Predictive biomarker modeling of pediatric atopic dermatitis severity based on longitudinal serum collection

The pathogenesis of atopic dermatitis (AD) results from complex interactions between environmental factors, barrier defects, and immune dysregulation resulting in systemic inflammation. Therefore, we sought to characterize circulating inflammatory profiles in pediatric AD patients and identify potential signaling nodes which drive disease heterogeneity and progression. We analyzed a sample set of 87 infants that were at high risk for atopic disease based on atopic dermatitis diagnoses. Clinical parameters, serum, and peripheral blood mononuclear cells (PBMCs) were collected upon entry, and at one and four years later. Within patient serum, 126 unique analytes were measured using a combination of multiplex platforms and ultrasensitive immunoassays. We assessed the correlation of inflammatory analytes with AD severity (SCORAD). Key biomarkers, such as IL-13 (rmcorr=0.47) and TARC/CCL17 (rmcorr=0.37), among other inflammatory signals, significantly correlated with SCORAD across all timepoints in the study. Flow cytometry and pathway analysis of these analytes implies that CD4 T cell involvement in type 2 immune responses were enhanced at the earliest time point (year 1) relative to the end of study collection (year 5). Importantly, forward selection modeling identified 18 analytes in infant serum at study entry which could be used to predict change in SCORAD four years later. We have identified a pediatric AD biomarker signature linked to disease severity which will have predictive value in determining AD persistence in youth and provide utility in defining core systemic inflammatory signals linked to pathogenesis of atopic disease.

Insights into adult atopic dermatitis heterogeneity derived from circulating biomarker profiling in patients with moderate-to-severe disease

Atopic dermatitis (AD) is a heterogeneous systemic inflammatory skin disease associated with dysregulated immune responses, barrier dysfunction and activated sensory nerves. To characterize circulating inflammatory profiles and underlying systemic disease heterogeneity within AD patients, blood samples from adult patients (N = 123) with moderate‐to‐severe AD in a phase 2 study of baricitinib (JAHG) were analysed. Baseline levels of 131 markers were evaluated using high‐throughput and ultrasensitive proteomic platforms, patient clusters were generated based on these peripheral markers. We implemented a novel cluster reproducibility method to validate cluster outcomes within our study and used publicly available AD biomarker data set (73 markers, N = 58 patients) to validate our findings. Cluster reproducibility analysis demonstrated best consistency for 2 clusters by k‐means, reproducibility of this clustering outcome was validated in an independent patient cohort. These unique JAHG patient subgroups either possessed elevated pro‐inflammatory mediators, notably TNFβ, MCP‐3 and IL‐13, among a variety of immune responses (high inflammatory) or lower levels of inflammatory biomarkers (low inflammatory). The high inflammatory subgroup was associated with greater baseline disease severity, demonstrated by greater EASI, SCORAD Index, Itch NRS and DLQI scores, compared with low inflammatory subgroup. African‐American patients were predominantly associated with the high inflammatory subgroup and increased baseline disease severity. In patients with moderate‐to‐severe AD, heterogeneity was identified by the detection of 2 disease subgroups, differential clustering amongst ethnic groups and elevated pro‐inflammatory mediators extending beyond traditional polarized immune responses. Therapeutic strategies targeting multiple pro‐inflammatory cytokines may be needed to address this heterogeneity.

Characterization of LY2775240, a selective phosphodiesterase-4 inhibitor, in nonclinical models and in healthy subjects

