A Phase 3 Trial of Seladelpar in Primary Biliary Cholangitis.

BACKGROUND: Effective treatments for patients with primary biliary cholangitis are limited. Seladelpar, a peroxisome proliferator-activated receptor delta agonist, has potential benefits. METHODS: In this phase 3, 12-month, double-blind, placebo-controlled trial, we randomly assigned (in a 2:1 ratio) patients who had had an inadequate response to or who had a history of unacceptable side effects with ursodeoxycholic acid to receive oral seladelpar at a dose of 10 mg daily or placebo. The primary end point was a biochemical response, which was defined as an alkaline phosphatase level less than 1.67 times the upper limit of the normal range, with a decrease of 15% or more from baseline, and a normal total bilirubin level at month 12. Key secondary end points were normalization of the alkaline phosphatase level at month 12 and a change in the score on the pruritus numerical rating scale (range, 0 [no itch] to 10 [worst itch imaginable]) from baseline to month 6 among patients with a baseline score of at least 4 (indicating moderate-to-severe pruritus). RESULTS: Of the 193 patients who underwent randomization and treatment, 93.8% received ursodeoxycholic acid as standard-of-care background therapy. A greater percentage of the patients in the seladelpar group than in the placebo group had a biochemical response (61.7% vs. 20.0%; difference, 41.7 percentage points; 95% confidence interval [CI], 27.7 to 53.4, P<0.001). Normalization of the alkaline phosphatase level also occurred in a greater percentage of patients who received seladelpar than of those who received placebo (25.0% vs. 0%; difference, 25.0 percentage points; 95% CI, 18.3 to 33.2, P<0.001). Seladelpar resulted in a greater reduction in the score on the pruritus numerical rating scale than placebo (least-squares mean change from baseline, -3.2 vs. -1.7; least-squares mean difference, -1.5; 95% CI, -2.5 to -0.5, P = 0.005). Adverse events were reported in 86.7% of the patients in the seladelpar group and in 84.6% in the placebo group, and serious adverse events in 7.0% and 6.2%, respectively. CONCLUSIONS: In this trial involving patients with primary biliary cholangitis, the percentage of patients who had a biochemical response and alkaline phosphatase normalization was significantly greater with seladelpar than with placebo. Seladelpar also significantly reduced pruritus among patients who had moderate-to-severe pruritus at baseline. The incidence and severity of adverse events were similar in the two groups. (Funded by CymaBay Therapeutics; RESPONSE ClinicalTrials.gov number, NCT04620733; EudraCT number, 2020-004348-27.).

Efficacy and Safety of Elafibranor in Primary Biliary Cholangitis.

BACKGROUND: Primary biliary cholangitis is a rare, chronic cholestatic liver disease characterized by the destruction of interlobular bile ducts, leading to cholestasis and liver fibrosis. Whether elafibranor, an oral, dual peroxisome proliferator-activated receptor (PPAR) α and δ agonist, may have benefit as a treatment for primary biliary cholangitis is unknown. METHODS: In this multinational, phase 3, double-blind, placebo-controlled trial, we randomly assigned (in a 2:1 ratio) patients with primary biliary cholangitis who had had an inadequate response to or unacceptable side effects with ursodeoxycholic acid to receive once-daily elafibranor, at a dose of 80 mg, or placebo. The primary end point was a biochemical response (defined as an alkaline phosphatase level of <1.67 times the upper limit of the normal range, with a reduction of ≥15% from baseline, and normal total bilirubin levels) at week 52. Key secondary end points were normalization of the alkaline phosphatase level at week 52 and a change in pruritus intensity from baseline through week 52 and through week 24, as measured on the Worst Itch Numeric Rating Scale (WI-NRS; scores range from 0 [no itch] to 10 [worst itch imaginable]). RESULTS: A total of 161 patients underwent randomization. A biochemical response (the primary end point) was observed in 51% of the patients (55 of 108) who received elafibranor and in 4% (2 of 53) who received placebo, for a difference of 47 percentage points (95% confidence interval [CI], 32 to 57; P<0.001). The alkaline phosphatase level normalized in 15% of the patients in the elafibranor group and in none of the patients in the placebo group at week 52 (difference, 15 percentage points; 95% CI, 6 to 23; P = 0.002). Among patients who had moderate-to-severe pruritus (44 patients in the elafibranor group and 22 in the placebo group), the least-squares mean change from baseline through week 52 on the WI-NRS did not differ significantly between the groups (-1.93 vs. -1.15; difference, -0.78; 95% CI, -1.99 to 0.42; P = 0.20). Adverse events that occurred more frequently with elafibranor than with placebo included abdominal pain, diarrhea, nausea, and vomiting. CONCLUSIONS: Treatment with elafibranor resulted in significantly greater improvements in relevant biochemical indicators of cholestasis than placebo. (Funded by GENFIT and Ipsen; ELATIVE ClinicalTrials.gov number, NCT04526665.).

