Dupilumab in prurigo nodularis: a systematic review of current evidence and analysis of predictive factors to response

[Treatment of chronic prurigo: update and perspectives]

BACKGROUND

Despite the high burden in patients with chronic prurigo (CPG), the first and so far only approved systemic therapy for this disease, dupilumab, has only been available since 2022. Therefore, treatment is mostly based on expert recommendations for off-label therapies. We aim to provide an overview of current therapies and possible future therapeutic drugs for CPG patients, which are currently in clinical trials.

MATERIALS AND METHODS

For this review, a systematic literature and clinical trial search was conducted via PubMed and Clinical Trials using the terms "chronic prurigo", "chronic nodular prurigo", "prurigo nodularis" and "therapy".

CONCLUSION

Multiple new therapeutic agents are currently under investigation in clinical trials, providing promising results for future treatment options. Moreover, an annotated checklist was developed recently to improve therapeutic decision-making in daily clinical practice with CPG patients.

A critical evaluation of nemolizumab for prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) is a chronic inflammatory skin condition that presents with intensely pruritic, hyperkeratotic nodules. The pathophysiology underlying PN is not entirely clear, making treatment challenging. Patients often require a multimodal approach, although many of the available therapies have low efficacy or adverse effects.

AREAS COVERED

In this review, we discuss the use of nemolizumab for the treatment of PN in adults. Nemolizumab is a biological therapy that reduces type 2 cytokines and the neuroimmune response implicated in the pathophysiology of PN. It also helps maintain skin barrier integrity, which may be damaged during the vicious itch-scratch cycle. Nemolizumab has demonstrated great efficacy in improving itch and clearing lesions in recent clinical trials with respectable tolerance.

EXPERT OPINION

Nemolizumab is a promising drug for PN that seems comparable to the recently approved dupilumab in terms of its therapeutic effect and excellent safety profile, although nemolizumab may work more rapidly on itch. JAK inhibitors are also emerging as competitors of biologics for PN, however, their safety profile in this population may differ. Trials evaluating these drugs are needed to assess which is preferable. Additional data on the durability and longevity of nemolizumab for PN treatment is highly anticipated.

Prurigo Nodularis: Pathogenesis and the Horizon of Potential Therapeutics

Chronic pruritus that lasts for over 6 weeks can present in various forms, like papules, nodules, and plaque types, with prurigo nodularis (PN) being the most prevalent. The pathogenesis of PN involves the dysregulation of immune cell-neural circuits and is associated with peripheral neuropathies, possibly due to chronic scratching. PN is a persistent and challenging condition, involving complex interactions among the skin, immune system, and nervous system. Lesional skin in PN exhibits the infiltration of diverse immune cells like T cells, eosinophils, macrophages, and mast cells, leading to the release of inflammatory cytokines and itch-inducing substances. Activated sensory nerve fibers aggravate pruritus by releasing neurotransmitters, perpetuating a vicious cycle of itching and scratching. Traditional treatments often fail, but recent advancements in understanding the inflammatory and itch transmission mechanisms of PN have paved the way for innovative therapeutic approaches, which are explored in this review.

A critical review of dupilumab for adult patients with prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) is a chronic inflammatory skin condition that presents with pruritus and hyperkeratotic nodules. These symptoms impact patients' quality of life and mental health. Treating prurigo nodularis is challenging, and many of the available topical and systemic therapies have limited efficacy and a myriad of adverse effects.

AREAS COVERED

In this article, we discuss the use of dupilumab for adult patients with prurigo nodularis. Dupilumab is a biologic that inhibits Th2-mediated inflammation and has been successfully used to treat a variety of dermatologic disorders. Dupilumab has revolutionized the management of PN, with recent clinical trials showing its efficacy in treating both pruritus and prurigo nodules, as well as improving quality of life. It has a favorable safety profile and is well tolerated. Other novel treatments are also currently under investigation for the treatment of PN, with early studies reporting promising results.

EXPERT OPINION

Dupilumab is becoming the drug of choice for the treatment of PN and may also be effective in treating patients with systemic underlying causes of their PN, although more studies are needed to assess this. Trials evaluating the long-term efficacy and durability of dupilumab in PN are also of interest.

Pruritus Anesis in Dystrophic Epidermolysis Bullosa Pruriginosa with Dupilumab

ABSTRACT

Dystrophic epidermolysis bullosa pruriginosa (DEB-Pr) is a rare subtype of dystrophic epidermolysis bullosa, and traditional treatments have limited efficacy. Dupilumab has demonstrated remarkable efficacy in relieving pruritus. In this case study, after traditional treatment failed, providers recommended the patient begin dupilumab to treat his pruritus. The patient was administrated a loading dose of 600 mg of dupilumab and a dose of 300 mg every 2 weeks. The Dermatology Life Quality Index and Pruritic Numeric Rating Scale were used to assess the patient's situation. After several months, the patient's DEB-Pr was considered in remission. Dupilumab may be a better choice than immunosuppressants for the treatment of pruritus in patients with DEB-Pr.

