Prurigo nodularis: new insights into pathogenesis and novel therapeutics.

Prurigo nodularis (PN) is an inflammatory skin condition characterized by intensely pruritic nodules on the skin. Patients with PN suffer from an intractable itch-scratch cycle leading to impaired sleep, psychosocial distress and a significant disruption in quality of life. The pathogenesis of PN is associated with immune and neural dysregulation, mediated by inflammatory cytokines [such as interleukin (IL)-4, -13, -17, -22 and -31] and neuropeptides (such as substance P and calcitonin gene-related peptide). There is a role for type 2 inflammation in PN in addition to T-helper (Th)17 and Th22-mediated inflammation. The neuroimmune feedback loop in PN involves neuropeptides released from nerve fibres that cause vasodilation and further recruitment of inflammatory cells. Inflammatory cells, particularly mast cells and eosinophils, degranulate and release neurotoxins, as well as nerve growth factor, which may contribute to the neuronal hyperplasia seen in the dermis of patients with PN and neural sensitization. Recent studies have also indicated underlying genetic susceptibility to PN in addition to environmental factors, the existence of various disease endotypes centred around degrees of type 2 inflammation or underlying myelopathy or spinal disc disease, and significant race and ethnicity-based differences, with African Americans having densely fibrotic skin lesions. Dupilumab became the first US Food and Drug Administration-approved therapeutic for PN, and there are several other agents currently in development. The anti-IL-31 receptor A inhibitor nemolizumab is in late-stage development with positive phase III data reported. In addition, the oral Janus kinase (JAK) 1 inhibitors, abrocitinib and povorcitinib, are in phase II trials while a topical JAK1/2 inhibitor, ruxolitinib, is in phase III studies.

Prurigo nodularis (PN) is a chronic skin condition featuring extremely itchy nodules on the skin of the legs, arms and trunk of the body. PN affects approximately 72 per 100 000 people and the severe itch associated with the condition can negatively impact a person's sleep, work and social life. However, the cause of PN remains unclear. Current understanding of PN is based on imbalances in the immune system leading to widespread inflammation as well as dysregulation of the nerves in the skin. Immune molecules released from T cells [such as interleukin (IL)-4, -13, -31, -17, -22 and -31] increase systemic inflammation and are elevated in people with PN. Activated inflammatory cells (such as mast cells or eosinophils) may also release factors that promote inflammation, itch and neural changes within the skin. Neural dysregulation in PN features a lower density of itch-sensing nerve fibres in the epidermis (upper layer of the skin) and a higher density of itch-sensing nerve fibres in the dermis (lower layer of the skin). Because the pathogenesis of PN is not fully understood, the therapies available for PN have had limited success in reducing itch and nodules. The only drug currently approved for PN in the USA and Europe is dupilumab, an IL-4Rα inhibitor that blocks signalling through IL-4 and IL-13, which is undergoing post-marketing surveillance. Other new drugs are being assessed in various phases of clinical trials, including nemolizumab, vixarelimab, barzolvolimab, ruxolitinib, abrocitinib, povorcitinib and nalbuphine.

An Oral Interleukin-23-Receptor Antagonist Peptide for Plaque Psoriasis.

BACKGROUND: The use of monoclonal antibodies has changed the treatment of several immune-mediated inflammatory diseases, including psoriasis. However, these large proteins must be administered by injection. JNJ-77242113 is a novel, orally administered interleukin-23-receptor antagonist peptide that selectively blocks interleukin-23 signaling and downstream cytokine production. METHODS: In this phase 2 dose-finding trial, we randomly assigned patients with moderate-to-severe plaque psoriasis to receive JNJ-77242113 at a dose of 25 mg once daily, 25 mg twice daily, 50 mg once daily, 100 mg once daily, or 100 mg twice daily or placebo for 16 weeks. The primary end point was a reduction from baseline of at least 75% in the Psoriasis Area and Severity Index (PASI) score (PASI 75 response; PASI scores range from 0 to 72, with higher scores indicating greater extent or severity of psoriasis) at week 16. RESULTS: A total of 255 patients underwent randomization. The mean PASI score at baseline was 19.1. The mean duration of psoriasis was 18.2 years, and 78% of the patients across all the trial groups had previously received systemic treatments. At week 16, the percentages of patients with a PASI 75 response were higher among those in the JNJ-77242113 groups (37%, 51%, 58%, 65%, and 79% in the 25-mg once-daily, 25-mg twice-daily, 50-mg once-daily, 100-mg once-daily, and 100-mg twice-daily groups, respectively) than among those in the placebo group (9%), a finding that showed a significant dose-response relationship (P<0.001). The most common adverse events included coronavirus disease 2019 (in 12% of the patients in the placebo group and in 11% of those across the JNJ-77242113 dose groups) and nasopharyngitis (in 5% and 7%, respectively). The percentages of patients who had at least one adverse event were similar in the combined JNJ-77242113 dose group (52%) and the placebo group (51%). There was no evidence of a dose-related increase in adverse events across the JNJ-77242113 dose groups. CONCLUSIONS: After 16 weeks of once- or twice-daily oral administration, treatment with the interleukin-23-receptor antagonist peptide JNJ-77242113 showed greater efficacy than placebo in patients with moderate-to-severe plaque psoriasis. (Funded by Janssen Research and Development; FRONTIER 1 ClinicalTrials.gov number, NCT05223868.).

