Evaluating the safety and efficacy of seladelpar for adults with primary biliary cholangitis.

INTRODUCTION: Seladelpar (MBX-8025) is a once-daily administered highly specific PPAR-δ agonist in Phase 3 and extension trials for use in patients with primary biliary cholangitis (PBC). AREAS COVERED: This review provides background on current treatment options for PBC, and summarizes clinical trial data regarding the safety and effectiveness of seladelpar within the context of these treatments. EXPERT OPINION: Clinical trials results demonstrate the safety and tolerability of seladelpar use for PBC, including in patients with cirrhosis. The primary composite endpoint (ALP <1.67 times ULN, decrease ≥ 15% from baseline, and TB ≤ULN) was met in 61.7% of the patients treated with seladelpar and in 20% receiving placebo (p < 0.001). Moreover, pruritus - a cardinal and often intractable symptom of PBC - was improved with seladelpar treatment, as were overall quality of life measurements. Improvements in markers of inflammation were likewise observed. These biochemical and clinical findings therefore represent landmark developments in PBC treatment and offer a therapeutic option for PBC.

More Time Spent with Clear Skin and No Itch with Upadacitinib versus Dupilumab for Atopic Dermatitis.

INTRODUCTION: Atopic dermatitis (AD), with its hallmark symptoms of pruritus and skin lesions, often impairs patients' quality of life. We assessed time spent with clear/almost clear skin and no/minimal itch during upadacitinib treatment versus placebo or dupilumab among patients with moderate-to-severe AD. METHODS: This analysis consisted of a post hoc analysis of Measure Up 1 (NCT03569293), Measure Up 2 (NCT03607422), and Heads Up (NCT03738397). Measure Up 1 and 2 were replicate, randomized, double-blind, placebo-controlled phase 3 studies with patients randomized (1:1:1) to once-daily oral upadacitinib 15 mg, upadacitinib 30 mg, or placebo for 16 weeks. Heads Up was a head-to-head, randomized, double-blind, double-dummy, phase 3b study with patients randomized (1:1) to upadacitinib 30 mg or subcutaneous dupilumab 300 mg for 24 weeks. Skin clearance was assessed with the Eczema Area and Severity Index (EASI) at baseline, weeks 1, 2, and 4, and every 4 weeks thereafter. Itch was assessed using the Worst Pruritus Numerical Rating Scale (WP-NRS) daily over 16 weeks and every 2 weeks thereafter to week 24 in Heads Up. RESULTS: This analysis included 1683 patients in Measure Up 1 and 2 and 673 patients in Heads Up. Through 16 weeks in Measure Up 1 and 2, patients receiving upadacitinib spent 9.8-13.4 times as many days with an EASI 90 response and 7.0-10.3 times as many days with a WP-NRS 0/1 response versus placebo. In Heads Up, patients receiving upadacitinib spent 2.0 and 1.7 times as many days through 16 and 24 weeks, respectively, with an EASI 90 response versus dupilumab. Through 16 and 24 weeks, patients receiving upadacitinib spent 3.0 and 2.6 times as many days, respectively, with a WP-NRS 0/1 response versus dupilumab. CONCLUSIONS: Patients with moderate-to-severe AD spent more time with clear/almost clear skin and no/minimal itch with upadacitinib versus placebo or dupilumab. TRIAL REGISTRATION: ClinicalTrials.gov identifier, Measure Up 1 (NCT03569293), Measure Up 2 (NCT03607422), Heads Up (NCT03738397).

Lysophosphatidic Acid Receptors LPAR5 and LPAR2 Inversely Control Hydroxychloroquine-Evoked Itch and Scratching in Mice.