Phase 2 Trial of Difelikefalin in Notalgia Paresthetica.

BACKGROUND: Notalgia paresthetica is a neuropathic disorder characterized by pruritus in a circumscribed region of the upper back. Difelikefalin, a selective kappa opioid receptor agonist, has shown efficacy in other chronic pruritic conditions and is being investigated for the treatment of notalgia paresthetica. METHODS: In this phase 2, double-blind, placebo-controlled trial, we randomly assigned, in a 1:1 ratio, patients with moderate-to-severe pruritus caused by notalgia paresthetica to receive 2 mg of oral difelikefalin or placebo twice daily for 8 weeks. The primary outcome was the change from baseline at week 8 in the weekly mean score on the daily Worst Itch Numeric Rating Scale (WI-NRS; scores range from 0 [no itch] to 10 [worst itch imaginable]). The secondary clinical outcomes were itch-related quality-of-life and itch-related sleep measures. RESULTS: A total of 126 patients were enrolled; 62 patients were assigned to receive difelikefalin, and 63 were assigned to receive placebo. One patient who had been assigned to receive difelikefalin withdrew consent before the first dose and is not included in the main analyses. The mean baseline WI-NRS score was 7.6 (indicating severe itch) in each group. The change from baseline in the weekly mean WI-NRS score at week 8 was -4.0 points in the difelikefalin group and -2.4 points in the placebo group (difference in change, -1.6 points; 95% confidence interval, -2.6 to -0.6; P = 0.001). The results for the secondary outcomes generally did not support those of the primary analysis. Headache, dizziness, constipation, and increased urine output occurred more frequently in the difelikefalin group than in the placebo group. CONCLUSIONS: Among patients with notalgia paresthetica, oral treatment with difelikefalin resulted in modestly greater reductions in itch intensity scores than placebo over a period of 8 weeks but was associated with adverse events. Larger and longer trials are needed to assess the efficacy and safety of difelikefalin treatment in this disorder. (Funded by Cara Therapeutics; KOMFORT ClinicalTrials.gov number, NCT04706975.).

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.).

Two Phase 3 Trials of Lebrikizumab for Moderate-to-Severe Atopic Dermatitis.

BACKGROUND: Lebrikizumab, a high-affinity IgG4 monoclonal antibody targeting interleukin-13, prevents the formation of the interleukin-4Rα-interleukin-13Rα1 heterodimer receptor signaling complex. METHODS: We conducted two identically designed, 52-week, randomized, double-blind, placebo-controlled, phase 3 trials; both trials included a 16-week induction period and a 36-week maintenance period. Eligible patients with moderate-to-severe atopic dermatitis (adults [≥18 years of age] and adolescents [12 to <18 years of age, weighing ≥40 kg]) were randomly assigned in a 2:1 ratio to receive either lebrikizumab at a dose of 250 mg (loading dose of 500 mg at baseline and week 2) or placebo, administered subcutaneously every 2 weeks. Outcomes for the induction period were assessed up to 16 weeks and are included in this report. The primary outcome was an Investigator's Global Assessment (IGA) score of 0 or 1 (indicating clear or almost clear skin; range, 0 to 4 [severe disease]) with a reduction (indicating improvement) of at least 2 points from baseline at week 16. Secondary outcomes included a 75% improvement in the Eczema Area and Severity Index score (EASI-75 response) and assessments of itch and of itch interference with sleep. Safety was also assessed. RESULTS: In trial 1, the primary outcome was met in 43.1% of 283 patients in the lebrikizumab group and in 12.7% of 141 patients in the placebo group (P<0.001); an EASI-75 response occurred in 58.8% and 16.2%, respectively (P<0.001). In trial 2, the primary outcome was met in 33.2% of 281 patients in the lebrikizumab group and in 10.8% of 146 patients in the placebo group (P<0.001); an EASI-75 response occurred in 52.1% and 18.1%, respectively (P<0.001). Measures of itch and itch interference with sleep indicated improvement with lebrikizumab therapy. The incidence of conjunctivitis was higher among patients who received lebrikizumab than among those who received placebo. Most adverse events during the induction period were mild or moderate in severity and did not lead to trial discontinuation. CONCLUSIONS: In the induction period of two phase 3 trials, 16 weeks of treatment with lebrikizumab was effective in adolescents and adults with moderate-to-severe atopic dermatitis. (Funded by Dermira; ADvocate1 and ADvocate2 ClinicalTrials.gov numbers, NCT04146363 and NCT04178967, respectively.).

