Omalizumab (Xolair) for Urticaria Treatment

Omalizumab (Xolair):

• recombinant humanized monoclonal antibody that binds to the free Immunoglobin IgE (produced byB lymphocytes), more specifically on the C3 domain of the IgE heavy chain complete, it block free IgE.
• Unlike ordinary anti-IgE antibodies, it does not bind to IgE that is already bound by the high affinity IgE receptor (FcεRI) on the surface of mast cells, basophils, and antigen-presenting dendritic cells.
• It also acts in many different ways

• Indications
  • moderate-to-severe asthma
  • chronic urticaria unresponsive to antihistamines
  • Note: studies suggest that physical urticaria responds to omalizumab

• monomeric murine IgE anti-bodies have been seen in atopic dermatitis

• Dosing
  • asthma = weight dependent
  • chronic urticaria 300mg subcutaneous injection

• study done in Germany which showed the following response rates:
  • “hive free”:
    • placebo group: 10% of untreated patients
    • 75mg dosage group: 18% of treated patients
    • 150mg dosage group: 23 % of treated patients
    • 300mg dosage group: 53% of treated patients
  • “itch and hive free”:
    • placebo group: 5% of untreated patients
    • 75mg dosage group: 16% of treated patients
    • 150mg dosage group: 22 % of treated patients
    • 300mg dosage group: 43% of treated patients
  • no safety effects reported: recommendation of surveillance one hour following the injection

• Remarks:
  • studies show that the 300mg dosage effect is similar to 600mg and of course far superior to placebo, 75mg or 150mg
  • the dosing schedule is unclear but in practice, it is administered monthly

Contributors

Dr Christophe Hsu – dermatologist. Geneva, Switzerland

S002 – Jackson JM et al. Systemic Therapies for Dermatologists: a Comprehensive Review and Update. AAD 2015 Annual Meeting, San Francisco CA – United States