Overview
Omalizumab injection is the first FDA (Food and Drug Administration) -approved medication designed to reduce allergic reactions to more than one type of food allergen, providing a new treatment option for patients dealing with immunoglobulin E (IgE)-mediated food allergies. While Omalizumab does not cure food allergies, its repeated use can help minimize the health impact if accidental exposure occurs. This medication has received FDA approval for treating immunoglobulin E (IgE)-mediated food allergy in adults and children aged one year or older.
Clinical Efficacy and Safety of Omalizumab Injection
The results from the OUtMATCH study, a phase 3 clinical trial, demonstrated Omalizumab's effectiveness in reducing allergic symptoms during food challenges. One more study concluded that both Omalizumab (OMA) monotherapy and Omalizumab combined with oral immunotherapy (OMA+OIT) are effective and safe approaches for treating patients with immunoglobulin E (IgE)-mediated food allergy.
For Patients:
What Is Omalizumab Injection?
Omalizumab injection is an injectable prescription medication used to treat food allergies in individuals one year of age and older. It is designed to reduce allergic reactions that may occur after accidentally consuming one or more foods to which the person is allergic. While using Omalizumab, individuals should continue to avoid all foods they are allergic to. However, Omalizumab should not be used for the emergency treatment of allergic reactions, including anaphylaxis (a severe, potentially life-threatening allergic reaction).
How Does Omalizumab Injection Work?
It reduces type 1 allergic reactions, including the risk of anaphylaxis resulting from accidental exposure to certain foods. One study concluded that Omalizumab monotherapy significantly increased the tolerated dose of multiple foods, including milk, eggs, wheat, and baked milk. It also improved quality of life (QoL) and reduced food-induced allergic reactions.
Omalizumab combined with oral immunotherapy significantly increased the tolerated dose of multiple foods and promoted desensitization. It increases immunoglobulin G4 levels.
What Is Immunoglobulin E-mediated Food Allergy?
Immunoglobulin E-mediated food allergy is characterized by an abnormal immune response in individuals when exposed to specific foods such as milk, eggs, wheat, or nuts. This type of food allergy typically elicits rapid reactions within minutes to a few hours after ingestion. Immediate reactions are triggered by allergen-specific immunoglobulin E (IgE) antibodies circulating in the bloodstream. Common food allergens include milk, eggs, soy, wheat, peanuts, tree nuts, fish, and shellfish.
What Should Patients Inform Healthcare Providers Before Taking Omalizumab?
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Individuals with a latex allergy or other conditions (such as seasonal allergies) should know that the needle cap on the Omalizumab prefilled syringe contains natural rubber latex.
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Individuals must inform their healthcare providers if they feel sudden breathing difficulties (bronchospasm), have a history of severe allergic reactions known as anaphylaxis, or have been diagnosed with a parasitic infection or cancer.
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If pregnant or planning to conceive, individuals should discuss the potential risks and benefits of Omalizumab with their healthcare providers, as its effects on unborn babies are not fully understood.
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Similarly, if breastfeeding or intending to breastfeed, individuals should consult their healthcare providers regarding the use of Omalizumab, as it is uncertain whether the medication passes into breast milk.
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Individuals should also inform their healthcare providers about all medications they are taking, including prescription drugs, over-the-counter medications, vitamins, and herbal supplements, to prevent potential interactions with Omalizumab.
How Should the Patient Take Omalizumab Injection?
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When initiating treatment, Omalizumab should be administered by a healthcare provider in a medical facility.
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Suppose a healthcare provider determines that an individual or a caregiver can administer their Omalizumab prefilled syringe or autoinjector injections. In that case, appropriate training should be provided on the correct method of preparation and injection.
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Individuals should only attempt to administer Omalizumab once a healthcare provider has instructed them on the proper technique. They should use it precisely as directed by the healthcare provider.
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The Omalizumab autoinjector (all doses) is designated for use exclusively in adults and adolescents aged 12 years and older. For individuals aged 12 and above, the Omalizumab prefilled syringe or autoinjector may be self-administered under adult supervision. A caregiver should administer the Omalizumab prefilled syringe for children aged one to 11 years.