Seladelpar treatment reduces IL-31 and pruritus in patients with primary biliary cholangitis.

BACKGROUND AND AIMS: Pruritus is a debilitating symptom for many people living with primary biliary cholangitis (PBC). In studies with seladelpar, a selective peroxisome proliferator-activated receptor-delta agonist, patients with PBC experienced significant improvement in pruritus and reduction of serum bile acids. Interleukin-31 (IL-31) is a cytokine known to mediate pruritus, and blocking IL-31 signaling provides relief in pruritic skin diseases. This study examined the connection between seladelpar's antipruritic effects and IL-31 and bile acid levels in patients with PBC. APPROACH AND RESULTS: IL-31 levels were quantified in serum samples from the ENHANCE study of patients with PBC receiving daily oral doses of placebo (n = 55), seladelpar 5 mg (n = 53) or 10 mg (n = 53) for 3 months, and for healthy volunteers (n = 55). IL-31 levels were compared with pruritus using a numerical rating scale (NRS, 0-10) and with bile acid levels. Baseline IL-31 levels closely correlated with pruritus NRS ( r = 0.54, p < 0.0001), and total ( r = 0.54, p < 0.0001) and conjugated bile acids (up to 0.64, p < 0.0001). Decreases in IL-31 were observed with seladelpar 5 mg (-30%, p = 0.0003) and 10 mg (-52%, p < 0.0001) versus placebo (+31%). Patients with clinically meaningful improvement in pruritus (NRS ≥ 2 decrease) demonstrated greater dose-dependent reductions in IL-31 compared to those without pruritus improvement (NRS < 2 decrease). Strong correlations were observed for the changes between levels of IL-31 and total bile acids ( r = 0.63, p < 0.0001) in the seladelpar 10 mg group. CONCLUSIONS: Seladelpar decreased serum IL-31 and bile acids in patients with PBC. The reductions of IL-31 and bile acids correlated closely with each other and pruritus improvement, suggesting a mechanism to explain seladelpar's antipruritic effects.

Systemic inflammation and its relationship with pruritus in early-stage mycosis fungoides.

The underlying mechanisms mycosis fungoides (MF)-related pruritus remain unclear, and the link between pruritus and systemic inflammation in MF is unexplored. We aimed to investigate systemic inflammation in MF patients and its potential connection to pruritus. In this retrospective study, demographic characteristics, MF stage, clinical and laboratory findings, and neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), systemic inflammation response index (SIRI) and pan-immune inflammation value (PIV) were assessed for all participants. Additionally, mSWAT scores, Dermatology Life Quality Index (DLQI), and pruritus presence and intensity via Visual Analogue Scale (VAS) scoring were recorded for MF patients. A total of 81 patients with early-stage MF and 50 controls were enrolled. Itching was present in 41 patients (50.6%). NLR, PLR, SII, SIRI and CRP values in the MF group were significantly higher. CRP, NLR, mSWAT and DLQI score were significantly higher in MF patients with pruritus than those without. Pruritus was positively correlated with DLQI, mSWAT, CRP, NLR, MLR and SIRI. VAS score was positively correlated with eosinophil count and DLQI. In the multivariate logistic regression model, only NLR was an independent and significant associate of pruritus in patients with MF. This study provides evidence of enhanced systemic inflammation in early-stage MF patients. Additionally, the correlation between pruritus with mSWAT scores and systemic inflammation parameters suggests a potential link between pruritus and the inflammatory milieu in MF.

Evaluation of measurement errors in the Patient-Oriented Eczema Measure (POEM) outcome.

BACKGROUND: The Patient-Oriented Eczema Measure (POEM) is the recommended core outcome instrument for atopic dermatitis (AD) symptoms. POEM is reported by recalling the presence/absence of seven symptoms in the last 7 days. OBJECTIVE: To evaluate measurement errors in POEM recordings due to imperfect recall. METHODS: Using data from a clinical trial of 247 AD patients aged 12-65 years, we analysed the reported POEM score (r-POEM) and the POEM derived from the corresponding daily scores for the same seven symptoms without weekly recall (d-POEM). We quantified recall error by comparing the r-POEM and d-POEM for 777 patient-weeks collected from 207 patients, and estimated two components of recall error: (1) recall bias due to systematic errors in measurements and (2) recall noise due to random errors in measurements, using a bespoke statistical model. RESULTS: POEM scores have a relatively low recall bias, but a high recall noise. Recall bias was estimated at 1.2 points lower for the r-POEM on average than the d-POEM, with a recall noise of 5.7 points. For example, a patient with a recall-free POEM of 11 (moderate) could report their POEM score anywhere from 5 to 14 (with 95% probability) because of recall error. Model estimates suggested that patients tend to recall itch and dryness more often than experienced (positive bias of less than 1 day), but less often for the other symptoms (bleeding, cracking, flaking, oozing/weeping and sleep disturbance; negative bias ranging 1-4 days). CONCLUSIONS: In this clinical trial data set, we found that patients tended to slightly underestimate their symptoms when reporting POEM, with significant variation in how well they were able to recall the frequency of their symptoms every time they reported POEM. A large recall noise should be taken into consideration when interpreting POEM scores.

