Peptide Optimization at the Drug Discovery-Development Interface: Tailoring of Physicochemical Properties Toward Specific Formulation Requirements

Multiparameter Peptide Optimization toward Stable Triple Agonists for the Treatment of Diabetes and Obesity

“…[ 15 ] As shown in Figure , 1 carries several modifications compared to the selective GLP‐1 RA exendin‐4 that were introduced to optimize 1) receptor activity and selectivity, 2) half‐life, and 3) solubility and physical stability. [ 15,16 ] The C‐terminal modifications Pro32‐Aib34‐Lys35‐Lys39 significantly improved physical stability by increasing polarity and electrostatic repulsion of peptide moieties without impacting the receptor activity profile and were therefore maintained for all peptides of the current study. Whereas 1 showed high chemical stability at neutral pH in buffered aqueous solutions, degradation was higher at acidic pH, due to pH‐dependent specific hydrolysis, deamidation, oxidation, and high molecular weight protein (HMWP) formation.…”

“…To minimize these risks, we implemented a strategy for iterative multiparameter peptide optimization that in parallel to in vitro receptor potency optimization considers physicochemical stability and developability of the peptide drug as explicit and early design parameter ( Figure ). [ 15,16 ] This strategy includes i) definition of relevant drug product aspects (e.g., stability, formulation, and device requirements), ii) continuous application of predictive and orthogonal in silico models, analytical (ultra high performance liquid chromatography ‐ reversed phase [UHPLC‐RP]/ultraviolet ‐ mass spectrometry [UV‐MS]) and biophysical assays (thioflavin T [ThT] binding and dynamic light scattering [DLS]) in a relevant formulation, and thereby iii) peptide optimization toward structural features that are compatible with this formulation.…”

“…Whereas 1 showed high chemical stability at neutral pH in buffered aqueous solutions, degradation was higher at acidic pH, due to pH‐dependent specific hydrolysis, deamidation, oxidation, and high molecular weight protein (HMWP) formation. [ 16 ] These labilities could be significantly improved in a formulation (pH 4.5) consisting of acetate, glycerol, l ‐methionine, and m‐cresol. Based on these observations we performed early physical and chemical stability profiling in this formulation instead of pure buffers.…”

Antimicrobial Excipient-Induced Reversible Association of Therapeutic Peptides in Parenteral Formulations

“…Specifically, peptides often marry two of the major challenges faced for other drug modalities, particularly for injectable products: chemical stability liabilities often experienced for small molecule drugs and physical stability considerations typically associated with larger proteins. 6,7 In a recently published Final Rule, the FDA delineates that peptides with less than 40 residues are not biologicals and are regulated as small molecule drugs. 8,9 While peptides defined as such generally lack the well-defined globular tertiary structure of larger proteins, 10 they still exhibit chemical stability liabilities associated with the amino acid sequence, specific residues, molecular polarity, and exposure of residues to reactive solution environments.…”

“…13 In addition to increasing solubility, the introduction of four point mutations to the 39 amino acid peptide resolved a peptide fibrillation liability that was only detected in the presence of metacresol. 7 There is a growing appreciation for the potential impact of formulating biomolecules with antimicrobial preservatives due an increasing number of systems studied and reported in the literature, including proteins, mAbs, and now smaller peptides. With less than 40 amino acids, peptides and their interactions with antimicrobial preservatives are differentiated from proteins since they lack well-defined tertiary structure.…”