Abstract

LY2775240 is a highly selective, potent and orally‐administered inhibitor of phosphodiesterase 4 (PDE4), and is being investigated as a treatment option for inflammatory disorders, such as psoriasis. LY2775240 was investigated in rodent and rhesus monkey nonclinical models. Treatment with LY2775240 led to significant reductions in TNFα production, a marker of PDE4 engagement upon immune activation, in both nonclinical models. In the first part of a 2‐part first‐in‐human randomized study, a wide dose range of LY2775240 was safely evaluated and found to be well‐tolerated with common adverse events (AEs) of nausea, diarrhea, and headache. No serious AEs were reported. The pharmacokinetic profile of LY2775240 was well‐characterized, with a half‐life that can support once‐a‐day dosing. An ex vivo pharmacodynamic (PD) assay demonstrated dose‐dependent PDE4 target engagement as assessed by reduction in TNFα production. A 20 mg dose of LY2775240 led to near‐maximal TNFα inhibition in this PD assay in the first part of the study and was selected for comparison with the clinical dose of apremilast (30 mg) in the crossover, second part of this study. The 20 mg dose of LY2775240 demonstrated sustained maximal (50%–80%) inhibition of TNFα over all timepoints over the 24‐h duration. The comparator apremilast achieved peak inhibition of ~ 50% at only 4 h postdose with a return to about 10% inhibition within 12 h of dosing. In summary, the nonclinical data and safety, tolerability, and PK/PD data in healthy subjects supports further investigation of LY2775240 in inflammatory indications.

Circulating Biomarkers of Testosterone's Anabolic Effects on Fat-Free Mass

BACKGROUND

Biomarkers that predict response to anabolic therapies could expedite the development of function promoting anabolic drugs. This study aimed to identify serum biomarkers that are responsive to testosterone administration and associated with increases in fat-free mass (FFM).

METHODS

Serum samples were obtained from the 5α-Reductase Trial, a randomized trial that compared the effects of graded doses of testosterone enanthate for 20-weeks in healthy men randomized to placebo or dutasteride (dual SRD5A inhibitor). Testosterone's effects on FFM or strength measures did not differ between placebo vs dutasteride groups. Accordingly, 54 subjects treated with testosterone plus placebo were included in the Discovery Cohort, and 48 randomized to dutasteride were included in the Validation Cohort. 1162 biomarkers were evaluated using pre-specified criteria.

RESULTS

In the Discovery Cohort, testosterone administration increased PRO-C3 and PRO-C6 levels in a dose- and concentration-dependent manner; increases in these biomarkers from baseline to week-12 were associated with changes in FFM from baseline to week-20 (PRO-C3: r2=0.437, p<0.001; PRO-C6: r2=0.434, p<0.001). Changes in PRO-C3 and PRO-C6 levels were significantly associated with changes in chest press strength (PRO-C3: r2=0.394, p<0.001; PRO-C6: r2=0.530, p<0.001). In the SOMAscan, changes in insulin-like growth factor binding protein-6 (IGFBP6) and Glypican 3 (GPC3) were associated with changes in total and free testosterone levels and FFM. These findings were replicated in the Validation Cohort.

CONCLUSION

PRO-C3, PRO-C6, IGFBP6 and GPC3 fulfilled the pre-specified criteria for biomarkers of testosterone-induced muscle anabolism: changes in these biomarkers were associated with changes in total and free testosterone concentrations and with testosterone-induced gains in FFM.

Measurement of IL-21 in human serum and plasma using ultrasensitive MSD S-PLEX® and Quanterix SiMoA methodologies

