D3.366 - Exploring potential predictive factors for time to response to Omalizumab treatment in a Romanian subset of patients with Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is characterized by the occurrence of wheals, angioedema, or both for a period exceeding six weeks and can exhibit a relapse-remission pattern. Omalizumab, an anti-IgE biological therapy, is indicated in patients who have failed high-dose second-generation antihistamine treatment. The response to this biological therapy is known to vary significantly, ranging from days to months.  

A group of patients undergoing treatment with 300 mg Omalizumab monthly was included in this study and was monitored over a one-year period in order to assess the correlation between paraclinical parameters, including baseline IgE, C-reactive protein (CRP), eosinophil, basophil, and D-dimer levels, and the time-to-response to Omalizumab.

A total of seventeen patients (15 females) with a mean age of 50 years old (18-71 years old) were stratified into two groups: rapid responders (n = 8), defined as achieving a Urticaria Activity Score 7 (UAS7) ≤6 within three months of treatment, and slow responders (n = 9), defined as achieving a UAS7 ≤6 after more than three months of biologic therapy. The majority had concomitant diseases, the most prevalent being autoimmune thyroiditis. Angioedema associated with chronic spontaneous urticaria (CSU) was observed in 88% of patients, while 10% had concurrent chronic inducible urticaria, and 21% exhibited hypersensitivity reactions induced by nonsteroidal anti-inflammatory drugs (NSAIDs). Regarding laboratory parameters at baseline (before initiating Omalizumab), 47% presented high levels of total serum IgE, 23% presented elevated CRP, 29% had eosinopenia, 0.05% had basopenia, and 52% had elevated D-dimers. No statistically significant association was observed between the aforementioned paraclinical findings and the time to response to Omalizumab. 

Numerous studies are conducted to identify predictive factors for treatment outcomes and timelines of response to omalizumab in order to better characterize patients receiving biological therapy. Although this study did not identify any laboratory predictive markers for the timeline of response to omalizumab, it is important to acknowledge the limitation posed by the small cohort size. These findings underscore the need for further research involving larger and more diverse patient populations.