Impact of Manufacturing Process and Compounding on Properties and Quality of Follow-On GLP-1 Polypeptide Drugs

The prevalence of follow-on and compounded products of glucagon-like peptide-1 analogs is increasing. We assessed glucagon-like peptide-1 analogs semaglutide and liraglutide for purity, potential immunogenicity, and expected stability, by comparing a representative selection of commercially available follow-on drug substances (DSs) and drug products (DPs) with their corresponding originators.

Tests included several chromatography methods coupled with ultraviolet and mass spectrometry detectors, inductively coupled plasma optical emission spectroscopy, inductively coupled plasma mass spectrometry, nuclear magnetic resonance, dissolution analyses, in silico peptide/major histocompatibility complex II-binding prediction, and fibrillation assays.

Overall, 16 injectable semaglutide, 8 oral semaglutide, and 2 injectable liraglutide follow-on products were analyzed alongside originator products. Compared with originator, follow-on injectable semaglutide DSs and DPs had new impurities and impurity patterns, including high molecular weight proteins, trace metals, anions, counterions, and residual solvents. Analyses showed that several commercialized follow-on oral semaglutide DPs had a markedly lower quantity of semaglutide than the label claim, while dissolution tests indicated different semaglutide and sodium N-(8-[2-hydroxybenzoyl] amino)caprylate (SNAC) release profiles, which may reduce bioavailability. Neoepitopes were identified in DS and DP semaglutide follow-ons, indicating potential immunogenicity. Fibrillation assays showed increased fibrillation tendency and reduced physical stability in liraglutide follow-on DP samples compared with originator.

This study highlights that differences in the manufacturing processes of follow-on semaglutide and liraglutide (vs those used for originators) can result in several changes to the DSs and DPs. The impact of these changes on efficacy and safety outcomes remains unknown and should be investigated by clinical studies.