Strategies to increase robustness in the optimization and CMC production of peptide therapeutics with parallel peptide synthesis

With the advancement of personalized medicine and newer disease targets, peptide therapeutic development has greatly expanded. Its potential to achieve increased receptor specificity and decreased toxicity satisfies efficacy and safety regulatory requirements. Technology advances in automated SPPS enable screening and CMC production of peptides with greater structural complexity allows for the design of more physiologically stable products with increased target specificity and membrane permeability. Structural modification strategies for peptide lead optimization can include cyclization, stapling, and PEGylation, which can be difficult to synthesize and purify, requiring more efficient synthesis protocols and automation to ensure reproducible and efficient manufacturability. 

Here we describe the process development and parallel optimization of SPPS relating to different biologically relevant peptides. Solid-support screening, reagent screening and temperature screening are demonstrated using an automated peptide synthesizer as part of the optimization process for difficult peptides such as Aib-Enkephalin (90% optimized crude purity vs 21% crude purity) and JR 10-mer (67% optimized crude purity vs 21% crude purity). In addition, the synthesis optimization in parallel of GLP-1 related peptides and dual GLP-1/glucagon receptor agonists will be shown, testing multiple resins and coupling reagents in search of optimal crude purities that may translate into ease of purification during the manufacturing process. Finally, the fully automated synthesis, from linear, on-resin cyclization, and resin cleavage, of NYAD-1 stapled peptide will be shared.