Omalizumab marketed by the name of Xolair is a monoclonal antibody that inhibits the binding of IgE (immunoglobulin E) antibodies to its receptors on mast cells and basophils. It is used in the treatment of patients with moderately to severe Persistent Allergic Asthma who are six years of age or older who do not respond adequately to inhaled corticosteroids. It is also indicated in the treatment of chronic idiopathic urticaria in patients older than 12 years of age. It is not indicated for other forms of hives.

Contraindications to Xolair (Omalizumab)

• Patients who are allergic to omalizumab or any of its components, those who have severe bronchospasm and patients with status asthmaticus, as well as patients who develop severe bronchospasm.

Warnings and Precautions:

• Anaphylactic reactions: [U.S.-Boxed Warning]
  • Omalizumab has been linked to severe allergic reactions, including anaphylaxis.
  • Usually, allergic reactions are seen within two hours after the administration of medication.
  • However, they can be observed as late as one to three days after. (Allergic reactions have been reported even after a year of receiving regular treatment).
  • After the administration of omalizumab, the patient should remain under observation for at least 2 hours.
  • If the patient has an allergy to omalizumab, therapy should be stopped.
  • Medications for the management of anaphylaxis should be available during the treatment and observation period.
• Malignant neoplasms:
  • Although data is limited, short-term studies have shown malignant neoplasms associated with its use.
  • Ischemic strokes and transient ischemic attacks have been reported with its use.
  • Rare cases of vasculitis and eosinophilia have been reported.
  • Physicians must take extra caution if the patient develops new-onset eosinophilia, pulmonary symptoms, rash, neuropathy or cardiovascular symptoms.
  • Patients may report symptoms similar to serum sickness as manifested by fever, arthralgias, arthritis, rash, and lymphadenopathy.
  • Patients are at risk of developing parasitic infections. Patients should be monitored for symptoms suggestive of any kind of parasitic infection.
  • Corticosteroids should not be stopped abruptly. Furthermore, Ig E levels may remain elevated even after 1 year following therapy.

Omalizumab: Drug Interaction

Omalizumab Dose in Adults

Xoair Dosing:

• Xolair/ omalizumab dose is based on the serum Ig E levels and body weight.
• IgE levels may remain elevated after one year of therapy, therefore, the dose should not be adjusted based on IgE levels up to one year after discontinuation of the therapy
• However, significant changes in body weight may need adjustment in the dose as follows:

IgE levels of 30-100 units/mL:

• Patients weighing 30-90 kgs:
  • 150 mg every 4 weeks
• Greater than 90-150 kg:
  • 300 mg every 4 weeks

IgE levels of more 100-200 units/mL:

• Patients weighing 30-90 kgs:
  • 300 mg every 4 weeks
• Greater than 90-150 kg:
  • 225 mg every 2 weeks

IgE levels of more than 200-300 units/mL:

• Patients weighing 30-60 kgs:
  • 300 mg every 4 weeks
• Greater than 60-90 kgs: 
  • 225 mg every two weeks
• Greater than 90-150 kgs:
  • 300 mg every 2 weeks

IgE levels of more than 300-400 units/mL:

• Patients weighing 30-70 kgs:
  • 225 mg every 2 weeks
• Greater than 70-90 kgs: 
  • 300 mg every 2 weeks
• Greater than 90 kgs:
  • Do not administer the dose.

IgE levels more than 400-500 units/mL:

• Patients weighing 30-70 kgs:
  • 300 mg every two weeks
• Greater than 70-90 kgs: 
  • 375 mg every two weeks
• More than 90 kgs:
  • Do not administer the dose

IgE levels more than 500-600 units/mL:

• Patients weighing 30-60 kgs:
  • 300 mg every two weeks
• Greater than 60-70 kgs: 
  • 375 mg every two weeks
• More than 70 kgs:
  • Do not administer the dose

IgE levels greater than 600-700 units/mL:

• Patients weighing 30-60 kgs:
  • 375 mg every two weeks
• Greater than 60 kgs:
  • Do not administer the dose

Omalizumab Dose in Childrens

• Omalizumab dosing in children should be based on the patients' weight and pre-treatment IgE levels.
• Ig E levels should not be used as a guide to dose adjustment after therapy has been initiated and up to one year after discontinuation.

Omalizumab dosing in Children:

IgE levels of 30-100 units/mL:

• 20-40 Kgs:
  • 75 mg every 4 weeks
• 40-90 kgs:
  • 150 mg every 4 weeks
• Greater than 90-150 kg:
  • 300 mg every 4 weeks

IgE levels of more 100-200 units/mL:

• 20 - 40 Kgs:
  • 150 mg every 4 weeks
• 40-90 kgs:
  • 300 mg every 4 weeks
• 90-125 kg:
  • 225 mg every 2 weeks
• 125 - 150 Kgs:
  • 300 mg every 2 weeks

IgE levels of more than 200-300 units/mL:

• 20 - 30 Kgs:
  • 150 mg every 4 weeks
• 30-40 kgs:
  • 225 mg every 4 weeks
• 40 - 60 Kgs:
  • 300 mg every 4 weeks
• 60-90 kgs: 
  • 225 mg every two weeks
• 90-125 kgs:
  • 300 mg every 2 weeks
• 125 - 150 Kgs:
  • 375 mg every 2 weeks

IgE levels of more than 300-400 units/mL:

• 20 - 30 Kgs:
  • 225 mg every 4 weeks
• 30-40 kgs:
  • 300 mg every 4 weeks
• 40 - 70 Kgs:
  • 225 mg every 2 weeks
• 70-90 kgs: 
  • 300 mg every 2 weeks
• Greater than 90 kgs:
  • Do not administer the dose.

