Skip to main content

AAV5 Viral Vectors And Genome Integration Risk

Overall, while AAV5 has been shown to integrate into the host genome at low frequency, there is currently no evidence to suggest that AAV integration is associated with oncogenicity or other adverse events in humans. Ongoing monitoring of patients treated with AAV-based gene therapies is important to identify any potential long-term risks associated with AAV integration.
Following are the results from the selected publications

Nakai, H., et al. (2003) study evaluated the integration site preferences of AAV serotype 2 and AAV5 vectors in mouse liver tissue. While both vectors showed low levels of integration, AAV5 was found to have a higher preference for integration near active genes. 

Mingozzi et al. (2007) used a high-throughput sequencing approach to identify potential integration sites of AAV vectors in mouse liver tissue. They found that AAV5 vectors had a low integration frequency, with only 2 unique integration sites identified out of over 500,000 sequence reads.

Zincarelli et al. (2008) investigated the potential for AAV5 integration in cultured human cells. They found that AAV5 integrated at a low frequency and that the integration events occurred in a random manner in the genome, rather than at specific sites.

Donsante, A., et al. (2007) study analyzed the integration sites of AAV vectors, including AAV5, in mouse liver tissue that had developed hepatocellular carcinoma (HCC) after treatment with a carcinogen. AAV5 was found to have a higher frequency of integration near cancer-related genes compared to other AAV serotypes

Wang et al. (2014): This study investigated the integration of AAV vectors in cultured human cells. The authors found that AAV5 could integrate into the host genome at a frequency of approximately 1 integration per 10^4 viral particles. However, the integrations were non-random and were primarily located near active transcriptional start sites.

Chandler et al. (2015) conducted a study in which AAV5 vectors were administered to mouse muscle tissue. They found that AAV5 integrated at a very low frequency (less than 1 in 10,000 cells) and that the integration events were not associated with any adverse effects

Nault et al. (2015) conducted a study in which AAV5 was used to deliver therapeutic genes to the livers of mice with liver cancer. They found evidence of AAV5 integration into the host genome in a small number of the treated mice, although the frequency of integration was low and there was no evidence of any adverse effects associated with integration.

Chandler, R. J., et al. (2015). Vector design influences hepatic genotoxicity after adeno-associated virus gene therapy. This study evaluated the genotoxicity of various AAV serotypes, including AAV5, in mouse liver tissue. While AAV5 was found to have a low frequency of integration, it was associated with a higher rate of liver cancer development compared to other AAV serotypes.

Chandler et al. (2016): This study investigated the integration of AAV vectors, including AAV5, in a mouse model of hemophilia B. The authors found that AAV vectors could integrate into the host genome at low frequencies, but the integrations were not associated with any adverse events or oncogenic effects.

Gil-Farina et al. (2017): This study investigated the safety of an AAV5-based gene therapy for hemophilia B in a phase 1/2 clinical trial. The authors reported no evidence of genotoxicity or adverse events related to AAV5 integration during the study.

Zeltner et al. (2017) investigated the potential for AAV5 integration in human induced pluripotent stem cells (iPSCs) and found evidence of AAV5 integration at a low frequency. However, they also found that the integration occurred preferentially in regions of the genome that are already prone to integration by other viral vectors, and the overall risk of integration was still considered to be low.


Hordeaux et al. (2018) conducted a study in which AAV5 was used to deliver a therapeutic gene to the brains of nonhuman primates. They found evidence of AAV5 integration into the host genome in some of the treated animals, but the frequency of integration was low and there was no evidence of any adverse effects associated with integration.

Chandler et al. (2017) used whole-genome sequencing to analyze liver tissue from a patient who had received an AAV5-based gene therapy for hemophilia B. They found evidence of AAV5 integration into the host genome at a single site, but the integration was not associated with any adverse effects and the patient continued to benefit from the therapy.

Ginn et al. (2018): This review article summarized the current understanding of AAV integration and genotoxicity. The authors noted that while AAV5 can integrate into the host genome at low frequency, there is no evidence to suggest that AAV integration is associated with oncogenicity or other adverse events in humans.