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Refer to the comprehensive instructions for use accompanying Omalizumab for guidance on the correct method of preparation and administration.
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Omalizumab is administered via subcutaneous injection, typically once every two or four weeks, as healthcare providers prescribe.
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In individuals with food allergies, a blood test for IgE levels must be conducted before initiating Omalizumab to determine the appropriate dosage and frequency of administration.
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Individuals should not reduce or discontinue any food allergy medications or allergen immunotherapy unless instructed to do so by their healthcare providers.
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Following Omalizumab treatment, immediate improvement in symptoms may not be observed. Individuals should contact their healthcare provider if symptoms persist or worsen.
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If an individual administers more Omalizumab than prescribed, they should promptly contact their healthcare provider.
What Are the Side Effects of Omalizumab Injection?
Omalizumab may result in some side effects, such as:
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Malignancy: Instances of cancer have been reported in certain individuals administered Omalizumab.
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Fever, Muscle Soreness, and Skin Rash: Some individuals experience these symptoms within one to five days following Omalizumab injection. If any of these symptoms occur, individuals should inform their healthcare provider.
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Parasitic Infection: Certain individuals at elevated risk of parasitic (worm) infections may develop infections after Omalizumab administration. Healthcare providers can conduct stool tests to assess for parasitic infections.
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Cardiovascular Issues: Some individuals receiving Omalizumab have reported occurrences of chest pain, heart attacks (blockage of blood flow to the heart causing damage to the heart muscle and potentially life-threatening symptoms), pulmonary or leg blood clots, or transient manifestations of unilateral weakness, slurred speech, or visual disturbances. It remains uncertain whether these are directly linked to Omalizumab.
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The most frequent adverse effects of Omalizumab in individuals with food allergies include injection site reactions and fever.
For Doctors:
Indications and Usage:
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Moderate to severe persistent asthma in adults and pediatric patients aged six years and older with positive skin tests or in vitro reactivity to perennial aeroallergens and inadequately controlled by inhaled corticosteroids.
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Chronic rhinosinusitis with nasal polyps (CRSwNP) in adult patients aged 18 years and older with an inadequate response to nasal corticosteroids as supplementary maintenance treatment.
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IgE-mediated food allergy in adult and pediatric patients aged one year and older reduces allergic reactions (Type I), including anaphylaxis, that may arise from accidental exposure to one or more foods. To be utilized alongside food allergen avoidance.
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Chronic spontaneous urticaria (CSU) in adults and adolescents aged 12 years and older who continue to experience symptoms despite H1 antihistamine therapy.
Limitations of Use:
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It is not intended for the treatment of acute bronchospasm or status asthmaticus.
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It is not intended for emergency management of allergic reactions, including anaphylaxis.
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It is not intended for other forms of urticaria.
Dosage and Administration:
For subcutaneous (SC) administration exclusively. Refer to the complete prescribing information for guidance on administration procedures.
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Asthma: Omalizumab dosage ranges from 75 to 375 mg (milligrams) SC every two or four weeks. Individualize the dose (mg) and frequency based on serum total IgE level (international units per milliliter - IU/mL), assessed before treatment initiation, and body weight (kilogram - kg). Consult the dose determination charts.
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Chronic Rhinosinusitis With Nasal Polyps: Omalizumab dosage ranges from 75 to 600 mg SC every two or four weeks. Determine the dose (mg) and frequency based on serum total IgE level (IU/mL), assessed before treatment initiation, and body weight (kg). Refer to the dose determination charts.
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IgE-Mediated Food Allergy: Omalizumab dosage ranges from 75 mg to 600 mg SC every two or four weeks. Tailor the dose (mg) and frequency based on serum total IgE level (IU/mL), assessed before treatment initiation, and body weight (kg). See the dose determination chart.
