Remibrutinib demonstrates favorable safety profile and sustained efficacy in chronic spontaneous urticaria over 52 weeks.

BACKGROUND: Remibrutinib (LOU064), an oral, highly selective Bruton tyrosine kinase inhibitor, offers fast disease control in patients with chronic spontaneous urticaria (CSU) who remain symptomatic despite treatment with second-generation H1 antihistamines. It is currently in phase 3 development for CSU. OBJECTIVE: We sought to evaluate long-term safety and efficacy of remibrutinib in patients with CSU inadequately controlled with H1 antihistamines. METHODS: In this phase 2b extension study, patients who completed the core study and had a weekly Urticaria Activity Score (UAS7) ≥16 at the beginning of the extension study received remibrutinib 100 mg twice daily for 52 weeks. The primary objective was to assess long-term safety and tolerability. Key efficacy end points included change from baseline in UAS7 and proportion of patients with complete response to treatment (UAS7 = 0) and well-controlled disease (UAS7 ≤6) at week 4 and over 52 weeks. RESULTS: Overall, 84.3% (194/230) of patients entered the treatment period and received ≥1 doses of remibrutinib. The overall safety profile of remibrutinib was comparable between the extension and core studies. Most treatment-emergent adverse events were mild to moderate and considered unrelated to remibrutinib by investigators. The 3 most common treatment-emergent adverse events by system organ class were infections (30.9%), skin and subcutaneous tissue (26.8%), and gastrointestinal disorders (16.5%). At week 4 and 52, mean ± SD change from baseline in UAS7 was -17.6 ± 13.40 and -21.8 ± 10.70; UAS7 = 0 (as observed) was achieved in 28.2% and 55.8% and UAS7 ≤6 (as observed) was achieved in 52.7% and 68.0% of patients, respectively. CONCLUSIONS: Remibrutinib demonstrated a consistent favorable safety profile with fast and sustained efficacy for up to 52 weeks in patients with CSU.

Long term safety and efficacy of ligelizumab in the treatment of Japanese patients with chronic spontaneous urticaria.

BACKGROUND: In Japan, urticaria is a common skin disorder with chronic spontaneous urticaria (CSU) being the most frequent subtype. This study evaluated the safety of ligelizumab (anti-IgE monoclonal antibody) in Japanese CSU patients. METHODS: This was a Phase 3 multicenter, open-label, single-arm 52-week study in adult Japanese patients with CSU inadequately controlled with locally approved doses of H1-antihistamines. The primary objective reported the safety of ligelizumab 120 mg subcutaneously every 4 weeks, by evaluation of treatment emergent adverse events (TEAE). Secondary objectives evaluated efficacy by absolute change from baseline (CFB) in weekly urticaria activity score (UAS7), and the proportion of patients with UAS7 = 0, and dermatology life quality index (DLQI) = 0-1 over time. RESULTS: From a total of 66 CSU patients (80.3% females; mean ± SD age 46.4 ± 13.2 years; mean ± SD baseline UAS7 28.7 ± 6.5) enrolled, 53 patients (80.3%) reported ≥1 TEAE during the study, with no severe or serious adverse events, no anaphylaxis events and low frequency of TEAEs leading to treatment discontinuations (6.1%). Absolute mean CFB of UAS7 showed a rapid onset of response at Week 4 (-14.2) with further improvement until end of treatment at Week 52 (-22.9). The proportion of patients achieving UAS7 = 0 improved over time (14.5% at Week 4; 50.0% at Week 52). A sizable proportion of patients achieved DLQI 0-1 with the first dose of ligelizumab (38.5%), and improvements observed throughout the study until Week 52 (68.8%). CONCLUSIONS: Treatment with ligelizumab 120 mg was well-tolerated with mild to moderate adverse events and was efficacious in Japanese patients.

Clinical study on the utility of allergy tests to detect IgE-mediated anaphylaxis after diclofenac etalhyaluronate administration.