Phase 3 Trial of Nemolizumab in Patients with Prurigo Nodularis.

BACKGROUND: Prurigo nodularis is a chronic, debilitating, and severely pruritic neuroimmunologic skin disease. Nemolizumab, an interleukin-31 receptor alpha antagonist, down-regulates key pathways in the pathogenesis of prurigo nodularis. METHODS: In this phase 3, double-blind, multicenter, randomized trial, we assigned adults with moderate-to-severe prurigo nodularis to receive an initial 60-mg dose of nemolizumab followed by subcutaneous injections of 30 mg or 60 mg (depending on baseline weight) every 4 weeks for 16 weeks or matching placebo. The primary end points were an itch response (a reduction of ≥4 points on the Peak Pruritus Numerical Rating Scale [PP-NRS; scores range from 0 to 10, with higher scores indicating more severe itch]) and an Investigator's Global Assessment (IGA) response (a score of 0 [clear] or 1 [almost clear] on the IGA [scores range from 0 to 4] and a reduction from baseline to week 16 of ≥2 points). There were five key secondary end points. RESULTS: A total of 274 patients underwent randomization; 183 were assigned to the nemolizumab group, and 91 to the placebo group. Treatment efficacy was shown with respect to both primary end points at week 16; a greater percentage of patients in the nemolizumab group than in the placebo group had an itch response (56.3% vs. 20.9%; strata-adjusted difference, 37.4 percentage points; 95% confidence interval [CI], 26.3 to 48.5), and a greater percentage in the nemolizumab group had an IGA response (37.7% vs. 11.0%; strata-adjusted difference, 28.5 percentage points; 95% CI, 18.8 to 38.2) (P<0.001 for both comparisons). Benefits were observed for the five key secondary end points: itch response at week 4 (41.0% vs. 7.7%), PP-NRS score of less than 2 at week 4 (19.7% vs. 2.2%) and week 16 (35.0% vs. 7.7%), and an improvement of 4 or more points on the sleep disturbance numerical rating scale (range, 0 [no sleep loss] to 10 [unable to sleep at all]) at week 4 (37.2% vs. 9.9%) and week 16 (51.9% vs. 20.9%) (P<0.001 for all comparisons). The most common individual adverse events were headache (6.6% vs. 4.4%) and atopic dermatitis (5.5% vs. 0%). CONCLUSIONS: Nemolizumab monotherapy significantly reduced the signs and symptoms of prurigo nodularis. (Funded by Galderma; ClinicalTrials.gov number, NCT04501679; EudraCT number, 2019-004789-17.).

Characterisation of IL-23 receptor antagonists and disease relevant mutants using fluorescent probes.

Association of single nucleotide polymorphisms in the IL-23 receptor with several auto-inflammatory diseases, led to the heterodimeric receptor and its cytokine-ligand IL-23, becoming important drug targets. Successful antibody-based therapies directed against the cytokine have been licenced and a class of small peptide antagonists of the receptor have entered clinical trials. These peptide antagonists may offer therapeutic advantages over existing anti-IL-23 therapies, but little is known about their molecular pharmacology. In this study, we use a fluorescent version of IL-23 to characterise antagonists of the full-length receptor expressed by living cells using a NanoBRET competition assay. We then develop a cyclic peptide fluorescent probe, specific to the IL23p19:IL23R interface and use this molecule to characterise further receptor antagonists. Finally, we use the assays to study the immunocompromising C115Y IL23R mutation, demonstrating that the mechanism of action is a disruption of the binding epitope for IL23p19.

