A Phase IV, Multicenter, Randomized, Double-blind, Placebo-controlled Study Evaluating the Persistency of Response With or Without Xolair After Long-term Therapy (XPORT)

This was a randomized, double-blind, placebo-controlled, 2-arm, 1-year study of participants who completed the EXCELS study (NCT00252135) and had received long-term treatment with Xolair. In addition, participants who did not participate in the EXCELS study but received long-term (\~5 years) treatment with Xolair were allowed to enter the study.