IL-21 is a pleiotropic cytokine that plays a key role in modulating inflammatory responses, including the promotion of autoimmune diseases. Several groups have quantitated circulating levels of IL-21 in plasma and serum samples using various commercial ELISAs. We determined, however, that the most commonly used commercial assays in published literature were not specific or sensitive enough to detect levels of IL-21 in heparin plasma or serum from healthy human individuals. This finding prompted an effort to develop more specific and sensitive methods to quantitate IL-21 in complex biological matrices using proprietary anti-IL-21 antibodies with the Quanterix SiMoA platform and the Meso Scale Discovery (MSD) S-PLEX® format. Assays developed on both technology platforms were characterized in heparin plasma and serum using spike recoveries across a range of concentrations. Each method was able to detect sub-pg/mL levels of IL-21 (predicted Limit of Detection [LOD] of approximately 1.0 fg/mL for both the Quanterix SiMoA and MSD S-PLEX® platforms) which is 200-500 times lower than current commercial assays. Additionally we demonstrated that rheumatoid factor did not interfere with measuring IL-21 in the Quanterix SiMoA assay. Results obtained with the two new ultrasensitive assays showed a strong correlation (r = 0.9428; p < .0001). Additionally, IL-21 levels were significantly increased in samples from patients with Systemic Lupus Erythematosus (mean+/- SD: n = 14, 202.64 +/- 111.47 fg/mL, p = .0001 for Quanterix SiMoA and 275.4 +/- 174.66 fg/mL p = .0001 for MSD S-PLEX®) as well as in samples from patients with Sjögren's Syndrome (mean+/- SD: n = 11, 122.18 +/- 84.50 fg/mL, p = .0029 for Quanterix SiMoA and 183.64 +/- 153.00 fg/mL, p = .0082 for MSD S-PLEX®) when compared to healthy donors (mean+/- SD: n = 11, 38.1 +/- 27.8 fg/mL for Quanterix SiMoA and 58.1 +/- 30.7 fg/mL for MSD S-PLEX®). These ultrasensitive assays, for the first time, allow for the accurate quantitation of human IL-21 in heparin plasma and serum. In addition, these experiments also provide a direct comparison of the MSD S-PLEX® format and Quanterix SiMoA platform technologies, which may have broader implications to future application of these methods to evaluate low abundance proteins in complex biological matrices.

A novel CDK9 inhibitor shows potent antitumor efficacy in preclinical hematologic tumor models

DNA-dependent RNA polymerase II (RNAP II) largest subunit RPB1 C-terminal domain (CTD) kinases, including CDK9, are serine/threonine kinases known to regulate transcriptional initiation and elongation by phosphorylating Ser 2, 5, and 7 residues on CTD. Given the reported dysregulation of these kinases in some cancers, we asked whether inhibiting CDK9 may induce stress response and preferentially kill tumor cells. Herein, we describe a potent CDK9 inhibitor, LY2857785, that significantly reduces RNAP II CTD phosphorylation and dramatically decreases MCL1 protein levels to result in apoptosis in a variety of leukemia and solid tumor cell lines. This molecule inhibits the growth of a broad panel of cancer cell lines, and is particularly efficacious in leukemia cells, including orthotopic leukemia preclinical models as well as in ex vivo acute myeloid leukemia and chronic lymphocytic leukemia patient tumor samples. Thus, inhibition of CDK9 may represent an interesting approach as a cancer therapeutic target, especially in hematologic malignancies.

The antiangiogenic property of docetaxel is synergistic with a recombinant humanized monoclonal antibody against vascular endothelial growth factor or 2-methoxyestradiol but antagonized by endothelial growth factors

Numerous chemotherapeutic agents have been shown to have an inhibitory effect on endothelial cell proliferation and migration, and tubule formation. In this study, we examined the antiangiogenic activity of docetaxel. Docetaxel inhibited endothelial cell proliferation and tubule formation in vitro in a dose-dependent fashion. Docetaxel treatment also inhibited angiogenesis in an in vivo Matrigel plug assay. The endothelial stimulating factors, vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor are able to protect endothelial cells from the antiangiogenic properties of docetaxel. This protective effect can be overcome by a recombinant humanized monoclonal antibody directed against VEGF in both in vitro and in vivo models. Similarly, combination of docetaxel with the antiangiogenic agent 2-methoxyestradiol also overcomes the protective effect of VEGF in both in vitro and in vivo models. These data suggest that microenvironmental factors (e.g., local release of VEGF and basic fibroblast growth factor) could play a role in decreasing the antiangiogenic effects of docetaxel, whereas agents such as 2- methoxyestradiol and recombinant humanized monoclonal antibody directed against VEGF may reverse this protective effect.