Lysophosphatidic acids (LPAs) evoke nociception and itch in mice and humans. In this study, we assessed the signaling paths. Hydroxychloroquine was injected intradermally to evoke itch in mice, which evoked an increase of LPAs in the skin and in the thalamus, suggesting that peripheral and central LPA receptors (LPARs) were involved in HCQ-evoked pruriception. To unravel the signaling paths, we assessed the localization of candidate genes and itching behavior in knockout models addressing LPAR5, LPAR2, autotaxin/ENPP2 and the lysophospholipid phosphatases, as well as the plasticity-related genes Prg1/LPPR4 and Prg2/LPPR3. LacZ reporter studies and RNAscope revealed LPAR5 in neurons of the dorsal root ganglia (DRGs) and in skin keratinocytes, LPAR2 in cortical and thalamic neurons, and Prg1 in neuronal structures of the dorsal horn, thalamus and SSC. HCQ-evoked scratching behavior was reduced in sensory neuron-specific Advillin-LPAR5-/- mice (peripheral) but increased in LPAR2-/- and Prg1-/- mice (central), and it was not affected by deficiency of glial autotaxin (GFAP-ENPP2-/-) or Prg2 (PRG2-/-). Heat and mechanical nociception were not affected by any of the genotypes. The behavior suggested that HCQ-mediated itch involves the activation of peripheral LPAR5, which was supported by reduced itch upon treatment with an LPAR5 antagonist and autotaxin inhibitor. Further, HCQ-evoked calcium fluxes were reduced in primary sensory neurons of Advillin-LPAR5-/- mice. The results suggest that LPA-mediated itch is primarily mediated via peripheral LPAR5, suggesting that a topical LPAR5 blocker might suppress "non-histaminergic" itch.

Quality of Care and Management of Atopic Dermatitis Across Different Levels of Healthcare-A Survey-Based Patient Experience.

Atopic dermatitis (AD) is a chronic and fluctuating disease. Optimal management of AD and related comorbidities requires seamless coordination across multiple layers of the healthcare system. The objective of this survey was to explore patients' experiences with current management of AD. Out of 251 responders to this anonymous survey, 76% reported to have moderate or severe AD. Sixty-nine percent with moderate and 45% with severe AD were followed up at primary care level only. Use of advanced systemic treatment options was rare, and the majority experienced itch (97%), dry skin, rash, negative impact on self-esteem and comorbidities despite ongoing treatment. Only 36% received a treatment plan, more often in secondary (78.3%) than primary care (25.0%). Forty-three percent did not know who was responsible for their follow-up and 54% felt no one was responsible. Treatment options were commonly not known or understood. The survey results demonstrate undertreatment, lack of a holistic approach for management of AD. A national pathway including clear referral criteria and timelines can streamline management of AD across multiple levels of the healthcare system.

Lasmiditan ameliorates serotonergic itch in mice: Possible involvement of 5-HT1F receptors.

Previously, some allergic conditions involving pruritus have been linked to migraine, raising the possibility that migraine and itching may be governed by similar underlying mechanisms. We aimed to investigate the efficacy of Lasmiditan, a highly selective agonist of the 5-hydroxytryptamine 1F (5-HT1F) receptor and a recently approved medication for the treatment of migraine headaches, in ameliorating serotonergic itching. Forty animals were employed in the present study (n = 40). Eight animals were randomly assigned to each of the following study groups (n = 8, in each group): (1) "Normal Saline": This group was given intradermal injections of normal saline (2) "5-HT": The animals were injected with intradermal 5-HT, which was used to induce itching. (3) "Lasmiditan 0.3", "Lasmiditan 1", and "Lasmiditan 3" groups: injected with 5-HT as well as intraperitoneal Lasmiditan at different dose levels (0.3, 1, and 3 mg/kg, respectively). Scratching behavior was recorded for 60 min, and the skin tissue of three mice was sampled at the end of the behavioral experiment to assess the levels of TLR-4, IL-31, 5-HT1F receptor, CGRP & TRPV4. In the present study, we found that Lasmiditan when administered at 1 mg/kg effectively reduced serotonin-induced itching compared to the "5-HT" group (P < 0.0001). Following the administration of Lasmiditan (1 mg/kg), the expression levels of the 5-HT1F receptor significantly increased (P < 0.01). Further, the levels of TLR-4, IL-31, CGRP & TRPV4 were substantially reduced upon the administration of Lasmiditan (1 mg/kg). We found that Lasmiditan is effective in reducing serotonergic itch in mice through its interaction with the 5-HT1F receptor in the skin tissue of mice.

