ß-Defensin 2 is a responsive biomarker of IL-17A-driven skin pathology in patients with psoriasis.

BACKGROUND: IL-17A is a key driver of human autoimmune diseases, particularly psoriasis. OBJECTIVE: We sought to determine the role of IL-17A in psoriasis pathogenesis and to identify a robust and measurable biomarker of IL-17A-driven pathology. METHODS: We studied 8 healthy subjects and 8 patients with psoriasis before and after administration of secukinumab, a fully human anti-IL-17A mAb, and used a combination of classical techniques and a novel skin microperfusion assay to evaluate the expression of 170 proteins in blood, nonlesional skin, and lesional skin. For validation, we also tested stored sera from 601 patients with a variety of autoimmune diseases. RESULTS: IL-17A was specifically expressed in lesional compared with nonlesional psoriatic skin (9.8 vs 0.8 pg/mL, P < .001). Proteomic and gene transcription analyses revealed dysregulated antimicrobial peptides, proinflammatory cytokines, and neutrophil chemoattractants, levels of which returned to normal after treatment with secukinumab. ß-Defensin 2 (BD-2) was identified as a biomarker of IL-17A-driven pathology by comparing protein expression in patients with psoriasis versus that in healthy subjects (5746 vs 82 pg/mL in serum, P < .0001; 2747 vs <218 pg/mL in dermis, P < .001), responsiveness to secukinumab therapy, and synergistic induction by IL-17A and TNF-α in epidermal keratinocytes. In a validation set of sera from 601 patients with autoimmune diseases thought to be IL-17A driven, we found that BD-2 levels are most highly increased in patients with psoriatic skin lesions, and in patients with psoriasis, BD-2 levels correlated well with IL-17A levels (r = 0.70, n = 199, P < .001) and Psoriasis Area and Severity Index scores (r = 0.53, n = 281, P < .001). CONCLUSION: IL-17A is a primary driver of skin pathology in patients with psoriasis, and serum BD-2 is an easily measurable biomarker of IL-17A-driven skin pathology.

Comprehensive Assessment of Pharmacokinetics, Pharmacodynamics, and Tolerability of Ligelizumab in Healthy Volunteers and Patients with Chronic Spontaneous Urticaria to Optimize Its Subcutaneous Delivery System.

Ligelizumab is a highly potent, humanized IgG1, anti-IgE monoclonal antibody. To explore its optimal subcutaneous delivery, the pharmacokinetics (PK), pharmacodynamics (PD), and tolerability of ligelizumab from two Phase 1 studies in healthy volunteers (HVs) and four Phase 2 and 3 studies in patients with chronic spontaneous urticaria (CSU) were assessed. Using different injection volumes or durations of a liquid-in-vial (LIVI) formulation or different formulations (LIVI vs. prefilled syringe (PFS)), single-dose ligelizumab showed comparable PK exposure in HVs. Steady-state exposure of ligelizumab was also comparable between LIVI and PFS following multiple dosing in CSU patients. The total IgE level (a PD marker) and tolerability were similar between the two formulations in both HVs and patients. Furthermore, the PK, total IgE, and tolerability were comparable for PFS administered either by patients or healthcare providers (HCPs). Collective evidence demonstrated that the injection duration or volume, formulation, or administrator had no apparent impact on the PK, PD, and tolerability of ligelizumab, supporting no clinically relevant difference between LIVI and PFS, and that PFS can be administered by patients or HCPs. This report provides a comprehensive assessment based on data of multiple clinical endpoints from both HVs and patients to inform formulation development and commercial use of a monoclonal antibody.

When to Extend Monitoring of Anti-drug Antibodies for High-risk Biotherapeutics in Clinical Trials: an Opinion from the European Immunogenicity Platform.

The determination of a tailored anti-drug antibody (ADA) testing strategy is based on the immunogenicity risk assessment to allow a correlation of ADAs with changes to pharmacokinetics, efficacy, and safety. The clinical impact of ADA formation refines the immunogenicity risk assessment and defines appropriate risk mitigation strategies. Health agencies request for high-risk biotherapeutics to extend ADA monitoring for patients that developed an ADA response to the drug until ADAs return to baseline levels. However, there is no common understanding in which cases an extension of ADA follow-up sampling beyond the end of study (EOS) defined in the clinical study protocol is required. Here, the Immunogenicity Strategy Working Group of the European Immunogenicity Platform (EIP) provides recommendations on requirements for an extension of ADA follow-up sampling in clinical studies where there is a high risk of serious consequences from ADAs. The importance of ADA evaluation during a treatment-free period is recognized but the decision whether to extend ADA monitoring at a predefined EOS should be based on evaluation of ADA data in the context of corresponding clinical signals. If the clinical data set shows that safety consequences are minor, mitigated, or resolved, further ADA monitoring may not be required despite potentially detectable ADAs above baseline. Extended ADA monitoring should be centered on individual patient benefit.