Immunomodulatory IL-23 receptor antagonist peptide nanocoatings for implant soft tissue healing.

OBJECTIVE: Peri-implantitis, caused by an inflammatory response to pathogens, is the leading cause of dental implant failure. Poor soft tissue healing surrounding implants - caused by inadequate surface properties - leads to infection, inflammation, and dysregulated keratinocyte and macrophage function. One activated inflammatory response, active around peri-implantitis compared to healthy sites, is the IL-23/IL-17A cytokine axis. Implant surfaces can be synthesized with peptide nanocoatings to present immunomodulatory motifs to target peri-implant keratinocytes to control macrophage polarization and regulate inflammatory axises toward enhancing soft tissue healing. METHODS: We synthesized an IL-23 receptor (IL-23R) noncompetitive antagonist peptide nanocoating using silanization and evaluated keratinocyte secretome changes and macrophage polarization (M1-like "pro-inflammatory" vs. M2-like "pro-regenerative"). RESULTS: IL-23R antagonist peptide nanocoatings were successfully synthesized on titanium, to model dental implant surfaces, and compared to nonfunctional nanocoatings and non-coated titanium. IL-23R antagonist nanocoatings significantly decreased keratinocyte IL-23, and downstream IL-17A, expression compared to controls. This peptide noncompetitive antagonistic function was demonstrated under lipopolysaccharide stimulation. Large scale changes in keratinocyte secretome content, toward a pro-regenerative milieu, were observed from keratinocytes cultured on the IL-23R antagonist nanocoatings compared to controls. Conditioned medium collected from keratinocytes cultured on the IL-23R antagonist nanocoatings polarized macrophages toward a M2-like phenotype, based on increased CD163 and CD206 expression and reduced iNOS expression, compared to controls. SIGNIFICANCE: Our results support development of IL-23R noncompetitive antagonist nanocoatings to reduce the pro-inflammatory IL-23/17A pathway and augment macrophage polarization toward a pro-regenerative phenotype. Immunomodulatory implant surface engineering may promote soft tissue healing and thereby reduce rates of peri-implantitis.

The dark side of the moon: the immune-mediated adverse events of IL-17A/IL-17R inhibition.

As aberrant IL-17 signaling plays a critical role in the pathogenesis of psoriasis, biologic agents targeting this pathway have become an important weapon against this disease. Some biologic agents such as IL-17 inhibitors (secukinumab and ixekizumab) and the IL-17 receptor (IL17R) inhibitor (brodalumab) are relatively safe, tolerable and efficacious drugs. Nevertheless, side effects of IL-17 pathway inhibition occur. This review focuses on the dermatological manifestations linked to these treatments. Paradoxical psoriasis and atopic-like eczema may be the most common cutaneous adverse events, while manifestations such as neutrophilic dermatoses, hypersensitivity reactions, lichenoid eruptions, vasculitides, bullous diseases, lupus-like reactions, pigmentation disorders, adnexal diseases and granulomatous dermatoses have been described less frequently.

Trial of Spesolimab for Generalized Pustular Psoriasis.

