Utilizing A hydrophobic primary container surface to reduce the formation of subvisible particles in monoclonal antibody solution caused by fluid shear.

The exposure of protein molecules to interfaces may cause protein aggregation and particle formation in protein formulations, especially hydrophobic interfaces, which may promote protein aggregation in solution. In this study, we found that modification of the surface properties by application of a hydrophobic Octadecyltrichlorosilane (OTS) could reduce the generation of protein aggregates and particles in protein solution induced by fluid shear. A stable protein adsorption layer was formed at the hydrophobic interface through the strong hydrophobic interaction between the protein and hydrophobic surface, which could prevent the aggregated protein from falling off into the bulk solution to form subvisible particles and insoluble protein aggregates. In addition, human complement enzyme linked immunosorbent assay results showed that the particles that were generated in the OTS-coated container did not activate human complement which indicated the OTS-coated container could be used as primary containers for certain types of monoclonal antibody formulation.

Generation and characterization of QLS22001, a humanized monoclonal antibody that neutralizes IL-17A and IL-17F with an extended half-life.

Therapeutic intervention to block IL-17A signaling has proven to be an effective treatment for numerous autoimmune diseases, including psoriasis, psoriatic arthritis, and axial spondylarthritis. Among the IL-17 family members, IL-17F, which shares 55% sequence homology with IL-17A, has been reported to functionally overlap with IL-17A in many inflammatory diseases. In this study, we describe the generation and characterization of QLS22001, a humanized monoclonal IgG1 antibody with an extended half-life and high affinity for both IL-17A and IL-17F. QLS22001 effectively blocks IL-17A and IL-17F mediated signaling pathways both in vitro and in vivo. Briefly, the YTE (M225Y/S254T/T256E) modification was introduced into the Fc fragment of QLS22001 WT Fc to prolong its half-life, and the resulting construct was named QLS22001. Functionally, it significantly inhibits IL-17A- and IL-17F-stimulated signaling in cell-based IL-6 release and reporter assays. The dual neutralization of the endogenous IL-17A and IL-17F produced by Th17 cells, as opposed to the selective blockade of IL-17A alone, results in a greater suppression of inflammatory cytokine secretion, according to in vitro blockade assays. Furthermore, in an in vivo mouse pharmacodynamic study, QLS22001 blocked human IL-17A-induced mouse keratinocyte chemoattractant (KC) release. In cynomolgus monkey pharmacokinetics evaluation, QLS22001 showed linear pharmacokinetic characteristics with a mean half-life of 31.2 days, while its parent antibody, QLS22001 WT Fc, had a mean half-life of 17.2 days. In addition, QLS22001 does not induce cytokine release in a human whole-blood assay. Collectively, these data provide a comprehensive preclinical characterization of QLS22001 and support its clinical development.

A mass spectrometry-based method to screen for α-amidated peptides.

Amidation is a post-translational modification found at the C-terminus of ~50% of all neuropeptide hormones. Cleavage of the C(α)-N bond of a C-terminal glycine yields the α-amidated peptide in a reaction catalyzed by peptidylglycine α-amidating monooxygenase (PAM). The mass of an α-amidated peptide decreases by 58 Da relative to its precursor. The amino acid sequences of an α-amidated peptide and its precursor differ only by the C-terminal glycine meaning that the peptides exhibit similar RP-HPLC properties and tandem mass spectral (MS/MS) fragmentation patterns. Growth of cultured cells in the presence of a PAM inhibitor ensured the coexistence of α-amidated peptides and their precursors. A strategy was developed for precursor and α-amidated peptide pairing (PAPP): LC-MS/MS data of peptide extracts were scanned for peptide pairs that differed by 58 Da in mass, but had similar RP-HPLC retention times. The resulting peptide pairs were validated by checking for similar fragmentation patterns in their MS/MS data prior to identification by database searching or manual interpretation. This approach significantly reduced the number of spectra requiring interpretation, decreasing the computing time required for database searching and enabling manual interpretation of unidentified spectra. Reported here are the α-amidated peptides identified from AtT-20 cells using the PAPP method.