Secukinumab for the treatment of psoriasis, psoriatic arthritis, and axial spondyloarthritis: Physical and pharmacological properties underlie the observed clinical efficacy and safety.

Psoriasis, psoriatic arthritis, and axial spondyloarthritis are systemic inflammatory diseases, each commonly manifesting as a spectrum of symptoms, complications, and comorbidities that arise differently in individual patients. Drugs targeting inflammatory cytokines common to the pathogenesis of each of these conditions have been developed, although their specific actions in the different tissues involved are variable. For a drug to be effective, it must be efficiently delivered to and locally bioactive in disease-relevant tissues. Detailed clinical data shed light on the therapeutic effects of individual biologics on specific domains or clinical manifestations of disease and assist in guiding treatment decisions. Pharmacologic, molecular, and functional properties of drugs strongly impact their observed safety and efficacy, and an understanding of these properties provides complementary insight. Secukinumab, a fully human monoclonal IgG1/κ antibody selectively targeting interleukin (IL)-17A, has been in clinical use for >6 years in the treatment of moderate to severe psoriasis, psoriatic arthritis, and both radiographic (also known as ankylosing spondylitis) and nonradiographic axial spondyloarthritis. In this review, we discuss pharmacokinetic and pharmacodynamic data for secukinumab to introduce clinicians to the pharmacological properties of this widely used drug. Understanding how these properties affect the observed clinical efficacy, safety, and tolerability of this drug in the treatment of IL-17A-mediated systemic inflammatory diseases is important for all physicians treating these conditions.

"Simulect" as a model compound for assessing placental transfer of monoclonal antibodies in minipigs.

The aim of this study was to directly test and measure in vivo, if placental transfer of monoclonal antibodies takes place in pregnant Göttingen Minipigs to assess their suitability for reproductive assessment of therapeutic monoclonal antibodies. Simulect®, an approved anti CD25 (anti IL-2 receptor alpha) chimeric monoclonal IgG1 antibody, was used as a model monoclonal antibody. Maternal systemic exposure and potential placental transfer of Simulect® to fetuses were investigated following 4 weekly bolus intravenous administration of 5.0 mg/kg from gestation day (GD) 79 or 80 (e.g GD 79, 86, 93 and 100) and with terminal Caesarean section on GD 108 or GD 109 respectively. Results clearly showed exposure in maternal animals, detectable compound in the amniotic fluid from one out of 9 maternal animals, but no exposure in fetuses confirming absence of placental transfer of the selected model antibody Simulect® in minipigs. The absence of Simulect® in the fetuses further supports that the presence of Simulect® in the amniotic fluid in one maternal animal was likely due to contamination with maternal blood during sampling. The demonstrated absence of fetal exposure clearly indicates that, the minipig is not a suitable species for conduct of reproductive toxicity studies with monoclonal antibodies.

Secukinumab Treatment Does Not Alter the Pharmacokinetics of the Cytochrome P450 3A4 Substrate Midazolam in Patients With Moderate to Severe Psoriasis.

This open-label disease-drug-drug interaction study assessed whether blockade of the interleukin (IL)-17A pathway by secukinumab and subsequent downregulation of inflammatory cytokines like IL-6 or high-sensitivity C-reactive protein affects the pharmacokinetics (PKs) of a sensitive probe substrate of the cytochrome P450 3A4 isoform (CYP3A4). The PKs of midazolam, metabolized by CYP3A4, was evaluated before and after 7 and 35 days of treatment initiation of subcutaneous secukinumab at a dose of 300 mg weekly in 24 patients with moderate-to-severe psoriasis. Although demonstrating the expected decrease in downstream inflammatory cytokines, secukinumab had no clinically relevant effects on the PKs of midazolam, provided substantial clinical benefit, and was generally well tolerated. In summary, blockade of IL-17A signaling in patients with moderate-to-severe psoriasis does not significantly affect CYP3A4 enzyme activities and, therefore, the use of secukinumab is unlikely to influence the PKs of CYP3A4 substrates.

