What is mepolizumab?
Mepolizumab is a monoclonal antibody approved for the treatment of eosinophilic granulomatosis with polyangiitis (EGPA).
How does mepolizumab work?
Mepolizumab blocks IL-5 – a molecule involved in the maturation and activation of eosinophils.
Eosinophils are a type of white blood cell associated with allergic reactions. Eosinophils are implicated in the inflammation present in EGPA, and are often found in the tissues affected by this form of vasculitis.
By blocking IL-5, mepolizumab inhibits the accumulation of eosinophils in the tissues affected by EGPA.
How is mepolizumab given?
Mepolizumab is given as a self-injection at a dose of 300 mg every 4 weeks for EGPA.
Eosinophils do not play as important a role in the normal immune response to typical infections as do other white blood cells, such as neutrophils or lymphocytes. Consequently, mepolizumab is not associated with the same sorts of infections that are the major risk encountered with other immunosuppressant medications.
All immunosuppressants require regular monitoring in the form of blood tests, in-person assessments, and vigilance for signs of infection.