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Medically reviewed on Feb 2, 2019


See also: Dulera

(me poe LIZ ue mab)

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution Reconstituted, Subcutaneous [preservative free]:

Nucala: 100 mg (1 ea) [contains mouse (murine) and/or hamster protein, polysorbate 80]

Brand Names: U.S.

  • Nucala

Pharmacologic Category

  • Interleukin-5 Receptor Antagonist
  • Monoclonal Antibody, Anti-Asthmatic


Mepolizumab is an interleukin-5 antagonist (IgG1 kappa). IL-5 is the major cytokine responsible for the growth and differentiation, recruitment, activation, and survival of eosinophils (a cell type associated with inflammation and an important component of the pathogenesis of asthma). Mepolizumab, by inhibiting IL-5 signaling, reduces the production and survival of eosinophils; however, the mechanism of mepolizumab action in asthma has not been definitively established.


Vd: ~3.6 L


Undergoes proteolytic degradation via enzymes that are widely distributed in the body and not restricted to hepatic tissue.



Half-Life Elimination

Terminal: 16 to 22 days

Use: Labeled Indications

Asthma: Add-on maintenance treatment of severe asthma in adults and pediatric patients ≥12 years of age with an eosinophilic phenotype

Limitations of use: Not indicated for the relief of acute bronchospasm or status asthmaticus

Eosinophilic granulomatosis with polyangiitis: Treatment of adult patients with eosinophilic granulomatosis with polyangiitis.

Off Label Uses

Eosinophilic granulomatosis with polyangiitis (relapsing or refractory)

Data from a small randomized, double blind, placebo controlled trial supports the use of mepolizumab in the treatment of relapsing or refractory eosinophilic granulomatosis with polyangiitis [Wechsler 2017]. Additional trials may be necessary to further define the role of mepolizumab in this condition.


Hypersensitivity to mepolizumab or any component of the formulation

Dosing: Adult

Asthma: SubQ: 100 mg once every 4 weeks

Eosinophilic granulomatosis with polyangiitis (treatment): SubQ: 300 mg once every 4 weeks

Eosinophilic granulomatosis with polyangiitis (relapsing or refractory) (off label use): SubQ: 300 mg once every 4 weeks (in combination with corticosteroids with or without immunosuppressive therapy) (Wechsler 2017)

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Asthma: Children ≥12 years and Adolescents: SubQ: Refer to adult dosing.

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer's labeling (has not been studied); however, adjustment based on renal function is unlikely to be necessary as mepolizumab is not renally eliminated.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer's labeling (has not been studied); however, adjustment based on hepatic function is unlikely to be necessary as mepolizumab is degraded by widely distributed proteolytic enzymes which are not restricted to hepatic tissue.


Reconstitute by adding 1.2 mL SWFI to the vial using a 2 or 3 mL syringe and a 21-gauge needle. Direct the stream of SWFI vertically onto the center of the lyophilized cake. Gently swirl the vial for 10 seconds with a circular motion at 15-second intervals until the powder is dissolved; do not shake. Manual reconstitution is typically complete within 5 minutes. If a mechanical reconstitution device (eg, swirler) is used, swirl at 450 rpm for no longer than 10 minutes or 1,000 rpm for no longer than 5 minutes. After reconstitution, the final concentration is 100 mg/mL (Note: vial contains 144 mg including overfill). The solution should be clear to opalescent, colorless to pale yellow or pale brown, and essentially particle free. If particulate matter remains in the solution or if the solution appears cloudy or milky, discard the solution. Do not mix with other medications.


SubQ: Administer via SubQ injection into the upper arm, thigh, or abdomen using a polypropylene syringe fitted with a 21- to 27-gauge 0.5 inch (13 mm) needle. For the 300 mg dose, administer as 3 separate 100 mg injections into the upper arm, thigh, or abdomen ≥5 cm apart if >1 injection administered at same site. Do not shake the reconstituted solution as this could lead to product foaming or precipitation.