Adsorbed layers of oriented fibronectin: a strategy to control cell-surface interactions.

Fibronectin (Fn) is a matrix protein known to induce cell attachment and spreading through its cell binding site and related synergy sites. Fn-coated surfaces are therefore useful in tissue engineering and other cell contacting applications, but a problem with many immobilization strategies is a random distribution of molecular orientations. We sought to control Fn orientation, and thus enhance the availability of its cell binding site, by immobilizing Fn via a carboxymethyl dextran layer onto which are chemically attached monoclonal antibodies specific to a region near to Fn's C terminus (and thus away from the cell binding site). Using optical waveguide lightmode spectroscopy, we show the presence of chemically coupled antibodies to yield a considerably denser and thicker Fn layer, consistent with a more vertically aligned protein. Human umbilical vein endothelial cells spread significantly faster, and in a more spherically symmetric way, on an oriented Fn layer (i.e., in the presence of immobilized monoclonal antibodies) as compared with a control Fn layer (i.e., in the absence of bound antibodies). However, we observe human umbilical vein endothelial cell spreading on the oriented Fn layer to be similar to that on a Fn layer in the absence of a carboxymethyl dextran layer, suggesting that although orienting Fn is a promising strategy, coupling strategies using linkers other than dextran may be needed.

Protein adsorption: kinetics and history dependence.

The adsorption of protein and other macromolecular species is often strongly history dependent owing to the slow relaxation of nonequilibrium structures. The rate at which molecules adsorb is exquisitely sensitive to, and thus a sensitive measure of, interfacial structure; adsorption kinetics may therefore serve both to identify and to quantify history dependence. Optical waveguide lightmode spectroscopy (OWLS) in multistep mode, where an adsorbing surface is alternately exposed to a protein solution and one free of protein, enables the comparison of adsorption rates onto interfacial layers of identical composition but different formation histories. Contributions to the overall kinetics from the apparent adsorption rate constant, the desorption rate constants of molecules in different adsorbed states, and the interfacial one-body cavity function (a measure of the probability of a "cavity" on the surface free of protein) may be isolated from OWLS kinetic data. We find the rate of adsorption and the corresponding cavity function to increase significantly-for systems of fibronectin, cytochrome c, and lysozyme adsorbing onto Si(Ti)O(2)-from a first to a subsequent adsorption step and attribute this to a clustering transition among adsorbed protein molecules. From the kinetic data, we determine important structural and temporal information on this event.

Automation practices in large molecule bioanalysis: recommendations from group L5 of the global bioanalytical consortium.

In recent years, the use of automated sample handling instrumentation has come to the forefront of bioanalytical analysis in order to ensure greater assay consistency and throughput. Since robotic systems are becoming part of everyday analytical procedures, the need for consistent guidance across the pharmaceutical industry has become increasingly important. Pre-existing regulations do not go into sufficient detail in regard to how to handle the use of robotic systems for use with analytical methods, especially large molecule bioanalysis. As a result, Global Bioanalytical Consortium (GBC) Group L5 has put forth specific recommendations for the validation, qualification, and use of robotic systems as part of large molecule bioanalytical analyses in the present white paper. The guidelines presented can be followed to ensure that there is a consistent, transparent methodology that will ensure that robotic systems can be effectively used and documented in a regulated bioanalytical laboratory setting. This will allow for consistent use of robotic sample handling instrumentation as part of large molecule bioanalysis across the globe.

Tracing pathway activities with kinase inhibitors and reverse phase protein arrays.

Controlling aberrant protein kinase activity is a promising strategy for a variety of diseases, particularly cancer. Hence, the development of kinase inhibitors is currently a focal point for pharmaceutical research. In this study we utilize a chip-based reverse phase protein array (RPA) platform for profiling of kinase inhibitors in cell-based assays. In combination with the planar wave-guide technology the assay system has an absolute LOD down to the low zeptomole range. A431 cell lysates were analyzed for the activation state of key effectors in the epidermal growth factor (EGF) and insulin signaling pathways to validate this model for compound screening. A microtiter-plate format for growing, treating, and lysing cells was shown to be suitable for this approach, establishing the value of the technology as a screening tool for characterization of large numbers of kinase inhibitors against a wide variety of cellular signaling pathways. Moreover, the reverse array format allows rapid development of site-specific phosphorylation assays, since in contrast to ELISA type systems only a single antigen-specific antibody is required.