BACKGROUND: Generalized pustular psoriasis (GPP) is a rare, life-threatening, inflammatory skin disease characterized by widespread eruption of sterile pustules. Interleukin-36 signaling is involved in the pathogenesis of this disorder. Spesolimab, a humanized anti-interleukin-36 receptor monoclonal antibody, is being studied for the treatment of GPP flares. METHODS: In a phase 2 trial, we randomly assigned patients with a GPP flare in a 2:1 ratio to receive a single 900-mg intravenous dose of spesolimab or placebo. Patients in both groups could receive an open-label dose of spesolimab on day 8, an open-label dose of spesolimab as a rescue medication after day 8, or both and were followed to week 12. The primary end point was a Generalized Pustular Psoriasis Physician Global Assessment (GPPGA) pustulation subscore of 0 (range, 0 [no visible pustules] to 4 [severe pustulation]) at the end of week 1. The key secondary end point was a GPPGA total score of 0 or 1 (clear or almost clear skin) at the end of week 1; scores range from 0 to 4, with higher scores indicating greater disease severity. RESULTS: A total of 53 patients were enrolled: 35 were assigned to receive spesolimab and 18 to receive placebo. At baseline, 46% of the patients in the spesolimab group and 39% of those in the placebo group had a GPPGA pustulation subscore of 3, and 37% and 33%, respectively, had a pustulation subscore of 4. At the end of week 1, a total of 19 of 35 patients (54%) in the spesolimab group had a pustulation subscore of 0, as compared with 1 of 18 patients (6%) in the placebo group (difference, 49 percentage points; 95% confidence interval [CI], 21 to 67; P<0.001). A total of 15 of 35 patients (43%) had a GPPGA total score of 0 or 1, as compared with 2 of 18 patients (11%) in the placebo group (difference, 32 percentage points; 95% CI, 2 to 53; P = 0.02). Drug reactions were reported in 2 patients who received spesolimab, in 1 of them concurrently with a drug-induced hepatic injury. Among patients assigned to the spesolimab group, infections occurred in 6 of 35 (17%) through the first week; among patients who received spesolimab at any time in the trial, infections had occurred in 24 of 51 (47%) at week 12. Antidrug antibodies were detected in 23 of 50 patients (46%) who received at least one dose of spesolimab. CONCLUSIONS: In a phase 2 randomized trial involving patients with GPP, the interleukin-36 receptor inhibitor spesolimab resulted in a higher incidence of lesion clearance at 1 week than placebo but was associated with infections and systemic drug reactions. Longer and larger trials are warranted to determine the effect and risks of spesolimab in patients with pustular psoriasis. (Funded by Boehringer Ingelheim; Effisayil 1 ClinicalTrials.gov number, NCT03782792.).

Interleukin-31 promotes fibrosis and T helper 2 polarization in systemic sclerosis.

Systemic sclerosis (SSc) is a chronic multisystem disorder characterized by fibrosis and autoimmunity. Interleukin (IL)-31 has been implicated in fibrosis and T helper (Th) 2 immune responses, both of which are characteristics of SSc. The exact role of IL-31 in SSc pathogenesis is unclear. Here we show the overexpression of IL-31 and IL-31 receptor A (IL-31RA) in dermal fibroblasts (DFs) from SSc patients. We elucidate the dual role of IL-31 in SSc, where IL-31 directly promotes collagen production in DFs and indirectly enhances Th2 immune responses by increasing pro-Th2 cytokine expression in DFs. Furthermore, blockade of IL-31 with anti-IL-31RA antibody significantly ameliorates fibrosis and Th2 polarization in a mouse model of SSc. Therefore, in addition to defining IL-31 as a mediator of fibrosis and Th2 immune responses in SSc, our study provides a rationale for targeting the IL-31/IL-31RA axis in the treatment of SSc.

Single Micelle Vectors based on Lipid/Block Copolymer Compositions as mRNA Formulations for Efficient Cancer Immunogene Therapy.

Immunogene therapy provides a new strategy for the treatment of colorectal cancer. Compared to plasmid DNA, mRNA possesses several advantages as a therapeutic nucleic acid material and shows high potential in cancer therapy. Although efforts have been made to conquer the limited efficiency of mRNA delivery, most of the current mRNA vectors possess complex structures or compositions, which introduces additional toxicity and hinders their further clinical application. Hence, it is highly necessary to develop potent mRNA delivery systems with simple structures. Here, we report efficient mRNA delivery using the biodegradable micelle delivery system of DMP (DOTAP-mPEG-PCL). Biodegradable DMP micelles were simply prepared by the self-assembly of cationic lipid DOTAP and the diblock polymer monomethoxy poly(ethylene glycol)-poly(ε-caprolactone). With an average size of only 30 nm, we proved that these single-structured cationic micelles are highly potent in condensing and protecting mRNA molecules, with a delivery efficiency of 60.59% on C26 mouse colon cancer cells. The micelles triggered specific internalization pathways and were fully degraded in vivo. After binding with IL-22BP (interleukin-22 binding protein)-encoding mRNA, a strongly elevated IL-22BP mRNA level was detected in C26 cells. After intraperitoneal and intratumoral injection of the DMP/mIL-22BP complex, strong inhibition effects on C26 colon cancer models were observed, with high therapeutic efficiency and safety when systemically administrated. These data suggest that the DMP micelle is an advanced single-structured mRNA delivery system with high safety.