Store unused vials below 25°C (77°F). Do not freeze; protect from light. Following reconstitution, use immediately. Alternatively, reconstituted solutions may be stored below 30°C (86°F) for up to 8 hours; do not freeze. Discard if not used within 8 hours of reconstitution.

Drug Interactions

There are no known significant interactions.

Adverse Reactions


Central nervous system: Headache (19%)

Local: Injection site reaction (8% to 15%)

1% to 10%:

Central nervous system: Fatigue (5%)

Dermatologic: Eczema (3%), pruritus (3%)

Gastrointestinal: Upper abdominal pain (3%)

Genitourinary: Urinary tract infection (3%)

Hypersensitivity: Hypersensitivity reaction (eosinophilic granulomatosis: 4%), angioedema (eosinophilic granulamatosis: 1%)

Immunologic: Immunogenicity (asthma: 6%, eosinophilic granulomatosis: <2%; neutralizing: <1%)

Infection: Influenza (3%)

Neuromuscular & skeletal: Back pain (5%), muscle spasm (3%)

Frequency not defined:

Hypersensitivity: Delayed hypersensitivity

Infection: Herpes zoster


Concerns related to adverse effects:

• Hypersensitivity reactions: Hypersensitivity reactions (eg, angioedema, anaphylaxis, bronchospasm, hypotension, urticarial, rash) may occur, typically within hours of administration. Delayed hypersensitivity reactions, occurring days after administration, have also been reported. Discontinue use in patients who experience a hypersensitivity reaction.

• Infection: Use may result in an opportunistic infection of herpes zoster; consider herpes zoster vaccination prior to initiation of therapy with mepolizumab.

Disease-related concerns:

• Asthma: Not indicated for the treatment of acute asthma symptoms (eg, acute bronchospasm) or acute exacerbations, including status asthmaticus. Appropriate rescue medication should be available. Patients who experience continued uncontrolled asthma or worsening of symptoms following treatment initiation with mepolizumab should seek medical attention.

• Helminth infections: It is unknown if administration of mepolizumab will influence a patient's response against parasitic infections. Therefore, patients with preexisting helminth infections should undergo treatment of the infection prior to initiation of mepolizumab therapy. Patients who become infected during treatment and do not respond to anti-helminth therapy should discontinue mepolizumab until the infection resolves.

Concurrent drug therapy issues:

• Corticosteroids: Do not discontinue systemic or inhaled corticosteroids abruptly upon initiation of mepolizumab. Reductions in corticosteroid dose should be gradual, if appropriate. Clinicians should note that a reduction in corticosteroid dose may be associated with withdrawal symptoms and/or unmask conditions previously suppressed by systemic corticosteroid therapy.

Other warnings/precautions:

• Limitation of use: Mepolizumab is not indicated for the treatment of other eosinophilic conditions.

Monitoring Parameters

FEV1, peak flow, and/or other pulmonary function tests. Monitor for increased use of short-acting beta2-agonist inhalers; may be a marker of a deteriorating asthma condition.

Pregnancy Considerations

Adverse events were not observed in animal reproduction studies. Mepolizumab is expected to cross the placenta; potential effects to the fetus may be greater in the second and third trimesters. Uncontrolled asthma is associated with adverse events on pregnancy (increased risk of preeclampsia, preterm birth, low birth weight infants). Asthma should be closely monitored in pregnant women.

Patients or health care providers are encouraged to enroll women exposed to mepolizumab during pregnancy in an asthma pregnancy registry (1-877-311-8972 or The Canadian labeling advises that women who become pregnant during therapy or up to 4 months after discontinuation of therapy notify their healthcare provider.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience back pain, loss of strength and energy, injection site pain, burning, edema, redness, or irritation. Have patient report immediately to prescriber severe headache, flushing, sensation of warmth, sensation of cold, shortness of breath, dizziness, or passing out (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.