IgE levels more than 400-500 units/mL:

• 20 - 25 kgs:
  • 225 mg every 4 weeks
• 25 - 30 kgs:
  • 300 mg every 4 weeks
• 30-50 kgs:
  • 225 mg every 2 weeks
• 50 - 70 Kgs:
  • 300 mg every 2 weeks
• 70-90 kgs: 
  • 375 mg every two weeks
• More than 90 kgs:
  • Do not administer the dose

IgE levels more than 500-600 units/mL:

• 20 - 30 Kgs:
  • 300 mg every 4 weeks
• 30 - 40 Kgs:
  • 225 mg every 2 weeks
• 40 - 60 kgs:
  • 300 mg every 2 weeks
• 60-70 kgs: 
  • 375 mg every two weeks
• More than 70 kgs:
  • Do not administer the dose

IgE levels greater than 600-700 units/mL:

• 20 - 25 Kgs:
  • 300 mg every 4 weeks
• 25 - 40 Kgs:
  • 225 mg every 2 weeks
• 40 - 50 Kgs:
  • 300 mg every 2 weeks
• 50-60 kgs:
  • 375 mg every 2 weeks
• Greater than 60 kgs: 
  • Do not administer the dose

IgE levels greater than 700-900 units/mL:

• 20 - 30 Kgs:
  • 225 mg every 2 weeks
• 30 - 40 Kgs:
  • 300 mg every 2 weeks
• 40 - 50 Kgs:
  • 375 mg every 2 weeks
• Greater than 50 kgs: 
  • Do not administer the dose

IgE levels greater than 900-1100 units/mL:

• 20 - 25 Kgs:
  • 225 mg every 2 weeks
• 25 - 30 Kgs:
  • 300 mg every 2 weeks
• 30 - 40 Kgs:
  • 375 mg every 2 weeks
• Greater than 40 kgs: 
• Do not administer the dose

IgE levels greater than 1100-1200 units/mL:

• 20 - 30 Kgs:
  • 300 mg every 2 weeks
• Greater than 30 kgs: 
  • Do not administer the dose

IgE levels greater than 1200-1300 units/mL:

• 20 - 25 Kgs:
  • 300 mg every 2 weeks
• 25 - 30 Kgs:
  • 375 mg every 2 weeks
• Greater than 30 kgs:
  •  Do not administer the dose

Omalizumab Dose in Renal Disease:

• The manufacturer has not recommended any dose adjustment in patients with renal disease

Omalizumab Dose in Liver Disease:

• The manufacturer has not recommended any dose adjustment in patients with liver disease

How to administer omalizumab (Xolair)?

• Omalizumab should be administered subcutaneously only.
• When doses greater than 150 mg is required, it should be divided over more than one site.
• Patients must be under direct medical supervision for up to two hours following the administration of Xolair injection.

Pregnancy Risk Factor B

• Since omalizumab is a human IgG molecule, it can cross the placenta.
• Prematurity, low birth weight, and minor birth defects were all reported in small case reports.
• These incidence rates are similar to those in severe asthma patients.
• GINA 2018 recommends controlling Asthma before conception and during pregnancy in order to reduce perinatal mortality and low birth weights, as well as preterm births.

Omalizumab during breastfeeding

• Breastfeeding infants should not use it. Excretion into human milk is normal and the effects on infants are unknown.  

Xolair side effects (common):

• Central nervous system:

  • Headache

• Local reactions:

  • Injection site reaction.

• Respiratory:

  • Upper respiratory tract infection, sinusitis, and pharyngitis

• Miscellaneous:

  • Viral infection

Xolair (Omalizumab) side effects (less common):

• Central nervous system:

  • Pain, fatigue, and dizziness

• Dermatologic:

  • Dermatitis and pruritus

• Neuromuscular & skeletal: 

  • Arthralgia, leg pain, arm pain, and fracture

• Otic:

  • Earache

Rare side effects of Omalizumab (Limited to important or life-threatening):

• Alopecia,
• Anaphylaxis (angioedema of the throat or tongue, chest tightness, bronchospasm, cough, cutaneous angioedema, hypotension, dyspnea, generalized pruritus, syncope, and urticaria),
• Antibody formation to omalizumab,
• Hot flushes,
• Malignancy, and
• Thrombocytopenia

Monitoring Parameters:

• Severe allergic reactions can occur following the administration of omalizumab.
• Patients should be monitored for anaphylactic reactions for two hours after the first three injections and at least 30 minutes after the subsequent injections.
• Baseline IgE levels, signs of infections, and pulmonary function tests (FEV - 1 and peak flow) should be monitored.

Mechanism of Action of Omalizumab (Xolair):

• Omalizumab, a monoclonal human IgG monoclonal anti-IgE antibody, inhibits IgE binding at its receptors on basophils and mast cells.
• Omalizumab thus inhibits basophil activation and mast cell activation, and inhibits mediator release by these cells.

Metabolism is by the liver. Degradation of IgG occurs in the reticuloendothelial system and endothelial cells

Bioavailability is 62%

Half-life elimination is 26 days

Time to peak serum levels is 7-8 days [/bg_collapse]

International Brand Names of Omalizumab:

• Xolair

Solution (reconstituted) (Xolair Subcutaneous)

• 150 mg (per each): $1,301.59

Solution Prefilled Syringe (Xolair Subcutaneous)

• 75 mg/0.5 mL (per 0.5 mL): $650.80
• 150 mg/mL (per mL): $1,301.59

Omalizumab brands in Pakistan:

Xolair injections (Novartis Pharma)

150 mg/ml: PKR: 38000/