mepolitsumabi

Mepolitsumabi, marketed as Nucala, is a humanized monoclonal antibody that targets interleukin-5 (IL-5). By binding IL-5, it blocks its interaction with the IL-5 receptor on eosinophils, reducing eosinophil production in the bone marrow and the survival of eosinophils in blood and tissues. The resulting decrease in eosinophilic inflammation is the basis for its therapeutic use in eosinophil-associated diseases.

Indications for mepolitsumabi include severe eosinophilic asthma in adults and adolescents aged 12 years and older, where it is used as an add-on to standard therapy. It is also approved for chronic rhinosinusitis with nasal polyps (CRSwNP) in adults and for eosinophilic granulomatosis with polyangiitis (EGPA) in adults. Dosing depends on the indication, but commonly involves 100 mg given subcutaneously every 4 weeks for asthma and CRSwNP, and 300 mg every 4 weeks for EGPA. Some patients may administer the injections themselves after appropriate training, under medical guidance.

Administration and pharmacology: mepolitsumabi is given by subcutaneous injection and has a relatively long circulating half-life, allowing monthly dosing for most indications. The therapy is generally well tolerated, but clinicians monitor for injection-site reactions, headaches, and fatigue. Rare but serious adverse events include hypersensitivity reactions and anaphylaxis. Because eosinophils play a role in defense against certain parasitic infections, clinicians consider regional infection risks when prescribing.

Regulatory status varies by region, but mepolitsumabi has received approvals for multiple eosinophil-associated conditions, reflecting its targeted approach to reducing eosinophilic inflammation.