Metabolites Associated With Uremic Symptoms in Patients With CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study.

RATIONALE & OBJECTIVE: The toxins that contribute to uremic symptoms in patients with chronic kidney disease (CKD) are unknown. We sought to apply complementary statistical modeling approaches to data from untargeted plasma metabolomic profiling to identify solutes associated with uremic symptoms in patients with CKD. STUDY DESIGN: Cross-sectional. SETTING & PARTICIPANTS: 1,761 Chronic Renal Insufficiency Cohort (CRIC) participants with CKD not treated with dialysis. PREDICTORS: Measurement of 448 known plasma metabolites. OUTCOMES: The uremic symptoms of fatigue, anorexia, pruritus, nausea, paresthesia, and pain were assessed by single items on the Kidney Disease Quality of Life-36 instrument. ANALYTICAL APPROACH: Multivariable adjusted linear regression, least absolute shrinkage and selection operator linear regression, and random forest models were used to identify metabolites associated with symptom severity. After adjustment for multiple comparisons, metabolites selected in at least 2 of the 3 modeling approaches were deemed "overall significant." RESULTS: Participant mean estimated glomerular filtration rate was 43mL/min/1.73m2, with 44% self-identifying as female and 41% as non-Hispanic Black. The prevalence of uremic symptoms ranged from 22% to 55%. We identified 17 metabolites for which a higher level was associated with greater severity of at least one uremic symptom and 9 metabolites inversely associated with uremic symptom severity. Many of these metabolites exhibited at least a moderate correlation with estimated glomerular filtration rate (Pearson's r≥0.5), and some were also associated with the risk of developing kidney failure or death in multivariable adjusted Cox regression models. LIMITATIONS: Lack of a second independent cohort for external validation of our findings. CONCLUSIONS: Metabolomic profiling was used to identify multiple solutes associated with uremic symptoms in adults with CKD, but future validation and mechanistic studies are needed. PLAIN-LANGUAGE SUMMARY: Individuals living with chronic kidney disease (CKD) often experience symptoms related to CKD, traditionally called uremic symptoms. It is likely that CKD results in alterations in the levels of numerous circulating substances that, in turn, cause uremic symptoms; however, the identity of these solutes is not known. In this study, we used metabolomic profiling in patients with CKD to gain insights into the pathophysiology of uremic symptoms. We identified 26 metabolites whose levels were significantly associated with at least one of the symptoms of fatigue, anorexia, itchiness, nausea, paresthesia, and pain. The results of this study lay the groundwork for future research into the biological causes of symptoms in patients with CKD.

Predictors of 6-year event-free survival in Alagille syndrome patients treated with maralixibat, an ileal bile acid transporter inhibitor.

BACKGROUND AND AIMS: Refractory pruritus and other complications of cholestasis are indications for liver transplantation (LT) in patients with Alagille syndrome (ALGS). We evaluated predictors of event-free survival and transplant-free survival in patients with ALGS treated with maralixibat (MRX), an ileal bile acid transporter inhibitor. APPROACH AND RESULTS: We assessed patients with ALGS from 3 clinical trials of MRX with up to 6 years of follow-up. Event-free survival was defined as the absence of LT, surgical biliary diversion, hepatic decompensation, or death; transplant-free survival was the absence of LT or death. Forty-three potential predictors were evaluated, including age, pruritus (ItchRO[Obs] 0-4 scale), biochemistries, platelets, and serum bile acids. Harrell's concordance statistic assessed goodness-of-fit, and then, Cox proportional hazard models confirmed the statistical significance of the predictors identified. A further analysis was performed to identify cutoffs using a grid search. Seventy-six individuals met the criteria of receiving MRX for ≥48 weeks with laboratory values available at week 48 (W48). The median duration of MRX was 4.7 years (IQR: 1.6-5.8); 16 had events (10 LT, 3 decompensation, 2 death, and 1 surgical biliary diversion). The 6-year event-free survival improved with a clinically meaningful >1-point ItchRO(Obs) reduction from baseline to W48 (88% vs. 57%; p = 0.005), W48 bilirubin < 6.5 mg/dL (90% vs. 43%; p < 0.0001), and W48 serum bile acid < 200 µmol/L (85% vs. 49%; p = 0.001). These parameters were also predictive of 6-year transplant-free survival. CONCLUSIONS: Improvement in pruritus by 48 weeks, and lower W48 bilirubin and serum bile acid levels were associated with fewer events. These data may help identify potential markers of disease progression for ALGS patients treated with MRX.

