Characterization of Excipient Effects on Reversible Self-Association, Backbone Flexibility, and Solution Properties of an IgG1 Monoclonal Antibody at High Concentrations: Part 2

• Published in: Journal of pharmaceutical sciences 2020-01, Vol.109 (1), p.353-363
• Main Authors: Hu, Yue, Toth, Ronald T., Joshi, Sangeeta B., Esfandiary, Reza, Middaugh, C. Russell, Volkin, David B., Weis, David D.
• Format: Article
• Language: English
• Subjects: Antibodies, Monoclonal - chemistry; colloidal stability; excipient effects; Excipients - chemistry; hydrogen exchange-mass spectrometry; Hydrophobic and Hydrophilic Interactions; Immunoglobulin G - chemistry; local dynamics; Molecular Docking Simulation; monoclonal antibody; phase separation; Phase Transition; Protein Aggregates; Protein Stability; protein-protein interactions; reversible self-association; Solutions; Solvents - chemistry; Viscosity
• ISSN: 0022-3549; 1520-6017
• DOI: 10.1016/j.xphs.2019.06.001

In this work, we continue to examine excipient effects on the reversible self-association (RSA) of 2 different IgG1 monoclonal antibodies (mAb-J and mAb-C). We characterize the RSA behavior of mAb-C which, similar to mAb-J (see Part 1), undergoes concentration-dependent RSA, but by a different molecular mechanism. Five additives that affect protein hydrophobic interactions to varying extents including a chaotropic salt (guanidine hydrochloride), a hydrophobic salt (trimethylphenylammonium iodide), an aromatic amino acid derivative (tryptophan amide hydrochloride), a kosmotropic salt (sodium sulfate, Na2SO4), and a less polar solvent (ethanol) were evaluated to determine their effects on the solution properties, molecular properties, and RSA of mAb-C at various protein concentrations. Four of the 5 additives examined demonstrated favorable effects on the pharmaceutical properties of high concentration mAb-C solutions (i.e., lower viscosity and weakened protein-protein interactions, PPIs) with a ranking order of guanidine hydrochloride > trimethylphenylammonium iodide > tryptophan amide hydrochloride > ethanol as measured by various biophysical techniques. Conversely, addition of Na2SO4 resulted in less desirable solution properties and enhanced PPIs. The effect of these 5 additives on mAb-C backbone dynamics were evaluated by hydrogen exchange-mass spectrometry (at high vs. low protein concentrations) to better understand their effects on the molecular sites of RSA in mAb-C.