Omalizumab (Xolair)

Anti-IgE monoclonal antibody

Response rate
Variable; effective for refractory anaphylaxis
Onset
Months
Route
SC monthly injection
Line
3rd
IgM effect
N/A

Evidence summary

Anti-IgE biologic used off-label for SM patients with refractory anaphylaxis despite antihistamines. Reduces IgE-mediated degranulation events. Observational data show significant reduction in anaphylaxis episodes. Small RCTs have not conclusively demonstrated efficacy for all SM symptoms.