Seladelpar efficacy and safety at 3 months in patients with primary biliary cholangitis: ENHANCE, a phase 3, randomized, placebo-controlled study.

BACKGROUND AND AIMS: ENHANCE was a phase 3 study that evaluated efficacy and safety of seladelpar, a selective peroxisome proliferator-activated receptor-δ (PPAR) agonist, versus placebo in patients with primary biliary cholangitis with inadequate response or intolerance to ursodeoxycholic acid (UDCA). APPROACH AND RESULTS: Patients were randomized 1:1:1 to oral seladelpar 5 mg (n=89), 10 mg (n=89), placebo (n=87) daily (with UDCA, as appropriate). Primary end point was a composite biochemical response [alkaline phosphatase (ALP) < 1.67×upper limit of normal (ULN), ≥15% ALP decrease from baseline, and total bilirubin ≤ ULN] at month 12. Key secondary end points were ALP normalization at month 12 and change in pruritus numerical rating scale (NRS) at month 6 in patients with baseline score ≥4. Aminotransferases were assessed. ENHANCE was terminated early following an erroneous safety signal in a concurrent, NASH trial. While blinded, primary and secondary efficacy end points were amended to month 3. Significantly more patients receiving seladelpar met the primary end point (seladelpar 5 mg: 57.1%, 10 mg: 78.2%) versus placebo (12.5%) ( p < 0.0001). ALP normalization occurred in 5.4% ( p =0.08) and 27.3% ( p < 0.0001) of patients receiving 5 and 10 mg seladelpar, respectively, versus 0% receiving placebo. Seladelpar 10 mg significantly reduced mean pruritus NRS versus placebo [10 mg: -3.14 ( p =0.02); placebo: -1.55]. Alanine aminotransferase decreased significantly with seladelpar versus placebo [5 mg: 23.4% ( p =0.0008); 10 mg: 16.7% ( p =0.03); placebo: 4%]. There were no serious treatment-related adverse events. CONCLUSIONS: Patients with primary biliary cholangitis (PBC) with inadequate response or intolerance to UDCA who were treated with seladelpar 10 mg had significant improvements in liver biochemistry and pruritus. Seladelpar appeared safe and well tolerated.

IL-31 levels correlate with pruritus in patients with cholestatic and metabolic liver diseases and is farnesoid X receptor responsive in NASH.

BACKGROUND AND AIMS: Pruritus is associated with multiple liver diseases, particularly those with cholestasis, but the mechanism remains incompletely understood. Our aim was to evaluate serum IL-31 as a putative biomarker of pruritus in clinical trials of an farnesoid X receptor (FXR) agonist, cilofexor, in patients with NASH, primary sclerosing cholangitis (PSC), and primary biliary cholangitis (PBC). APPROACH AND RESULTS: Serum IL-31 was measured in clinical studies of cilofexor in NASH, PSC, and PBC. In patients with PSC or PBC, baseline IL-31 was elevated compared to patients with NASH and healthy volunteers (HVs). IL-31 correlated with serum bile acids among patients with NASH, PBC, and PSC. Baseline IL-31 levels in PSC and PBC were positively correlated with Visual Analog Scale for pruritus and 5-D itch scores. In patients with NASH, cilofexor dose-dependently increased IL-31 from Week (W)1 to W24. In patients with NASH receiving cilofexor 100 mg, IL-31 was higher in those with Grade 2-3 pruritus adverse events (AEs) than those with Grade 0-1 pruritus AEs. IL-31 weakly correlated with C4 at baseline in patients with NASH, and among those receiving cilofexor 100 mg, changes in IL-31 and C4 from baseline to W24 were negatively correlated. IL-31 messenger RNA (mRNA) was elevated in hepatocytes from patients with PSC and NASH compared to HVs. In a humanized liver murine model, obeticholic acid increased IL-31 mRNA expression in human hepatocytes and serum levels of human IL-31. CONCLUSIONS: IL-31 levels correlate with pruritus in patients with cholestatic disease and NASH, with FXR agonist therapy resulting in higher serum levels in the latter group. IL-31 appears to derive in part from increased hepatocyte expression. These findings have therapeutic implications for patients with liver disease and pruritus.