Treatment of patients with evidence of mast cell-mediated itch in the absence of hives with omalizumab.

PURPOSE: The presence of wheals or hives has been viewed as a hallmark symptom of urticaria, a highly debilitating disease. This study explores our experience with omalizumab in patients with apparent mast-cell mediated pruritus in the absence of hives. MATERIALS AND METHODS: This is a retrospective case series examining all patients with mast cell-mediated pruritus in the absence of hives from April 2022 to May 2024 at a tertiary referral clinic at Icahn School of Medicine at Mount Sinai in New York. Peak pruritus-numerical rating scale (PP-NRS) itch score changes over time were recorded and analyzed. RESULTS: Six patients (67% women; mean [SD] age, 47.67 [13.52] years) were included in the analysis. The median [IQR] pruritus PP-NRS itch score before omalizumab injection was 9 [6 - 10] and the final median [IQR] PP-NRS itch score was 2.5 [0 - 5]. The mean [SD] reduction in the PP-NRS itch score was 6 [3.16]. CONCLUSIONS: This study suggests that patients with evidence of mast cell-mediated pruritus can be identified based on clinical features and may benefit from omalizumab therapy.

Spinal histamine H4 receptor mediates chronic pruritus via p-ERK in acetone-ether-water (AEW)-induced dry skin mice.

Dry skin is common to many pruritic diseases and is difficult to improve with oral traditional antihistamines. Recently, increasing evidence indicated that histamine H4 receptor (H4R) plays an important role in the occurrence and development of pruritus. Extracellular signal-regulated kinase (ERK) phosphorylation activation in the spinal cord mediates histamine-induced acute and choric itch. However, whether the histamine H4 receptor regulates ERK activation in the dry skin itch remains unclear. In the study, we explore the role of the histamine H4 receptor and p-ERK in the spinal cord in a dry skin mouse model induced by acetone-ether-water (AEW). q-PCR, Western blot, pharmacology and immunofluorescence  were applied in the study. We established a dry skin itch model by repeated application of AEW on the nape of neck in mice. The AEW mice showed typically dry skin histological change and persistent spontaneous scratching behaviour. Histamine H4 receptor, instead of histamine H1 receptor, mediated spontaneous scratching behaviour in AEW mice. Moreover, c-Fos and p-ERK expression in the spinal cord neurons were increased and co-labelled with GRPR-positive neurons in AEW mice. Furthermore, H4R agonist 4-methyhistamine dihydrochloride (4-MH)induced itch. Both 4-MH-induced itch and the spontaneous itch in AEW mice were blocked by p-ERK inhibitor U0126. Finally, intrathecal H4R receptor antagonist JNJ7777120 inhibited spinal p-ERK expression in AEW mice. Our results indicated that spinal H4R mediates itch via ERK activation in the AEW-induced dry skin mice.

Managing Pruritus in Advanced Chronic Disease.

Even though pruritus affects a significant number of people with chronic disease, it is rarely adequately treated. Drug therapies often rely on antihistamines, which have not shown to be beneficial in systemic pruritus. Hydroxyzine is frequently used to treat pruritus associated with kidney failure. Since Canada's sole manufacturer of hydroxyzine is no longer making this product, this is an ideal time to review the mechanisms of itch in advanced organ failure and the specific therapies that give relief. Although there is literature describing itch in patients with cancer, this article is limited to pathogenesis and treatment of systemic itch secondary to chronic, noncancer diseases. We summarize recent systematic reviews, although the studies included in these reviews are often small, and mostly cohort studies.

Mirogabalin inhibits scratching behavior of spontaneous model mouse of atopic dermatitis.