Potential Indications of Dupilumab in Th-2 Inflammatory Disease

Dupilumab is a fully humanized IgG4 monoclonal antibody, inhibiting IL-4 and IL-13 signaling, which are the main cytokines involved in type 2 inflammatory diseases. Its introduction was a breakthrough in the treatment of moderate-to-severe atopic dermatitis, but it is also used in other inflammatory diseases, including asthma, eosinophilic esophagitis and chronic rhinosinusitis with nasal polyposis. Recent advances in the understanding of inflammatory pathways have revealed that Th2-type inflammation is involved in a wider range of diseases than previously thought. The aim of our review is to examine off-label therapeutic indications of dupilumab, including bullous dermatoses (pemphigus, bullous pemphigoid) and alopecia areata, and to investigate its potential applications in cancer patients on anti-PD1 therapy.

Chronic Prurigo Including Prurigo Nodularis: New Insights and Treatments

Chronic prurigo (CPG) is a neuroinflammatory, fibrotic dermatosis that is defined by the presence of chronic pruritus (itch lasting longer than 6 weeks), scratch-associated pruriginous skin lesions and history of repeated scratching. Patients with CPG experience a significant psychological burden and a notable impairment in their quality of life. Chronic prurigo of nodular type (CNPG; synonym: prurigo nodularis) represents the most common subtype of CPG. As CNPG is representative for all CPG subtypes, we refer in this review to both CNPG and CPG. We provide an overview of the clinical characteristics and assessment of CPG, the burden of disease and the underlying pathophysiology including associated therapeutic targets. The information provided results from a PubMed search for the latest publications and a database search for current clinical trials (ClinicalTrials.gov, EU Clinical Trials Register [European Medicines Agency]; using the following terms or combinations of terms: 'chronic prurigo', 'prurigo', 'prurigo nodularis', 'pathophysiology', 'therapy', 'biologics', 'treatment'). Dupilumab is the first authorized systemic therapy by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for CNPG to date. Topical and systemic agents that are currently under investigation in clinical randomized, placebo-controlled phase II and III trials such as biologics (e.g., nemolizumab, vixarelimab/KPL-716, barzolvolimab/CDX-0159), small molecules (ruxolitinib cream, povorcitinib/INCB054707, abrocitinib) and the opioid modulator nalbuphine are highlighted. In the last past 15 years, several milestones have been reached regarding the disease understanding of CPG such as first transcriptomic analysis, first terminology, first guideline, and first therapy approval in 2022, which contributed to improved medical care of affected patients. The broad range of identified targets, current case observations and initiated trials offers the possibility of more drug approvals in the near future.

Molecular mechanisms of pruritus in prurigo nodularis

Pruritus is the most common symptom of dermatological disorders, and prurigo nodularis (PN) is notorious for intractable and severe itching. Conventional treatments often yield disappointing outcomes, significantly affecting patients' quality of life and psychological well-being. The pathogenesis of PN is associated with a self-sustained "itch-scratch" vicious cycle. Recent investigations of PN-related itch have partially revealed the intricate interactions within the cutaneous neuroimmune network; however, the underlying mechanism remains undetermined. Itch mediators play a key role in pruritus amplification in PN and understanding their action mechanism will undoubtedly lead to the development of novel targeted antipruritic agents. In this review, we describe a series of pruritogens and receptors involved in mediating itching in PN, including cytokines, neuropeptides, extracellular matrix proteins, vasculogenic substances, ion channels, and intracellular signaling pathways. Moreover, we provide a prospective outlook on potential therapies based on existing findings.

Effectiveness of Dupilumab for Chronic Prurigo in Chinese Patients: A Real-World Case Series Study

BACKGROUND

Treatment of chronic prurigo (CPG) is challenging. As an antagonist of IL-4R, dupilumab has shown effectiveness in treating CPG in several clinical studies. Recently, the US Food and Drug Administration (FDA) approved dupilumab for the treatment of prurigo nodularis (PN).

OBJECTIVES

The purpose of this study was to examine the efficacy of dupilumab in Chinese patients with CPG, and to analyze the difference in response between subtypes of CPG.

METHODS

This retrospective study included 18 patients with CPG who were treated with dupilumab for at least 16 weeks from March 2022 to October 2022. Disease severity and patient self-assessment questionnaires were assessed at baseline and each visit, including the peak Pruritus Visual Analogue Scale (PP-VAS), Prurigo Activity and Severity Score (PAS), Investigator Global Assessment (IGA), Dermatology Life Quality Index (DLQI), Hospital Anxiety and Depression Scale (HADS) and Itchy-specific Quality of Life questionnaire (ItchyQoL).

RESULTS

After 2 weeks of dupilumab treatment, pruritus scores were significantly reduced as measured by PP-VAS scores. Prurigo Activity and Severity scores decreased significantly at Week 2, whereas IGA improved significantly at Week 8. The DLQI, HADS, and ItchyQoL scores at Week 16 also showed significant improvement from baseline. Patients in all subtypes showed improvement in pruritus and lesion severity.

CONCLUSIONS

Dupilumab was effective in improving pruritus and lesions in patients with various subtypes of CPG.

