Non-immunoglobulin based protein scaffolds.

Non-immunoglobulin based protein scaffolds have been reported as promising alternatives to traditional monoclonal antibodies for over a decade and are often mentioned as part of the next-generation immunotherapeutics. Today, this class of biologics is beginning to demonstrate its potential for therapeutic applications and several are currently in preclinical or clinical development. A common denominator for most of these new scaffolds is the attractive properties that differentiate them from monoclonal antibodies including small size, cysteine-free sequence, flexible pharmacokinetic properties, and ease of generating multispecific molecules. In addition to therapeutic applications, substantial evidence point to superior performance of several of these scaffolds in molecular imaging compared to full-length antibodies. Here we review the most recent progress using alternative protein scaffolds for therapy and medical imaging.