Introduction: Atopic dermatitis (AD) is one of the most prevalent intractable chronic itch diseases worldwide. In recent years, new molecular-targeted drugs have emerged, but side effects and economic challenges remain. Therefore, since it is important for AD patients to have a wider range of treatment options, it is important to explore new therapeutic agents. Gabapentinoids, gabapentin and pregabalin, have been shown to be effective for the clinical treatment of several chronic itch. Recently, mirogabalin (MGB) was developed as a novel gabapentinoid. MGB is a drug for neuropathic pain and has a margin of safety between its side effects and the analgesic effect for animal experiments. Herein, we showed that MGB exhibited an antipruritic effect in a mouse model of AD using NC/Nga mice. Methods and results: The oral administration of MGB (10 mg/kg) inhibited spontaneous scratching behavior in AD mice and its effect was dose dependently. Then, when MGB (10 mg/kg) was orally administrated to healthy mice, it did not affect motor function, including locomotor activity, wheel activity, and coordinated movement. Moreover, gabapentin (100 mg/kg) and pregabalin (30 mg/kg), inhibited spontaneous scratching behavior in AD mice and decreased motor function in healthy mice. Furthermore, intracisternal injection of MGB (10 µg/site) significantly suppressed spontaneous scratching behavior in AD mice. Discussion: In summary, our results suggest that MGB exerts an antipruritic effect via the spinal dorsal horn using NC/Nga mice. We hope that MGB is a candidate for a novel therapeutic agent for AD with relatively few side effects.

Stable Response and Sustained Improvement of Itch and Sleep Symptoms in Patients with Atopic Dermatitis Treated with Lebrikizumab over 52 Weeks.

BACKGROUND: Lebrikizumab demonstrated significant improvement versus placebo for measures of skin clearance and patient-reported outcomes at weeks 16 and 52 in patients with moderate-to-severe atopic dermatitis (AD). We report the sustained impact of lebrikizumab monotherapy, over 52 weeks and between visits, on the frequency of itch and sleep loss symptoms, as assessed by Patient-Oriented Eczema Measure (POEM), in patients with moderate-to-severe AD. METHODS: In ADvocate1 and ADvocate2, Week-16 lebrikizumab responders (EASI75 or IGA 0/1 with ≥ 2-point improvement and without rescue medication) were randomized to lebrikizumab every 2 weeks (Q2W), every 4 weeks (Q4W), or placebo for 36 weeks. This pooled analysis reports improvement from Week 16 to 52 in patients achieving POEM response 0 (no days) or 1 (1-2 days) for Items 1 (itch) and 2 (sleep disturbance) for the lebrikizumab Q2W and Q4W treatment arms. Observed (excluding data collected after treatment discontinuation, rescue medication use, or patient transfer to escape arm) results were reported. RESULTS: At Week 16, for lebrikizumab Q2W and Q4W, 35.9% (n = 37/103) and 39.3% (n = 42/107) of patients responded 0 or 1 to Item 1 of POEM (Itch) and 12.6% (n = 13/103) and 12.1% (n = 13/107) responded 0. A total of 66.0% (n = 68/103) and 72.6% (n = 77/106) of patients responded 0 or 1 to Item 2 of POEM (Sleep) and 37.9% (n = 39/103) and 44.3% (n = 47/106) responded 0, respectively. By Week 52, for lebrikizumab Q2W and Q4W, 44.6% (n = 29/65) and 48.0% (n = 36/75) responded 0 or 1 to Item 1 of POEM (Itch), and 21.5% (n = 14/65) and 18.7% (n = 14/75) of patients responded 0. A total of 83.1% (n = 54/65) and 78.4% (n = 58/74) responded 0 or 1 to Item 2 of POEM (Sleep), and 67.7% (n = 44/65) and 59.5% (n = 44/74) responded 0, respectively. CONCLUSION: Weekly POEM responses for itch and sleep disturbance remained stable between doses and visits, and continued to improve from Week 16 through 52, in lebrikizumab-treated patients, demonstrating consistent improvement over time for key AD symptoms. TRIAL REGISTRATION NUMBERS: ADvocate1 (NCT04146363) and ADvocate2 (NCT04178967).