Single-cell RNA sequencing defines disease-specific differences between chronic nodular prurigo and atopic dermatitis

BACKGROUND

Chronic nodular prurigo (CNPG) is an inflammatory skin disease that is maintained by a chronic itch-scratch cycle likely rooted in neuroimmunological dysregulation. This condition may be associated with atopy in some patients, and there are now promising therapeutic results from blocking type 2 cytokines such as IL-4, IL-13, and IL-31.

OBJECTIVES

This study aimed to improve the understanding of pathomechanisms underlying CNPG as well as molecular relationships between CNPG and atopic dermatitis (AD).

METHODS

We profiled skin lesions from patients with CNPG in comparison with AD and healthy control individuals using single-cell RNA sequencing combined with T-cell receptor sequencing.

RESULTS

We found type 2 immune skewing in both CNPG and AD, as evidenced by CD4+ helper T cells expressing IL13. However, only AD harbored an additional, oligoclonally expanded CD8A+IL9R+IL13+ cytotoxic T-cell population, and immune activation pathways were highly upregulated in AD, but less so in CNPG. Conversely, CNPG showed signatures of extracellular matrix organization, collagen synthesis, and fibrosis, including a unique population of CXCL14-IL24+ secretory papillary fibroblasts. Besides known itch mediators such as IL31 and oncostatin M, we also detected increased levels of neuromedin B in fibroblasts of CNPG lesions compared with AD and HC, with neuromedin B receptors detectable on some nerve endings.

CONCLUSIONS

These data show that CNPG does not harbor the strong disease-specific immune activation pathways that are typically found in AD but is rather characterized by upregulated stromal remodeling mechanisms that might have a direct impact on itch fibers.

Age of onset defines two distinct profiles of atopic dermatitis in adults

BACKGROUND

The incidence of adult-onset atopic dermatitis (AOAD) is increasing. However, the unique characteristics of AOAD compared to pediatric-onset AD persisting into adulthood (POAD) are underexplored, hampering the development of targeted-therapeutics for this growing population. We thus assessed the profile of AOAD in skin and blood compared to that of POAD.

METHODS

We collected skin biopsies and blood from adults with AOAD, POAD, and healthy controls (n = 15 in each group). Skin samples were analyzed by RNA sequencing, qRT-PCR, and immunohistochemistry, and Olink Proseek multiplex assay was used to identify the serum proteomic profile.

RESULTS

Compared to healthy controls, both AOAD and POAD showed cutaneous immune and barrier dysregulations with a shared Th2/Th22 hyperactivation. Overall, POAD showed greater inflammation in lesional skin, with more prominent expression of Th2/Th17/Th22 markers (CCL17/22, S100A8/9, IL-36A, PI3/Elafin, DEFB4) in POAD compared to AOAD (p-value < .05). In contrast, higher Th1-(IFN-γ, IL-2, IL-15, CCL5) upregulation and Th1-skewing were seen in AOAD. The epidermal barrier was also more compromised in POAD, with greater epidermal hyperplasia and lower expression of markers related to terminal differentiation, lipids, and cell adhesion. In parallel with increased rates of cardiovascular comorbidities, AOAD demonstrated many more significantly dysregulated proteins in serum (n = 148) compared to POAD (n = 86), including pro-inflammatory and cardiovascular-risk markers. Th1-related products showed significant correlations between their skin and blood expressions only in AOAD subjects.

CONCLUSION

Age-of-onset delineates two distinct endophenotypes in adult AD potentially suggesting the need for broader (beyond Th2) therapeutic targeting in AOAD.

Dupilumab for Chronic Prurigo: Case Series on Effectiveness, Safety, and Quality of Life

BACKGROUND

Chronic prurigo (CPG) is a pruritic skin disease, characterized by an itch-scratch cycle and scarring. It reduces patients' quality of life (QoL). Dupilumab is a monoclonal human IgG antibody that inhibits signaling of the interleukin 4 (IL-4) and interleukin 13 (IL-13) pathways through blockade of the IL-4 receptor. Patients with CPG who receive dupilumab often report great improvement in itch and overall QoL. We therefore reviewed our experience in order to follow up on QoL, safety, and treatment response in patients with CPG who received dupilumab.

METHODS

We conducted a real-world retrospective single-center case series. Outcomes were assessed by phone interviews and photographs using validated questionnaires and scores. Demographic data were obtained from the hospital files. Follow-up was up to 2 years. We assessed QoL with the Dermatology Life Quality Index (DLQI) and the Itchy quality of life questionnaire (ItchyQoL). Numerical Rating Scale (NRS) was used to assess itch. Prurigo lesions were documented with the Prurigo activity and severity score (PAS).

RESULTS

Ten patients were included in this study. Results were reported up to 2 years after treatment with dupilumab. The response variables for DLQI, ItchyQoL, NRS, and PAS analyses showed a statistically significant decrease over time (DLQI: p ≤ 0.0001 [-0.84; -1.27], ItchyQoL: p ≤ 0.0001 [-9.89; -18.69], NRS maximum and average: p ≤ 0.0001 [-0.52; -0.86] and p ≤ 0.0001 [-0.55; -0.94], and PAS number of lesions: p = 0.0005 [-1.70; -5.28]). The percent decrease after 1 year of treatment (this estimate is based on model estimates) ranges from -42% to -82%. Four (40%) patients reported mild side effects. No serious side effects were reported.

