The Impact of <scp>QSP</scp> Modeling on the Design and Optimization of Gene Therapy Approaches

Quantitative Systems Pharmacology (QSP) is increasingly utilized to support the design and translation of gene therapies. This perspective outlines the application of QSP modeling across three domains of gene therapy: mRNA-based therapeutics, adeno-associated virus (AAV) vectors, and genome editing systems. We highlight opportunities for dose optimization, biomarker interpretation, and mechanistic understanding, while addressing current limitations in model generalizability, data sparsity, and translational relevance. Examples include QSP platforms for lipid nanoparticle (LNP)-delivered mRNA, physiologically based pharmacokinetics (PBPK)-informed AAV biodistribution models, and CRISPR-Cas9-based editing systems. These case studies demonstrate QSP's value in de-risking development and personalizing therapies for rare and complex diseases.