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Background Physicians treating COVID-19 patients increasingly believe that the hyperinflammatory acute stage of COVID-19 results in a cytokine storm. The circulating biomarkers seen across the spectrum of COVID-19 have not been characterized compared to healthy controls, but such analyses are likely to yield insights into the pursuit of interventions that adequately reduce the burden of these cytokine storms. Objective To identify and characterize the host inflammatory response to SARS-CoV-2 infection, we assessed levels of proteins related to immune responses and cardiovascular disease, in patients stratified as mild, moderate, and severe, versus matched healthy controls. Methods Blood samples from adult patients hospitalized with COVID-19 were analyzed using high-throughput and ultrasensitive proteomic platforms and compared with age- and sex-matched healthy controls to provide insights into differential regulation of 185 markers. Results Results indicate a dominant hyperinflammatory milieu in the circulation and vascular endothelial damage markers within COVID-19 patients, and strong biomarker association with patient response as measured by Ordinal scale. As patients progress, we observe statistically significant dysregulation of IFNγ, IL-1RA, IL-6, IL-10, IL-19, MCP-1, -2, -3, CXCL9, CXCL10, CXCL5, ENRAGE and PARP-1. Furthermore, in a limited series of patients who were sampled frequently confirming reliability and reproducibility of our assays, we demonstrate that intervention with baricitinib attenuates these circulating biomarkers associated with the cytokine storm. Conclusion These wide-ranging circulating biomarkers show an association with increased disease severity and may help stratify patients and selection of therapeutic options. They also provide insights into mechanisms of SARS-CoV-2 pathogenesis and the host response.

Because development of reliable biomarkers in psoriasis and atopic dermatitis has lagged behind therapeutic progress, we created a blood-based test to fill the void in objective methods available for dermatological assessments. Our novel interleukin-19 (IL-19) immunoassay was initially tested to determine concentrations of IL-19 serum levels, then correlated with the psoriasis activity and severity index (PASI) in psoriasis, and the eczema area and severity index (EASI) in atopic dermatitis. Not only was IL-19 increased in psoriasis and correlated to PASI, but ixekizumab administration led to rapid, sustained IL-19 decreases to normal levels, with decreases at 2-weeks correlating with PASI improvement at 16-weeks. IL-19 increased upon ixekizumab withdraw, prior to relapse, and decreased following re-treatment. In baricitinib- and etanercept-treated psoriasis patients, IL-19 decreases also correlated with improvement. Many patients with limited skin disease, including genital psoriasis and psoriatic arthritis patients, also had increased IL-19, which was reduced to normal levels upon ixekizumab treatment, correlating with PASI improvement. We also measured IL-19 in baricitinib-treated atopic dermatitis patients. In atopic dermatitis, IL-19 was significantly elevated, correlated with EASI scores, and decreased with skin improvement. Therefore, measurement of serum IL-19 provides clinicians with an objective disease-activity assessment tool for psoriasis and atopic dermatitis patients.

Despite recent advances in the development of tools to predict immunogenicity risk of biotherapeutic molecules, the ability of a protein to elicit the formation of anti-drug antibodies (ADA) remains one of the most common causes for termination of clinical development programs. In this study, we use ADA assays to detect and measure pre-existing reactivity or the ability of a molecule to produce an ADA-like response in serum from treatment-naïve, healthy donors. We report herein that the magnitude of pre-existing reactivity evaluated pre-clinically and expressed as the 90th percentile of Tier 2 inhibition correlates with the subsequent rate of ADA emergence in the clinic. Furthermore, a multi-domain biotherapeutic (IgG-scFv bispecific antibody) showed the highest pre-existing reactivity and incidence of treatment-emergent ADA (TE-ADA) (57% and 93%, respectively). Using the components of the multidomain molecule in the Tier 2 step of the ADA assay, we were able to identify the scFv as the target of the serum pre-existing reactivity. Most importantly, the domain specificity of pre-existing ADA was the same as that of the TE-ADA from patients treated with the molecule. Based on these data, we propose the evaluation of the magnitude and of the domain specificity of pre-existing reactivity as a powerful tool to understand the immunogenic potential of novel biotherapeutics.

This article describes the development of micro-opioid receptor (MOR) binding and GTPgammaS functional SPAs as improved screening tools for the identification of MOR antagonists. Opioid receptors are members of the seven-transmembrane G protein-coupled receptor (GPCR) family and are involved in the control of various aspects of human physiology, including pain, stress, reward, addiction, respiration, gastric motility, and pituitary hormone secretion. Activation of the MOR initiates intracellular signaling pathways leading to a reduction in intracellular cyclic AMP levels, inhibition of calcium channels, and activation of potassium channels resulting in a reduction of the excitability of neurons. Characterization of opioid receptor ligand binding has traditionally been accomplished through the use of low throughput filtration-based binding assays, whereas functional activity has been based upon cyclic AMP measurements or filtration-based GTPgammaS functional assays. This report describes the development of a MOR displacement binding SPA using the radiolabeled antagonist [(3)H]diprenorphine ((3)H-DPN). The assay was optimized using statistical experimental design and demonstrates the stability and robustness necessary for HTS. The assay was biased toward the identification of MOR antagonists through the addition of Na(+). Our assay conditions also minimized the phenomenon of ligand depletion, a problem commonly observed in low-volume assays using high receptor-expressing cell lines. The optimized procedure revealed (3)H-DPN affinity constants at the MOR that were consistent with results obtained using filtration methods (K(D) (SPA) = 1.89 +/- 0.24 nM, K(D) (filtration) = 1.88 +/- 0.35 nM). The binding SPA identified known opioid receptor modulators contained within the Library of Pharmacological Active Compounds (LOPAC) cassette, and the GTPgammaS scintillation proximity assay (SPA) was used to confirm the functional activity of the LOPAC antagonists acting at the MOR. Conversion of the ligand binding and GTPgammaS functional assays to a homogeneous SPA generated a simple assay with dramatically increased throughput. Data from the development and implementation of the displacement binding and GTPgammaS functional SPAs are presented.