid Vector System Expands Adeno-associated Viral Vector Packaging Capacity in a Transgene-independent Manner

British Society for Gene and Cell Therapy Annual Conference and Joint UK Regenerative Medicine Platform Meeting Royal Welsh College of Music & Drama Cardiff, Wales, United Kingdom Wednesday April 19-Friday April 21, 2017 Conference Abstracts.

Somatic gene transfer has been extensively used to express genes of interest and probe the molecular physiology of lipoprotein metabolism and many other processes in animal models.1 Among its advantages over germ-line transgenic animals are the ability to rapidly express genes on selected genetic backgrounds without time-intensive backcrossing, the greater ability to control expression level through dosing of the gene transfer vector, and the greater ability to directly compare 2 genes, or 2 variants of the same gene, with regard to their effects in vivo. The latter advantage has not been fully exploited in the investigation of the functional consequences of naturally occurring human mutations. See page 2143 In this issue of Arteriosclerosis, Thrombosis, and Vascular Biology is a report by Ross and colleagues of the rescue of lipoprotein lipase (LPL)-deficient mice from lethality using neonatal intramuscular injection of an adenoviral vector to achieve somatic gene transfer and expression of a naturally occurring gain-of-function mutant of LPL.2 This report presents a variety of important issues for investigators interested in lipoprotein metabolism as well as those generally interested in somatic gene transfer and therapy. Unlike in humans, LPL deficiency in mice is lethal within the first 48 hours of birth.3,4 Whereas a previous study demonstrated that neonatal intraperitoneal administration of an adenoviral vector encoding wild-type LPL rescued 3% of the mice to adulthood,5 the current study achieved 95% rescue to adulthood. The major difference appears to be that Ross et al used a naturally-occurring variant of LPL, known …

Adeno-associated viruses (AAV) have attracted significant attention in the field of gene and cell therapy due to highly effective delivery of therapeutic genes into human cells. The ability to generate recombinant AAV vectors compromised of unique or substituted protein sequences has led to the development of capsid variants with improved therapeutic properties. Seeking novel AAV vectors capable of enhanced transduction for therapeutic applications, we have developed a series of unique capsid variants termed AAV X-Vivo (AAV-XV) derived from chimeras of AAV12 VP1/2 sequences and the VP3 sequence of AAV6. These AAV variants showed enhanced infection of human primary T cells, hematopoietic stem cells, and neuronal cell lines over wildtype parental viruses, and superiority over AAV6 for genomic integration of DNA sequences by AAV alone or in combination with CRISPR gene editing. AAV-XV variants demonstrate transduction efficiency equivalent to AAV6 at multiplicities of infection 2 logs lower, enabling T cell engineering at low AAV doses. The protein coding sequence of these novel AAV chimeras revealed disruptions within the assembly-activating protein (AAP) which likely accounted for observed lower virus yield. A series of genome alterations, reverting the AAP sequence back to wildtype AAV6, had a negative impact on the enhanced transduction seen with AAV-VX, indicating overlapping functions within this sequence for both viral assembly and effective T cell transduction. Our findings show these AAV-XV variants are highly efficient at cell transduction at low dose and demonstrates the importance of the AAP coding region in both viral particle assembly and cell infection.IMPORTANCE A major hurdle to the therapeutic potential of AAV in gene therapy lies in achieving clinically meaningful AAV doses, and secondarily, ability to manufacture commercially viable titers of AAV to support this. By virtue of neutralizing antibodies against AAV that impede patient repeat-dosing, the dose of AAV for in vivo gene delivery has been high, which has resulted in unfortunate recent safety concerns and deaths in patients given higher-dose AAV gene therapy. We have generated new AAV variants possessing unique combinations of capsid proteins for gene and cell therapy applications termed AAV-XV, which have high levels of cell transduction and gene delivery at lower MOI. Furthermore, we demonstrate a novel finding, and an important consideration for recombinant AAV design, that a region of the AAV genome encoding the capsid viral protein and AAP is critical for both virus yield and the enhancement of infection/transduction.

Although research and development of gene therapy have encountered several difficulties in recent years, they have also begun to show potential for the treatment of acquired and inherited human diseases. Gene therapy may have wide applicability for the treatment of numerous cardiovascular diseases, including congestive heart failure (CHF), ischemic heart disease, and cardiomyopathy. CHF remains a leading cause of death and morbidity in industrialized nations, and the number of patients with CHF continues to increase as the population ages. Pharmacological therapies control symptoms, reduce left ventricular (LV) dilation, improve function, and reduce mortality. These therapies control the disease but do not cure it. Currently, however, the growing knowledge of molecular mechanisms involved in myocardial dysfunction has allowed the identification of potential therapeutic targets designed with the aim of curing CHF. Several studies in animal models have provided hope that gene therapy may be one of the future strategies for the treatment of clinical CHF. In these studies, myocardial gene transfer has been used to target at least 3 different biological pathways that play a crucial role in the pathophysiology of CHF: Intracellular calcium signaling, β1-adrenergic receptor (β1-AR) signaling, and antiapoptotic signaling. The activity of sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) is decreased in failing myocardium, and this results in abnormal Ca2+ handling.1 In an animal model of heart failure, Miyamoto et al2 showed that in vivo overexpression of SERCA2a, achieved by catheter injection of an adenovirus carrying the SERCA2a gene into the aortic root, restored systolic and diastolic function to normal levels. In another study, Muller et al3 analyzed the chronic overexpression of SERCA2a in both normal and pressure-overloaded hearts (induced by abdominal aortic banding of transgenic rats). Overexpression of SERCA2a resulted in a …

Generation of Novel AAV Variants by Directed Evolution for Improved CFTR Delivery to Human Ciliated Airway Epithelium

Suppression and Replacement Gene Therapy for Autosomal Dominant Disease in a Murine Model of Dominant Retinitis Pigmentosa

Lysosomal storage disorders (LSDs) are a group of single-gene inherited metabolic diseases caused by defects in lysosomal enzymes or function-related proteins. Enzyme replacement therapy is the main treatment method in clinical practice, but it has a poor effect in patients with neurological symptoms. With the rapid development of multi-omics, sequencing technology, and bioengineering, gene therapy has been applied in patients with LSDs. As one of the vectors of gene therapy, adeno-associated virus (AAV) has good prospects in the treatment of genetic and metabolic diseases. More and more studies have shown that AAV-mediated gene therapy is effective in LSDs. This article reviews the application of AAV-mediated gene therapy in LSDs.

Neuroprotection by Gene Therapy Targeting Mutant SOD1 in Individual Pools of Motor Neurons Does not Translate Into Therapeutic Benefit in fALS Mice