The Protective Effects of IL-31RA Deficiency During Bleomycin-Induced Pulmonary Fibrosis.

Idiopathic Pulmonary Fibrosis (IPF) is a severe fibrotic lung disease characterized by excessive collagen deposition and progressive decline in lung function. Th2 T cell-derived cytokines including IL-4 and IL-13 have been shown to contribute to inflammation and fibrotic remodeling in multiple tissues. Interleukin-31 (IL-31) is a newly identified cytokine that is predominantly produced by CD4 Th2 T cells, but its signaling receptor IL-31RA is primarily expressed by non-hematopoietic cells. However, the potential role of the IL-31-IL31RA axis in pulmonary inflammation and fibrosis has remained largely unknown. To determine the role of IL-31RA deficiency in pulmonary fibrosis, wildtype, and IL-31RA knockout mice were treated with bleomycin and measured changes in collagen deposition and lung function. Notably, the loss of IL-31 signaling attenuated collagen deposition and lung function decline during bleomycin-induced pulmonary fibrosis. The total lung transcriptome analysis showed a significant reduction in fibrosis-associated gene transcripts including extracellular matrix and epithelial cell-associated gene networks. Furthermore, the lungs of human IPF showed an elevated expression of IL-31 when compared to healthy subjects. In support, the percentage of IL-31 producing CD4+ T cells was greater in the lungs and PBMCs from IPF patients compared to healthy controls. Our findings suggest a pathogenic role for IL-31/IL-31RA signaling during bleomycin-induced pulmonary fibrosis. Thus, therapeutic targeting the IL-31-IL-31RA axis may prevent collagen deposition, improve lung function, and have therapeutic potential in pulmonary fibrosis.

Anti-pruritic effect of nemolizumab in hemodialysis patients with uremic pruritus: a phase II, randomized, double-blind, placebo-controlled clinical study.

BACKGROUND: The pathophysiology of uremic pruritus (UP), which is characterized by systemic and intractable itching, remains unclear. As interleukin (IL)-31 may be involved, we conducted a phase II, randomized, controlled study to evaluate nemolizumab (anti-IL-31 receptor A antibody) in Japanese hemodialysis patients with UP. METHODS: Patients were randomly assigned (1:1:1:1:1) to one of four double-blind groups (receiving a single subcutaneous injection of nemolizumab 0.125, 0.5, or 2.0 mg/kg, or placebo on Day 1) or an open-label reference group (receiving oral nalfurafine hydrochloride 2.5-5 µg once daily for 12 weeks). The primary endpoint was the difference in the absolute change in pruritus visual analog scale (VAS) at Week 4 between placebo and each nemolizumab group. RESULTS: The primary efficacy endpoint was not met. The mean change from baseline with all three nemolizumab doses at Week 1, and with 0.5 mg/kg at Week 4, was greater than with placebo. Least square mean differences (95% confidence intervals) in the absolute changes between the placebo arm and each nemolizumab arm were - 2.4 (- 19.7, 14.9) for 0.125 mg/kg, - 8.7 (- 26.6, 9.2) for 0.5 mg/kg, and 0.4 (- 17.0, 17.8) for 2.0 mg/kg. Secondary efficacy parameters including the Shiratori severity score and 5-D itch score failed to show between-group differences. Patients with higher serum IL-31 levels at screening tended to have greater pruritus VAS reductions following nemolizumab treatment. CONCLUSIONS: In this phase II study in patients with UP, the primary efficacy parameter was not met. Nemolizumab was generally well tolerated with no clinically significant safety concerns. CLINICAL TRIAL REGISTRATION: JAPIC: JapicCTI-152961, https://www.clinicaltrials.jp/cti-user/trial/ShowDirect.jsp?japicId=JapicCTI-152961 .

Characteristic of chronic plaque psoriasis patients treated with biologics in Italy during the COVID-19 Pandemic: Risk analysis from the PSO-BIO-COVID observational study.

