Viral vector characterization is the comprehensive analytical process used to evaluate the quality, identity, purity, potency, and safety of viral vectors used in gene therapy. It ensures the vector consistently delivers the correct genetic material and performs predictably during development and clinical use.
Vector integrity includes several assays to evaluate a gene therapy product’s quality, safety, and efficacy. Vector genome integrity specifically assesses whether vectors remain intact and functional throughout production, purification, and administration, including tests for purity and identity. These assays provide essential insights into viral vector quality and ensure suitability for therapeutic applications.
Assessing integrity is crucial during drug development to correlate administered doses with potency and bioanalytical data. In clinical trials, it ensures the accurate delivery of the specified genetic material to target cells.
Integrity testing encompasses:
- Transgene and vector completeness
- Robustness and stability under varying conditions over time
- Quantification of vector copy numbers for dosage consistency and safety
- Purity and sterility testing for safety
- Integration site analysis to evaluate specificity, transduction efficiency, and potential off-target effects on adjacent genes
To perform these evaluations, various molecular techniques are employed:
- Quantitative and digital PCR (qPCR/dPCR) provide high sensitivity and specificity, allowing quantification of key vector components such as ITRs and offering insights into vector genome integrity and concentration.
- Next-Generation Sequencing (NGS) provides a comprehensive view of the vector genome, identifying unexpected genetic alterations and contaminants, and confirming the overall genome structure.
Together, these analyses form the basis of viral vector characterization, ensuring safety, regulatory compliance, and efficacy in gene therapy development.