OBJECTIVES: This study was conducted to investigate factors involved in anaphylaxis related to diclofenac etalhyaluronate (DEH) [product name: Joyclu® (JCL)] (containing DEH and macrogol 400), which is used to treat patients with osteoarthritis. METHODS: Patients with osteoarthritis were divided into two groups that had (experienced patients) or had not experienced anaphylactic symptoms after JCL administration (non-experienced patients). Five tests performed to assess factors related to anaphylaxis consisted of a skin prick test (SPT) as the primary endpoint and the other tests including basophil activation test, allergen-specific IgE (sIgE) tests using enzyme-linked immunosorbent assay or immunochromatographic kits, and genetic study were secondary endpoints. RESULTS: The SPT showed 4 (wheal)/7 (erythema) of 15 experienced patients and 0/3 of 19 non-experienced patients were positive for any of the test reagents containing DEH. The basophil activation test showed two experienced patients were positive for test reagents containing DEH. DEH- and diclofenac-sIgE were detected in 3 and 1 of 12 experienced patients, respectively. No clear results were shown in the other tests. CONCLUSIONS: DEH may be the main factor involved in the development of anaphylaxis. The SPT was more sensitive than the basophil activation and allergen-sIgE tests for identifying factors associated with anaphylaxis.

Remibrutinib, a novel BTK inhibitor, demonstrates promising efficacy and safety in chronic spontaneous urticaria.

BACKGROUND: Chronic spontaneous urticaria (CSU) is inadequately controlled in many patients and greatly affects quality of life. Remibrutinib, a highly selective, oral, novel covalent Bruton tyrosine kinase inhibitor, might be effective in CSU. OBJECTIVE: This first-in-patient trial aimed to evaluate the efficacy and safety of remibrutinib in CSU treatment and characterize the dose-response. METHODS: This randomized, double-blind, placebo-controlled, phase 2b dose-finding trial evaluated remibrutinib (12 weeks) in patients inadequately controlled with second-generation H1-antihistamines, with at least moderately active CSU, with or without prior anti-IgE treatment (NCT03926611). Patients received remibrutinib 10 mg once daily, 35 mg once daily, 100 mg once daily, 10 mg twice daily, 25 mg twice daily, 100 mg twice daily, or placebo (1:1:1:1:1:1:1 ratio). The main end points were weekly Urticaria Activity Score change from baseline at week 4 and safety. RESULTS: Overall, 311 patients were randomized. Reduced symptom score was observed for all remibrutinib doses from week 1 until week 12, with weekly Urticaria Activity Score change from baseline at week 4: -19.1 (10 mg once daily), -19.1 (35 mg once daily), -14.7 (100 mg once daily), -16.0 (10 mg twice daily), -20.0 (25 mg twice daily), -18.1 (100 mg twice daily), and -5.4 for placebo (nominal P < .0001 for all doses vs placebo). Most adverse events were mild or moderate, with no dose-dependent pattern. CONCLUSION: Remibrutinib was highly effective in the treatment of CSU over the entire dose range, with a rapid onset of action and a favorable safety profile.

miR103a-3p in extracellular vesicles from FcεRI-aggregated human mast cells enhances IL-5 production by group 2 innate lymphoid cells.

BACKGROUND: Mast cells (MCs) are key regulators of IgE-mediated allergic inflammation. Cell-derived extracellular vesicles (EVs) contain bioactive compounds such as microRNAs. EVs can transfer signals to recipient cells, thus using a novel mechanism of cell-to-cell communication. However, whether MC-derived EVs are involved in FcεRI-mediated allergic inflammation is unclear. OBJECTIVE: We sought to investigate the effect of EVs derived from FcεRI-aggregated human MCs on the function of human group 2 innate lymphoid cells (ILC2s). METHODS: Human cultured MCs were sensitized with and without IgE for 1 hour and then incubated with anti-IgE antibody, IL-33, or medium alone for 24 hours. EVs in the MC supernatant were isolated by using ExoQuick-TC. RESULTS: Coculture of ILC2s with EVs derived from the FcεRI-aggregated MCs significantly enhanced IL-5 production and sustained upregulation of IL-5 mRNA expression in IL-33-stimulated ILC2s, but IL-13 production and IL-13 mRNA expression were unchanged. miR103a-3p expression was upregulated in IL-33-stimulated ILC2s that had been cocultured with EVs derived from anti-IgE antibody-stimulated MCs. Transduction of an miR103a-3p mimic to ILC2s significantly enhanced IL-5 production by IL-33-stimulated ILC2s. miR103a-3p promoted demethylation of an arginine residue of GATA3 by downregulating protein arginine methyltransferase 5 (PRMT5) mRNA. Reduction of protein arginine methyltransferase 5 expression in ILC2s by using a small interfering RNA technique resulted in upregulation of IL-5 production by IL-33-stimulated ILC2s. Furthermore, the level of miR103a-3p expression was significantly higher in EVs from sera of patients with atopic dermatitis than in EVs from nonatopic healthy control subjects. CONCLUSION: Eosinophilic allergic inflammation may be exacerbated owing to ILC2 activation by MC-derived miR103a-3p.

