Subcutaneous efgartigimod PH20 in generalized myasthenia gravis: A phase 3 randomized noninferiority study (ADAPT-SC) and interim analyses of a long-term open-label extension study (ADAPT-SC+).

ADAPT-SC (NCT04735432) was designed to evaluate noninferiority of subcutaneous (SC) efgartigimod PH20 to intravenous (IV) efgartigimod in participants with generalized myasthenia gravis (gMG). ADAPT-SC+ (NCT04818671) is an open-label extension study designed to assess long-term safety, tolerability, and efficacy of efgartigimod PH20 SC. Adult participants in ADAPT-SC were randomly assigned to receive a treatment cycle of 4 once-weekly administrations of efgartigimod PH20 SC 1000 â€‹mg or efgartigimod IV 10 â€‹mg/kg, followed by 7 weeks of follow-up. Primary endpoint was percentage change from baseline in total immunoglobulin G (IgG) level at week 4 (1 week after the fourth administration). Secondary efficacy endpoints assessed number and percentage of Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) responders and mean change from baseline in total score for each measure. The primary endpoint was met, demonstrating noninferiority in total IgG reduction between efgartigimod PH20 SC 1000 â€‹mg and efgartigimod IV 10 â€‹mg/kg. Clinically meaningful improvements were seen as early as 1 week following the first administration in both treatment arms, with maximal improvements at week 4. Continued treatment cycles of efgartigimod PH20 SC in ADAPT-SC+ have demonstrated long-term safety and consistent improvements in MG-ADL total score. Findings from ADAPT-SC and ADAPT-SC+ demonstrate similar safety and efficacy as observed in the placebo-controlled ADAPT study. Collectively, these findings support noninferiority between efgartigimod PH20 SC 1000 â€‹mg and efgartigimod IV 10 â€‹mg/kg, as well as long-term safety, tolerability, and efficacy of efgartigimod PH20 SC for treatment of a broad population of patients with gMG.

Multidimensional LC-MS with 1D multi-method option and parallel middle-up and bottom-up MS acquisition for in-depth characterization of antibodies.

Monoclonal antibodies (mAbs) are large and highly heterogeneous species typically characterized using a plethora of analytical methodologies. There is a trend within the biopharmaceutical industry to combine several of these methods in one analytical platform to simultaneously assess multiple structural attributes. Here, a protein analyzer for the fully automated middle-up and bottom-up liquid chromatography-mass spectrometry (LC-MS) analysis of charge, size and hydrophobic variants is described. The multidimensional set-up combines a multi-method option in the first dimension (1D) (choice between size exclusion - SEC, cation exchange - CEX or hydrophobic interaction chromatography - HIC) with second dimension (2D) on-column reversed-phase (RPLC) based desalting, denaturation and reduction prior to middle-up LC-MS analysis of collected 1D peaks and parallel on-column trypsin digestion of denatured and reduced peaks in the third dimension (3D) followed by bottom-up LC-MS analysis in the fourth dimension (4D). The versatile and comprehensive workflow is applied to the characterization of charge, hydrophobic and size heterogeneities associated with an engineered Fc fragment and is complemented with hydrogen-deuterium exchange (HDX) MS and FcRn affinity chromatography - native MS to explain observations in a structural/functional context.

Analysis of the gamma-secretase interactome and validation of its association with tetraspanin-enriched microdomains.

Gamma-secretase, an aspartyl protease that belongs to the iCLiPs (intramembrane cleaving proteases) family, is a multiprotein complex that consists of presenilin (PS), nicastrin (NCT), Aph-1 and Pen-2 (ref. 1). It is responsible for generation of the beta-amyloid peptide (Abeta), the primary component of senile plaques in the brains of patients with Alzheimer's disease. Although the four components are necessary and sufficient for gamma-secretase activity, additional proteins are possibly involved in its regulation. Consequently, we purified proteins associated with the active gamma-secretase complex from reconstituted PS-deficient fibroblasts, using tandem affinity purification (TAP) and identified a series of proteins that transiently interact with the gamma-secretase complex and are probably involved in complex maturation, membrane trafficking and, importantly, the tetraspanin web. Tetraspanins form detergent-resistant microdomains in the cell membrane and regulate cell adhesion, cell signalling and proteolysis. Association of the gamma-secretase complex with tetraspanin-enriched microdomains provides an explanation for the previously documented localization of gamma-secretase to raft-like domains. Thus, these studies suggest that maintenance of the integrity of tetraspanin microdomains contributes to the refinement of proteolytic activity of the gamma-secretase complex.

Comparison of library screening techniques used in the development of dsDNA ligands.

The gel retardation and FID (fluorescent intercalator displacement) techniques have been compared for the selection of dsDNA binding ligands out of library mixtures. The selection procedure involves the synthesis and screening of unnatural oligopeptide libraries based on an iterative deconvolution procedure. Both methods yield comparable selection results and binding constants for the selected compounds, meaning that they can be considered as complementary in the discovery process of new antigene compounds. Furthermore, a quinazolin-2,4-dione amino acid has been identified as possessing interesting properties for interaction with dsDNA.