Biomarkers for Monitoring Treatment Response of Omalizumab in Patients with Chronic Urticaria

Characterization of omalizumab updosing patterns and predictive factors in chronic spontaneous urticaria: A prospective multicentric observational study

BACKGROUND

Limited information is available on the use of omalizumab (OMA) updosing since its introduction as a second-line therapy in chronic spontaneous urticaria (CSU) in 2014. Practical guidelines from health authorities are lacking, and the specific characteristics of patients requiring higher doses remain unknown. Our objectives were to characterize the patterns of OMA updosing (defined as changes in dose and/or injection intervals), to identify the predictive factors associated with updosing, and to improve CSU management.

METHODS

We conducted a prospective, multicentric, real-life observational study, including patients diagnosed with CSU and starting OMA. The data were collected at 0, 3, 6, and 9 months. The primary endpoint was the frequency of OMA updosing at 3 months. The secondary endpoints included an analysis of updosed patients' profile, and an assessment of OMA efficacy and safety.

RESULTS

We included 153 patients. Twenty percent of patients were updosed at 3 months, and 27% in total during the 9-month follow-up. Practitioners mainly chose to increase the frequency of injections (66%). At baseline, the updosed patients were more likely to have more severe CSU (UCT < 4, p < 0.030), a lower lymphocyte count (<2000/mm3, p = 0.037), and low IgE levels (<70 UI/mL, p = 0.024). The side effects of OMA were not more frequent after updosing.

CONCLUSION

One in five patient underwent updosing within just 3 months. OMA updosing is frequent in particular in cases of severe disease and low IgE blood levels.

Chronic Urticaria in Special Populations: Pediatric, Pregnancy, and the Elderly

Chronic urticaria is an inflammatory skin disorder defined by the presence of evanescent erythematous pruritic wheals, angioedema, or both. While treatment guidelines are continuing to become more clearly defined, there is still a gap in the medical literature surrounding chronic spontaneous urticaria (CSU) treatment in vulnerable populations such as children (aged 0-18 years), pregnant women, and the elderly (aged >65 years). The purpose of this review is to provide an update on CSU in each of these special population categories by defining prevalence, identifying diagnostic considerations, and exploring current and future management options.

Omalizumab withdrawal outcomes in chronic spontaneous urticaria are linked with baseline IgE and eosinophil levels

Background

Chronic Spontaneous Urticaria (CSU) is an immune-mediated skin disease that may require prolonged treatments. Currently, there are no recommendations for treatment discontinuation once CSU symptoms are controlled, particularly among patients primarily diagnosed with severe CSU.

Objective

In this real-life study we aimed to describe our experience of omalizumab (Oma) treatment withdrawal in CSU and define biomarkers related to these outcomes.

Methods

CSU patients followed at our allergy clinic from January 2016 to December 2022 were included. Response to Oma therapy, and Oma-withdrawal outcomes among patients who reached complete remission for >6 months were analyzed.

Results

During the study period 192/335(%) CSU patients were categorized as severe-CSU and entitled to receive Oma according to our country's regulations. Of them, 131/192(68%) were considered "Oma-responders", and 95/131(72.5%) patients underwent gradual treatment withdrawal. Successful Oma-withdrawal was documented in 47/95(49.5%) whereas 48/95(50.5%) patients experienced flare and were defined as unsuccessful OMA-withdrawal. The first was associated with shorter disease duration 7.1 ± 7.4 years vs. 10.7 ± 9.4 (P = 0.042), lower baseline-IgE 81.6 ± 84.1IU/ml vs. 324.7 ± 555.9 (P = 0.005), and lower baseline-eosinophils count 131.4 ± 110.5 vs. 195.6 ± 98.4 (P = 0.043) in comparison to failure of Oma-withdrawal group.

Conclusion

OMA may be successfully withdrawn in up to 50% of severe CSU patients following complete remission of disease symptoms, utilizing a gradual withdrawal protocol. Oma-withdrawal failure was linked with longer duration of disease as well as high IgE and eosinophil counts prior to initiation of Oma therapy. These parameters may enable the design of a treatment withdrawal algorithm.

The Alarmin Triad-IL-25, IL-33, and TSLP-Serum Levels and Their Clinical Implications in Chronic Spontaneous Urticaria

This study delves into the critical role of alarmins in chronic spontaneous urticaria (CSU), focusing on their impact on disease severity and the quality of life (QoL) of patients. We investigated the alterations in alarmin levels in CSU patients and their correlations with the Urticaria Activity Score (UAS7) and the Dermatology Life Quality Index (DLQI). We analyzed serum levels of interleukin-25 (IL-25), interleukin-33 (IL-33), and thymic stromal lymphopoietin (TSLP) in 50 CSU patients, comparing these to 38 healthy controls. The study examined the relationship between alarmin levels and clinical outcomes, including disease severity and QoL. Elevated levels of IL-33 and TSLP in CSU patients (p < 0.0001) highlight their potential role in CSU pathogenesis. Although IL-25 showed higher levels in CSU patients, this did not reach statistical significance (p = 0.0823). Crucially, IL-33's correlation with both UAS7 and DLQI scores underscores its potential as a biomarker for CSU diagnosis and severity assessment. Of the alarmins analyzed, IL-33 emerges as particularly significant for further exploration as a diagnostic and prognostic biomarker in CSU. Its substantial correlation with disease severity and impact on QoL makes it a compelling candidate for future research, potentially serving as a target for therapeutic interventions. Given these findings, IL-33 deserves additional investigation to confirm its role and effectiveness as a biomarker and therapeutic target in CSU.