Nucala (Mepolizumab)

Nucala is used to target eosinophil‑driven diseases, reducing inflammation and disease activity.

• Severe eosinophilic asthma: decreases the rate of severe exacerbations, improves lung‑function measurements and reduces oral corticosteroid dependence.
• Eosinophilic granulomatosis with polyangiitis (EGPA): contributes to disease remission, lowers eosinophil counts and helps control vasculitic manifestations.
• Chronic rhinosinusitis with nasal polyps: reduces polyp size, improves nasal congestion and overall quality of life.

• Mepolizumab is a humanized IgG1 monoclonal antibody that selectively binds to interleukin‑5 (IL‑5). By preventing IL‑5 from interacting with its receptor on eosinophil precursors and mature cells, the drug blocks eosinophil differentiation, activation, survival and migration. The resulting reduction in circulating and tissue eosinophils diminishes eosinophil‑mediated inflammation in the airways and other affected tissues. This targeted immunomodulation translates into clinical benefit for conditions driven by eosinophilic inflammation.

Mepolizumab may be associated with a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Injection site pain: mild to moderate discomfort at the injection site.
• Headache: transient headache occurring shortly after administration.
• Upper respiratory tract infection: mild symptoms such as sore throat or nasal congestion.
• Fatigue: general tiredness not interfering with daily activities.
• Dysphonia: hoarseness of voice.
• Nausea: mild gastrointestinal upset.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction requiring immediate medical attention.
• Hypersensitivity reactions: including rash, angioedema or bronchospasm.
• Parasitic infections: emergence of helminth infections due to reduced eosinophil surveillance.

When prescribing or handling Nucala, several precautions should be observed to ensure patient safety and product integrity.

• Assess eosinophil levels: confirm elevated eosinophil counts before initiating therapy.
• Monitor for infections: watch for signs of parasitic or other infections during treatment.
• Evaluate hypersensitivity history: avoid use in patients with known severe allergic reactions to mepolizumab or any component.
• Use caution in immunocompromised patients: increased risk of infection may occur.
• Pregnancy and lactation: safety has not been established; weigh potential benefits against risks.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Mepolizumab has a limited interaction profile, but certain concomitant therapies require attention.

Major Interactions (Avoid)

• Live vaccines: concurrent administration may increase risk of vaccine‑derived infection.
• Other IL‑5 targeting agents: combined use can lead to excessive eosinophil suppression.

Moderate Interactions (Monitor Closely)

• Immunosuppressants: monitor infection risk when used together.
• Antihistamines: may mask early signs of hypersensitivity.
• Systemic corticosteroids: dose adjustments may be needed based on clinical response.