Single-chain Fv designs for protein, cell and gene therapeutics

One decade after the invention of single-chain Fv (sFv) proteins and methods for their facile engineering in microbial systems, there have been several recent engineering advances which combine the avidity, effector and pharmacological properties of intact monoclonal antibodies (mAbs) with the simplicity of the sFv formats. These developments may serve as the prelude for a new wave of immunomolecule therapeutics which can surpass mAbs in efficacy, biodistribution and abundance of applications. Additionally, sFv formats are now used extensively in the fields of gene and cell therapy as intracellular target-binding drugs; targeting agents for vectors with redesigned tropism; and engineered chimeric receptors for targeted immune cells.