Omalizumab
- Monoclonal antibody IgG1 that selectively bind IgE
- Downregulates high affinity receptors on mast cells, basophils and dendritic cells
- FDA: >12 years old for chronic spontaneous urticaria and >6 years in patients with asthma
- Off label: eosinophilic granulomatosis with polyangiitis, bullous pemphigoid and mastocytosis and atopic dermatitis
- Subcutaneous
- 150-300 mg every 4 weeks (NOT weight based unlike in asthma)
- Hypersensitivity reaction
- Active helminthic infection
- Anaphylaxis reported only in 1 patient with chronic spontaneous urticaria
- Injection site reaction in 10-15% of patients
- Systematic review didn’t show increased malignancy risk in chronic spontaneous urticaria
- Serum sickness like reaction
- Helminth infections
- Pregnancy category B
- Administer first dose in the hospital to exclude anaphylaxis reaction
- Do not abruptly Discontinue prednisone in patients with urticaria and recently started on Omalizumab
- 30-40% achieve complete relive
- Discontinue after 6 months if no response
- No baseline investigations are needed