Efficacy of lebrikizumab in adolescent patients with moderate-to-severe atopic dermatitis: 16-week results from three randomized phase 3 clinical trials.

BACKGROUND: Lebrikizumab, a high-affinity monoclonal antibody targeting IL-13, previously demonstrated clinical efficacy in three randomized, double-blind, placebo-controlled Phase 3 trials that included adults and adolescents with moderate-to-severe atopic dermatitis (AD): ADvocate1, ADvocate2, and ADhere. AIM: This subset analysis evaluated 16-week physician- and patient-reported outcomes of lebrikizumab in the adolescent patients enrolled in these three trials. METHODS: Eligible adolescents (≥12 to <18 years weighing ≥40kg) were randomized 2:1 to subcutaneous lebrikizumab (500 mg loading doses at baseline and Week 2 followed by 250 mg every 2 weeks) or placebo as monotherapy in ADvocate1&2, and in combination with topical corticosteroids (TCS) in the ADhere study. Week 16 analyses included clinical efficacy outcomes (IGA (0,1) with ≥2-point improvement, EASI 75, EASI 90), patient-reported Pruritus NRS ≥4-point improvement and Sleep-Loss Scale ≥2-point improvement. RESULTS: Pooled ADvocate1&2 16-week results in lebrikizumab (N = 67) vs placebo (N = 35) were: IGA (0,1) 46.6% vs 14.3% (p < 0.01), EASI 75 62.0% vs 17.3% (p < 0.001), EASI 90 40.7% vs 11.5% (p < 0.01), Pruritus NRS 48.9% vs 13.1% (p < 0.01), and Sleep-Loss Scale 26.9% vs 6.9% (p = 0.137). Corresponding results for ADhere, (lebrikizumab + TCS, N = 32; placebo + TCS, N = 14), were consistent. CONCLUSIONS: Lebrikizumab treatment demonstrated efficacy in improving the signs and symptoms of AD in adolescent patients, consistent with the ADvocate and ADhere overall population results.

Physiologic Effects of Housing Rats in Metabolic Cages.

Currently, metabolic cages (MC) are the only way to achieve serial sampling of urine and feces in rodents. However, the use of this caging creates a dramatic change from an animal's usual microenvironment. Here we sought to examine the effect of MC on physiologic parameters that are stress-responsive in rats. We surgically implanted 8 male Wistar rats (weight, 150 to 175 g) with telemetric transmitters and allowed them to recover for at least 2 wk. At the beginning of the study, the rats were moved to conventional open-top cages, and telemetry recording was initiated. After 24 h, the rats were moved to MC or to another conventional cage and the recording continued for another 24 h. Finally, the rats were returned to their home cages, and telemetry recording was performed for a final 24 h. After 10 days, this process was then repeated, with MC and conventional assignments switched. During the 78-h monitoring period, we recorded heart rate, arterial blood pressure, locomotor activity, body weight, and food and water consumption. Heart rate and arterial blood pressure showed transient but significant changes. Locomotor activity during the dark phase was greatly decreased in MC compared with conventional cages, perhaps due to space constraints. In addition, when the rats were housed in MC, they showed a small but significant weight loss. Food consumption did not differ between housing environments, but water consumption was lower when rats were in MC. In conclusion, the housing of rats in MC for 24 h can elicit mild and reversible cardiovascular changes. This finding is consistent with European Directive 2010/63/EU, which considers short-term (less than 24 h) restraint in MC a procedure of mild severity.

Discovery of a Potent, Selective, and Orally Available PI3Kδ Inhibitor for the Treatment of Inflammatory Diseases.

The delta isoform of the phosphatidylinositol 3-kinase (PI3Kδ) has been shown to have an essential role in specific immune cell functions and thus represents a potential therapeutic target for autoimmune and inflammatory diseases. Herein, the optimization of a series of pyrrolotriazinones as potent and selective PI3Kδ inhibitors is described. The main challenge of the optimization process was to identify an orally available compound with a good pharmacokinetic profile in preclinical species that predicted a suitable dosing regimen in humans. Structure-activity relationships and structure-property relationships are discussed. This medicinal chemistry exercise led to the identification of LAS191954 as a candidate for clinical development.

Pharmacological characterization of CRTh2 antagonist LAS191859: Long receptor residence time translates into long-lasting in vivo efficacy.

