An Exploratory, Multi-centre, Two-part Study to Describe Chronic Induced Urticaria Characteristics and Explore Novelbiomarkers With a Multimodal Patient Profiling Approach by Comparing CIndU Patients to Chronic Spontaneousurticaria Patients and Healthy Volunteers
Chronic inducible urticaria (CIndU) is a group of skin disorders defined by recurrent itchy or burning wheals or angioedema that recur for more than six weeks with a specific triggering factor. This is different from chronic spontaneous urticaria which does not have a specific triggering factor. CIndU is subclassified in nine subtypes with each having its own specific trigger. These subtypes are further divided in physical urticarias (symptomatic dermographism, cold urticaria, delayed pressure urticaria, solar urticaria, heat urticaria, vibratory angioedema) or non-physical urticarias, i.e., cholinergic urticaria, aquagenic urticaria, and contact urticaria. Symptomatic dermographism (SD) is the most prevalent subtype of the physical urticarias. Its prevalence in Western populations is estimated to be between 1-5%. Following SD, cold urticaria (ColdU) is the next most common form, its annual incidence is estimated to be 0.05%. In this study, patients with the ColdU and symptomatic SD subtypes will be enrolled. As of yet, disease diagnosis of SD and ColdU is mostly purely clinical (clinical picture + patients' history), as there is a lack of objective biomarkers. Currently only two objective tools are available for the diagnosis of SD and ColdU, which are the FricTest and Temptest (both provocation tests). In addition, there is a lack of objective biomarkers for the prediction of treatment response and for the monitoring of treatment effects, as this is nowadays only monitored by patient reported outcomes.
∙ Healthy volunteers
• Male and female subjects between 18-69 years of age; in general, stable good health as per judgement of the investigator based upon the results of a medical history, physical examination and vital signs.
• No clinically significant skin disease in the research area
• No history of hypertrophic scarring or keloid.
• Willing to give written informed consent and willing and able to comply with the study protocol.
• Negative TempTest and FricTest at screening.
• Participant is willing to refrain from extensively washing (including bathing, swimming, showering and excessive sweating) the skin 12 hours before study visit 1.
∙ Eligible patients:
• Male and female subjects aged ≥18 years
• Diagnosis of SD, ColdU or CSU (moderate to severe according to international guidelines (Zuberbier et al, 2022)) for ≥3 months and symptomatic disease despite treatment with H1 antihistamines (up to fourfold the approved dose).
• Patients currently on an antihistamine (up to fourfold the approved dose) must be on a stable dose for at least 2 weeks prior to day 1 and must maintain the same stable dose throughout the treatment period. Patients are according to the stepped care model eligible to start treatment with omalizumab
• Willing to give written informed consent and willing and able to comply with the study protocol.
• Positive provocation test:
‣ For ColdU patients: developing a wheal at the test site within 10 min after using TempTest® at any temperature at both screening and Baseline. Alternatively, patients with a negative TempTest® may also be included if they have a positive ice cube test;
⁃ For SD patients: developing a wheal at the test site within 10 min after using FricTest® with ≥ 3mm at both screening and Baseline.
• For CSU patients: negative TempTest® and FricTest® at screening
• Participant is willing to refrain from extensively washing (including bathing, swimming, showering and excessive sweating) the skin 12 hours prior to Day 1 and EOS.
• Female participants of reproductive potential must agree to use contraception from screening until EOS.