CONCLUSION

Dupilumab treatment of CGP for up to 2 years is associated with improved QoL and less itching.

Dupilumab Therapy of Prurigo Nodularis: A Single-Center, Real-Life Observational Study

Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by severe itching accompanied by multiple nodules throughout the body. There is currently no effective drug-targeted treatment for PN. Dupilumab is a fully human monoclonal antibody which can suppress the Th2 inflammatory reaction. We aimed to assess the efficacy and safety of dupilumab in PN. There were 29 PN patients who received dupilumab treatment for four months. Serum total immunoglobulin E (Ig E), eosinophil counts, dermatology life quality index (DLQI), and numeric rating scale (NRS) were assessed on patients before and after treatment. We count the vaccination of novel coronavirus pneumonia (COVID-19) in patients and the impact on PN and treatment measures after vaccination. Plotting was performed using GraphPad Prism8, and the statistical analysis was performed using PASW Statistics18. The eosinophil counts in patients higher decreased to normal, and the Ig E levels gradually decreased and tended to normal levels after receiving dupilumab injection. The average DLQI score at the baseline was 23.93 ± 0.66 and decreased to 11.66 ± 0.55 ( $P<0.01$ ) and 1.83 ± 0.22 ( $P<0.01$ ) at 1-month and 6-monthfollow-up of treatment, respectively. The average NRS score at the baseline was 9.79 ± 0.08 and decreased to 3.52 ± 0.23 ( $P<0.01$ ) and 0.31 ± 0.15 ( $P<0.01$ ) at the 1-month and 6-monthfollow-up of treatment, respectively. Our study shows that dupilumab has achieved good efficacy in PN with few adverse reactions and high safety. We can recommend that patients follow the advice of specialists to be vaccinated and under the condition of stable disease, separated from dupilumab treatment for one week.

Serum Mediators in Patients with Both Type 2 Diabetes Mellitus and Pruritus

Chronic pruritus is an unpleasant sensory perception that negatively affects quality of life and is common among patients with type 2 diabetes mellitus. Current antipruritic therapies are insufficiently effective. Thus, the mediation of diabetic pruritus by histamine-independent pathways is likely. The aim of this study was to identify possible mediators responsible for diabetic pruritus. A total of 87 patients with type 2 diabetes mellitus were analysed, of whom 59 had pruritus and 28 did not. The 2 groups were assessed for baseline demographics, serum biochemistry parameters, cytokines, and chemokines. This study also investigated the associations of these factors with the severity of itching. Neither haemoglobin A1c nor serum creatinine levels were correlated with severity of itching. Significantly higher levels of interleukin-4 (p = 0.004), interleukin-13 (p = 0.006), granulocyte-macrophage colony-stimulating factor (p < 0.001) and C-X-C motif chemokine ligand 10 (p = 0.028) were observed in the patients with pruritus than in those without pruritus. Moreover, the levels of these mediators were positively correlated with the severity of itching. Thus, novel antipruritic drugs can be developed to target these molecules. This is the first study to compare inflammatory mediators comprehensively in patients with diabetes mellitus with pruritus vs those without pruritus.

Generalized prurigo nodularis with dramatic response to dupilumab treatment: A case report

BACKGROUND

Prurigo nodularis (PN) is a chronic condition characterized by a papulonodular pruriginous eruption of unknown aetiology. Currently, there are no medications for PN that the United States Food and Drug Administration has approved, which leads to very variable practices in the prescription of off-label treatments. Treatment of PN is based on clinical experience rather than controlled trials. We present our case of generalized PN, in which we had a dramatic response with dupilumab.

CASE SUMMARY

A 58-year-old female patient was admitted to our clinic with severe itchy, erythematous nodular lesions that were widespread all over her body, especially on the legs and back. It was learned that the patient's complaints started 4 years ago, and there was a significant increase in the lesions in the last period. Dermatological examination revealed diffuse firm erythematous excoriated nodular lesions all over the body. In the blood tests of the patient, serum Immunoglobulin E (IgE) was measured at 9330 IU/mL. The patient was diagnosed with generalized prurigo nodularis together with clinical and histopathological findings. Due to severe clinical findings and the presence of comorbidities, dupilumab treatment was planned for the patient. In the follow-up 4 mo later, it was observed that all nodular lesions healed with postinflammatory hypopigmentation. The IgE value decreased to 1500 IU/mL after 4 mo of dupilumab treatment.

CONCLUSION

Dupilumab treatment stands out as an effective and safe systemic treatment agent among existing systemic treatments.

Dupilumab for the treatment of prurigo nodularis: A systematic review

Background

Conventional treatment techniques have limited efficacy and more side effects in the treatment of prurigo nodularis. The better alternative treatment option for better outcomes of the disease is dupilumab.

Objective

The objective of this study was to systematically review dupilumab-related treatment outcomes in prurigo nodularis.

Methods

Several databases like Embase, PubMed, Web of Science, and Cochrane library were searched for data acquisition on October 8, 2022. Based on Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, 24 publications were included in this study.