Efficacy and safety of narrowband ultraviolet B versus combined ultraviolet A/narrowband ultraviolet B phototherapy in the treatment of chronic atopic dermatitis: A randomised double-blind study.

Phototherapy is a useful treatment modality for atopic dermatitis (AD). This is a prospective randomised double-blind study comparing the clinical efficacy of combined ultraviolet-A (UVA)/narrowband ultraviolet-B (NBUVB) versus NBUVB phototherapy in the treatment of chronic AD. Patients with moderate-to-severe AD were randomised to receive either UVA/NBUVB or NBUVB phototherapy twice weekly over 12 weeks. At baseline, weeks 6 and 12, Eczema Area And Severity Index (EASI), itch score and adverse effects were assessed. At baseline and week 12, disease-related quality of life was evaluated using the Dermatology Life Quality Index (DLQI). Nine patients were randomised to receive UVA/NBUVB and 10 received NBUVB. At week 12, both groups showed significant improvement in EASI and itch scores (p < 0.05). Significant improvement in DLQI was seen in the UVA/NBUVB arm (p = 0.009) with a trend towards improvement in the NBUVB arm (p = 0.11). The efficacy of both modalities were comparable, as were reported adverse effects aside from skin dryness which was higher in the NBUVB arm (40% vs. 0%, p = 0.033). Combined UVA/NBUVB and NBUVB phototherapy have comparable clinical efficacy and safety in the treatment of chronic AD. NBUVB may induce greater skin dryness.

Impact of 1-year treatment with dupilumab on work productivity in Japanese patients with atopic dermatitis.

Atopic dermatitis (AD) places a burden on work productivity. Recently, dupilumab was approved for AD, but its impact on work productivity in Japanese patients has not been reported. Furthermore, data on the effect of long-term treatment with dupilumab on work productivity are limited. We investigated the work productivity and activity in Japanese patients with moderate-to-severe AD, utilizing the Japanese version of the Work Productivity and Activity Impairment (WPAI-AD-Japan) questionnaire. Furthermore, we examined the impact of dupilumab on work productivity. Adult moderate-to-severe AD patients treated with dupilumab for more than 12 months from March 2020 to June 2022 who filled out the WPAI-AD-Japan questionnaire were included. Twenty-eight adult AD patients were analysed. Absenteeism was low (mean: 5.3%), but presenteeism, work productivity loss and activity impairment were high (36.8%, 39.7%, 48.9%, respectively). Significant positive correlations were observed between work productivity loss and visual analogue scale (VAS) score of pruritus and between activity impairment and dermatology life quality index (DLQI). Dupilumab treatment significantly reduced presenteeism, work productivity loss and activity impairment at both 6 and 12 months. The extent of their amelioration was numerically higher at 12 months than at 6 months. The reduction rates in presenteeism, work productivity loss and activity impairment were positively correlated with the reduction rates in DLQI and VAS score of pruritus at 12 months. Dupilumab improved work productivity in Japanese AD patients. Long-term remission of pruritus and improved quality of life are important for comprehensive improvement of work productivity.

IL-4 and IL-13 are not involved in IL-31-induced itch-associated scratching behaviour in mice.

Itchy skin or pruritus is a common cutaneous symptom that causes an urge to scratch, and the role of interleukins (IL) in itchy skin has been widely studied. IL-4 and IL-13 are known to induce chronic itch. Similarly, the direct role of IL-31 in inducing itch has been demonstrated in clinical situations such as atopic dermatitis and prurigo nodularis. Moreover, IL-4 receptor α antibodies (dupilumab) and IL-31 receptor A antibodies (nemolizumab) inhibit pruritus. However, the interplay between these ILs in pruritus remains unclear. Therefore, we investigated the reciprocal effects of these cytokines on pruritus in mice. The intradermal administration of IL-31 induced itch-associated scratching behaviour in a dose-dependent manner. Interestingly, the amount of IL-31 and IL-4/IL-13, co-administration or 30 min pre-administration of IL-4/IL-13 and intradermal or intravenous pre-administration of IL-4 did not affect IL-31-induced itch-associated scratching behaviour when it was observed for 30 min, 2 h, 24 h or 48 h. Pre-administration of neutralising antibodies against IL-4 and IL-13 also did not affect IL-31-induced itch-associated scratching behaviour. These results suggest that IL-31 can induce itching independently of IL-4 and IL-13 in vivo.

The involvement of keratinocytes in pruritus of chronic inflammatory dermatosis.

