Does Xolair (omalizumab) have a new FDA indication for the treatment of pruritus associated with high Immunoglobulin E (IgE) levels?

Omalizumab (Xolair) for Pruritus Associated with High IgE Levels

Omalizumab (Xolair) does not currently have an FDA-approved indication specifically for pruritus associated with high IgE levels, although it has demonstrated efficacy in treating pruritus in several IgE-mediated conditions.

Current FDA-Approved Indications for Omalizumab

Omalizumab is a humanized monoclonal antibody that binds to IgE, preventing it from attaching to high-affinity receptors on mast cells and basophils 1. It is currently FDA-approved for:

• Moderate to severe persistent allergic asthma
• Chronic idiopathic urticaria
• Nasal polyps

Evidence for Omalizumab in Pruritus Management

Chronic Urticaria with Pruritus

• Omalizumab has shown significant efficacy in treating chronic urticaria, with complete protection from wheal development observed in 70.4% of patients with IgE autoantibodies against thyroperoxidase compared to only 4.5% in the placebo group 2
• Resolution of cold urticaria has been noted in a patient treated with omalizumab for asthma 3

Pruritus in Other Conditions

• Omalizumab has demonstrated clinical benefit in pruritus-associated dermatoses including atopic dermatitis and bullous pemphigoid 4
• In a study of patients with severe atopic dermatitis, all patients reported a decrease in pruritus and improved quality of life with omalizumab treatment 5
• A recent study showed that 82% of cancer patients with pruritus related to immune checkpoint inhibitors and anti-HER2 therapies responded to omalizumab treatment 4

Safety Considerations

When administering omalizumab, important safety considerations include:

1. Risk of anaphylaxis (0.2% of patients) 3
2. Observation requirements:
   • Patients should be kept under observation for 30 minutes after each injection
   • This should be extended to 2 hours for the first 3 injections 3
3. Patient education:
   • Patients should be educated on signs and symptoms of anaphylaxis
   • Epinephrine autoinjector should be prescribed 3

Treatment Algorithm for Pruritus with High IgE Levels

For patients with pruritus associated with high IgE levels:

1. First-line treatment:

   • Non-sedating antihistamines (for generalized pruritus) 3, 6
   • Emollients and topical steroids (for at least 2 weeks) 3, 6

2. Second-line options:

   • Gabapentin (particularly useful in elderly patients) 3, 6
   • Nifedipine (may reduce pruritus in chronic urticaria) 3, 6

3. For refractory cases:

   • Ciclosporin (effective in about two-thirds of patients with severe autoimmune urticaria) 3, 6
   • Narrow-band UVB phototherapy 6
   • Consider omalizumab, especially if associated with urticaria or other IgE-mediated conditions 3, 4, 2

Conclusion

While omalizumab has shown promising results in treating pruritus associated with high IgE levels in various conditions, it does not yet have a specific FDA indication for this purpose. Its use for pruritus should be considered in patients with refractory symptoms, particularly when associated with conditions like chronic urticaria, atopic dermatitis, or medication-induced pruritus where IgE plays a pathogenic role.

For patients with high IgE levels and severe pruritus not responding to conventional therapies, omalizumab may be considered as an off-label treatment option based on the growing body of evidence supporting its efficacy in IgE-mediated pruritic conditions.