Results

After 4,12,16 and more than 16 weeks of dupilumab treatment, 8.3% (n=5/60), 34.4% (n=11/32), 3.6% (n=2/56), and 45.3% (n=29/64) of patients had complete remission, respectively. In addition, 85.0% (n=51/60), 59.4% (n=19/32), 83.9% (n=47/56), and 43.8% (n=28/64) had partial remission, respectively. Moreover, 6.7% (n=4/60), 6.3% (n=2/32), 12.5% (n=7/56), and 10.9% (n=7/64) showed no remission, respectively, and significant reduction of numeric rating scale itch intensity (from 9.0 to 4.9, 2.1, 2.8, 0.9) was attained. There were no serious adverse events observed during treatment, but the most common event observed was conjunctivitis (12.6%, n=15/119).

Conclusions

Dupilumab has definite effectiveness and safety in prurigo nodularis treatment.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier (CRD42022365802).

Circulating plasma IL-13 and periostin are dysregulated type 2 inflammatory biomarkers in prurigo nodularis: A cluster analysis

Importance

Prurigo nodularis (PN) is a chronic heterogeneous inflammatory skin disease.

Objective

To elucidate which components of type 2 inflammation are dysregulated systemically in PN.

Design

Whole blood was obtained from PN patients with uncontrolled disease and control patients without pruritus. Plasma was assayed for IL-4, IL-5, IL-13, IgE, and periostin. ANOVA was utilized to compare PN and control patients and multiple-hypothesis adjusted p-value was calculated with the significance threshold at 0.05. Clustering was performed using K-means clustering.

Participants

PN patients (n = 29) and controls (n = 18) from Johns Hopkins Dermatology had similar age sex, and race distributions.

Results

Single-plex assays of the biomarkers demonstrated elevated circulating plasma IL-13 (0.13 vs. 0.006 pg/mL, p = 0.0008) and periostin (80.3 vs. 60.2 ng/mL, p = 0.012) in PN compared to controls. IL-4 (0.11 vs. 0.02 pg/mL, p = 0.30) and IL-5 (0.75 vs. 0.40 pg/mL, p = 0.10) were not significantly elevated, while IgE approached significance (1202.0 vs. 432.7 ng/mL, p = 0.08). Clustering of PN and control patients together revealed two clusters. Cluster 1 (n = 36) consisted of 18 PN patients and 18 controls. Cluster 2 (n = 11) consisted entirely of PN patients (p < 0.01). Cluster 2 had higher levels of IL-13 (0.33 vs. 0.008 pg/mL, p = 0.0001) and IL-5 (1.22 vs. 0.43 pg/mL, p = 0.03) compared to cluster 1.

Conclusion and relevance

This study demonstrates elevation of IL-13 and periostin in the blood of PN patients, with distinct clusters with varying degrees of type 2 inflammation. Given this heterogeneity, future precision medicine approaches should be explored in the management of PN.

Boxed Warnings and Off-Label Use of Allergy Medications: Risks, Benefits, and Shared Decision Making

The Food and Drug Administration is tasked with evaluating the efficacy and safety of a drug. Despite having a regimented appraisal process in place, safety evidence can emerge during clinical trials as well as from observations and studies conducted after the drug has been on the market, which might require a boxed warning. The boxed warning is the most severe warning that the Food and Drug Administration can give to an approved drug. It is commonly referred to as a Black Box Warning because it is outlined in the package insert by a thick black box to garner the attention of prescribers and patients. There are currently more than 400 medications that have boxed warnings, and the information addressing major risks associated with a particular drug may, appropriately or inappropriately, influence patient and clinician decision making. Health care professionals must use the best evidence and clinical judgment in determining whether to prescribe medications with these warnings. Use of an approved drug at dosages or for indications other than what it was originally licensed for is referred to as "off-label" and is legal, commonplace, and may be evidence-based. All drugs may expose patients to possible harm, so prescribers have an obligation to discuss the best available evidence regarding benefits and harms so that patients can participate in shared decision making.

Chronic Nodular Prurigo: An Update on the Pathogenesis and Treatment

Chronic nodular prurigo (CNPG) is a recalcitrant chronic itchy disorder that affects the quality of life. It can be triggered by multiple etiologies, such as atopic dermatitis, diabetes, and chronic renal diseases. The mechanisms of CNPG are complicated and involved the interaction of the cutaneous, immune, and nervous systems. Diverse immune cells, including eosinophils, neutrophils, T cells, macrophages, and mast cells infiltrated the lesional skin of CNPG, which initiated the inflammatory cytokines and pruritogens release. In addition, the interaction between the immune cells and activated peripheral sensory nerve fibers by neurotransmitters caused neuroinflammation in the skin and intractable itch. This itch-scratch vicious cycle of CNPG results in disease exacerbation. CNPG is difficult to treat with traditional therapies. Recently, great advances have been made in the pathophysiology of both inflammation and pruritus transmission in CNPG. In this review, we summarize the updated mechanisms and novel therapies for CNPG.

The use of dupilumab in patients with HIV

BACKGROUND

The goal of this study was to complete the first Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) based systematic review of dupilumab use in patients living with human immunodeficiency virus (HIV).

METHODS

A systematic literature review was performed using PubMed, Google Scholar, Ovid MEDLINE, and Science Direct databases as well as an internal review using University of Virginia's electronic medical record system. All reports of dupilumab use in patients with confirmed HIV were included.

