6 research outputs found
Development of a Topical Treatment for Psoriasis Targeting RORĪ³: From Bench to Skin
<div><p>Background</p><p>Psoriasis is a chronic inflammatory skin disorder involving marked immunological changes. IL-17-targeting biologics have been successful in reducing the disease burden of psoriasis patients with moderate-to-severe disease. Unfortunately, the stratum corneum prevents penetration of large molecule weight proteins, including monoclonal antibodies. Thus, for the majority of psoriasis patients ineligible for systemic treatments, a small molecule targeting RORĪ³t, the master regulator of IL-17 family cytokines, may represent an alternative topical medicine with biologic-like efficacy.</p><p>Methods and Findings</p><p>The preclinical studies described in this manuscript bridge the gap from bench to bedside to provide the scientific foundation for a compound entering clinical trials for patients with mild to moderate psoriasis. In addition to several ex vivo reporter assays, primary T cell cultures, and the imiquimod mouse model, we demonstrate efficacy in a newly developed human ex vivo skin assay, where Th17-skewed cytokine expression is induced from skin-resident immune cells. Importantly, the skin barrier remains intact allowing for the demonstration of topical drug delivery. With the development of this novel assay, we demonstrate potent compound activity in the target tissue: human skin. Finally, target engagement by this small molecule was confirmed in <i>ex vivo</i> lesional psoriatic skin.</p><p>Conclusions</p><p>Our work describes a progressive series of assays to demonstrate the potential clinical value of a novel RORĪ³ inverse agonist small molecule with high potency and selectivity, which will enter clinical trials in late 2015 for psoriasis patients.</p></div
GSK2981278 attenuates inflammation in a mouse model of psoriasis.
<p>(A) Mice were treated topically with placebo or 1% GSK2981278 (1278) in ointment, and with imiquimod (IMQ) or petrolatum (vehicle). At studyās end (day +9 of IMQ treatment), back skin was imaged and stained (H&E). (B) Mean epidermal thickness is shown across 6ā9 mice per treatment group. (C-E) Changes to local cytokine expression was determined following topical application of 1% or 0.1% compound in a simple ethanolic solution (60:40 ethanol:water). (C) Description of study groups for panels D-E. Skin cytokine levels on day +3 (D) or day +9 (E). Data reflect the mean Ā± SEM gene expression level across 6ā9 mice per treatment group. Significant inhibition was determined by Studentās <i>t</i> test. (*pā¤0.05;**pā¤0.01).</p
Skin Resident Immune Cell Activation (sRICA) leads to pro-inflammatory cytokine responses that are reduced by GSK2981278.
<p>(A) Skin explants were cultured ā„4 days under the indicated conditions. Explants were analyzed for tissue integrity by H&E. (B) Samples were pre-treated with 10 Ī¼M compound (closed bar) or vehicle (DMSO; open barsāset to 100%) for 1 day prior to 24ā48 hrs of Th17 stimulation. Relative transcript levels were determined by qRT-PCR. (C) Samples were treated as in B, then analyzed daily for tissue integrity by H&E. Images are representative at least 3 independent experiments. (D) Samples were treated as in B. Graphs show the mean percent maximum stimulation of 3 independent experiments. Significant inhibition was determined by Studentās <i>t</i> test. (*pā¤0.05; **pā¤0.01; ***pā¤0.001).</p
Suppression of Th17-type cytokine production following topical application.
<p><i>Ex vivo</i> human skin was cultured in Franz Cell chambers for a total of 48 hours. GSK2981278 was applied to the dry surface of the skin at time zero followed 24 hrs later by activation of skin resident immune cells under Th17 polarizing conditions. The experimental schema is shown in panel A. Skin sections were harvested after 24 hrs of stimulation (48 hrs of compound treatment) and analyzed for relative gene expression of <i>il17a</i> (B) or <i>il17f</i> (C). Data are shown as the percent maximum expression of each cytokine as compared to Th17-stimulated samples treated topically with vehicle only.</p
Treatment of psoriatic tissue with the RORĪ³ inverse agonist GSK2981278 reduces proinflammatory cytokine levels.
<p>Three psoriatic skin biopsies were obtained via 3-4mm punch biopsy and placed in Unisol buffer for overnight shipment. Upon arrival, biopsy sections were placed in Cornification media without stimulation for 12ā14 hours with either 0.2% DMSO or 10 Ī¼M compound. The percent inhibition of each biomarker compared to culture with DMSO alone is shown. Each point represents an individual patient sample. The percent maximum expression Ā± SEM for each analyte assayed of each tissue was calculated relative to time zero. Significant inhibition was determined by Paired <i>t</i>-test. (**pā¤0.01).</p
Discovery of Epigenetic Regulator IāBET762: Lead Optimization to Afford a Clinical Candidate Inhibitor of the BET Bromodomains
The
bromo and extra C-terminal domain (BET) family of bromodomains
are involved in binding epigenetic marks on histone proteins, more
specifically acetylated lysine residues. This paper describes the
discovery and structureāactivity relationships (SAR) of potent
benzodiazepine inhibitors that disrupt the function of the BET family
of bromodomains (BRD2, BRD3, and BRD4). This work has yielded a potent,
selective compound I-BET762 that is now under evaluation in a phase
I/II clinical trial for nuclear protein in testis (NUT) midline carcinoma
and other cancers