Frequent itching and incessant scratching are commonly observed in various chronic inflammatory skin conditions, including atopic dermatitis and psoriasis. The persistent and prolonged nature of pruritus can worsen one's quality of life. Keratinocytes (KCs), the predominant cells of the epidermis, have been confirmed to interact with sensory neurons and immune cells and be involved in chronic skin inflammatory diseases associated with pruritus. Initially, KCs and sensory neurons form a unique synapse-like connection within the epidermis, serving as the structural foundation for their interaction. Additionally, several receptors, including toll-like receptors and protease-activated receptor 2, expressed on KCs, become activated in an inflammatory milieu. On the one hand, activated KCs are sources of pro-inflammatory cytokines and neurotrophic factors, such as adenosine triphosphate, thymic stromal lymphopoietin, and nerve growth factor, which directly or indirectly participate in stimulating sensory neurons, thereby contributing to the itch sensations. On the other hand, KCs also function as primary transducers alongside intraepidermal nerve endings, directly initiating pruritic responses. This review summarizes the current literature and highlights the critical role of KCs in the development and persistence of chronic itch in inflammatory skin disorders.

Eosinophils in hidradenitis suppurativa patients exhibit pro-inflammatory traits, implicating a potential pathogenic role in the disease.

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful nodules, abscesses and purulent secretions in intertriginous regions. Intense pruritus frequently accompanies HS lesions, adding further discomfort for patients. While Th17 pathway activation is implicated in HS pathogenesis, disease mechanisms are still not fully understood, and therapeutics are lacking. Previous reports raise a potential role for eosinophils in HS, showing a strong association of eosinophil levels with disease severity. To investigate eosinophils in HS, we recruited patients and matched healthy controls and then performed flow-cytometry studies, eosinophil stimulation assays, and lesional skin staining for eosinophils. We found that HS patients reported similar levels of pain and itch. Compared to matched controls, HS blood exhibited decreased mature eosinophils and increased numbers of immature eosinophils, coupled with a significant increase in dermal eosinophilic infiltrates. Additionally, IL-17RA+ eosinophils were highly and significantly correlated with multiple HS-related clinical scores. In both stimulated and unstimulated conditions, HS eosinophils showed an inflammatory phenotype versus controls, including an increase in costimulatory T- and B-cell markers (e.g. CD5 and CD40) following all stimulations (TNFα/IL-17A/IL-17F). These findings highlight the significance of pruritus in HS and suggest a higher turnover of eosinophils in HS blood, potentially due to the consumption of eosinophils in skin lesions. Our data delineate the features and functions of eosinophils in HS and suggest that eosinophils participate in disease pathogenesis, advancing Th17-related inflammation. Further studies are needed to investigate eosinophils' response to current HS treatments and their potential as a therapeutic target in the disease.

Propionate alleviates itch in murine models of atopic dermatitis by modulating sensory TRP channels of dorsal root ganglion.

BACKGROUND: Itch is the most common symptom of atopic dermatitis (AD) and significantly decreases the quality of life. Skin microbiome is involved in AD pathogenesis, whereas its role in the regulation of itch remains elusive. In this study, we aimed to investigate the effects of skin microbial metabolite propionate on acute and chronic pruritus and to explore the mechanism. METHODS: Using various mouse models of itch, the roles of propionate were explored by behavioral tests and histopathology/immunofluorescent analysis. Primary-cultured dorsal root ganglion neurons and HEK293 cells expressing recombinant human TRP channels were utilized for in vitro calcium imaging/in vivo miniature two-photon imaging in combination with electrophysiology and molecular docking approaches for investigation of the mechanism. RESULTS: Propionate significantly alleviated itch and alloknesis in various mouse models of pruritus and AD and decreased the density of intraepidermal nerve fibers. Propionate reduced the responsiveness of dorsal root ganglion neurons to pruritogens in vitro, attenuated the hyper-excitability in sensory neurons in MC903-induced AD model, and inhibited capsaicin-evoked hTRPV1 currents (IC50 = 20.08 ± 1.11 µM) via interacting with the vanilloid binding site. Propionate also decreased the secretion of calcitonin gene-related peptide by nerves in MC903-induced AD mouse model, which further attenuated itch and skin inflammation. CONCLUSION: Our study revealed a protective effect of propionate against persistent itch through direct modulation of sensory TRP channels and neuropeptide production in neurons. Regulation of itch via the skin microbiome might be a novel strategy for the treatment of AD.

Difelikefalin in Black/African American Hemodialysis Patients with Moderate-to-Severe Pruritus: Post hoc Analysis of KALM-1 and KALM-2.