RESULTS

14 published cases comprising 23 patients were identified and included in the review. Additionally, four unpublished cases from our own institution were included for a final cohort of 27 patients. A total of 25 patients (96%) were observed to have a clinical response, defined as improvement or complete resolution of their cutaneous or asthmatic symptoms. In 100% of patients, viral load improved or did not change, and in 80% of patients, CD4 counts remained stable. Side effects occurred in 48% of patients but were self-limited.

DISCUSSION AND CONCLUSIONS

All reported cases indicate that dupilumab is safe in patients with HIV with stable CD4 counts and low viral loads. Most patients had significant improvement within 2 months of treatment with mild side effects.

Nemolizumab efficacy in prurigo nodularis: onset of action on itch and sleep disturbances

BACKGROUND

Patients with prurigo nodularis (PN) have multiple itchy nodules, impaired quality of life and sleep deprivation. Prurigo nodularis patients have a high burden of disease, primarily due to the intensity of the itch. It is reasonable to expect that rapid relief of itch - and associated improvement of sleep - are highly valued clinical outcomes for patients. Nemolizumab is an IL-31A-receptor inhibitor that modulates the neuroimmune response with reported positive efficacy and safety data in a phase 2 study of PN.

OBJECTIVES

To evaluate the onset of action of nemolizumab on itch and sleep disturbances.

METHODS

Post hoc analysis of a phase 2 trial of nemolizumab 0.5 mg/kg SC vs. placebo in patients (n = 70) with moderate-to-severe PN (≥20 nodules) and severe pruritus (NRS ≥ 7). Time to significant reduction was assessed for peak pruritus (PP) and sleep disturbance (SD) using numerical rating scales (NRS), also assessed was scratching time during sleep.

RESULTS

Nemolizumab significantly reduced itch vs. placebo within 48 h (PP NRS -19.5% vs. -5.8%, respectively, P = 0.014). Significant difference between nemolizumab and placebo in reducing itch by ≥4 on PP NRS was achieved at Day 3 (23.5% vs. 0%, P < 0.001). A significant difference in SD NRS was reported by Day 4 (-24.0% vs. -4.3% placebo, P = 0.012). In addition, there was a separation between groups in SD responders (decrease of ≥4 points) in favour of nemolizumab by Day 2 (8.8% vs. 0%, P = 0.037). Sleep continued improving through Week 4, when there was a -56.0% reduction in SD NRS vs. -22.9% placebo (P < 0.001). Actigraphy data showed improvement in scratch/sleep duration for nemolizumab vs. placebo, respectively, by Week 1 (-32.15 vs. +28.15 min/h, P = 0.001).

CONCLUSION

Nemolizumab has a rapid and robust onset of action in PN with itch reduction and improvement of sleep within 48 h.

[Update on the treatment of chronic prurigo]

Chronic prurigo is an inflammatory dermatosis defined by the presence of chronic pruritus and single to multiple symmetrically distributed pruriginous lesions such as nodules, papules, and plaques. Various dermatological, systemic, neurological, and/or psychiatric diseases are associated with chronic prurigo. The care of these patients is very complex due to the multifactorial character and also because of the sometimes very pronounced consequences such as an impairment of quality of life with sleep disorders. Furthermore, there are no approved therapies. The current guideline-based treatment recommendations include topical application of steroids, capsaicin, calcineurin inhibitors, phototherapy, and systemic use of gabapentinoids, μ‑opioid receptor antagonists, immunosuppressants, or dupilumab. Results from randomized controlled trials and case series on new therapies including biologics (e.g., nemolizumab) and Janus kinase inhibitors are promising. This article provides an overview of currently available treatment options and discusses the latest data on the efficacy of future therapies.

Efficacy of dupilumab in chronic prurigo and chronic idiopathic pruritus: A systematic review of current evidence and analysis of response predictors