The chemoattractant receptor-homologous molecule expressed on T-helper type 2 cells (CRTh2) is a G protein-coupled receptor expressed on the leukocytes most closely associated with asthma and allergy like eosinophils, mast cells, Th2-lymphocytes and basophils. At present it is clear that CRTh2 mediates most prostaglandin D2 (PGD2) pro-inflammatory effects and as a result antagonists for this receptor have reached asthma clinical studies showing a trend of lung function improvement. The challenge remains to identify compounds with improved clinical efficacy when administered once a day. Herein we described the pharmacological profile of LAS191859, a novel, potent and selective CRTh2 antagonist. In vitro evidence in GTPγS binding studies indicate that LAS191859 is a CRTh2 antagonist with activity in the low nanomolar range. This potency is also maintained in cellular assays performed with human eosinophils and whole blood. The main differentiation of LAS191859 vs other CRTh2 antagonists is in its receptor binding kinetics. LAS191859 has a residence time half-life of 21h at CRTh2 that translates into a long-lasting in vivo efficacy that is independent of plasma levels. We believe that the strategy behind this compound will allow optimal efficacy and posology for chronic asthma treatment.

Effects of Changing to Individually Ventilated Caging on Guinea Pigs (Cavia porcellus).

The goal of this study was to evaluate the effect of changing to IVC housing on guinea pigs by recording several physiologic parameters in guinea pigs housed sequentially in open-top cages (OTC) and IVC. To register heart rate and locomotor activity, 10 male Dunkin-Hartley guinea pigs implanted with telemetric transmitters were moved from OTC to new, freshly prepared OTC or IVC and subsequently monitored by telemetry during the 4 d after the first cage change. Body weight and food consumption were measured twice during the study. Comparison of data from OTC- and IVC-housed guinea pigs showed no relevant differences in heart rate (mean ± 1 SD; 213 ± 10 bpm and 207 ± 9 bpm, respectively) at any time point. In contrast, locomotor activity varied: whereas activity during the first 4 h after the change of cage type was greater in IVC-housed animals, that during the following 24 h was greater in OTC but was similar between groups thereafter. Animals housed in OTC consumed more food than did those in IVC and, under both conditions, consumption was statistically related to body weight changes. Together, these results show that a change to IVC housing induced only transient increases in locomotor activity in guinea pigs without a marked increase in heart rate but with a decrease in food consumption. Because decreased food consumption was the only stress-associated sign during the 4-d observation, longer studies are needed to ascertain the importance of this finding.

Discovery of a novel class of zwitterionic, potent, selective and orally active S1P1 direct agonists.

Amido-1,3,4-thiadiazoles have been identified as a novel structural class of potent and selective sphingosine-1-phosphate receptor subtype 1 agonists. Starting from a micromolar HTS hit with the help of an in-house homology model, robust structural-activity relationships were developed to yield compounds with good selectivity and excellent in vivo efficacy in rat models.

Morphological characterization of pecteneal hyalocytes in the developing quail retina.

The periphery of the vitreous body contains a population of cells termed hyalocytes. Despite the existence for more than one century of publications devoted to the pecten oculi, a convoluted coil of blood vessels that seems to be the primary source of nutrients for the avian avascular retina, little information can be found concerning the pecteneal hyalocytes. These cells are situated on the inner limiting membrane in close relationship with the convolute blood vessels. To characterize the origin and macrophagic activity of pecteneal hyalocytes, we have analysed two different stages of quail eye development using histochemistry and immunohistochemistry. Pecteneal hyalocytes express the QH1 epitope and cKit, confirming that these cells belong to the haematopoietic system. They also express vimentin, an intermediate filament protein present in cells of mesenchymal origin and very important for differentiation of fully active macrophages. However, similarly as described in porcine hyalocytes, pecteneal hyalocytes express the glial fibrillary acidic protein, a recognized neuroglial marker. Pecteneal hyalocytes did not express other neuroglial markers, such as glutamine synthetase or S100. Acidic phosphatase was activated and Lep100 was found in secondary lysosomes, confirming phagocytic activity of pecteneal hyalocytes during ocular development. Pecteneal hyalocytes strongly react with RCA-I, WFA, WGA, PNA, SNA, LEA and SBA lectins, whereas other avian macrophages from thymus and the bursa of Fabricius did not bind PNA, SNA and LEA lectins. Interestingly, WGA lectin reacts with all kinds of avian macrophages, including pecteneal hyalocytes, probably reflecting the specific binding of WGA to components of the phagocytic and endocytic pathways. In conclusion, pecteneal hyalocytes are a special subtype of blood-borne macrophages that express markers not specifically associated with the haematopoietic system.