Background: The susceptibility of patients with chronic plaque psoriasis and the risks or benefits related to the use of biological therapies for COVID-19 are unknown. Few data about prevalence, clinical course and outcomes of COVID-19 among psoriatic patients were reported. The aims of this study were 1) to assess the prevalence and severity of COVID-19 in psoriatic patients treated with biologic agents during the first phase of the emergency (22 February to 22 April 2020) in Italy, and 2) to report the clinical outcomes of patients who have been exposed to individuals with confirmed SARS-CoV-2 infection. Methods: Patients with moderate-to-severe chronic plaque psoriasis, aged ≥18 years and undergoing treatment with biologic agents as of 22 February 2020, were eligible to be included in PSO-BIO-COVID study. Demographic and clinical characteristics of patients using any biologic for psoriasis treatment between 22 February and 22 April 2020 were registered. Results: A total of 12,807 psoriatic patients were included in the PSO-BIO-COVID study. In this cohort 26 patients (0.2%) had a swab confirmation of SARS-CoV-2 infection. Eleven patients required hospitalization and two died. Conclusion: The incidence of COVID-19 observed in our cohort of psoriatic patients (0.2%) is similar to that seen in the general population (0.31%) in Italy. However, the course of the disease was mild in most patients. Biological therapies may likely lessen 'cytokine storm' of COVID-19, which sometimes lead to multiple organ failure, ARDS, and death.

Biologics for Atopic Dermatitis.

Atopic dermatitis (AD) is a common chronic inflammatory skin disease that has become a global health problem. The pathophysiology of AD includes both skin barrier and immune abnormalities, with type 2 immune deviation central to several clinical phenotypes and underlying endotypes. Recognition of the persistent nature and systemic aspects of AD provides a rationale for treatment with a biologic. Dupilumab has been approved for patients 6 years of age and older with moderate to severe AD. Monoclonal antibodies are in phase 3 trials and may become part of a precision medicine approach to AD.

Análisis de seguridad de dupilumab en práctica clínica real. Experiencia a 52 semanas de cinco centros de referencia en Andalucía / The Safety of Dupilumab in Clinical Practice: 52 Weeks of Experience at 5 Referral Hospitals in Andalusia

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Potential drug-drug interactions associated with drugs currently proposed for COVID-19 treatment in patients receiving other treatments.

Patients with COVID-19 are sometimes already being treated for one or more other chronic conditions, especially if they are elderly. Introducing a treatment against COVID-19, either on an outpatient basis or during hospitalization for more severe cases, raises the question of potential drug-drug interactions. Here, we analyzed the potential or proven risk of the co-administration of drugs used for the most common chronic diseases and those currently offered as treatment or undergoing therapeutic trials for COVID-19. Practical recommendations are offered, where possible.

De novo development of proteolytically resistant therapeutic peptides for oral administration.

The oral administration of peptide drugs is hampered by their metabolic instability and limited intestinal uptake. Here, we describe a method for the generation of small target-specific peptides (less than 1,600 Da in size) that resist gastrointestinal proteases. By using phage display to screen large libraries of genetically encoded double-bridged peptides on protease-resistant fd bacteriophages, we generated a peptide inhibitor of the coagulation Factor XIa with nanomolar affinity that resisted gastrointestinal proteases in all regions of the gastrointestinal tract of mice after oral administration, enabling more than 30% of the peptide to remain intact, and small quantities of it to reach the blood circulation. We also developed a gastrointestinal-protease-resistant peptide antagonist for the interleukin-23 receptor, which has a role in the pathogenesis of Crohn's disease and ulcerative colitis. The de novo generation of targeted peptides that resist proteolytic degradation in the gastrointestinal tract should help the development of effective peptides for oral delivery.

Preclinical characterization of the ADME properties of a surrogate anti-IL-36R monoclonal antibody antagonist in mouse serum and tissues.