Dupilumab has demonstrated a great reduction on chronic pruritus that is the hallmark of atopic dermatitis (AD). Underscoring relevant pathogenesis similarities emerging from AD, chronic idiopathic pruritus (CIP) and chronic prurigo (CP), several authors suggested the beneficial role of dupilumab in these conditions. The evidence on this subject is limited with no precise data available. In this study, we carried out a systematic literature review in order to evaluate the efficacy of dupilumab on both pruritus and skin manifestations in the two largest retrospective cohorts of patients with CP and CIP and tried to identify potential response predictors. Electronic searches were conducted on 4 databases. Our primary outcome was the improvement in pruritus measured by a reduction in patient's reported numerical rating scale of itch (NRSI) by > 4. Secondary outcomes included: proportion of patients with complete response at the end of treatment, reduction in the number of lesions by the Investigator Global Assessment (IGA), improvement in numerical rating scale of sleep (NRSS), improvement in quality of life measured by the Dermatology Life Quality Index (DLQI), time until patient perceived any improvement (Time-First) and time until patient reported absence of pruritus (Time-Final). Descriptive statistics were calculated for each demographic and clinical variable. Univariate logistic regression analyses were conducted to explore association between response to dupilumab and potential predictive factors. We included 25 articles in the analysis, counting a total of 153 patients. Based on CP patients' cohort (n=132), the mean NRSI at baseline was 8.79 ±0.86 and the NRSI final was 2.32 ±1.27. The mean time to first improvement was 5.18 ±3.13 weeks, while the time to complete improvement of pruritus (Time-final) was 13.6 ±12.0 weeks. Ninety patients out of 109 (83%) noticed improvement in pruritus before 4 weeks of dupilumab therapy. At the end of treatment, 18 patients out of 126 (14%) had a complete remission of pruritus and 110 patients out of 123 (89%) had a reduction of NRSI > 4. The reduction in NRSI was significantly greater in patients improving before 4 weeks of treatment (6.57 ±1.71) compared to patients improving in more than 4 weeks (5.49 ±1.39, p<0.001). Patients with history of AD and those who have been previously treated with cyclosporine or methotrexate had a significantly lower reduction in NRSI (e.g. 6.05 ±1.34 vs 7.08 ±1.90 p<0.01 for non-associated AD patients). Based on CIP patient's cohort (n=21), the mean NRSI at baseline was 8.33 ±0.80 and the NRSI final was 0.95 ±0.59. The mean time to first improvement was 2 ±0 weeks, while the time to complete improvement (Time-final) was 14.6 ±10 weeks. At the end of treatment, 3 patients out of 21 (14%) had a complete remission of pruritus and 100% of patients had a reduction of NRSI > 4. No serious treatment-emergent adverse events were reported. The most common adverse event was mild conjunctivitis (13 cases). We highlight the importance of one early sign of improvement as predictor of the future response to dupilumab: the improvement before 4 weeks of treatment that leads significantly to a greater final reduction in NRSI. Furthermore, patients with the presence or history of atopy appear to be less responsive to dupilumab than non-atopic patients and develop more side effects, in particular conjunctivitis.

Immunotargets and Therapy for Prurigo Nodularis

Prurigo nodularis is a chronic inflammatory skin disease consisting of severely pruritic nodules that can be very debilitating for patients. The basis of this skin condition is immunological dysregulation and neural amplification, driven by T-lymphocytes, mast cells, eosinophilic granulocytes, macrophages, and cytokines mediating itchy processes. Further complicating this already taxing diagnosis is the lack of approved treatment and consensus on management; although there are off-label treatments utilized as therapy. Immunomodulators are the cornerstone of treatment for PN, and additional novel therapies targeting key players in the immunological cascade are currently undergoing investigation. In this review, we will highlight targets of the immune cascade and explore current immunomodulating treatments as well as immunotherapies on the horizon for the management of prurigo nodularis.

Efficacy and safety of oral nalbuphine extended release in prurigo nodularis: results of a phase 2 randomized controlled trial with an open-label extension phase

BACKGROUND

Treatment of prurigo nodularis (PN) is challenging and new treatment options are needed.

OBJECTIVE

To evaluate the efficacy and safety of two oral doses of the kappa opioid agonist and mu opioid antagonist nalbuphine extended release (NAL-ER) tablets in a phase 2, multicentre, randomized, double-blind, placebo-controlled trial with an open-label, 50-week extension phase.

METHODS

Subjects with moderate-to-severe PN were randomized to NAL-ER 81 mg (NAL-ER81) or 162 mg (NAL-ER162) tablets twice-daily or placebo for 8 weeks of stable dosing following a 2-week titration period. Subjects completing Week 10 with a Worst Itch Numerical Rating Scale (WI-NRS) score ≥5 at the time of rollover (or during the observation period) were eligible for open-label treatment.

RESULTS

Of 63 randomized subjects, 62 were treated and comprised the modified intent-to-treat population (MITT), 50 completed 10 weeks of treatment. In the MITT analysis, 8 subjects (44.4%) treated with NAL-ER162 (P = 0.32) and 6 (27.3%) treated with NAL-ER81 (P = 0.78) achieved ≥30% reduction from baseline in 7-day WI-NRS at Week 10 (primary efficacy endpoint) vs. 8 (36.4%) in the placebo group. Itch reduction was significant among 8/12 (66.7%) subjects completing Week 10 treated with NAL-ER162 vs. placebo (8/20, 40.0%; P = 0.03). Additionally, 6 subjects (33.3%) treated with NAL-ER162 and 3 (13.6%) treated with NAL-ER81 achieved ≥50% reduction from baseline in 7-day WI-NRS at Week 10 (coprimary endpoint). Extended open-label treatment was associated with further improvements in itch reduction and favourable changes in PN lesion activity as assessed by Prurigo Activity Score. Adverse events occurred predominantly during dose titration and were of mild-to-moderate severity. The safety profile did not change with extended open-label treatment.

CONCLUSION

In adult subjects with PN, oral treatment with NAL-ER 162 mg twice daily provided measurable anti-pruritic efficacy in subjects completing ≥10 weeks of treatment and was well tolerated (ClinicalTrials.gov: NCT02174419).

