Bilastine in Refractory Chronic Spontaneous Urticaria: Disease Control and Cytokine Modulation in an Open-label Prospective Study.

INTRODUCTION: The treatment options for chronic spontaneous urticaria (CSU) primarily include second generation non-sedative antihistamine (SGAHs). Bilastine is a newer, nonsedating SGAH approved for urticaria in February 2019 by the Drugs Controller General of India. Its major advantages are in terms of superior efficacy, lack of drug interactions and adverse effects, including sedation, compared to conventional SGAHs. The role of cytokines in the pathogenesis of CSU is well known. However, there is a shortage of data regarding the change in serum levels of proinflammatory cytokines following H1 antihistamines. We conducted this trial to evaluate the role of bilastine in cytokine modulation and autoimmunity, thereby explaining its role in modifying the disease process in CSU.

MATERIALS AND METHODS: This prospective study was conducted in a tertiary institute in Kolkata on patients aged 12 years and above with a CSU >6 months. These patients had an unsatisfactory response, as per the Urticaria Activity Score 7 (UAS7), to previous antihistamine therapies in standard doses. Treatment effectiveness was determined by comparing the UAS7 at baseline with that at weeks 4, 8 and 12. Also, baseline serum interleukin-6 (IL-6) and IL-17 were compared with those at the end of the study, that is, 12 weeks.

RESULTS: Thirty patients who matched the inclusion criteria and signed informed consent were included in the study. At the end of 12 weeks, 10% of patients ( n = 3) achieved a complete treatment response (UAS = 0), whereas 43.33% of patients ( n = 13) were labelled as having well-controlled urticaria (UAS <6). At 12 weeks, the mean UAS7 score (6.47 ± 4.45) was statistically significant compared to the baseline score (25.47 ± 7.74). The mean values of serum IL-6 (pg/ml) and IL-17 (pg/ml) at baseline were 5.96 ± 5.24 pg/ml and 6.96 ± 5.97 pg/ml, respectively. At the end of treatment, that is, 3 months, the mean values were reduced to 4.61 ± 4.56 pg/ml and 5.08 ± 3.87 pg/ml. The reduction was statistically significant for both serum IL-6 ( P < 0.001) and IL-17 ( P < 0.0001).

CONCLUSION: We conclude that bilastine at a once-daily continuous dose of 40 mg for 3 months is safe and effective in CSU patients who are refractory to treatment at the standard doses of SGAHs. Improved symptomatic control with bilastine was also associated with better control over the inflammatory process, as suggested by the lowering of mean cytokine levels in our study.