Serum level of hemokinin-1 is significantly lower in patients with chronic spontaneous urticaria than in healthy subjects.

BACKGROUND: We previously reported upregulation of expression of Mas-related G protein-coupled receptor X2 (MRGPRX2) on mast cells (MCs) in the skin of patients with severe chronic spontaneous urticaria (CSU). Serum levels of substance P (SP) were reportedly significantly elevated, in correlation with the severity of CSU. Hemokinin-1 (HK-1) reportedly induced histamine release from LAD2 cells via MRGPRX2. We aimed to investigate HK-1's role in CSU. METHODS: The concentrations of HK-1 and SP were measured using ELISAs. Skin- and synovium-derived cultured MCs were generated by culturing dispersed skin and synovial cells, respectively, with stem cell factor. MRGPRX2 expression in the MCs was reduced using a lentiviral shRNA silencing technique. RESULTS: Anti-SP Ab used in the SP ELISA showed 100% cross-reactivity to HK-1, but anti-HK-1 Ab showed 0% cross-reactivity to SP. The serum level of HK-1 was significantly lower in patients with CSU (n = 151) than in non-atopic healthy control (NC) subjects (n = 114). The EC50 of histamine release from MCs induced by HK-1 (5056 nM) was 12-fold higher than by SP (426 nM). Brief pretreatment of MCs with HK-1 at concentrations of 3.0-10 µM significantly reduced histamine release by 0.1 µM SP. However, brief incubation of MCs with HK-1 did not elicit rapid MRGPRX2 internalization. CONCLUSIONS: In NC subjects, high HK-1 concentrations may desensitize MGRPRX2-mediated MC activation, thereby preventing MC degranulation by SP.

Differentiation between control subjects and patients with chronic spontaneous urticaria based on the ability of anti-IgE autoantibodies (AAbs) to induce FcεRI crosslinking, as compared to anti-FcεRIα AAbs.

BACKGROUND: The reported prevalences of IgG autoantibodies (AAbs) to FcεRIα and IgE in sera from patients with chronic spontaneous urticaria (CSU) have varied, and these AAbs are also often observed in healthy control subjects. Regarding the histamine release activity of purified IgG from patients with CSU, the number of examined patients has been small. Thus, we sought to determine the prevalence and FcεRI crosslinking ability of these AAbs in a large number of patients with CSU and non-atopic control (NC) subjects. METHODS: We compared the concentrations of anti-IgE and anti-FcεRIα AAbs and the abilities of these AAbs to cause FcεRI aggregation in patients with CSU (n = 134) and NC subjects (n = 55) using ELISA and an in vitro elicitation test, respectively. RESULTS: The concentration of anti-IgE AAbs was significantly different between the NC subjects and the CSU patients (P < 0.0001, cutoff value: 0.558 µg/mL), whereas the concentration of anti-FcεRIα AAbs was not. A significant difference in the duration of illness was noted between patients with lower and those with higher concentrations of anti-IgE AAbs relative to the cutoff value. The abilities of anti-IgE AAbs, but not anti-FcεRIα AAbs, to induce FcεRI crosslinking were significantly higher in CSU patients than in NC subjects (P = 0.0106). CONCLUSIONS: In the Japanese population of CSU patients studied, the ability of the anti-IgE AAbs to induce FcεRI crosslinking differed significantly between NC subjects and CSU patients, suggesting the involvement of anti-IgE AAbs in the pathogenesis of CSU in the Japanese population.

Effectiveness of a heparinoid-containing moisturiser to treat senile xerosis.