Comparison of Epidermal Barrier Integrity in Adults with Classic Atopic Dermatitis, Atopic Prurigo and Non-Atopic Prurigo Nodularis

A deficient epidermal barrier is a key feature of atopic dermatitis (AD) and comprises altered lipid and protein content and composition of the stratum corneum resulting in disturbed water balance. Clinically, eczematous lesions on dry skin and pruritus develop. Pruritic nodules occur in prurigo nodularis (PN), another chronic skin disease, which can be associated with atopy. We aimed at comparing the three clinical pictures, classic AD, atopic prurigo (AP), and non-atopic PN, to healthy controls regarding the epidermal barrier. We determined clinical parameters and performed biophysical measurements, histology/immunohistochemistry, electron microscopy, and molecular biological analysis. We found distinctively elevated clinical scores, reduced hydration and increased transepidermal water loss, epidermal hyperplasia and inflammation reduced filaggrin and increased loricrin and involucrin expression, as well as reduced intercellular lipid lamellae in all three disease groups. These findings show a severe disruption in epidermal barrier structure and function in all three disorders so that epidermal barrier impairment is now proven not only for AD but also for PN.

Therapeutic potential of biologics in prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) or chronic prurigo of nodular type (CNPG) is a subtype of chronic prurigo with severe pruritus and neuroimmune underlying pathophysiology occurring in a plethora of dermatological, systemic, neurologic, and psychiatric conditions.

AREAS COVERED 

We review the increasing repertoire of biologics in the treatment of CNPG focusing on those targeting interleukins 4, 13, 31, oncostatin M and IgE. Presented information is based on a database research on current clinical trials (clinicaltrials.gov, European Clinical Trials Database (EudraCT), US clinical trial registry ICH-GCP) and a PubMed search for latest publications conducted with the combinations of the terms 'chronic prurigo,' 'prurigo nodularis,' 'pathophysiology,' 'treatment,' 'therapy', and 'biologics.'

EXPERT OPINION

CNPG gets more and more attention as new therapeutic targets have been revealed in recent years, thus allowing the use of targeted approaches. The off-label advent of dupilumab offered advanced insight into the pathogenesis of CNPG and showed an impressive relief of pruritus in the vast majority of patients. New therapies including biologics (e.g. nemolizumab, tralokinumab, lebrikizumab), small molecules (e.g. neurokinin-1 receptor antagonists, janus kinase inhibitors) as well as mu-opioid receptor antagonists and nalbuphine, a μ-antagonist/κ-agonist, are in the pipeline and offer new hope for an improved future patient care.

Dupilumab shows slow, steady effectiveness for intractable prurigo in patients with atopic dermatitis

Prurigo lesions in atopic dermatitis are intractable. This single-center, retrospective study examined dupilumab's clinical effects on intractable prurigo. Twenty adult atopic dermatitis patients (12 with prurigo, eight without) were administrated dupilumab. Its effects on itching and disease severity were examined with Numerical Rating Scale-Itch (NRS-I), Eczema Area and Severity Index (EASI), and Investigator Global Assessment (IGA) scores; body surface areas (BSA); and thymus- and activation-regulated chemokine (TARC), total immunoglobulin (Ig)E, and eosinophil levels. NRS-I scores, EASI scores, TARC levels, and total IgE levels before dupilumab treatment were not statistically different between the prurigo and non-prurigo groups. With dupilumab treatment, NRS-I scores, EASI scores, IGA scores, BSA, TARC levels, and total IgE levels were significantly reduced from baseline in both groups at 1-2 months and onward, but skin symptom improvement in the prurigo group was slower than in the non-prurigo group, as evidenced by significantly higher EASI scores, BSA, and TARC levels at several time points during the 12 months of dupilumab treatment. Prurigo patients were slower in EASI-50 achievement and significantly lower in EASI-90 achievement at 12 months than non-prurigo patients. Adherence to dupilumab was not different, but total equivalent amounts of concomitant therapeutic agents (corticosteroids and tacrolimus) used during dupilumab treatment were significantly higher in the prurigo group (median, 56.2 g/week) than in the non-prurigo group (median, 33.7 g/week). There were 2.2 adverse events per patient on average; ocular complaints were most frequent. Dupilumab was effective in treating intractable prurigo, but despite significantly greater concomitant therapeutic agent use, skin symptom improvement was slower in prurigo patients than in non-prurigo patients.

Dupilumab as promising treatment for prurigo nodularis: current evidences

Prurigo nodularis (PN) is a debilitating chronic disease characterized by intense itching and excoriated hyperkeratotic nodules distributed on the trunk and extremities, especially the extensor surfaces. The pathophysiology includes complex and not yet well-understood mechanisms involving inflammation and dysregulation of the nervous system. Currently, there are no approved therapies by the Food and Drug Administration (FDA) and the few treatment approaches for this condition are often ineffective and related to severe side effects. An emerging therapeutic option is dupilumab, a monoclonal antibody for adults and adolescents with moderate-to-severe atopic dermatitis, that inhibits interleukin-4 receptor alpha subunit (IL4-Rα) and the signaling pathways activated by interleukin (IL)-4 and IL-13. These cytokines seem to be involved in the development and perpetuation of PN and other type-2 inflammation diseases. Data on this topic are limited, but the emergent positive effects of this drug, reported in the literature and summarized in this review, suggest that it can be a safe and efficient therapy in PN.