- Open label phase: On week 16 subjects who were randomized to the placebo arm originally will receive 600 mg omalizumab by subcutaneous injection whereas those in the omalizumab arm will receive 300 mg omalizumab by subcutaneous injection in a blinded fashion. After that all subjects will receive omalizumab 300 mg by subcutaneous injection every 4 weeks, on weeks 20, 24, 28.