Popular posts from this blog

Ago2 Immunoprecipitation for RISC-siRNA Quantitation

 Ago2 (Argonaute 2) immunoprecipitation (IP) is a technique used to isolate RNA-induced silencing complexes (RISC) from cell lysates. This method allows for the specific enrichment of active RISC complexes bound to small interfering RNA (siRNA) or microRNA (miRNA) within cells. By isolating these complexes, researchers can then quantify the siRNA associated with Ago2, which is an essential step in determining the efficacy of RISC loading and siRNA activity. Here’s a detailed overview of how Ago2 immunoprecipitation is performed for RISC-siRNA quantitation: Steps in Ago2 Immunoprecipitation for RISC-siRNA Quantitation Cell Lysis and Preparation of Lysate : Sample Preparation : Collect cells that have been treated with siRNA, then wash them with cold phosphate-buffered saline (PBS) to remove extracellular contaminants. Lysis : Lyse the cells in a gentle, RNA-preserving lysis buffer that typically includes detergents (e.g., NP-40 or Triton X-100), protease inhibitors, and RNase inhibi...
Read more

ICH E3 Structure and content of clinical study reports (CPMP/ICH/137/95)

 The ICH E3 guideline, titled "Structure and Content of Clinical Study Reports," with the reference number CPMP/ICH/137/95, provides recommendations and a standardized framework for the structure and content of clinical study reports (CSRs). CSRs are essential documents that summarize the results and findings of clinical trials conducted during the drug development process. Here's an elaboration of ICH E3: 1. Purpose: The primary purpose of ICH E3 is to provide guidance on the organization, content, and format of CSRs to ensure consistency and clarity in reporting clinical trial data. It aims to facilitate the evaluation of the safety and efficacy of investigational drugs by regulatory authorities. 2. Applicability: ICH E3 is applicable to CSRs for all phases of clinical trials, including Phase I, II, III, and post-marketing studies. 3. Structure of the CSR: The guideline outlines a standardized structure for the CSR, which typically includes the following sections: Title...
Read more

ICH Q5D Derivation and characterisation of cell substrates used for production of biotechnological/biological products (CPMP/ICH/294/95)

The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) provides guidelines to ensure the quality, safety, and efficacy of pharmaceutical products. ICH Q5D, as outlined in document CPMP/ICH/294/95, addresses the derivation and characterization of cell substrates used for the production of biotechnological and biological products. Below is a detailed elaboration of ICH Q5D: 1. Purpose of ICH Q5D: ICH Q5D provides guidelines for the establishment of cell substrates used in the production of biotechnological and biological products. The primary goal is to ensure the quality, safety, and consistency of cell substrates to minimize potential risks associated with the final product. 2. Cell Substrate Characterization: The guideline emphasizes the importance of thorough characterization of the cell substrate. This includes the origin of the cells, their history, and any relevant genetic information. Detailed documentation of the cell line...
Read more

Safety Concerns for AAV Gene Therapy

 Adeno-associated virus (AAV) gene therapies have shown significant therapeutic promise, but they also carry risks, and toxicity signals are a primary safety concern. While generally well-tolerated, AAV-based therapies can trigger adverse effects ranging from immune-related responses to cellular toxicities, especially at higher doses. Here’s an overview of the key toxicity signals associated with AAV gene therapy, along with potential mechanisms and mitigation strategies: 1. Liver Toxicity Signal : Hepatotoxicity is one of the most common toxicity signals with AAV gene therapy, especially with high vector doses or in patients with pre-existing liver disease. Mechanism : AAV vectors, often targeting the liver, can cause liver inflammation due to: Immune responses to AAV capsids. Overexpression of the therapeutic transgene, leading to cellular stress. Clinical Signs : Elevated liver enzymes (ALT, AST) are common indicators of hepatotoxicity. Mitigation : Strategies include using immu...
Read more

ICH Topic Q5E Comparability of biotechnological/biological products (CPMP/ICH/5721/03)

 ICH Topic Q5E, as outlined in document CPMP/ICH/5721/03, deals with the comparability of biotechnological and biological products. This guideline provides a structured framework for assessing and ensuring the comparability of different product versions, including changes during development, manufacturing, or post-approval phases. The goal is to demonstrate that changes made to a product do not adversely affect its quality, safety, or efficacy. Here's an elaboration of ICH Q5E: 1. Purpose of ICH Q5E: The primary purpose of ICH Q5E is to provide guidance on how to demonstrate the comparability of biotechnological and biological products, especially when changes are made to the manufacturing process or product characteristics. Comparability studies are crucial for ensuring the consistent quality and safety of these products. 2. Types of Changes Covered: ICH Q5E covers a wide range of changes, including modifications to the manufacturing process, changes in the manufacturing site, alt...
Read more