INTRODUCTION: Black and African American (AA) people are over-represented in the kidney failure population; therefore, the safety and efficacy of difelikefalin in Black/AA patients was evaluated. METHODS: This was a post hoc, pooled exploratory subgroup analysis of the Phase 3 KALM-1 and -2 studies. Patients undergoing hemodialysis (HD) who had moderate-to-severe chronic kidney disease-associated pruritus (CKD-aP) at enrollment were stratified into self-reported Black/AA or White subgroups. Patients were randomized (1:1) to receive intravenous (IV) difelikefalin 0.5 µg/kg or placebo for 12 weeks. Difelikefalin efficacy was assessed with validated patient-reported outcome questionnaires: 24-h Worst Itch Numerical Rating Scale (WI-NRS), 5-D itch, and Skindex­10. RESULTS: There were 249 (29.3%) patients from the KALM studies that self-identified as Black/AA (n = 135 difelikefalin; n = 114 placebo). Clinically meaningful (≥3-point) reduction in WI-NRS score was achieved by 47.9% of Black/AA patients with difelikefalin versus 24.6% with placebo (p < 0.001). More Black/AA patients achieved a ≥5-point 5-D itch total improvement (54.9% vs. 35.7%; p = 0.013) and a ≥15-point Skindex-10 score improvement with difelikefalin versus placebo (49.0% vs. 28.9%; p = 0.006) compared with White patients. Incidence of treatment-emergent adverse events (TEAEs) was higher for Black/AA patients (difelikefalin: 78.5%; placebo: 70.8%) versus White patients (difelikefalin: 64.8%; placebo: 61.8%). CONCLUSION: In this post hoc analysis, difelikefalin was efficacious in the Black/AA population and had an acceptable safety profile.

Efficacy and safety of nemolizumab and topical corticosteroids for prurigo nodularis: results from a randomized double-blind placebo-controlled phase II/III clinical study in patients aged ≥ 13†years.

BACKGROUND: Prurigo nodularis (PN), a chronic inflammatory skin condition, adversely affects the quality of life of affected individuals. Current treatment options for PN in Japan are limited. OBJECTIVES: To evaluate the optimal dose, efficacy and safety of long-term treatment with nemolizumab in patients with PN in Japan. METHODS: In a 16-week double-blind phase II/III study, patients aged ≥ 13 years with PN were randomly assigned (1 : 1 : 1) to nemolizumab 30-mg, 60-mg or placebo groups, with concomitant topical corticosteroids, every 4 weeks. The primary efficacy endpoint was the percentage change in the weekly mean Peak Pruritus Numerical Rating Scale (PP-NRS) score (range 0-10, with higher scores indicating worse itching) from baseline to week 16. Secondary efficacy endpoints assessed the impact of treatment on pruritus, PN severity, sleep and quality of life. RESULTS: At week 16, the least-squares mean percentage change from baseline in the PP-NRS score was -61.1% in the nemolizumab 30-mg group (n = 77), -56.0% in the 60-mg group (n = 76), and -18.6% in the placebo group (n = 76). Differences between both nemolizumab groups and placebo were significant; the difference between the 30-mg and placebo groups was -42.5% [95% confidence interval (CI) -51.9 to -33.1; P < 0.0001], and between the 60-mg and placebo groups was -37.4% (95% CI -46.7 to -28.1; P < 0.0001). Patients treated with nemolizumab also had greater improvements in the number and severity of prurigo nodules, and in sleep and quality of life compared with the placebo group. Both nemolizumab doses were well tolerated. CONCLUSIONS: Improvements in PN were greater following nemolizumab treatment, despite continuation of topical corticosteroids in both groups.

Prurigo nodularis (PN) is a skin condition in which firm, raised bumps are seen on the arms, legs and trunk. These bumps are extremely itchy and can cause interruptions to sleep, as well as anxiety and distress. There are few available treatments for PN in Japan; and better options are needed. Nemolizumab is a new treatment which has been shown to reduce itching associated with several skin conditions, including PN. In this study, we investigated whether nemolizumab could reduce itch and nodules and improve quality of life in patients aged 13 years or older in Japan who had already tried topical steroids or antihistamines to treat their PN. We treated 229 patients with PN by injecting either nemolizumab or placebo under the skin every 4 weeks. Seventy-seven patients received a first dose of nemolizumab 60 mg, followed by 30 mg every 4 weeks, and 76 patients received nemolizumab 60 mg at every injection. Another 76 patients received placebo at each injection. All patients were allowed to continue using their topical treatments during the study. We found that both doses of nemolizumab were better than placebo at reducing itch over 16 weeks. After nemolizumab treatment, patients also had less severe PN, better sleep and better quality of life. Both doses of nemolizumab were well tolerated by patients and there were no severe side-effects associated with nemolizumab treatment. Overall, nemolizumab could be a helpful new treatment option for people with PN who do not get enough itch relief with current medication.