Table 4 Presumed mechanisms of action of Omalizumab and effects in asthma

Direct effects

Binding to constant region of IgE

Decreased free levels of IgE

Decreased mast cell/basophil FcεR1 expression

Indirect effects

Decreased mucosal eosinophils

Decreased sputum eosinophils

Decreased tissue IgE+ mast cells

Decreased tissue B and T lymphocytes

Inhibition of early and late phase reactions

Improved BHR/unchanged BHR

Improved response to methacholine challenge

Mast cell stabilization: inhibits degranulation

Clinical Effects

Effects on asthma

Decreased exacerbations

Improved peak flow

Small improvement in FEV₁

Decreased rescue β₂-agonist use

Improved quality of life

Decreased mean nocturnal clinical score

Decreased total asthma clinical score

Decreased hospitalizations

Improved asthma control

Steroid-sparing effect