SignificanceThere are literally thousands of biologically active, clinically relevant peptide motifs in mammalian species. Surprisingly, however, despite this abundance of potential peptide reagents for ligand-directed delivery, applications for targeted gene therapy are generally lacking. Here we used a hybrid AAV/phage (AAVP) vector for octreotide ligand-directed therapeutic gene delivery to pancreatic neuroendocrine tumors in a transgenic mouse model that faithfully recapitulates the cognate human disease. This platform is readily available for a translational clinical trial. In a broader context, this proof-of-concept work establishes a unique targeting paradigm in which existing ligand/receptors may be exploited in nature while minimizing or eliminating several rate-limiting steps of conventional phage display library selection that require cumbersome experimental discovery work.