Safety of omalizumab in chronic urticaria during pregnancy: a real-life study

Background Managing a pregnant patient with chronic spontaneous urticaria (CSU) is often challenging. Recent data have shown that most CSU treatments in pregnant patients are second-generation H1 antihistamines (sgAHs), while data on the safety of omalizumab are scant.Objectives To evaluate, in a routine clinical practice setting, the efficacy and safety of omalizumab in patients with severe CSU refractory to sgAHs who either became pregnant during treatment or who started the drug during pregnancy.Methods We conducted a retrospective study of women aged >= 18 years who were pregnant, who received one or more doses of omalizumab at any time during their pregnancy or who were taking omalizumab at the time of, or in the 8 weeks before, conception.Results Twenty-nine pregnant patients were evaluated: 23 (79%) conceived a child while taking omalizumab (group A), while 6 (21%) started omalizumab treatment during pregnancy (group B). Among patients in group A, we observed 23 births (21 liveborn singletons and 1 liveborn twin pair) and 1 miscarriage. Fifteen (65%) patients discontinued omalizumab after confirming their pregnancy, while eight (35%) were exposed to omalizumab during their entire pregnancy. In group B, omalizumab was introduced at a mean (SD) 10.83 (3.60) weeks' gestation and all patients were exposed to it until the end of pregnancy. In this group, there were seven liveborn infants (five singletons and one twin pair). No adverse events, pregnancy complications or congenital anomalies in newborns were recorded in either group.Conclusions Omalizumab for CSU treatment before and during pregnancy does not appear to have negative effects on maternal or fetal outcomes. Omalizumab is a recombinant humanized IgG1K monoclonal antibody that selectively binds to human IgE. Data on chronic spontaneous urticaria treatment choices and their safety with regard to conception, pregnancy and pregnancy outcomes are limited. Our study showed that omalizumab exposure in women who started omalizumab therapy during pregnancy, or who took the drug at the time of conception and continued therapy throughout pregnancy, does not seem to be associated with an increased risk of adverse events (AEs), pregnancy-related AEs or AEs in newborns.