Prevalence of pruritus in the elderly in an outpatient dermatologic clinic: a monocentric pilot study.

Few studies have examined pruritus in elderly patients, a common dermatological condition. The study examines pruritus prevalence and characteristics in elderly patients referred to the Dermatology Unit, at Genoa's Galliera Hospital. The demographic characteristics of all Outpatient Clinic patients with any skin condition were examined, focusing on pruritus patients over 65. Pruritus was present in 36/262 patients (14%; M:F =20:16; mean age: 59.55 years). About 14% of 140 patients aged ≥65 years had pruritus, with 20/262 (8%; M:F =14:6; mean age: 74.6 years) exhibiting it. Visual analog score pruritus did not differ between patients aged ≥65 years (20/36) and <65 years (16/36) statistically. In 89% of patients, itch was related to a dermatological condition, mainly psoriasis. Only extracutaneous diseases resulted more frequently in the patients aged >65. No anamnestic link was found between drug use and pruritus in these patients. We confirm that pruritus is a common skin problem that affects both sexes, young and old, and is almost always caused by an underlying skin condition (mainly psoriasis). It is rarely caused by a new drug.

LPS exacerbates TRPV4-mediated itch through the intracellular TLR4-PI3K signalling.

Pruritus is often accompanied with bacterial infections, but the underlying mechanism is not fully understood. Although previous studies revealed that lipopolysaccharides (LPS) could directly activate TRPV4 channel and TRPV4 is involved in the generation of both acute itch and chronic itch, whether and how LPS affects TRPV4-mediated itch sensation remains unclear. Here, we showed that LPS-mediated TRPV4 sensitization exacerbated GSK101-induced scratching behaviour in mice. Moreover, this effect was compromised in TLR4-knockout mice, suggesting LPS acted through a TLR4-dependent mechanism. Mechanistically, LPS enhanced GSK101-evoked calcium influx in mouse ear skin cells and HEK293T cells transfected with TRPV4. Further, LPS sensitized TRPV4 channel through the intracellular TLR4-PI3K-AKT signalling. In summary, our study found a modulatory role of LPS in TRPV4 function and highlighted the TLR4-TRPV4 interaction in itch signal amplification.

Sleep-loss related to itch in atopic dermatitis: assessing content validity and psychometric properties of a patient-reported sleep-loss rating scale.

BACKGROUND: Sleep loss is a key factor contributing to disease burden in people with atopic dermatitis (AD). Mitigating itch to improve sleep is an important outcome of AD treatment. This study explored the content validity and measurement properties of the Sleep-Loss Scale, a single-item rating scale for assessing itch interference with sleep in clinical trials of AD treatments. METHODS: Concept elicitation and cognitive debriefing interviews were conducted with 21 adults and adolescents (12-17 years of age) with moderate-to-severe AD to develop a conceptual model of patient experience in AD and explore the content validity of the scale. Data collected from adults with moderate-to-severe AD enrolled in a phase 2b study (NCT03443024) were used to assess Sleep-Loss Scale's psychometric performance, including reliability, construct validity, and ability to detect change. Meaningful within-patient change (MWPC) thresholds were also determined using anchor-based methods. RESULTS: Qualitative findings from concept elicitation highlighted the importance of sleep-loss related to itch in AD. Debriefing analysis of the Sleep-Loss Scale indicated that the scale was relevant, appropriate, and interpreted as intended. Trial data supported good reliability, construct validity and ability to detect improvement. MWPC was defined as a 1-point improvement using trial data, a finding supported by qualitative data. CONCLUSIONS: The Sleep-Loss Scale provides a valid and reliable patient-reported measure of the impact of itch on sleep in patients with AD, and can detect change, indicating it is fit-for-purpose to evaluate the efficacy of AD treatments in moderate-to-severe patients.

Device-based physical therapies in chronic pruritus: A narrative review.