BACKGROUND AND OBJECTIVES: With the increasing elderly population in Japan, skin problems have become a greater concern. A heparinoid-containing moisturiser is frequently used in Japan, but there is a lack of evidence for its efficacy in treating senile xerosis. To determine whether there is a correlation between age and the hydration state of the stratum corneum (SC) assessed by skin capacitance, and to evaluate the efficiency of a heparinoid-containing moisturiser and a bed bath to treat senile xerosis. METHODS: We recruited 73 individuals to assess the hydration state of the SC on their flexor forearm by measuring their skin capacitance. To evaluate the efficacy of a heparinoid-containing moisturiser on senile xerosis, we recruited seven inpatients with an inactive daily life (IDL) who had senile xerosis. They were treated with the moisturiser in addition to a bed bath in two different protocols, and we measured the skin capacitance on their flexor forearms on days 0, 7 and 14. RESULTS: There was a weak negative correlation (-0.3854, P < 0.01) between skin capacitance and age. Following the moisturiser treatments, the seven inpatients had increased hydration of both arms on days 7 and 14. The skin capacitance of the right forearm slightly decreased on day 14, even though it was significantly different from day 0 (P < 0.05). CONCLUSIONS: These findings indicate that treatment with a heparinoid-containing moisturiser together with a bed bath is an effective method for treating patients who have senile xerosis and IDL.

Expression of Mas-related gene X2 on mast cells is upregulated in the skin of patients with severe chronic urticaria.

BACKGROUND: Wheal reactions to intradermally injected neuropeptides, such as substance P (SP) and vasoactive intestinal peptide, are significantly larger and longer lasting in patients with chronic urticaria (CU) than in nonatopic control (NC) subjects. Mas-related gene X2 (MrgX2) has been identified as a receptor for basic neuropeptides, such as SP and vasoactive intestinal peptide. Mast cell (MC) responsiveness to eosinophil mediators contributes to the late-phase reaction of allergy. OBJECTIVE: We sought to compare the frequency of MrgX2 expression in skin MCs from patients with CU and NC subjects and to identify the receptor for basic eosinophil granule proteins on human skin MCs. METHODS: MrgX2 expression was investigated by using immunofluorescence in skin tissues from NC subjects and patients with severe CU and on skin-derived cultured MCs. MrgX2 expression in human MCs was reduced by using a lentiviral small hairpin RNA silencing technique. Ca(2+) influx was measured in CHO cells transfected with MrgX2 in response to eosinophil granule proteins. Histamine and prostaglandin D2 levels were measured by using enzyme immunoassays. RESULTS: The number of MrgX2(+) skin MCs and the percentage of MrgX2(+) MCs in all MCs in patients with CU were significantly greater than those in NC subjects. Eosinophil infiltration in urticarial lesions was observed in 7 of 9 patients with CU. SP, major basic protein, and eosinophil peroxidase, but not eosinophil-derived neurotoxin, induced histamine release from human skin MCs through MrgX2. CONCLUSION: MrgX2 might be a new target molecule for the treatment of wheal reactions in patients with severe CU.

Prognosis of chronic spontaneous urticaria with an inadequate response to omalizumab.

BACKGROUND: Chronic spontaneous urticaria (CSU) exhibits notable responsiveness to omalizumab (OMA). The prognosis and subsequent therapeutic strategies warrant comprehensive exploration in cases exhibiting inadequate responses to OMA. METHODS: We conducted a multicenter retrospective analysis to investigate the 12-month prognosis of patients inadequately responding to three injections of OMA. The endpoints encompassed identifying predictive factors for a favorable prognosis and assessing interventions related to an ameliorated prognostic outlook. RESULTS: The study involved 48 patients who met the inclusion criteria. After three OMA administrations, therapeutic interventions included the continuation of OMA in 34 patients, systemic corticosteroids in seven patients, and immunosuppressants in 12 patients. After 12 months, 28 of the 48 patients exhibited a good prognosis, whereas the remaining 20 displayed a less favorable prognosis. Good prognostic determinants encompassed the duration of CSU within 51 weeks, the presence of angioedema, IgE levels ≤100 IU/mL pre-OMA, blood eosinophil counts ≥100/mm3 post-OMA, and urticaria control test (UCT) scores ≥5 pre-OMA and ≥6 post-OMA. Following the third OMA injection, the implementation of immunosuppressants presented an association with a good prognosis, while the employment of systemic corticosteroids correlated with an unfavorable prognosis. CONCLUSIONS: More than half of patients inadequately responding to OMA achieved a good prognosis 12 months later. Several clinical variables appear to be predictive of prognosis, and certain therapeutic agents can be associated with prognostic outcomes.