Published online: April 6, 2020
Chronic spontaneous urticaria (CSU) is a skin disease which negatively affects many aspects of patients’ daily lives. Currently, treatment guidelines recommend the use of omalizumab as an add-on therapy after H1-antihistamines at up to 4 times the normal dose fail to provide sufficient benefit to patients. Studies have shown that while both doses of 150 mg or 300 mg help in controlling CSU symptoms, omalizumab at a dose of 300 mg shows greater benefit. However, it is not fully understood if stopping the administration of omalizumab after patients’ symptoms have been controlled leads to the symptoms reappearing. In patients who have a reappearance of CSU symptoms, it is important to know if re-starting the doses of omalizumab (retreatment) would again lead to sufficient control of the disease. Also noteworthy is the question of whether continuing on the 300 mg dose is beneficial in patients who do not experience a control of symptoms on the same dose. Finally, it is important to know if patients being treated with omalizumab at the lower dose of 150 mg will experience any benefit if their dose is increased to 300 mg (step-up) in cases where sufficient control of symptoms is not seen.
In a recent publication from The Journal of Allergy and Clinical Immunology: In Practice, Sussman et al investigated symptom reappearance after omalizumab is stopped, results of retreatment with omalizumab, and step-up of omalizumab dose. In this study, patients who provided their informed consent were randomly assigned to receive either omalizumab at the 150 mg or 300 mg dose every 4 weeks until 24 weeks (initial dosing period). Patients receiving the 150 mg dose could be stepped-up to the 300 mg dose between week 8 to week 24 of their treatment, if their disease symptoms did not show sufficient control as measured by the Urticaria Activity Score (UAS7) assessed for 7 days. The maximum score possible with UAS7 is 42 corresponding to the highest disease severity, and a score of ≤ 6 represents good control. Treatment in patients taking either dose was stopped only if their symptoms were assessed as being well-controlled using UAS7. If symptoms reappeared within 8 weeks of treatment withdrawal after 24 weeks, patients could start taking omalizumab again at the same dose as before. If symptoms were not well-controlled as assessed by UAS7, they remained on the 300 mg dose till the end of the study. The primary endpoint studied, was the proportion of patients in whom symptoms had reappeared once the treatment was stopped, and demonstrated symptom control after omalizumab was started again.
A total of 314 patients were treated in this study, and 115 were assessed to have adequate symptom control in the initial dosing period. In all, 56 patients were re-treated with omalizumab after symptoms reappeared, and 87.8% of re-treated patients experienced symptom control again. Re-treated patients took 3.1 weeks on average to regain control of CSU symptoms, which was similar to the time taken to control symptoms during the initial treatment (3.6 weeks). In 59 patients, symptoms did not reappear during the 8 week withdrawal period. Amongst the 178 patients who were treated with the lower 150 mg dose, 141 needed their dose to be increased to 300 mg. As a result of this increase in dosage, the UAS7 score decreased by an average of 9.5 points, thereby showing better symptom control. These results indicate that even when symptoms reappear after omalizumab treatment is stopped, symptoms are quickly controlled by restarting omalizumab. It is also clear that the higher 300 mg dose helped a greater proportion of patients achieve symptom control.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.