The decision to pursue a monoclonal antibody (mAb) as a therapeutic for disease intervention requires the assessment of many factors, such as target-biology, including the total target burden and its accessibility at the intended site of action, as well as mAb-specific properties like binding affinity and the pharmacokinetics in serum and tissue. Interleukin-36 receptor (IL-36 R) is a member of the IL-1 family cytokine receptors and an attractive target to treat numerous epithelial-mediated inflammatory conditions, including psoriatic and rheumatoid arthritis, asthma, and chronic obstructive pulmonary disease. However, information concerning the expression profile of IL-36 R at the protein level is minimal, so the feasibility of developing a therapeutic mAb against this target is uncertain. Here, we present a characterization of the properties associated with absorption, distribution, metabolism, and excretion of a high-affinity IL-36 R-targeted surrogate rat (IgG2a) mAb antagonist in preclinical mouse models. The presence of IL-36 R in the periphery was confirmed unequivocally as the driver of non-linear pharmacokinetics in blood/serum, although a predominant site of tissue accumulation was not observed based upon the kinetics of radiotracer. Additionally, the contribution of IL-36 R-mediated catabolism of mAb in kidney was tested in a 5/6 nephrectomized mouse model where minimal effects on serum pharmacokinetics were observed, although analysis of functional mAb in urine suggests that target can influence the amount of mAb excreted. Our data highlight an interesting case of target-mediated drug disposition (TMDD) where low, yet broadly expressed levels of membrane-bound target result in a cumulative effect to drive TMDD behavior typical of a large, saturable target sink. The potential differences between our mouse model and IL-36 R target profile in humans are also presented.

An update on generalized pustular psoriasis.

Introduction: Generalized pustular psoriasis (GPP) is a rare, severe relapsing/remitting, multisystem disease that can be difficult to treat. Recent clinical, histological, and genetic evidence suggests that GPP is a distinct clinical entity from plaque psoriasis and requires a separate diagnosis. The interleukin-36 pathway appears to be central to GPP pathogenesis. As no therapeutic agents have been approved for GPP to date in the United States or Europe, the introduction of anti-IL-36 therapies may change disease management. Areas covered: Using PubMed and Google Scholar, we reviewed the literature for articles related to GPP, psoriasis, and the genetics, pathogenesis, and treatment thereof. Expert opinion: New therapeutic options and updated guidelines for GPP treatment are needed. Ideal agents would have rapid onset of action and rapid time to achieve disease clearance, have the ability to prevent acute flares and avert recurrence, and possess a favorable safety profile. Such therapies should be readily accessible via approval or listing on formularies. Scoring systems to establish GPP disease burden and objective outcome measures could also help with further evaluation of therapies and treatment access issues. IL-36 remains a promising target, as supported by early phase data suggesting efficacy and safety for a novel anti-IL-36 therapy.

Scoping review of biological treatment of deficiency of interleukin-36 receptor antagonist (DITRA) in children and adolescents.

BACKGROUND: Deficiency of interleukin-36 receptor antagonist (DITRA) is a life threatening monogenic autoinflammatory disease caused by loss of function mutations in the IL36RN gene. Affected patients develop recurrent episodes of generalized pustular psoriasis (GPP) with systemic inflammation and fever. We here review and analyze the literature on pediatric DITRA patients who have been treated by biologicals targeting inflammatory cytokines. METHOD: A database research was performed to identify all relevant articles on pediatric DITRA patients treated with biologicals. According to defined response criteria therapeutic efficacy was analyzed. RESULTS: Our literature research revealed 12 pediatric patients with DITRA who have received treatment with biologicals and we add a further not yet reported patient. Out of these 13 patients 10 were homozygous including 6 with the p.Leu27Pro, 3 with the p.Arg10 Argfs* and 1 with the p.Thr123Met mutation. 3 patients were compound heterozygous. In total 28 flares were treated with biological agents- targeting IL-1, IL-17, IL-12/23 and TNF-α. Complete response was achieved in 16 flares (57%), a partial reponse was seen in 2 flares (7%), and no response was observed in 10 flares (36%). Response rates were heterogeneous among the different agents. While complete/partial/no response with inhibition of TNF-alpha could be achieved in 7 (58%)/1 (8%)/4 (33%), the inhibition of IL-17 and of IL-12/23 led in each 4 flares to a 100% complete response. IL-1 inhibition led to complete/partial response in each 1 (13%) and was not effective in 6 (76%) flares. Of note, the novel patient was successfully treated with weekly dosed adalimumab. CONCLUSIONS: DITRA is a rare disease that has to be considered in GPP with systemic inflammation and fever. It can be effectively treated with specific biological inhibition of TNF-alpha, IL-12/23 and IL- 17, while anti-IL-1 treatment seems less effective. Weekly dosed adalimumab appears to be a treatment option for pediatric patients. Further reports and studies of biological treated pediatric DITRA patients are warranted for evaluation of optimal treatment.