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Chronic Spontaneous Urticaria (CSU): Omalizumab doses of 150 or 300 mg SC every four weeks. Dosing for CSU is not influenced by serum IgE level or body weight.
Clinical Pharmacology
1. Mechanism of Action:
The mechanism of action of Omalizumab injection involves inhibiting the binding of IgE to the high-affinity IgE receptor (FcεRI) present on the surface of mast cells, basophils, and dendritic cells. This inhibition reduces the surface-bound IgE on FcεRI-bearing cells, thereby limiting the release of allergic response mediators. Additionally, Omalizumab treatment reduces the number of FcεRI receptors on basophils in individuals with atopic conditions.
In allergic asthmatics, Omalizumab therapy inhibits IgE-mediated inflammation by decreasing blood and tissue eosinophils and reducing inflammatory mediators such as IL (interleukin)-4, IL-5, and IL-13. For chronic spontaneous urticaria (CSU), Omalizumab binds to IgE, decreasing free IgE levels and subsequent down-regulation of IgE receptors (FcεRI) on cells. However, the precise mechanism by which Omalizumab improves CSU symptoms remains unknown.
2. Pharmacokinetics:
Volume of Distribution: Following subcutaneous (SC) administration, Omalizumab's apparent distribution volume in asthmatic patients is 78 ± 32 mL/kg (milliliters per kilogram of body weight).
Absorption: Omalizumab is absorbed with an average absolute bioavailability of 62 percent after SC administration. Peak serum concentrations are reached seven to eight days after administration, both in asthma patients and those with chronic spontaneous urticaria (CSU). Omalizumab's pharmacokinetics exhibit linearity at doses greater than 0.5 mg/kg (milligrams per kilogram of body weight).
Metabolism: Omalizumab undergoes clearance involving IgG clearance processes and clearance via specific binding and complex formation with its target ligand, IgE. Liver elimination of IgG involves degradation in the liver reticuloendothelial system (RES) and endothelial cells, with intact IgG also excreted in bile.
Clearance: In patients with asthma, Omalizumab serum elimination half-life averages 26 days, with apparent clearance averaging 2.4 ± 1.1 mL/kg/day. Doubling body weight approximately doubles apparent clearance. In CSU patients, Omalizumab serum elimination half-life averages 24 days, with apparent clearance averaging 240 mL/day (corresponding to 3.0 mL/kg/day for an 80 kg patient).
3. Pharmacodynamics:
In clinical studies, Omalizumab treatment reduces serum-free IgE levels in a dose-dependent manner within one hour following the initial dose, which is maintained between subsequent doses. The decrease in mean serum-free IgE exceeds 96 percent with recommended doses. Post the first dose, serum total IgE levels, including bound and unbound forms, increase due to the formation of Omalizumab: IgE complexes with a slower elimination rate. At 16 weeks following initiation, average serum total IgE levels are approximately five-fold higher than pre-treatment, as assessed by standard assays. After discontinuing Omalizumab treatment, the induced increase in total IgE and decrease in free IgE can be reversed, with no rebound in IgE levels after drug washout. Total IgE levels may take up to one year to return to pre-treatment levels post-discontinuation.
The pharmacokinetics of Omalizumab in special populations indicate that no dose adjustments are necessary for age (12-76 years), race, ethnicity, or gender.
What Are the Contraindications of Omalizumab Injection?
Individuals with a severe hypersensitivity reaction to Omalizumab or any component of Omalizumab should not receive this medication.
What Are the Adverse Effects of Omalizumab Injection?
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Asthma: In clinical trials involving adult and adolescent asthmatic patients aged 12 years and older, the most commonly reported adverse reactions (occurring in ≥ one percent of individuals) were arthralgia, general pain, leg pain, fatigue, dizziness, fracture, arm pain, pruritus, dermatitis, and earache. Among pediatric patients aged six to <12 years, the most commonly reported adverse reactions (> three percent of patients) included nasopharyngitis, headache, pyrexia, upper abdominal pain, streptococcal pharyngitis, otitis media, viral gastroenteritis, arthropod bites, and epistaxis.
