What Is Nucala?

Nucala is the brand name for the active ingredient mepolizumab, a type of monoclonal antibody designed to reduce inflammation caused by eosinophils — a type of white blood cell involved in certain chronic immune conditions.

Mepolizumab specifically blocks the action of interleukin-5 (IL-5), a signaling protein (cytokine) that encourages eosinophil growth and survival. By inhibiting IL-5, Nucala helps reduce eosinophil levels, lowering inflammation in conditions where these cells play a damaging role.

What Conditions Is Nucala Used to Treat?

Nucala is approved by the U.S. Food and Drug Administration (FDA) for the treatment of the following diseases:

1. Severe Eosinophilic Asthma
   • As an add-on maintenance treatment for patients aged 6 years and older
   • Used when asthma is not well controlled by inhaled corticosteroids or other long-term medications
   • Not for emergency or sudden asthma attacks
2. Eosinophilic Granulomatosis with Polyangiitis (EGPA)
   • A rare autoimmune condition involving blood vessels and high eosinophil counts
   • For adults, helps reduce flare-ups and steroid use
3. Hypereosinophilic Syndrome (HES)
   • A chronic condition with elevated eosinophils in blood and tissues
   • Approved for patients 12 years and older
   • Helps prevent organ damage and symptom flare-ups
4. Chronic Rhinosinusitis with Nasal Polyps (CRSwNP)
   • Used in adults as an add-on to nasal steroid therapy
   • Helps reduce nasal polyps and the need for surgery

How Is Nucala Administered?

Nucala is given as a subcutaneous injection (under the skin), typically once every 4 weeks.

• It comes in:
  • A pre-filled syringe
  • An autoinjector pen

Who Administers It?

• The first few doses may be administered in a clinical setting to monitor for reactions.
• After training, patients may self-inject at home if their doctor agrees.

Injection Sites:

• Upper arm
• Thigh
• Abdomen

When Does Nucala Start Working?

• Many patients notice improvement in symptoms such as reduced asthma attacks, better breathing, and less steroid dependence within 4 to 12 weeks.
• In some chronic conditions (like EGPA or HES), it may take several months to see full benefit.
• Regular monthly use is critical to maintain effect — skipping doses may reduce efficacy.

What Is the Composition of Nucala?

Each dose contains:

• Active Ingredient: Mepolizumab 100 mg
• Excipients: Polysorbate 80, citric acid, sodium citrate, sucrose, and water for injection

These excipients are standard and help maintain stability, pH balance, and injectability.

Common Side Effects of Nucala

Frequent (Mild to Moderate):

• Injection site reactions: redness, pain, swelling
• Headache
• Fatigue
• Back pain
• Upper respiratory infections (e.g., sinusitis, sore throat)

Less Common but Serious:

• Hypersensitivity reactions: rash, swelling, anaphylaxis (rare)
• Herpes zoster (shingles) reactivation
• Possible reduction in immune function (as eosinophils play a role in parasite defense)

Report any unusual symptoms to your healthcare provider immediately.

Who Should Not Use Nucala?

Nucala is contraindicated (should not be used) in:

• Individuals with a known allergy to mepolizumab or any of its ingredients
• Those experiencing acute asthma attacks — this is not a rescue medication
• Children under 6 years old (for asthma) or under 12 years old (for HES)

Special Considerations and Warnings

• Pregnancy & Breastfeeding:
  There’s limited data; use only if benefits outweigh potential risks. Discuss with your doctor.
• Immunizations:
  Avoid live vaccines during treatment. Inform your doctor before getting any vaccine.
• Infections:
  Nucala may slightly increase risk of infection. Let your doctor know if you have a parasitic infection, or symptoms of infection (fever, cough, sores).
• Do Not Stop Suddenly:
  Discontinuing may lead to return of symptoms or disease flare-ups. Always follow medical advice.

Can You Buy Nucala Without a Prescription in the U.S.?

No.
Nucala is classified as a prescription-only medication (Rx only) in the United States. It must be prescribed by a licensed medical provider and dispensed through a pharmacy or specialty pharmacy. Insurance plans often require prior authorization.

Storage Instructions

• Store in refrigerator (36°F to 46°F / 2°C to 8°C)
• Do not freeze
• Keep in original carton to protect from light
• Let it reach room temperature (30 minutes) before injecting
• Do not shake