Carbohydrate characterization of quail primordial germ cells during migration and gonadal differentiation.

A selection of lectins were used to study changes in the distribution of sugar residues in primordial germ cells (PGCs) during gonadal colonization and differentiation. Although the cytochemical characteristics of PGCs have been described in the chick, little is known about such characteristics in other avian species of interest to experimental biology. Therefore, we studied embryos of Japanese quail (Coturnix coturnix japonica) by light and laser confocal scanning microscopy, using the QH1 antibody as a tool to identify PGCs in both sexes and at all stages. LEA, WGA and RCA-I bound to PGCs in a similar way to QH1. LEA was the best marker for all stages. The presence of acid phosphatase and the intense reaction of LEA, WGA, RCA-I and WFA at the cell surface were shown to be a useful tool in the study of the migratory PGCs of the quail. Quails were sexed histologically in younger embryos than in chick; results were confirmed by PCR. The lectin-binding pattern changed drastically in differentiated gonads. Cell surface reactivity was almost entirely lost. Quail differentiating oogonia showed a characteristic binding pattern to QH1 and to the lectins WGA, RCA-I and WFA. Binding was observed in intense spots in the Golgi complex, and there was a specific PNA reaction. These results suggest that some selective sugar binding sites on the PGCs play a significant role in their migration, colonization and maturation.

The quail mesonephros: a new model for renal senescence?

BACKGROUND/AIMS: Renal senescence during normal aging is associated with specific vascular alterations and tissue degeneration. Although the degenerative program executed during embryonic kidney development is known to include vascular alterations, studies yet have to examine whether it involves replicative senescence. In this study, we assessed the potential of the quail mesonephros, a transitory embryonic kidney, as a model of human renal senescence. METHODS: Quail embryos with developing or degenerating mesonephros were studied on day 6 or day 11 of incubation, respectively. Senescence-associated beta-galactosidase activity, a marker of replicative senescence, was examined on whole mounts and sections. Senescent vascular characterization was performed by the scanning electron-microscopic analysis of vascular corrosion casts. RESULTS: Senescence-associated beta-galactosidase activity was found only in old mesonephros. Moreover, at 11 days of incubation glomerular capillaries showed discontinuities and were thinner and more tortuous than those observed at 6 days, characteristics also reported for the aging human kidney. CONCLUSION: The degenerating quail mesonephros is a potential model of renal senescence, showing biochemical and morphological characteristics of the aging human kidney.

beta-Catenin expression during vascular development and degeneration of avian mesonephros.

beta-Catenin is a structural component of adherens junctions, a regulator of the Wnt signalling pathway and a transcriptional co-activator with a key role in vascular patterning. The avian mesonephros is a transitory embryonic kidney that is used in the study of vascular development and degeneration. Here we examine beta-catenin expression in this model during vascular development and degeneration. Quail embryos with developing or degenerating mesonephros were studied, on day 6 (30HH) or day 11 of incubation (40HH), respectively. QH1 whole mounts of developing mesonephros revealed numerous angioblast-like cells situated in the paramesonephric duct that seem to invade the mesonephros. Although these cells did not express beta-catenin, the surrounding periductal mesenchymal cells translocated high levels of beta-catenin into the nucleus. In contrast, degenerating mesonephros were devoid of angioblast-like cells and beta-catenin was lower than in the developing mesonephros. beta-Catenin was significantly reduced in the glomerular capillary tuffs, indicating that it was particularly down-regulated in the vascular system. No sex-related differences in beta-catenin expression were observed in degenerating mesonephros. Furthermore, two special populations of glomerular and peritubular endothelial cells were observed in degenerating mesonephros: one translocating beta-catenin into the nucleus and the other in apoptosis that did not translocate it. In conclusion, our results indicate that the paramesonephric duct is a potential new vasculogenetic pathway, and suggest that beta-catenin plays a role in the fate of mesonephric endothelial cells.