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Chronic Rhinosinusitis with Nasal Polyps: Among adult patients, the most frequent adverse reactions (≥ three percent of patients) in clinical studies included headache, injection site reaction, arthralgia, upper abdominal pain, and dizziness.
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IgE-Mediated Food Allergy: The most frequently reported adverse reactions (≥ three percent of patients) when Omalizumab injection is employed for IgE-mediated food allergy cases include injection site reactions and pyrexia.
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Chronic Spontaneous Urticaria: Adverse reactions occurring in at least two percent of patients included nausea, nasopharyngitis, sinusitis, upper respiratory tract infection, viral upper respiratory tract infection, arthralgia, headache, and cough.
Warnings and Precautions:
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Anaphylaxis: Commence Omalizumab therapy in a healthcare facility equipped to manage anaphylaxis, a potentially life-threatening condition, and monitor individuals appropriately following administration.
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Malignancy: Incidences of malignancy have been noted in clinical trials.
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Acute Asthma Symptoms: Omalizumab is not indicated for treating acute bronchospasm or status asthmaticus.
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Corticosteroid Reduction: Avoid sudden cessation of corticosteroids when starting Omalizumab therapy.
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Eosinophilic Conditions: Remain vigilant for eosinophilia, vasculitic rash, exacerbation of pulmonary symptoms, cardiac complications, and/or neuropathy, particularly when reducing oral corticosteroid dosage.
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Fever, Arthralgia, and Rash: Discontinue Omalizumab if individuals exhibit signs and symptoms resembling serum sickness.
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Potential Medication Error Related to Emergency Treatment of Anaphylaxis: Omalizumab is unsuitable for emergency management of allergic reactions, including anaphylaxis.
What Are the Drug Interactions of Omalizumab Injection?
No formal drug interaction research has been conducted with Omalizumab injection, and the concurrent administration of Omalizumab and allergen immunotherapy has not been assessed.
The simultaneous use of Omalizumab and allergen immunotherapy has not been evaluated in patients with asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), and IgE-mediated food allergy.
In patients with chronic spontaneous urticaria (CSU), the utilization of Omalizumab alongside immunosuppressive therapies has not been investigated.
Clinical Studies:
Clinical studies of Omalizumab have evaluated its safety and efficacy in various conditions such as asthma, chronic rhinosinusitis with nasal polyps (CRSwNP), IgE-mediated food allergy, and chronic spontaneous urticaria (CSU).
Individuals aged 12 to 76 with moderate to severe persistent asthma participated in asthma trials. These trials, including asthma trials 1, 2, and 3, were randomized, double-blind, placebo-controlled. Patients had positive skin test reactions to perennial aeroallergens and were symptomatic despite treatment with inhaled corticosteroids (ICS) and short-acting beta-agonists. The trials showed a reduction in asthma exacerbations with Omalizumab compared to placebo, particularly in patients with FEV1 between 40 and 80 percent predicted.
For chronic rhinosinusitis with nasal polyps, two randomized, multicenter, double-blind, placebo-controlled trials (CRSwNP trial 1 and CRSwNP trial 2) assessed the efficacy of Omalizumab. Patients with bilateral polyps and an inadequate response to nasal corticosteroids were included. Omalizumab treatment led to significant improvements in nasal polyp scores and nasal congestion compared to placebo.
Omalizumab demonstrated efficacy in reducing allergic reactions during food challenges in a food allergy trial involving individuals allergic to peanuts and other foods. The primary endpoint, the percentage of patients able to take a single dose of ≥600 mg of peanut protein without dose-limiting symptoms, was much higher in the Omalizumab group compared to placebo.
In chronic spontaneous urticaria trials, Omalizumab showed efficacy in reducing symptoms compared to placebo over 24 weeks. These trials included adult and adolescent patients with chronic spontaneous urticaria.
Overall, clinical studies of Omalizumab across these conditions have demonstrated its safety and efficacy in reducing symptoms and exacerbations associated with allergic diseases.
