Peptide mapping analysis of synthetic semaglutide and liraglutide for generic development of drugs originating from recombinant DNA technology

Semaglutide and liraglutide are long-acting glucagon-like peptide-1 receptor agonists used to treat type-2 diabetes and obesity. Recent advances in peptide synthesis and analytical technologies have enabled the development of synthetic generic peptide for reference listed drugs (RLD) originating from recombinant DNA (rDNA) technology. Since the original semaglutide and liraglutide were produced through rDNA technology, there has been great interest in developing their synthetic peptides as generic versions of the original drugs. Therefore, this study aimed to develop a peptide mapping method to describe the primary structure of semaglutide and liraglutide using ultra-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS), and to apply this method to demonstrate the sameness between synthetic peptides for generic drugs and rDNA peptides of the original drugs. Masses of the peptide fragments were identified using HRMS at an accurate level of mass error below 10 ppm, and their sequences were determined via MSE sequencing using in-source fragmentation, which was also useful for identifying the fatty acid chain modification site. Full sequence coverage of each semaglutide and liraglutide was accomplished by combining peptide maps generated using Glu-C and chymotrypsin. The proposed peptide mapping method using UPLC-HRMS was useful for determining active ingredient sameness between generic synthetic peptides and previously approved peptide drug products of rDNA origin.