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Omalizumab

Pronunciation: OH-ma-LIZ-oo-mab
Class: Monoclonal antibody

Trade Names

Xolair
- Injection, lyophilized powder for solution 202.5 mg (150 mg per 1.2 mL after reconstitution)

Pharmacology

Selectively binds to human immunoglobulin E (IgE), inhibiting the binding of IgE to the high-affinity IgE receptor on the surface of mast cells and basophils and limiting the degree of release of mediators of the allergic response.

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Pharmacokinetics

Absorption

Average absolute bioavailability after subcutaneous administration is 62%. T max is about 7 to 8 days. AUC from day 0 to 14 at steady state is up to 6-fold higher than those after the first dose.

Distribution

Vd 78 mL/kg.

Metabolism

Degraded by the liver.

Elimination

Average serum elimination half-life is 26 days.

Special Populations

No dosage adjustments are necessary for age, ethnicity, gender, or race.

Indications and Usage

Treatment of moderate to severe persistent asthma in patients who have a positive skin test or in vitro reactivity to a perennial aeroallergen and whose symptoms are inadequately controlled with inhaled corticosteroids.

Unlabeled Uses

Seasonal allergic rhinitis.

Contraindications

Standard considerations.

Dosage and Administration

Adults and children 12 yr of age and older

Subcutaneous 150 to 375 mg every 2 or 4 wk. Doses (mg) and dosing frequency are determined by serum total IgE level (units/mL), measured before the start of treatment, and body weight (kg). Doses more than 150 mg are divided among more than 1 injection site in order to limit injections to no more than 150 mg/site.

Dosage adjustments

Because total IgE levels are elevated during treatment and remain elevated for up to 1 yr after discontinuation of treatment, retesting of IgE levels during omalizumab treatment cannot be used as a guide for dose determination. Base dose determination after treatment interruptions lasting less than 1 yr on serum IgE levels obtained at the initial dose determination. If treatment is interrupted for 1 yr or more, IgE levels may be retested for dose determination. Adjust doses for changes in body weight.

General Advice

  • For subcutaneous administration only. Not for intradermal, IM, or IV administration.
  • Follow manufacturer's instructions for reconstituting the lyophilized powder.
  • Swirl vial during reconstitution. Do not shake. Reconstitution may take up to 40 min. Do not use if contents of vial do not dissolve completely by 40 min.
  • Do not administer if particulate matter is noted.
  • Reconstituted solution is slightly viscous and may take 5 to 10 sec to inject.
  • Rotate injection sites (eg, thigh, abdomen, upper arm). Give new injections at least 1 inch from old site and never into areas where the skin is tender, bruised, red, or hard.
  • Discard any unused solution. Do not save unused solution for later administration.

Storage/Stability

Store vials in refrigerator (36° to 46°F). After reconstitution, the solution should be used within 8 h if stored in refrigerator or within 4 h if stored at room temperature. Protect reconstituted solution from direct sunlight.

Drug Interactions

None well documented.

Laboratory Test Interactions

Elevated serum total IgE levels may persist for up to 1 yr after discontinuation of omalizumab; therefore, serum total IgE levels obtained during this time may not reflect steady-state free IgE levels and should not be used to reassess the dosing regimen.

Adverse Reactions

CNS

Headache (15%); dizziness, fatigue (3%).

Dermatologic

Dermatitis, pruritus (2%); hair loss (postmarketing).

EENT

Sinusitis (16%); pharyngitis (11%); earache (2%).

Hematologic-Lymphatic

Severe thrombocytopenia (postmarketing).

Respiratory

Upper respiratory tract infections (20%).

Musculoskeletal

Arthralgia (8%); leg pain (4%); arm pain, fracture (2%).

Miscellaneous

Injection-site reactions (45%); viral infections (23%); pain (7%); malignancy (0.5%); anaphylaxis, including signs and symptoms of angioedema of the throat and tongue, bronchospasm, chest tightness, cough, cutaneous angioedema, dyspnea, hypotension, syncope, urticaria (postmarketing).

Precautions

Warnings

Anaphylaxis, presenting as bronchospasm, hypotension, syncope, urticaria, and/or angioedema of the throat or tongue, has been reported. Anaphylaxis has occurred with the first dose as well as beyond 1 yr after beginning regularly administered treatment.


Monitor

Monitor patients at high risk of parasitic infection (eg, helminth) for such infection while receiving omalizumab therapy.


Pregnancy

Category B .

Pregnancy registry

A pregnancy exposure registry has been established to monitor the outcome of pregnant women exposed to omalizumab, including women who are exposed to at least 1 dose within 8 wk prior to conception or any time during pregnancy.

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 12 yr of age.

Elderly

The number of patients aged 65 and older who were studied was not sufficient to determine if they respond differently from younger patients.

Hypersensitivity

Anaphylaxis has occurred after the first dose or and after 1 yr of beginning administration of omalizumab.

Asthma

Should not be used to treat acute bronchospasm or status asthmaticus.

Corticosteroid reduction

Do not abruptly discontinue corticosteroids upon initiation of omalizumab therapy.

Eosinophilic conditions

Patients with asthma may present with serious systemic eosinophilia sometimes presenting with clinical features of vasculitis.

Malignancy

Malignant neoplasms were observed; the variety of types included breast, nonmelanoma skin, prostate, melanoma, and parotid.

Parasitic infection

The risk for parasitic infections (eg, hookworm, roundworm, threadworm, whipworm) may be increased.

Overdosage

Symptoms

The max tolerated dose has not been determined. Single IV doses of up to 4 g have been administered without evidence of dose-limiting toxicities.

Patient Information

  • Advise patient that medication will be prepared and administered by health care provider in a medical setting.
  • Instruct patient to continue taking other asthma medications as prescribed by health care provider and to not change the dose or stop taking unless advised by health care provider.
  • Inform patients of the signs and symptoms of anaphylaxis and instruct them to seek immediate medical attention should symptoms occur.
  • Advise patient that therapy will not immediately improve asthma symptoms but that improvement should be noted as therapy is continued.
  • Advise patient that injection-site reactions are common but that these should become less of a problem as therapy continues.
  • Advise patient to report intolerable injection-site reactions or any unexplained symptoms to health care provider.

Copyright © 2009 Wolters Kluwer Health.

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