Chronic pruritus is a highly prevalent disease associated with high psychosocial and economic burdens. In addition to pharmacological treatments, device-based physical therapies also offer antipruritic effects. Phototherapy, laser, electrical neurostimulation technologies, acupuncture, cryotherapy, and cold atmospheric plasma are, in part, still experimental but emerging treatment options that augment our repertoire to treat patients with chronic pruritus. In this narrative review, we provided an overview of these physical modalities and their role in itch management.

Itch and Pain Behaviors in Irritant Contact Dermatitis Produced by Sodium Lauryl Sulfate in Mice.

Irritant contact dermatitis (ICD) is a nonspecific skin inflammation caused by irritants, leading to itch and pain. We tested whether differential responses to histamine-dependent and -independent pruritogens can be evoked in ICD induced by sodium lauryl sulfate (SLS). An ICD mouse model was established with 5% SLS in acetone versus a vehicle topically applied for 24 h to the cheek. Site-directed itch- and pain-like behaviors, occurring spontaneously and in response to mechanical, thermal, and chemical stimuli (histamine, ß-alanine, BAM8-22, and bradykinin) applied to the cheek, were recorded before (day 0) and after irritant removal (days 1, 2, 3, and 4). Skin inflammation was assessed through visual scoring, ultrasound, and measurements of skin thickness. SLS-treated mice exhibited hyperalgesia-like behavior in response to mechanical and heat stimuli on day 1 compared to the controls. SLS mice exhibited more spontaneous wipes (pain) but not scratching bouts (itch) on day 1. Pruritogen injections caused more scratching but not wiping in SLS-treated mice compared to the controls. Only bradykinin increased wiping behavior compared to saline. SLS-treated mice developed noticeable erythema, scaling, and increased skin thickness on days 1 and 2. SLS induced cutaneous inflammation and behavioral signs of spontaneous pain and itching, hyperalgesia to mechanical and heat stimuli and a chemical algogen, and enhanced itch response to pruritogens. These sensory reactions preceded the inflammation peak and lasted up to two days.

Predicting Factors and Clinical Characteristics of Pruritus in Psoriasis: A Cross-Sectional Survey.

Pruritus is an important symptom among patients affected by psoriasis. To date, no general agreement has been established regarding pruritus as a measure of psoriasis severity. This study aims to assess psoriatic pruritis prevalence and characteristics using a comprehensive itch questionnaire. A semi-structured questionnaire consisting of 48 questions was applied to patients diagnosed with psoriasis and admitted to the Dermatology Department of Mures Clinical County Hospital, Romania. A total of 163 patients were enrolled, out of which 115 (70.55%) reported itch. Patients with itch had higher PASI (p = 0.003) and DLQI scores (p < 0.001). The itch was most frequently described as a crawling sensation, mainly located in the lesional skin and aggravated by stress and temperature variation. It had a moderate intensity (6.18 ± 2.46). Emollients were the treatment preferred by most patients in alleviating itch, while biologics exerted a protective effect on itch development (OR = -0.24; p < 0.0001) and negatively correlated with itch intensity (r = -0.23; p < 0.0001). Advanced age, high BMI, and PASI scores were indicators of itch presence, while female gender, high PASI score, and frequent itch episodes indicate highly intense pruritus (≥7 on the VAS). A better understanding of itch and its clinical features will guide physicians toward the best treatment option and would, ultimately, benefit the patient.

Discovery of the first selective, small-molecule GFRα2/3 inhibitors through DNA-encoded library technology.

Studies have shown that disrupting the formation of the ligand-RET-GFRα complex could be an effective way of treating pain and itch. Compared to traditional high-throughput screens, DNA encoded libraries (DELs) have distinguished themselves as a powerful technology for hit identification in recent years. The present work demonstrates the use of DEL technology identifying compound 16 as the first GFRa2/GFRa3 small molecule inhibitor (0.1/0.2 µM respectively) selective over RET. This molecule represents an opportunity to advance the development of small-molecule inhibitors targeting the GFRα-RET interface for the treatment of pain and itch.