Omalizumab (Omalizumab (Recombinant humanized IgG1 monoclonal antibody))
Also sold as: Xolair
Pregnancy
Cat B
Lactation
Safe
Schedule
H
Forms
Subcutaneous injection 150mg, 300mg vial
Indications
- Moderate-to-severe IgE-mediated allergic asthma (not responding to ICS+LABA)
- Chronic spontaneous urticaria (CSU)
- Allergic rhinitis (off-label)
- Eosinophilic diseases (off-label)
Adult Dosing
Allergic asthma
150-375 mg SC Q2-4 weeks (based on IgE level and weight)
Maintenance: ongoing
Chronic urticaria
300 mg SC monthly
Monthly, long-term
Pediatric Dosing
Requires IgE level and weight for dose calculation; reference nomogram
Renal Dose Adjustment
| CrCl / eGFR | Dose Adjustment |
|---|---|
| CrCl any level | No adjustment required |
Hepatic Adjustment
No adjustment required
Pregnancy & Lactation
Pregnancy: Category B
Safe in pregnancy; IgG antibody does not cross placenta significantly.
Lactation: Safe
IgG unlikely to pass into breast milk; compatible.
Top Drug Interactions
| Interacting Drug | Effect | Severity |
|---|---|---|
| No significant drug interactions | Minimal; monoclonal antibody with unique mechanism | Minor |
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Side Effects
Common
- Injection site reaction (erythema, itching)
- Headache
- Upper respiratory tract infection
- Sinusitis
- Viral infection
- Fatigue
Serious / Discontinue If
- Anaphylaxis (0.1-0.2%)
- Malignancy (rare, controversial; FDA reviewed)
- Serum sickness-like reaction
- Thromboembolic events (rare)
Contraindications
- IgE >700 IU/mL or <30 IU/mL (outside dosing range)
- Hypersensitivity to omalizumab
- Acute respiratory distress
Available Indian Brands
| Brand | Manufacturer | Price (approx) |
|---|---|---|
| Xolair 150 mg SC injection | Novartis/Roche | 1 vial ₹12,000-15,000 (indicative; cost varies with IgE) |
Monitoring Required
- IgE level at baseline (need 30-700 IU/mL)
- Asthma control (ACT/AQLQ)
- Urticaria activity score (UAS7) if CSU
- Signs of anaphylaxis for first 2 hours post-injection
- Baseline malignancy screening (controversial)
Patient Counseling Points
- Requires baseline IgE testing; only effective if IgE 30-700 IU/mL
- SC injection every 2-4 weeks; observe for 2 hours after first dose
- Slow onset: takes 4-8 weeks for asthma improvement
- Continue background asthma therapy (ICS+LABA)
- Expensive; requires insurance pre-authorization
- Report signs of allergic reaction (rash, throat tightness) immediately
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Clinically reviewed by: Dr. Arjun Sharma, MD (Immunology), Fellowship (Allergology)
Last reviewed: 2026-04-12
References
- BNF — Omalizumab
- GINA Biologic Asthma 2024
- FDA Omalizumab Monograph