Study of Efficacy and Safety of Omalizumab in Severe Japanese Cedar Pollinosis Adult and Adolescent Patients

Inclusion criteria: * A clinical history of Japanese cedar pollinosis defined by the following * Took nasal corticosteroid plus one or more medications out of antihistamine (second generation), leukotriene receptor antagonist, or prostaglandin D2 thromboxane A2 receptor antagonist in Japanese cedar pollen seasons in 2016 and 2017. * Had inadequately controlled symptoms of Japanese cedar pollinosis lasting at least one week in the Japanese cedar pollen season in 2017 despite the nasal corticosteroid plus one or more medications out of anti-histamine (second generation), leukotriene receptor antagonist, or prostaglandin D2/thromboxane A2 receptor antagonist (regardless of having perennial allergic rhinitis or not) * Serum cedar pollen-specific Immunoglobulin E (IgE) levels of ≥ score of 3 by CAP/RAST-FEIA, ImmunoCAP or MAST at the screening epoch. * Developing a symptom of Japanese cedar pollinosis during the period from first observational day in cedar pollen in Kanto area to initial drug administration (Visit 101), as defined by the following * Having any nasal or ocular symptom (≥ score of 1 in sneezing, rhinorrhea, nasal congestion, itchy eye or watery eye) in at least 2 days or * Having both any nasal symptom (≥ score of 1 in sneezing, rhinorrhea, nasal congestion) and any eye symptom (≥ score of 1 in itchy eye or watery eye) in at least one day, which is confirmed by patient e-diary (unless a symptom is clearly consider to take place due to other than Japanese …