Skip to main content

Overview of Guidance for Non Clinical Biodistribution Studies For AAV Gene Therapy

The ICH (International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) provides guidance on the conduct of nonclinical biodistribution studies for AAV gene therapy products. The guidance is designed to ensure that biodistribution studies are conducted in a manner that is consistent with regulatory requirements and that provides relevant information on the distribution and persistence of the AAV vector in different tissues and organs.

According to the ICH guidance, nonclinical biodistribution studies for AAV gene therapy products should include the following:
  • Dose selection: The highest dose tested in the study should be the intended clinical dose, or a dose that is expected to produce a similar level of transgene expression.
  • Study design: The study should include a minimum of three animal species, with at least two non-rodent species.
  • Sample collection: Samples should be collected at multiple time points after administration of the AAV vector, with a focus on tissues that are likely to be affected by the gene therapy.
  • Analytical methods: Analytical methods should be validated and sensitive enough to detect low levels of the AAV vector in tissues and organs.
  • Data analysis: Data should be analyzed to determine the tissue distribution, persistence, and clearance of the AAV vector.
  • Reporting: Results of the biodistribution study should be reported in a comprehensive manner, including details of the study design, sample collection, analytical methods, and data analysis.

Compliance with the ICH guidance on nonclinical biodistribution studies is important for demonstrating the safety and efficacy of AAV gene therapy products, and for obtaining regulatory approval for their use in clinical trials and commercialization.

Reference: ICH SGT 5: Guidance on nonclinical safety studies for the conduct of human clinical trials and marketing authorization for pharmaceuticals.

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...

Guideline on development and manufacture of lentiviral vectors (CHMP/BWP/2458/03)

The guideline with the reference number "CHMP/BWP/2458/03" pertains to the "Guideline on Development and Manufacture of Lentiviral Vectors." This guideline was developed by the Committee for Medicinal Products for Human Use (CHMP) and the Biotechnology Working Party (BWP) of the European Medicines Agency (EMA). It provides recommendations and regulatory guidance for the development and manufacture of lentiviral vectors, which are widely used in gene therapy and cell therapy applications. Here's an overview of the key points covered in this guideline: 1. Introduction: The guideline begins with an introduction highlighting the increasing importance of lentiviral vectors in advanced therapies and the need for guidance on their development and manufacture. 2. Scope: It defines the scope of the guideline, which covers the development and manufacture of lentiviral vectors intended for use in gene therapy and cell therapy products for human use. 3. Quality and Characte...

Stem-Loop PCR for siRNA

 Stem-loop PCR is a method often used for detecting and quantifying small RNAs, such as siRNA or miRNA, which are typically difficult to amplify directly due to their short lengths. The method involves the design of a stem-loop reverse transcription (RT) primer, which enhances specificity and stability of the short RNA during the RT-PCR process, allowing for sensitive detection and quantification of the siRNA. Here’s a detailed guide to how stem-loop PCR can be applied to siRNA detection: Key Steps in Stem-Loop PCR for siRNA Designing the Stem-Loop RT Primer : Structure : The stem-loop RT primer consists of a loop region flanked by complementary sequences on either side (the "stem"), which will fold back on itself to form a hairpin structure. Specific Binding Region : A short sequence complementary to the 3’ end of the siRNA is added at the end of the stem-loop primer to ensure specific binding to the siRNA target. Stabilization : The loop structure helps prevent primer-dimer...

FDA Guidance on Studying Multiple Versions of Cellular or Gene Therapy Products in Early-Phase Clinical Trials

 The purpose of this guidance is to offer advice to sponsors interested in conducting early-phase clinical trials for a single disease involving multiple variations of a cellular or gene therapy product. Sponsors aim to gather preliminary safety and efficacy data for these product variations within a single clinical trial. It's important to note that even though multiple product versions are studied together, each version is distinct and typically requires a separate investigational new drug application (IND) submission to the FDA. The primary goal of these early-phase clinical studies is to inform decisions about which product version(s) should be advanced for further development in later-phase trials. As such, these studies are not designed to provide the main evidence of effectiveness needed for a marketing application. They are generally not statistically powered to demonstrate a significant difference in efficacy between the different study arms. In this guidance, the FDA prov...

Stem loop RT-PCR for Detection of siRNA in Animal Tissues

Step Loop RT-PCR for Detection of Small Interfering RNA (siRNA) The recent publications described a novel used the novel method for the detection of siRNAs using a TaqMan®-based approach. This approach utilizes similar strategy that has been used for microRNA detection. The approach is illustrated in below.  In brief, the RT step occurs in the presence of a stem-loop RT primer that is complementary to the last 6–10 bases of the 3′ end of the antisense strand of the target siRNA. The stem-loop primer contains an additional universal sequence at the 5′ end that facilitates a TaqMan-based detection strategy in the subsequent qPCR step. As in the case of microRNA, the forward primer for qPCR is sequence-specific for the target siRNA. For sequence compositions that yield a low predicted melting temperature (Tm), the forward primer is designed as a tailed primer to help increase Tm. Stem Loop PCR for SiRNA Detection Step 1: Preparation of liver and plasma samples for the quanti...