Xolair use in our clinic for Food Allergy
Xolair (Omalizumab) for Food Allergy: Patient Information for patients in London Allergy Consultants.
What is Xolair?
Xolair is a medication used to reduce allergic reactions from accidental food exposure in patients with IgE-mediated food allergies. It is administered via subcutaneous injections and is not for emergency treatment of allergic reactions.
Xolair may be used for three different reasons.
Ongoing treatment, over many months, to protect against food allergic reactions.
Used for 2-4 months to protect during higher risk life events e.g travel, commencing university…
To facilitate Oral Immunotherapy (this is offered in ACE - Allergy Centre of Excellence, starting 2026)
Who Can Use Xolair?
Age: Approved for patients aged 1 year and older. However, repeat injections may be challenging for younger children.
Eligibility: Suitable for patients with severe or multiple food allergies, confirmed by a rigorous diagnosis.
Contraindications:
Severe hypersensitivity to Xolair or its ingredients.
Latex allergy (present in needle caps of prefilled syringes).
Certain parasitic infections may increase risk.
Patients with cancer (potential increased risk of certain cancers).
Note: Xolair is not for emergency treatment of allergic reactions.
Pre-Treatment Requirements
Total Serum IgE Test: Must be measured and written on the prescription to determine dosing based on IgE levels and body weight.
Confirmed Diagnosis: A thorough diagnosis of severe or multiple food allergies is required.
Dosing and Administration
Dosing:
Determined by pre-treatment total IgE levels and body weight.
Ranges from 150 mg (1 injection) to 600 mg (4 injections).
Administered every 2 or 4 weeks (most commonly every 4 weeks; 2-weekly for very high IgE levels).
Duration:
Continuous treatment for ongoing protection.
For travel, at least 2–3 months of treatment is needed before departure, with monthly injections during travel.
No "fast-track" option; the medication requires time to be effective.
Administration:
Initiated in a healthcare setting, prepared to manage potential anaphylactic reactions.
After training, patients may self-inject.
Storage and Travel
Storage:
Store in a refrigerator (2°C–8°C / 36°F–46°F) in its original carton to protect from light.
Do not freeze.
Can be kept at room temperature (up to 25°C / 77°F) for a maximum of 48 hours. Discard if not used within this time.
Travel:
Ensure proper refrigeration during transport.
Plan for consistent dosing (at least 2 months before travel for effectiveness).
Benefits of Long-Term Use
Reduced Severity: Desensitises the immune system, making accidental exposure reactions less severe.
Improved Quality of Life: Decreases anxiety and fear related to food allergies.
Enhanced Safety: Provides an added layer of protection against life-threatening reactions.
Important: Xolair must be used with ongoing food allergen avoidance and standard allergy management (e.g., carrying adrenaline auto-injectors).
Key Reminders and what happens when we stop Xolair but continue with OIT
Xolair is a maintenance therapy, not a cure or emergency treatment.
Continue all standard allergy management protocols.
Tolerance to the food allergen generally decreases when omalizumab is discontinued in patients undergoing food oral immunotherapy (OIT) with adjunctive omalizumab. Omalizumab acts by binding free IgE, thereby reducing allergic reactivity, but it does not induce long-term immunologic tolerance. Multiple studies and systematic reviews indicate that while omalizumab facilitates rapid and safer desensitisation during OIT, its discontinuation is associated with a loss of protection and an increased risk of allergic reactions, including anaphylaxis, particularly if OIT is continued without omalizumab or if omalizumab is stopped abruptly.
Real-world registry data and clinical trials show that a subset of patients can maintain desensitisation after omalizumab withdrawal. Still, a significant proportion experience a decline in tolerance, with some reverting to clinical reactivity and experiencing adverse events. The risk of loss of tolerance is higher in those with higher allergen-specific IgE/total IgE ratios and in those with more severe baseline allergy.
Sustained unresponsiveness (i.e., long-term tolerance after stopping both OIT and omalizumab) is achieved in only a minority of patients.
Therefore, omalizumab should be viewed as a facilitator of desensitisation rather than a curative therapy, and discontinuation requires careful monitoring and risk assessment. The need for ongoing therapy versus the risk of adverse events after withdrawal should be individualised, and patients should be counselled that omalizumab does not induce permanent tolerance to food allergens.
