Pharmacokinetics, safety, and efficacy of cedirogant from phase I studies in healthy participants and patients with chronic plaque psoriasis.

Cedirogant is an inverse agonist of retinoic acid-related orphan receptor gamma thymus (RORγt) developed for the treatment of moderate to severe chronic plaque psoriasis. Here, we report the results from two phase I studies in which the pharmacokinetics (PK), safety, and efficacy of cedirogant in healthy participants and patients with moderate to severe chronic plaque psoriasis were evaluated. The studies consisted of single (20-750 mg) and multiple (75-375 mg once-daily [q.d.]) ascending dose designs, with effect of food and itraconazole on cedirogant exposure also evaluated. Safety and PK were evaluated for both healthy participants and psoriasis patients, and efficacy was assessed in psoriasis patients. Following single and multiple doses, cedirogant mean terminal half-life ranged from 16 to 28 h and median time to reach maximum plasma concentration ranged from 2 to 5 h across both populations. Cedirogant plasma exposures were dose-proportional after single doses and less than dose-proportional from 75 to 375 mg q.d. doses. Steady-state concentrations were achieved within 12 days. Accumulation ratios ranged from approximately 1.2 to 1.8 across tested doses. Food had minimal effect and itraconazole had limited impact on cedirogant exposure. No discontinuations or serious adverse events due to cedirogant were recorded. Psoriasis Area and Severity Index (PASI) and Self-Assessment of Psoriasis Symptoms (SAPS) assessments demonstrated numerical improvement with treatment of cedirogant 375 mg q.d. compared with placebo. The PK, safety, and efficacy profiles of cedirogant supported advancing it to phase II clinical trial in psoriasis patients.

Enhanced Spatially Resolved Proteomics Using On-Tissue Hydrogel-Mediated Protein Digestion.

The identification of proteins from tissue specimens is a challenging area of biological research. Many current techniques for identification forfeit some level of spatial information during the sample preparation process. Recently, hydrogel technologies have been developed that perform spatially localized protein extraction and digestion prior to downstream proteomic analysis. Regiospecific protein identifications acquired using this approach have thus far been limited to 1-2 mm diameter areas. The need to target smaller populations of cells with this technology necessitates the production of smaller diameter hydrogels. Herein, we demonstrate hydrogel fabrication processes that allow hydrogel applications down to a diameter of ∼260 µm, approximately 1/15 of the area of previous approaches. Parameters such as the percent polyacrylamide used in hydrogel construction as well as the concentration of trypsin with which the hydrogel is loaded are investigated to maximize the number of protein identifications from subsequent liquid chromatography tandem MS (LC-MS/MS) analysis of hydrogel extracts. An 18% polyacrylamide concentration is shown to provide for a more rigid polymer network than the conventional 7.5% polyacrylamide concentration and supports the fabrication of individual hydrogels using the small punch biopsies. Over 600 protein identifications are still achieved at the smallest hydrogel diameters of 260 µm. The utility of these small hydrogels is demonstrated through the analysis of sub regions of a rat cerebellum tissue section. While over 900 protein identifications are made from each hydrogel, approximately 20% of the proteins identified are unique to each of the two regions, highlighting the importance of targeting tissue subtypes to accurately characterize tissue biology. These newly improved methods to the hydrogel process will allow researchers to target smaller biological features for robust spatially localized proteomic analyses.

Next-generation technologies for spatial proteomics: Integrating ultra-high speed MALDI-TOF and high mass resolution MALDI FTICR imaging mass spectrometry for protein analysis.

MALDI imaging mass spectrometry is a powerful analytical tool enabling the visualization of biomolecules in tissue. However, there are unique challenges associated with protein imaging experiments including the need for higher spatial resolution capabilities, improved image acquisition rates, and better molecular specificity. Here we demonstrate the capabilities of ultra-high speed MALDI-TOF and high mass resolution MALDI FTICR IMS platforms as they relate to these challenges. High spatial resolution MALDI-TOF protein images of rat brain tissue and cystic fibrosis lung tissue were acquired at image acquisition rates >25 pixels/s. Structures as small as 50 µm were spatially resolved and proteins associated with host immune response were observed in cystic fibrosis lung tissue. Ultra-high speed MALDI-TOF enables unique applications including megapixel molecular imaging as demonstrated for lipid analysis of cystic fibrosis lung tissue. Additionally, imaging experiments using MALDI FTICR IMS were shown to produce data with high mass accuracy (<5 ppm) and resolving power (∼75 000 at m/z 5000) for proteins up to ∼20 kDa. Analysis of clear cell renal cell carcinoma using MALDI FTICR IMS identified specific proteins localized to healthy tissue regions, within the tumor, and also in areas of increased vascularization around the tumor.

MALDI FTICR IMS of Intact Proteins: Using Mass Accuracy to Link Protein Images with Proteomics Data.

MALDI imaging mass spectrometry is a highly sensitive and selective tool used to visualize biomolecules in tissue. However, identification of detected proteins remains a difficult task. Indirect identification strategies have been limited by insufficient mass accuracy to confidently link ion images to proteomics data. Here, we demonstrate the capabilities of MALDI FTICR MS for imaging intact proteins. MALDI FTICR IMS provides an unprecedented combination of mass resolving power (~75,000 at m/z 5000) and accuracy (<5ppm) for proteins up to ~12kDa, enabling identification based on correlation with LC-MS/MS proteomics data. Analysis of rat brain tissue was performed as a proof-of-concept highlighting the capabilities of this approach by imaging and identifying a number of proteins including N-terminally acetylated thymosin ß(4) (m/z 4,963.502, 0.6ppm) and ATP synthase subunit ε (m/z 5,636.074, -2.3ppm). MALDI FTICR IMS was also used to differentiate a series of oxidation products of S100A8 (m/z 10,164.03, -2.1ppm), a subunit of the heterodimer calprotectin, in kidney tissue from mice infected with Staphylococcus aureus. S100A8 - M37O/C42O(3) (m/z 10228.00, -2.6ppm) was found to co-localize with bacterial microcolonies at the center of infectious foci. The ability of MALDI FTICR IMS to distinguish S100A8 modifications is critical to understanding calprotectin's roll in nutritional immunity.